I used to daily a bone stock L98, it felt so much stronger than the numbers would suggest. It made no power past 5K but all that torque with the 700R4's super low first gear made it a stoplight to stoplight superstar.
I have a 86 corvette, the L98 on it is a masterpiece, it used to be my daily for years & like I can say is that it’s powerful, fun & it’s really reliable I rarely had to fix anything on it.
@@apl.2018 a guy wants to trade me for his 89 vette, it looks perfect-garage kept low mileage but I can’t decide if I should or not. That engine is stock and is rated for only 240hp and I don’t want to spend thousands to make it actually make some power..
Exactly why I want the GM TPI on my 5.7L LT1 engine in my 1997 Trans Am WS6. Now just consider how things would improve with a good extrude hone of the base, smoothing out the air flow, increasing it as far as 260cfm if possible, and maintaining velocity. Now add on AS&M runners with the necessary port matching of the plenum and with a ZZ4 camshaft, things start to get pretty interesting with the LT1. As I often regard it, the TPI intake was the prototype for the LS1 intake.
Someone I met at the SVRA in Austin, Texas in 2018 was running a carb on his C4 Corvette - he said too that those engines make more power with a carb than fuel injection.
The 4.3 motor should never have been the slug that it was, i get it that GM ran its smaller displacement in a bid for fuel economy numbers back in the day but using the available TPI manifold would not have changed that but as Richard just showed it would have been a torque monster in comparison and still had the fuel economy, GM missed the boat on that one
I have a feeling the issue would've been cost. The TPI manifold is extremely complex to produce, assemble, and install compared to the LT1 intake, especially for a production line.
That’s why my 91 Z28 5.7 was such a beast stop light to stop light. When I got 3.73s, shorty TPIS runners, a cam, aluminum corvette heads, underdrive pulley, chip, CAI and exhaust it was as fast as LT1/LS1 cars or faster. I remember making my buddy with a new era Cobra very mad. Man I miss that car, but tbh I’m looking for another 3rd gen to put a LS2,3 or if I’m lucky a LS7
I’m following along something similar. 4.3 L99 block, 305 Vortec rebuild kit, ported B-Body LT1 iron heads with stock valves, LT4 Hot cam, and I believe I just decided to go with a carb instead of FI. It’s basically 305 LT4 with a carb. It’s gonna find it’s way into a s10 blazer I’m building. Sweet part is damn near every major component came out of a junkyard.
Jim Hall made my current L98 Mini-Ram intake. It is one of the last Manifolds he made before discontinuing them as the LS engines have taken over. I am very appreciative of his work and Richard's that has made my Blue Print 427sb engine scream!
Okay Richard, I see a lot of comments from guys from "back in the day", so I feel compelled to tell my "old school" story, keeping it brief. 1992 H town,Tex I wanted a late model car I could drive every day, enjoy and have fun. GM guy and 88-89 models where in my $ range so I decided on a 89 Formula 350.( If a Ford guy it would have been Mustang LX 5.0) Although it went through stages, I'll skip all that. .30 block, SCAT 400 crank, KB dished pistons, GM vette alum. heads ported, TPIS ZZ-9 cam. HS 1.6 rr Accel lower intake, TPIS runners, ported stock upper, 58mm TB, airfoil, ford injectors, adj, fuel presssure reg, MSD 6A, underdrve c/pulley, 700R4 transpack/vette servo, 3.27 gear. weighed 3470 with me and 1/2 tank, ran a 12.66 baytown, best 1.56 60ft, would eek out a 12 in drive shifting at 4800. Have always been curious what the power curve must have looked like. The best truck motor never made is what i always thought as well. (I thought a NOS shot would have been the best next thing, as it does not require as much additional airflow).
You continue to validate why I'm building a TPI 383 to replace the carburated 350 in my class 3 RV "The TPI is the best truck intake GM never put in a truck".
A good dual plane intake makes similar torque to a TPI intake. First Fuel Injection makes a VERY nice TPI style intake. If I was building a truck engine but wanted it to still have some top end power, I would run one in a heartbeat.
The 1989 350TPI engines had 3.27 gears, the 1998 350LT1 engines had 3.42 gears. The LT1 engines had lower emissions and better fuel economy. The LT1 cars were faster at the drag strip. The TPI cars were quicker across an intersection. It was money that kept the 4.3 from getting the TPI intake, and the LT intake is a smaller package. Plus you needed horsepower to fight the BMWs.
When my dad was out in California about 20 years ago he picked up a badass firebird formula 350. It had LT1 heads on it because the sand ate up the original heads. You guys got a lot of sand. We're in pa. But that thing was one bad SOB.... It had a built 700R4 that would chirp tire and all four gears not even trying. With them LT1 heads and the tune port that thing freaking ripped. He wouldn't give it to me because he told me I'd kill myself. Well now I got a car 10 times that shit I just need a good fuel injection system. Thank you Richard for all your hard work and dedication and teaching. From our house to yours thank you
The dual plane has “medium” length runners but also isolates the dilution of the intake charge by operating as two 4-cylinder engines. Long runners between the plenum and the intake valves will have somewhat the same effect but short runners, whether single plane carb manifold or EFI plenum, hurt low- to mid-range due to lack of isolation. It appears the LT1 manifold runners are tuned for rpm well above the range of that cam since the dual plane manifold beats it on both torque and power. The L98 runner length looks good for barges and trucks but I think a tunnel Ram might be better for ultimate performance. Really interesting results in this test. Thanks, Richard!
" It appears the LT1 manifold runners are tuned for rpm well above the range of that cam since the dual plane manifold beats it on both torque and power". OR tuned for a larger displacement engine.
The sedans and wagons of Buick, Caddy, and Olds could have really distinguished themselves to be old school torque monsters had they come up with a TPI intake to fit the LT1 in their cars. I'm looking into installing a TPI on the LT1 in my Roadmaster wagon. I might try the factory intake base modification route and see how it works before going with a FIRST intake setup. All I want is more towing power. The sedans and wagons already got a slightly higher torque cam right from the factory.
I had an 86 Corvette with the TPI. It was all about torque, not a high RPM engine like you’d expect from a SBC. Your dyno runs confirmed what I expected to see.
@@scoutleader06 I’d like to see something that backs up your statement. I’ve never heard of what sounds like nonsense. There were eight injectors, one per port. The injectors fired in batch mode, maybe twice per engine revolution, not sequentially. But it was certainly fuel injection, nothing like a carburetor.
@@CrazyPetez batch mode injection was a crude run-up to the 87 TPI true sequential fuel injection, maybe not quite a carb on steroids, but nothing like the 87 TPI sequential controlled by the ECM. do your home work then come back here and tell me its nonsense.
The TPI Corvettes really do jump off the line. Awesome comparison. Nice work Richard! Who would have thought the baby LT1 could have been a baby beast in a Caprice. They could have just hashed up some block off plates and go to the old bolt pattern on the iron head. L98, LT1 both great GM motors
Intake runner length produces a pulse wave...on a tpi 1st power wave at 2k rpm the second wave at 4k rpm....porting will move them both equally in general
A while back I had a chance to build a 307 TPI setup but I blew it. 307 is essentially a 283 bore engine with 327 stroke (the opposite of the DZ302). Probably would have made great torque for a light duty hauler. I still have the complete TPI setup (polished manifold) but couldn't get to the 307 in time to snag it. I ended up swapping in a 5.3L LM7
The L98 TPI was a perfect set up for a Automatic trans. street car that low end Torque was a kick in the pants .We don't need no stinkin Holley Double pumper to make power!
A lot of people hated TPI intakes, but for the correct application they are absolutely superior. For a street vehicle that will almost never got over 4500 RPM where you want good torque and fuel economy it is the GOAT intake. I have long said that the TRUCKS should have had TPI 350's and the camaro's and corvettes should have come with the TBI intakes. The TBI engines were easier to modify and generally made better horsepower with some simple intake swaps (once you get around those awful early ecms). The reason I bet that only vettes and Fbody cars came with TPI was cost. I bet most truck buyers didn't want the complexity and extra cost of the TPI. Moral of the story is, always go for an aftermarket tunable ECM (this was a lot harder 20 years ago), then put the TPI on you big cars and trucks with a wide LSA cam and some tight headers. I built a 78 oldsmobile delta 88 with a 93 Silverado junkyard 350, accel sequential DFI, 1-1/2" long tubes, stock TPI base/runners/plenum, aftermarket throttle body, and MSD 6A. With the original oldsmobile (still on original build) non lockup th-350, and 308 gears, that car would get 22-24 mpg highway towing an 92 camaro with a complete cast iron 454 and a T5 trans in the trunk (@ 55mph). I wish I was able to swap that 4l80E in there I had to see some OD w/ lockup numbers.
Some things to keep in mind: 1 Late TPI 305s made almost as much hp as late tpi 350s. 230:245 where as torque was 300:345 2 Most people look at 305s as junk but look at the Ford 225hp 5.0 as a good engine. Wrong 3 When the TPI engines were still in production I read a story that included John Lingenfelter. What he found was that the TPI 305s and 350s used the exact same TPI intake manifold. The problem was that they were sized for the 305. When they learned this they designed their own manifold for the TPI 350 (L98). Lingenfelter's manifold made around 40hp more than the stock TPI manifold on the L98. An L98 with a Lingenfelter intake manifold made almost as much hp as a stock LT1. If you look at this, the LT1 wasn't as big of a leap in power from the L98 as people think. I believe the LT1 short runner intake manifold was actually designed around the larger displacement of there LT1. Horrible choice for the 4.3.
I had a built lt1 in my 96 camaro. Cam motion. Meaux ported heads it was my adult size gocart. Lost it in the flood in 2016. It's really hard to start over when it's gone like that
@@richardholdener1727 I thought it was '86 when the first TPI came out. Reason being was I had an '85 T/A and my buddy had an '86 iroc. His was tuned port and mine had a quadrajet. He was always just a little quicker than me, so I went and picked up an '89 L98 GTA. Fixed that problem right up.
Richard, There is not a cam that allows a broader torque curve, however there are roller lifters that reduce duration by 15-20° at lower rpm. Rhoads V-Max. They lash like a solid lifter. 0.020" feeler gauge cold for an iron block and heads or 0.014" feeler gauge for iron block and aluminum heads. My 11:1 383 went from 195 psi to 210 psi cranking compression. Much more low-end torque.
That's interesting. The horsepower and torque peaks on that TPI intake equipped 4.3 are at almost the exact same rpm they are in my turbocharged, TPI equipped, L98 5.7. (My torque curve is much flatter though.) Just goes to show you how much influence the runner length has on the rpm range of the engine.
Any thoughts on how a RAM air might help get the best of both worlds? I ask because Ive built two of them for my little work trucks. They always felt wheezy at higher RPMs; knowing a little bit about runner length I decided to try something...combined with getting cooler air into the engine. The first truck was a 2.5l Iron Duke; second was the LN2 2.2l. Both saw some benefit at highway speeds, but the LN2 really seemed to benefit even around 30mph. On the highway it was a night and day difference...It would pull hard all the way up to 95. I realize that its not the same thing; but having all of that air ready to be pushed in as soon as the valve starts opening has to be of SOME benefit. I almost got to building a custom intake for it but then traded it in on a new Ranger.
Very good comparison Richard. Cant wait to see the results of the rotating assembly swap. You should overlay the 305 LB9 TPI results with the L99 TPI and compare the difference between 3"/5.94 rod & 3.48"/5.7 rod. and 1 point of compression does.
I had a '89 Firebird Formula 350 many years ago. The car felt really fast from stoplight to stoplight. It ran low 14's in the quarter mile and that was quick back in the day.
The Formula 350 TPI. It was all that the Ford rustang could do to try to keep up with that Formula 350. I like it because it's a lighter Firebird than the TA. No ground effects , leather seats etc to weigh it down. and it had the same Ws6 handling and power as the TA Firebird. It also had the Knight Rider hood. 89 was a good year . Duel cats!
That thing sounded like a beast with the l98 intake in comparison to both the carb’d and original intakes. I agree with others the l98 intakes should’ve been in the trucks for tq purposes. It’d be interesting to see one carefully cut and welded back together to run on a 4.3 v6.
there's one guy on TH-cam, i think Boosted_V6 is his name but he did exactly that with an intake manifold to out on his built 4.3! he had to take a big cut out of it diagonally th-cam.com/video/4k6PBCUqIq4/w-d-xo.html
Richard, what I havent seen is anyone set this thing up for success by optimizing the combo... totally required to get that torque surge the TPI is capable of, though even with CSA and runner length not matched or optimized, the runner length is still great for added torque. The plenum is unported (10 min of entry porting helps ALOT). There is also minor work on the runners and base that helps with optimizing the factory TPI parts. The achilles heel of the intake is the poor (low) port entry angle meeting the cylinder head. That is why the FIRST TPI preforms so much better. The factory TPI intake was designed around 305 ci. You can 'stroke' an L99 into a 305 and if you do the math you will see the runner length and diameter will give you a 4000 RPM torque peak on 305 ci, but only 3400 on a 350., however the length and torque peak together is a better match for the TPI on a 305 in stock form. That explains the SLP siamesed runners, that arent too large but effectively shorten runner length to match a 350. Ever wonder why the peanut cam ended up in the 305 TPI's? TPI 305 engines run very strong with a more optimized stock TPI intake and a cam like the corvette LT1 or small aftermarket cam 208-210 deg duration range. Cant have a 305 walk a 350 that close. Also, runners Iike the as&m are sized accordingly, if you do the math, for 383 ci. TPI engines are vacuum leak prone but very fun and got a bad rap, largely because people were looking at it like an antituned intake and focusing on merely flow numbers while ignoring the runner length, diameter and quality of airflow which is what makes the TPI 'tuned'. Possibly one of the most misunderstood intakes out there. Increase compression. Run an electric pump. Port the plenum, use an airfoil or bettef yet a 52mm TB, increase to 305 ci, clean up the intake(hand blend and tap out bulges in the runners near the flanges). Bump fuel pressure to 50psi at idle. I bet it turns into a stump puller!!!
Hi Dave, thank you for typing out the detailed comment. How does one calculate peak torque rpm based off of runner length and diameter? Where do you get the 4000 and 3500 numbers? Those #'s sound about right from what I've seen in these videos. I am really curious what sort of #s could be achieved from a tpi 400. Probably not ideal in a "typical" performance set up, but it sounds good for a truck/offroader vehicle that would benefit from the torque.
I have two Buick Roadmasters, one has the LO5, the other has the LT1. I really prefer the LO5 in this application as the LO5 has a noticeable torque difference. Off the line I believe the LO5 would get the LT1 for a few yards, although the LT1 will get it down the line. The LO5 is really a better setup I believe for a heavy Roadmaster. Would like to try the TPI on one of them, however just don't really want to get that deep in when both are working well at this time. Interesting results.
I often wondered what it would be like to combine a TPI intake with a TBI engine, since TBI heads are also designed for low end torque more than anything. The TPI runners would maximize low end torque, and then they would eliminate the fuel distribution limitations of the TBI.
A 117 LCA "computer" EFI camshaft is way wrong for a Carburator setup that can handle 108 LCA with ease. Looking forward to see what heppens next. :) I am still amazed than no one is offering a EFI converted carb style dual plane manifold for the V8 engines, only single planes style manifolds.
Mercruiser had one for Vortec heads with a large monoblade throttle body on an adapter. I ran one on my 383 in my Express van. Lots of torque and good hp. I used a 1200 cfm 4bbl throttle body and a low profile carb bonnet with a 4" air intake.
I would like a 300 HP 350 ft lbs tq L98 . In my 89 Formula Ws6 . I can't go too crazy with a ttop car with stock 700r4 tranny . Will need subframe connectors first though. A car from the 80s that's still the best looking car on the road running in the mid to high 12s or even low 13s would tickle my fancy. A third gen Firebird being 200 lbs lighter that a 4th gen doesn't hurt either. I still think it's wild that the first gen F bodies were the lightest weight.
So, it's worth mentioning that the carb intake was also the only "performance" intake tested here. I would be interested to see what this engine would do with something like a superram, which is kinda a middle of the road for runner length compared to the TPI and LT1. Personally, I don't like the TPI style intakes, they're too much of a pita to put together, that being said there aren't alot of options out there for a gen 1 sbc that produce the torque that they do.
Accel made a Superram induction system for 92-97 LT based engines. It was the same as the Superram induction system for the LB9/L98 engines except it had a base intake manifold that was TPI on the top and LT1 on the bottom, had the same short runners, and a shorter upper plenum to clear the lower cowl on the 4th generation F bodies because the back part of the engine sat under the windshield in those cars. You could think of the base intake on the LT Superram system like the SD Vortec TPI base intake manifold except it was for LT based engines and it didn't flow like a turd like the SD Vortec TPI base does.
@@Airwolf1971 I'm pretty sure the superram runners and plenum can be bolted to a stock TPI base. Theoretically he could put those parts on the modified base he already has.
@@ericjon262 Yes they can be. The high flow base that Accel used on the Superram is the exact same base used with Accel's high flow TPI runners and plenum. Accel had a complete high flow TPI system and a step up from that was their Superram.
FYI the long runner intakes produce a ram effect at upshift & the rpm drop that occurs at upshift....it adds a bit of torque shock,the kind that kills 700r4 transmissions
The Tpi intake probably would have made more peak power than the l99 intake with the stock camshaft. The stock l99 makes peak power at 5200 rpm and every point up to that that rpm the tpi intake is better. This gets worse for the l99 intake at lower rpm because the restriction of the runner isn't as pronounced at a lower rpm and airflow. Tpi intakes are expensive to manufacture and install on cars though, even as a manufacturer. The l99 intake is one.piece, the tpi intake is at least four that are all unique and need to be relatively precise with multiple machined surfaces. I know someone is going to say that the runners aren't a restriction, they are. A well aligned, all those pieces I mentioned, tpi will flow less than 200cfm per runner. It really doesn't matter what heads and camshaft you put on it when you have an intake manifold that flows less than stock vortec heads with a truck cam.
@@shadowopsairman1583 what I was trying to explain, is that you can see the drastic difference in tq loss with the short runner intake, but also drastic hp fall off with the long runner intake manifold with the same internal parts. If you were to utilize an intake manifold that had a variable intake runner design, you could have a long runner intake for better low end power and have an additional set of short runners that open up in the higher rpm range to give better upper end hp, so giving the best of both worlds, on this particular engine.
So with the long runner intake it wouldent be a bad set up for a truck atleast a half ton. I have a lt1 an a l99 im thinking about throwing the l99 crank an connecting rods in the lt1 to make a 302 with the aluminum lt1 heads an mabye doing something like modding a tpi intake it could have some really good results.
Have a corvette C4 with the L98. Then when I finally got my hands on a Camaro SS Fbody with first gen LS1 i was very disappointed. L98 just made the LS1 feel tired and down on power. The trany was also not as aggressive making the camaro feeling even slower
I'm wondering if you can block off the throttle body opening and convert a tpi plenum to carb. Sort of like holley hi ram manifolds with interchangeable tops. That would be a killer combo for a pickup.
@@TurtlDrip I was more thinking of optimal fuel distribution. The ports are dry until right before the cylinder head. The places of the carb flange would need to be in the right spot to supply the corners. Maybe some fins to guide the flow. I know it's possible to plug a hole and cut a hole. I just think it would take a little more r&d than the average Joe welder is willing to do.
I've never heard of a 4.3L L99 V8. The only L99 I know is the 6.2L LS style L99 that came in the 2010 and up Camaro SS. As I listened to the rest of the video, the 4.3L L99 came in the full size Caprice. I thought that was a 5.0 that was in the Caprice. This video pretty sums up why GM eliminated the TPI manifold when they introduced the 5.7L LT1 V8 for the 4th gen Camaro/Trans Am in 1993. The TPI's weakness was after 5000 rpm, the LT1's strength was after 5000 rpm, and why that engine was rated at 285 hp. I love these GM engines, but I'm not using anything under 5.7L's. Lol
One of the big advantages of the LT1 reverse flow cooling is that there are no coolant passages or thermostat housing in the LT1 intake which eliminates coolant leaks and allows for a 3.5" lower intake than L98. My question is how is coolant flow changed if at all by using a L98 intake on LT1.
It's what they had but ya, they're too big. 1 1/2" would probably work good. For this back to back test the data is still good because it was only one change.
@@joed5472 it's would probably add a bunch especially under the peak. It's making so little power that even smaller pipes might work but none are really available.
Grind down the restrictive nubs behind the throttle body on the upper intake and get a pair of Siamesed intake runners and that tpi will pick up a bunch of top end hp.
I don't know about it being a mistake, but you kinda worked well for what it was designed, mostly a small displacement, low rpm engine, when I had one, I was trying to figure how to keep the overall shape, only make the lower intake ports larger, and the intake runners larger with similar length, with larger ports in the plenum, and throttle body, maybe twin 58-60mm, however, I only port matched everything on mine, and ported the throttle body a bit, (and the plenum, ). I'm thinking tpi may worked well on a 283, in a early 60's Nova! I think something with a short stroke, Maybe a 327 also, a short stroke taking a quick, large gulp filling the cylinders, over a slower big gulp from a longer stroke, but I guess it comes to cam duration and timing, it just seems if the runner volume is equal to cylinder volume, or greater, it would have a ram air effect at a certain rpm range, where the moving air and reflected waves all work together, it all works out, and is plainly simple! (Totally inside my head of course, ) but even reading this not so much, but the total port volume, seems it equal or greater than cylinder volume, should fill the cylinders , maybe crazy, but I am a bit tired, just got out of the hospital, and had to watch your video first thing!! I'm just curious tohow the same (or close) displacement, only difference.is bore and stroke, to make it simple, say a 3" x 4" and a 4" x 3" bore to stroke, with similar intakes and cams, it would be interesting!
Hmmmm, this is something to think about. My 96 corvette LT1 feels like I'm really stretching it out going to 6,000rpm. I'd give up 700rpm to gain everywhere else. Low rpms agree with my ability to finance engine builds
@@grandmasmalibu there is lots of 5.7l iron head engines that are 260hp. Dunno the code. If you see a 94-96 car with duel exhaust it's a 5.7l, a single exhaust is 4.3l. The impala ss and cadillac fleetwood apparently had the lt1 aluminum head engine.
@@grandmasmalibu I've had nearly all of the LT1 cars - SS, Roady sedan & station wagon, Fleetwood & Caprice sedan & 9C1 cop car..... I'm fairly confident that All were iron headed 5.7s but my buddy who's sister raced Camaro & Firebirds had aluminum headed engines.... Which reminds me - I've got a set of her old aluminum heads laying in the garage if anyone wants them.. haha
5.0L 302 (4.0 x 3.0) with LT1 crank? 5.0L equal L99 crank and rods with LT1 pistons in LT1 block. or...305 equal LT1 crank and rods with l99 pistons in l99 block
@@richardholdener1727 L99 305ci using the L99 block, heads & pistons with LT1 crank & rods. The increased displacement from the longer stroke will increase the static compression ratio and make more power (or will it?) Than the LT1 302ci because the reduced L99 stroke will also lower the static compression ratio.
What upgrades would you do to the l99 engine to make it better I have a 1996 caprice classic bubble and I'm not sure I can afford the lt1 engine swap at the moment or is it a complete waste should I just save up for the lt1 swap
@@EBO47 The LT1 Engine is almost identical to the L99. It is a direct swap with absolutely no issues, as long as you swap from another Caprice or roadmaster. Camaro/Corvette engines can work too but oil pans and accessory drives can be different, as well as the optispark setup. The Computer can even run both engines. That being said, any little upgrades you do to the L99 can easily transfer over the LT1 engine when you do swap one in. There are a few things on these cars outside of the engine to boost performance, changing the rear end gears is a big one. One of the biggest upgrades to my car was swap the torque converter when I rebuilt my trans, I used one from a Blazer, its the same converter but with a higher stall speed, feels like a totally different car now. Its nothing crazy but a nice boost. I think the stock converter in these cars has a stall speed of 1100 RPM while the blazer one is around 2500.
@@richardholdener1727 You will have my forever support if we can figure the max torque combo for a 6.0 ls I can say I bet it will be your hardest and most opposed or supported vlog yet cause the powers that be won't let you do it .
This is good info I have a 86 Trans am with a newer vortec 350 truck motor and a aluminum intake and edelbroch carb. Looks like I make more power then the stock intake systems and my big cam should breath better too
your carb and the one used in this vid are two totally different carbs lol richard states the air foil yielded no gains on the efi but doesnt use 300-600 dollar street carbs
i would like to see what a throttle body injection would do on this engine.and I'm not sure the the fuel injection was optimized on these setups seem like the drop off in power at higher rpm's might be not enough fuel.
Ok now repeat the test on a 383. I want to see how the airflow demand affects the comparison. Would the "LT1" intake overtake the TPI at a lower RPM? or would the TPI still dominate up to the ~4700 rpm wall?
L98 is a torque monster but man once you hit around 4k all the power falls off. It’s a fun stop light to stop light engine though. 2-3k RPMs hits hard in the L98
Disregard my last comment haha didn’t expect you to do the carb intake haha. I was right tho.... other than the torque of the tuned port. Richard this was an awesome video. This is why I still run carbs. Easy to tune and for some reason they just seem to always make power.
There's one thing that has to be considered in why GM didn't put the TPI intake where the LT1 lived... does it actually fit in the applications where the LT1 lived? The throttle body is sitting quite a bit higher. I don't have the time to go hunting for hood profiles for various GM vehicles, but it may well be that they didn't want to change the stamping dies or it wasn't worth the unit cost for custom changes.
Can you modify a TPI manifold to accept a carb or something with similar runner length and carb for comparison? Probably not cost effective but would be interesting to see if it beats the fuel injection TPI.
A friend of mine did this. Stock van Vortec 5.7L. Home ported the bowls in the heads. Port matched Vortec TPI base. Stock un ported runners, plenum, and throttle body. Lunati street/strip hyd roller. 12.28@111mph in the 1/4 mile in a 1992 Z28. The engine has loads of torque. Excellent street engine.
I have a 1996 Suburban with a 5.7 vortec engine. I have a rear mounted distributor and coolant runs through the intake. My engine must be a SBC correct? Were they still installing SBC engines 1992-97 in trucks but not cars?
So, a happy medium would be to go with bolt-on TBI? That's what I gather. Maybe that's what you should investigate next, Richard: Get a Sniper EFI TBI, and see where it takes you. ;)
I used to daily a bone stock L98, it felt so much stronger than the numbers would suggest. It made no power past 5K but all that torque with the 700R4's super low first gear made it a stoplight to stoplight superstar.
I ran a 1.93 60 foot time!
Got a 1.7 60 foot on mine
They give a good sound too
I have a 86 corvette, the L98 on it is a masterpiece, it used to be my daily for years & like I can say is that it’s powerful, fun & it’s really reliable I rarely had to fix anything on it.
@@apl.2018 a guy wants to trade me for his 89 vette, it looks perfect-garage kept low mileage but I can’t decide if I should or not. That engine is stock and is rated for only 240hp and I don’t want to spend thousands to make it actually make some power..
I wish the TPI intake was a good option for 5-600hp builds. It just looks so damn cool.
IT DOES THAT WITH BOOST
TPIS mini ram
FIRST Performance
@@cuzz63 will the first actually make 500+ though?
@@zachkuby87 don't know...over 450;for sure
Exactly why I want the GM TPI on my 5.7L LT1 engine in my 1997 Trans Am WS6. Now just consider how things would improve with a good extrude hone of the base, smoothing out the air flow, increasing it as far as 260cfm if possible, and maintaining velocity. Now add on AS&M runners with the necessary port matching of the plenum and with a ZZ4 camshaft, things start to get pretty interesting with the LT1. As I often regard it, the TPI intake was the prototype for the LS1 intake.
A set of AFR heads and a cam from Tick Performance on a stock LT1 will smoke that combination you just listed.
Someone I met at the SVRA in Austin, Texas in 2018 was running a carb on his C4 Corvette - he said too that those engines make more power with a carb than fuel injection.
The 4.3 motor should never have been the slug that it was, i get it that GM ran its smaller displacement in a bid for fuel economy numbers back in the day but using the available TPI manifold would not have changed that but as Richard just showed it would have been a torque monster in comparison and still had the fuel economy, GM missed the boat on that one
I have a feeling the issue would've been cost.
The TPI manifold is extremely complex to produce, assemble, and install compared to the LT1 intake, especially for a production line.
GM has missed the boat on other things, too. LS7 heads come to mind......
That’s why my 91 Z28 5.7 was such a beast stop light to stop light. When I got 3.73s, shorty TPIS runners, a cam, aluminum corvette heads, underdrive pulley, chip, CAI and exhaust it was as fast as LT1/LS1 cars or faster. I remember making my buddy with a new era Cobra very mad. Man I miss that car, but tbh I’m looking for another 3rd gen to put a LS2,3 or if I’m lucky a LS7
I’m following along something similar. 4.3 L99 block, 305 Vortec rebuild kit, ported B-Body LT1 iron heads with stock valves, LT4 Hot cam, and I believe I just decided to go with a carb instead of FI. It’s basically 305 LT4 with a carb. It’s gonna find it’s way into a s10 blazer I’m building. Sweet part is damn near every major component came out of a junkyard.
Jim Hall made my current L98 Mini-Ram intake. It is one of the last Manifolds he made before discontinuing them as the LS engines have taken over. I am very appreciative of his work and Richard's that has made my Blue Print 427sb engine scream!
Okay Richard, I see a lot of comments from guys from "back in the day", so I feel compelled to tell my "old school" story, keeping it brief. 1992 H town,Tex I wanted a late model car I could drive every day, enjoy and have fun. GM guy and 88-89 models where in my $ range so I decided on a 89 Formula 350.( If a Ford guy it would have been Mustang LX 5.0) Although it went through stages, I'll skip all that.
.30 block, SCAT 400 crank, KB dished pistons, GM vette alum. heads ported, TPIS ZZ-9 cam. HS 1.6 rr Accel lower intake, TPIS runners, ported stock upper, 58mm TB, airfoil, ford injectors, adj, fuel presssure reg, MSD 6A, underdrve c/pulley, 700R4 transpack/vette servo, 3.27 gear. weighed 3470 with me and 1/2 tank, ran a 12.66 baytown, best 1.56 60ft, would eek out a 12 in drive shifting at 4800. Have always been curious what the power curve must have looked like. The best truck motor never made is what i always thought as well. (I thought a NOS shot would have been the best next thing, as it does not require as much additional airflow).
Was it on the stock ecm?
You continue to validate why I'm building a TPI 383 to replace the carburated 350 in my class 3 RV
"The TPI is the best truck intake GM never put in a truck".
A good dual plane intake makes similar torque to a TPI intake. First Fuel Injection makes a VERY nice TPI style intake. If I was building a truck engine but wanted it to still have some top end power, I would run one in a heartbeat.
Motoracer
Did you build it?
L98 intakes are great. Miss my L98. SLP siamesed runners, port matched upper and lower , a cam, longtubes, that IROC was a beast on the street...
The 1989 350TPI engines had 3.27 gears, the 1998 350LT1 engines had 3.42 gears. The LT1 engines had lower emissions and better fuel economy. The LT1 cars were faster at the drag strip. The TPI cars were quicker across an intersection. It was money that kept the 4.3 from getting the TPI intake, and the LT intake is a smaller package. Plus you needed horsepower to fight the BMWs.
When my dad was out in California about 20 years ago he picked up a badass firebird formula 350. It had LT1 heads on it because the sand ate up the original heads. You guys got a lot of sand. We're in pa. But that thing was one bad SOB.... It had a built 700R4 that would chirp tire and all four gears not even trying. With them LT1 heads and the tune port that thing freaking ripped. He wouldn't give it to me because he told me I'd kill myself. Well now I got a car 10 times that shit I just need a good fuel injection system. Thank you Richard for all your hard work and dedication and teaching. From our house to yours thank you
The dual plane has “medium” length runners but also isolates the dilution of the intake charge by operating as two 4-cylinder engines. Long runners between the plenum and the intake valves will have somewhat the same effect but short runners, whether single plane carb manifold or EFI plenum, hurt low- to mid-range due to lack of isolation. It appears the LT1 manifold runners are tuned for rpm well above the range of that cam since the dual plane manifold beats it on both torque and power. The L98 runner length looks good for barges and trucks but I think a tunnel Ram might be better for ultimate performance. Really interesting results in this test. Thanks, Richard!
" It appears the LT1 manifold runners are tuned for rpm well above the range of that cam since the dual plane manifold beats it on both torque and power". OR tuned for a larger displacement engine.
The sedans and wagons of Buick, Caddy, and Olds could have really distinguished themselves to be old school torque monsters had they come up with a TPI intake to fit the LT1 in their cars. I'm looking into installing a TPI on the LT1 in my Roadmaster wagon. I might try the factory intake base modification route and see how it works before going with a FIRST intake setup. All I want is more towing power. The sedans and wagons already got a slightly higher torque cam right from the factory.
I had an 86 Corvette with the TPI. It was all about torque, not a high RPM engine like you’d expect from a SBC. Your dyno runs confirmed what I expected to see.
the 86 was not true and pure fuel injection. it was a carb on steroids
@@scoutleader06 I’d like to see something that backs up your statement. I’ve never heard of what sounds like nonsense. There were eight injectors, one per port. The injectors fired in batch mode, maybe twice per engine revolution, not sequentially. But it was certainly fuel injection, nothing like a carburetor.
@@scoutleader06 You’re thinking of Cross Fire injection on the 1982 & 1984 Corvettes.
@@CrazyPetez batch mode injection was a crude run-up to the 87 TPI true sequential fuel injection, maybe not quite a carb on steroids, but nothing like the 87 TPI sequential controlled by the ECM. do your home work then come back here and tell me its nonsense.
The TPI Corvettes really do jump off the line. Awesome comparison. Nice work Richard! Who would have thought the baby LT1 could have been a baby beast in a Caprice. They could have just hashed up some block off plates and go to the old bolt pattern on the iron head. L98, LT1 both great GM motors
Surprising how much the TPI intake was still a restriction to top-end flow on the 4.3. I was expecting more top-end power, or less of a drop at least.
The power roll off was less a function of flow restriction than runner length.
@@jackcurrence263 heads. 265 was like the 305- emissions anemic power
Intake runner length produces a pulse wave...on a tpi 1st power wave at 2k rpm the second wave at 4k rpm....porting will move them both equally in general
0:47 that's the coolest looking intake ever on American small blocks.
what about using the carb intake but drop a Holley sniper fuel injection carb and see what it does....
+1 this! You would ideally have your cake of power and not have to fight adjustments through winter/summer
A while back I had a chance to build a 307 TPI setup but I blew it. 307 is essentially a 283 bore engine with 327 stroke (the opposite of the DZ302). Probably would have made great torque for a light duty hauler. I still have the complete TPI setup (polished manifold) but couldn't get to the 307 in time to snag it. I ended up swapping in a 5.3L LM7
The L98 TPI was a perfect set up for a Automatic trans. street car that low end Torque was a kick in the pants .We don't need no stinkin Holley Double pumper to make power!
We don't need NO Stinking Badges.
It would be awesome if you could test some intake and throttlebody combinations on a beefier 383 to see where the gains or losses are.
A lot of people hated TPI intakes, but for the correct application they are absolutely superior. For a street vehicle that will almost never got over 4500 RPM where you want good torque and fuel economy it is the GOAT intake.
I have long said that the TRUCKS should have had TPI 350's and the camaro's and corvettes should have come with the TBI intakes. The TBI engines were easier to modify and generally made better horsepower with some simple intake swaps (once you get around those awful early ecms).
The reason I bet that only vettes and Fbody cars came with TPI was cost. I bet most truck buyers didn't want the complexity and extra cost of the TPI.
Moral of the story is, always go for an aftermarket tunable ECM (this was a lot harder 20 years ago), then put the TPI on you big cars and trucks with a wide LSA cam and some tight headers.
I built a 78 oldsmobile delta 88 with a 93 Silverado junkyard 350, accel sequential DFI, 1-1/2" long tubes, stock TPI base/runners/plenum, aftermarket throttle body, and MSD 6A. With the original oldsmobile (still on original build) non lockup th-350, and 308 gears, that car would get 22-24 mpg highway towing an 92 camaro with a complete cast iron 454 and a T5 trans in the trunk (@ 55mph). I wish I was able to swap that 4l80E in there I had to see some OD w/ lockup numbers.
Some things to keep in mind:
1 Late TPI 305s made almost as much hp as late tpi 350s. 230:245 where as torque was 300:345
2 Most people look at 305s as junk but look at the Ford 225hp 5.0 as a good engine. Wrong
3 When the TPI engines were still in production I read a story that included John Lingenfelter. What he found was that the TPI 305s and 350s used the exact same TPI intake manifold. The problem was that they were sized for the 305. When they learned this they designed their own manifold for the TPI 350 (L98). Lingenfelter's manifold made around 40hp more than the stock TPI manifold on the L98. An L98 with a Lingenfelter intake manifold made almost as much hp as a stock LT1. If you look at this, the LT1 wasn't as big of a leap in power from the L98 as people think.
I believe the LT1 short runner intake manifold was actually designed around the larger displacement of there LT1. Horrible choice for the 4.3.
Exactly.
Would like to try l 98 intake on 406 sbc with torque cam and sequential
Fuel injection for my one ton chassis rv. Bet on great torque and mileage.!
I’m digging this series, wouldn’t mind seeing a tall deck 427bbc or a Chevy 366 for the other guys
If they had an LT1 truck motor it would DEFINITELY need that TPI intake
Its why the LS1 (LR4, LM7) has a truck intake as well
The GM L98 TPI intake manifold is one of the best looking EFI intakes, if not THE best.
That would make a nice little daily driver in the Nova!
I had a built lt1 in my 96 camaro. Cam motion. Meaux ported heads it was my adult size gocart. Lost it in the flood in 2016. It's really hard to start over when it's gone like that
the '87 L98 with the first true fuel injection TPI was automotive genius by Chevy engineers and it also looked so cool with the runners
that would be 1985-but agree
@@richardholdener1727 I thought it was '86 when the first TPI came out. Reason being was I had an '85 T/A and my buddy had an '86 iroc. His was tuned port and mine had a quadrajet. He was always just a little quicker than me, so I went and picked up an '89 L98 GTA. Fixed that problem right up.
@@bisurdaddy '85 Corvettes had TPI
That tpi intake is a monster.. i love it
In a drag race it's clear who would win the race
@@joed5472 probably the carb, but the tpi would pull outta hole better looks like.
@@joed5472 not the tpi. Unless you’re drag racing to the 60 foot lol
@@Hugo350R yeah I see your point.it would make a better truck engine if it was bigger or in a s10
Richard,
There is not a cam that allows a broader torque curve, however there are roller lifters that reduce duration by 15-20° at lower rpm. Rhoads V-Max. They lash like a solid lifter. 0.020" feeler gauge cold for an iron block and heads or 0.014" feeler gauge for iron block and aluminum heads. My 11:1 383 went from 195 psi to 210 psi cranking compression. Much more low-end torque.
The TPI manifold was replaced with the lower profile LT1 manifold for hood clearance in the Vette and Z28..
the Vette and Z/28 ran TPI motors and manifolds then LT1 motors and manifolds
My only question now is would a tunnel ram be the best of both worlds?
Long runners for torque and a straight shot into the head for flow?
That's interesting. The horsepower and torque peaks on that TPI intake equipped 4.3 are at almost the exact same rpm they are in my turbocharged, TPI equipped, L98 5.7. (My torque curve is much flatter though.) Just goes to show you how much influence the runner length has on the rpm range of the engine.
That was the idea behind the r26b rotary engines in the 787b's. They had variable length intake runners.
Cam, heads
Any thoughts on how a RAM air might help get the best of both worlds?
I ask because Ive built two of them for my little work trucks. They always felt wheezy at higher RPMs; knowing a little bit about runner length I decided to try something...combined with getting cooler air into the engine. The first truck was a 2.5l Iron Duke; second was the LN2 2.2l. Both saw some benefit at highway speeds, but the LN2 really seemed to benefit even around 30mph. On the highway it was a night and day difference...It would pull hard all the way up to 95.
I realize that its not the same thing; but having all of that air ready to be pushed in as soon as the valve starts opening has to be of SOME benefit. I almost got to building a custom intake for it but then traded it in on a new Ranger.
I love the tpi. It isn’t the greatest manifold in the world but it works good for the 80’s and it looks awesome.
Very good comparison Richard. Cant wait to see the results of the rotating assembly swap. You should overlay the 305 LB9 TPI results with the L99 TPI and compare the difference between 3"/5.94 rod & 3.48"/5.7 rod. and 1 point of compression does.
I had a '89 Firebird Formula 350 many years ago. The car felt really fast from stoplight to stoplight. It ran low 14's in the quarter mile and that was quick back in the day.
The Formula 350 TPI. It was all that the Ford rustang could do to try to keep up with that Formula 350. I like it because it's a lighter Firebird than the TA. No ground effects , leather seats etc to weigh it down. and it had the same Ws6 handling and power as the TA Firebird. It also had the Knight Rider hood. 89 was a good year . Duel cats!
That thing sounded like a beast with the l98 intake in comparison to both the carb’d and original intakes. I agree with others the l98 intakes should’ve been in the trucks for tq purposes. It’d be interesting to see one carefully cut and welded back together to run on a 4.3 v6.
there's one guy on TH-cam, i think Boosted_V6 is his name but he did exactly that with an intake manifold to out on his built 4.3! he had to take a big cut out of it diagonally th-cam.com/video/4k6PBCUqIq4/w-d-xo.html
Great video, I am Ford guy but I love the L98 TPI intake. Great video.
I'm a SBC die-hard but wish the distributer was at the front like Ford !!
Richard, what I havent seen is anyone set this thing up for success by optimizing the combo... totally required to get that torque surge the TPI is capable of, though even with CSA and runner length not matched or optimized, the runner length is still great for added torque. The plenum is unported (10 min of entry porting helps ALOT). There is also minor work on the runners and base that helps with optimizing the factory TPI parts. The achilles heel of the intake is the poor (low) port entry angle meeting the cylinder head. That is why the FIRST TPI preforms so much better.
The factory TPI intake was designed around 305 ci. You can 'stroke' an L99 into a 305 and if you do the math you will see the runner length and diameter will give you a 4000 RPM torque peak on 305 ci, but only 3400 on a 350., however the length and torque peak together is a better match for the TPI on a 305 in stock form. That explains the SLP siamesed runners, that arent too large but effectively shorten runner length to match a 350. Ever wonder why the peanut cam ended up in the 305 TPI's? TPI 305 engines run very strong with a more optimized stock TPI intake and a cam like the corvette LT1 or small aftermarket cam 208-210 deg duration range. Cant have a 305 walk a 350 that close. Also, runners Iike the as&m are sized accordingly, if you do the math, for 383 ci. TPI engines are vacuum leak prone but very fun and got a bad rap, largely because people were looking at it like an antituned intake and focusing on merely flow numbers while ignoring the runner length, diameter and quality of airflow which is what makes the TPI 'tuned'. Possibly one of the most misunderstood intakes out there.
Increase compression. Run an electric pump. Port the plenum, use an airfoil or bettef yet a 52mm TB, increase to 305 ci, clean up the intake(hand blend and tap out bulges in the runners near the flanges). Bump fuel pressure to 50psi at idle. I bet it turns into a stump puller!!!
Hi Dave, thank you for typing out the detailed comment.
How does one calculate peak torque rpm based off of runner length and diameter? Where do you get the 4000 and 3500 numbers? Those #'s sound about right from what I've seen in these videos.
I am really curious what sort of #s could be achieved from a tpi 400. Probably not ideal in a "typical" performance set up, but it sounds good for a truck/offroader vehicle that would benefit from the torque.
I have two Buick Roadmasters, one has the LO5, the other has the LT1. I really prefer the LO5 in this application as the LO5 has a noticeable torque difference. Off the line I believe the LO5 would get the LT1 for a few yards, although the LT1 will get it down the line. The LO5 is really a better setup I believe for a heavy Roadmaster. Would like to try the TPI on one of them, however just don't really want to get that deep in when both are working well at this time. Interesting results.
I often wondered what it would be like to combine a TPI intake with a TBI engine, since TBI heads are also designed for low end torque more than anything. The TPI runners would maximize low end torque, and then they would eliminate the fuel distribution limitations of the TBI.
This info is very helpful in my 95 impala. Many thanks Richard. Your work is appreciated.
A 117 LCA "computer" EFI camshaft is way wrong for a Carburator setup that can handle 108 LCA with ease. Looking forward to see what heppens next. :) I am still amazed than no one is offering a EFI converted carb style dual plane manifold for the V8 engines, only single planes style manifolds.
Mercruiser had one for Vortec heads with a large monoblade throttle body on an adapter. I ran one on my 383 in my Express van. Lots of torque and good hp. I used a 1200 cfm 4bbl throttle body and a low profile carb bonnet with a 4" air intake.
I would like a 300 HP 350 ft lbs tq L98 . In my 89 Formula Ws6 . I can't go too crazy with a ttop car with stock 700r4 tranny . Will need subframe connectors first though. A car from the 80s that's still the best looking car on the road running in the mid to high 12s or even low 13s would tickle my fancy. A third gen Firebird being 200 lbs lighter that a 4th gen doesn't hurt either. I still think it's wild that the first gen F bodies were the lightest weight.
What do you mean by first gen fbody?
@@TheJMan1K First generation Camaros and Firebirds 1967-1969
So, it's worth mentioning that the carb intake was also the only "performance" intake tested here. I would be interested to see what this engine would do with something like a superram, which is kinda a middle of the road for runner length compared to the TPI and LT1. Personally, I don't like the TPI style intakes, they're too much of a pita to put together, that being said there aren't alot of options out there for a gen 1 sbc that produce the torque that they do.
Accel made a Superram induction system for 92-97 LT based engines. It was the same as the Superram induction system for the LB9/L98 engines except it had a base intake manifold that was TPI on the top and LT1 on the bottom, had the same short runners, and a shorter upper plenum to clear the lower cowl on the 4th generation F bodies because the back part of the engine sat under the windshield in those cars. You could think of the base intake on the LT Superram system like the SD Vortec TPI base intake manifold except it was for LT based engines and it didn't flow like a turd like the SD Vortec TPI base does.
@@Airwolf1971 I'm pretty sure the superram runners and plenum can be bolted to a stock TPI base. Theoretically he could put those parts on the modified base he already has.
@@ericjon262 Yes they can be. The high flow base that Accel used on the Superram is the exact same base used with Accel's high flow TPI runners and plenum. Accel had a complete high flow TPI system and a step up from that was their Superram.
FYI the long runner intakes produce a ram effect at upshift & the rpm drop that occurs at upshift....it adds a bit of torque shock,the kind that kills 700r4 transmissions
RAM EFFECT AT UPSHIFT?
Love this "other guy's" series, keep it up Richard!
The Tpi intake probably would have made more peak power than the l99 intake with the stock camshaft. The stock l99 makes peak power at 5200 rpm and every point up to that that rpm the tpi intake is better. This gets worse for the l99 intake at lower rpm because the restriction of the runner isn't as pronounced at a lower rpm and airflow. Tpi intakes are expensive to manufacture and install on cars though, even as a manufacturer. The l99 intake is one.piece, the tpi intake is at least four that are all unique and need to be relatively precise with multiple machined surfaces.
I know someone is going to say that the runners aren't a restriction, they are. A well aligned, all those pieces I mentioned, tpi will flow less than 200cfm per runner. It really doesn't matter what heads and camshaft you put on it when you have an intake manifold that flows less than stock vortec heads with a truck cam.
Would the TPI Be better if the manifold was ported ?? Plus I think it looks better
Guess that motor needs variable intake runner length design
Cam, springs, heads help like on the 305
@@shadowopsairman1583 what I was trying to explain, is that you can see the drastic difference in tq loss with the short runner intake, but also drastic hp fall off with the long runner intake manifold with the same internal parts. If you were to utilize an intake manifold that had a variable intake runner design, you could have a long runner intake for better low end power and have an additional set of short runners that open up in the higher rpm range to give better upper end hp, so giving the best of both worlds, on this particular engine.
So with the long runner intake it wouldent be a bad set up for a truck atleast a half ton. I have a lt1 an a l99 im thinking about throwing the l99 crank an connecting rods in the lt1 to make a 302 with the aluminum lt1 heads an mabye doing something like modding a tpi intake it could have some really good results.
for a truck you should keep it at 350 inches
Have a corvette C4 with the L98. Then when I finally got my hands on a Camaro SS Fbody with first gen LS1 i was very disappointed. L98 just made the LS1 feel tired and down on power. The trany was also not as aggressive making the camaro feeling even slower
an LS1 make 100 hp more than an L98-but the L98 does feel very torquey (initially)
I'm wondering if you can block off the throttle body opening and convert a tpi plenum to carb. Sort of like holley hi ram manifolds with interchangeable tops. That would be a killer combo for a pickup.
Anything is possible with a welder
@@TurtlDrip I was more thinking of optimal fuel distribution. The ports are dry until right before the cylinder head. The places of the carb flange would need to be in the right spot to supply the corners. Maybe some fins to guide the flow. I know it's possible to plug a hole and cut a hole. I just think it would take a little more r&d than the average Joe welder is willing to do.
@@TurtlDrip question answered. Lol. Not just a Joe-welder solution.
@@EricErnst yes sir. Happy he made it happen
no
Love these format of videos
Do you have a 383 LT1 you could test this combo out on, I would really love to see the torque that makes
You could also put a fuel injection setup on top that carbed intake manifold.
IT WOULD ONLY HELP TUNING
Really appreciate these videos. Would be cool to see an elapsed time comparison of this engine in the nova with both manifolds.
I've never heard of a 4.3L L99 V8. The only L99 I know is the 6.2L LS style L99 that came in the 2010 and up Camaro SS. As I listened to the rest of the video, the 4.3L L99 came in the full size Caprice. I thought that was a 5.0 that was in the Caprice. This video pretty sums up why GM eliminated the TPI manifold when they introduced the 5.7L LT1 V8 for the 4th gen Camaro/Trans Am in 1993. The TPI's weakness was after 5000 rpm, the LT1's strength was after 5000 rpm, and why that engine was rated at 285 hp. I love these GM engines, but I'm not using anything under 5.7L's. Lol
For some dumbass reason GM likes to reuse engine designations, which is why there are three completely different LT1 engines.
@@fryloc359 it doesn't matter because each LT1 engine is bad ass!
One of the big advantages of the LT1 reverse flow cooling is that there are no coolant passages or thermostat housing in the LT1 intake which eliminates coolant leaks and allows for a 3.5" lower intake than L98.
My question is how is coolant flow changed if at all by using a L98 intake on LT1.
Morning
Can you try a intake with the in jectors mounted further away from the head like Infront of the butterfly and mybe at the top of the runner
that video is up-tested that on a Honda
Does anyone else think that 1 3/4" headers aren't the best for a 262 ci engine?
It's what they had but ya, they're too big. 1 1/2" would probably work good. For this back to back test the data is still good because it was only one change.
at most, 1 5/8"
@@timothybayliss6680 with those 1.5 inch headers the torque would have over 300lbs
@@joed5472 it's would probably add a bunch especially under the peak. It's making so little power that even smaller pipes might work but none are really available.
Richard just added a video where he uses 1 5/8" headers. 5 hp, 9 lb-ft gain.
im curious now how bad the vortec and tbi intakes are
Grind down the restrictive nubs behind the throttle body on the upper intake and get a pair of Siamesed intake runners and that tpi will pick up a bunch of top end hp.
hes also using the stock throttle body with no air foil while he has a 1k race carb on the dual plane
Tune port intake would've made more sense on the 4.3 in those heavy caprice cars
Absolutely
Trucks as well.
Would have made more sense on the 5.7 in all the 90s B bodies too IMO save for maybe the Impala SS
Tpi is the coolest looking set up and gives great low end torque
Have you tried the TPI intake on the 5.7?
I don't know about it being a mistake, but you kinda worked well for what it was designed, mostly a small displacement, low rpm engine, when I had one, I was trying to figure how to keep the overall shape, only make the lower intake ports larger, and the intake runners larger with similar length, with larger ports in the plenum, and throttle body, maybe twin 58-60mm, however, I only port matched everything on mine, and ported the throttle body a bit, (and the plenum, ). I'm thinking tpi may worked well on a 283, in a early 60's Nova! I think something with a short stroke, Maybe a 327 also, a short stroke taking a quick, large gulp filling the cylinders, over a slower big gulp from a longer stroke, but I guess it comes to cam duration and timing, it just seems if the runner volume is equal to cylinder volume, or greater, it would have a ram air effect at a certain rpm range, where the moving air and reflected waves all work together, it all works out, and is plainly simple! (Totally inside my head of course, ) but even reading this not so much, but the total port volume, seems it equal or greater than cylinder volume, should fill the cylinders , maybe crazy, but I am a bit tired, just got out of the hospital, and had to watch your video first thing!! I'm just curious tohow the same (or close) displacement, only difference.is bore and stroke, to make it simple, say a 3" x 4" and a 4" x 3" bore to stroke, with similar intakes and cams, it would be interesting!
I thought this too but never built it
What about middle lenght runners. Maybe you could bolt on a Superram plenum and runners on TPI lower intake.
I'm curious how the TPI intake would perform with a set of ported 193 heads.
193 heads are worth their value as scrap...
@@ericjon262 ok, but I'm not trying to sell a set so....
Hmmmm, this is something to think about. My 96 corvette LT1 feels like I'm really stretching it out going to 6,000rpm. I'd give up 700rpm to gain everywhere else. Low rpms agree with my ability to finance engine builds
GM should have just put the 5.7L in the Caprice instead of a completely different 4.3.
Or whent with a 4.3 V6 or 305.
@@grandmasmalibu there is lots of 5.7l iron head engines that are 260hp. Dunno the code. If you see a 94-96 car with duel exhaust it's a 5.7l, a single exhaust is 4.3l. The impala ss and cadillac fleetwood apparently had the lt1 aluminum head engine.
@@grandmasmalibu I've had nearly all of the LT1 cars - SS, Roady sedan & station wagon, Fleetwood & Caprice sedan & 9C1 cop car..... I'm fairly confident that All were iron headed 5.7s but my buddy who's sister raced Camaro & Firebirds had aluminum headed engines.... Which reminds me - I've got a set of her old aluminum heads laying in the garage if anyone wants them.. haha
Can you build a high compression 5.0L with the L99 block, LT1 crank, LT1 rods, & ported L99 heads. Thanks for the great videos..
5.0L 302 (4.0 x 3.0) with LT1 crank? 5.0L equal L99 crank and rods with LT1 pistons in LT1 block. or...305 equal LT1 crank and rods with l99 pistons in l99 block
@@richardholdener1727 L99 305ci using the L99 block, heads & pistons with LT1 crank & rods. The increased displacement from the longer stroke will increase the static compression ratio and make more power (or will it?) Than the LT1 302ci because the reduced L99 stroke will also lower the static compression ratio.
that would be a fun motor in a s10 with the tpi setup good video
Best upgrade I ever did to my L99 caprice? Pull it out and drop at real LT1 in there. Its a direct swap and adds 60hp and 100 ft/lbs of torque.
What upgrades would you do to the l99 engine to make it better I have a 1996 caprice classic bubble and I'm not sure I can afford the lt1 engine swap at the moment or is it a complete waste should I just save up for the lt1 swap
@@EBO47 The LT1 Engine is almost identical to the L99. It is a direct swap with absolutely no issues, as long as you swap from another Caprice or roadmaster. Camaro/Corvette engines can work too but oil pans and accessory drives can be different, as well as the optispark setup. The Computer can even run both engines. That being said, any little upgrades you do to the L99 can easily transfer over the LT1 engine when you do swap one in. There are a few things on these cars outside of the engine to boost performance, changing the rear end gears is a big one. One of the biggest upgrades to my car was swap the torque converter when I rebuilt my trans, I used one from a Blazer, its the same converter but with a higher stall speed, feels like a totally different car now. Its nothing crazy but a nice boost. I think the stock converter in these cars has a stall speed of 1100 RPM while the blazer one is around 2500.
Can you do this on a 6.0 ls .torque NOT hp max for boats.
Please please
YES
@@richardholdener1727 You will have my forever support if we can figure the max torque combo for a 6.0 ls I can say I bet it will be your hardest and most opposed or supported vlog yet cause the powers that be won't let you do it .
X2
I have an 87 Corvette with stock aluminum heads and a carb and it's way faster than my 86 aluminum head Corvette with stock TPI.
Would a stealth ram probably be similar to the carb intake, but with even runner length? Just spitballing.
THOSE WORK WELL-CHECK OUT THE TPI INTAKE TEST VIDEO
This is good info I have a 86 Trans am with a newer vortec 350 truck motor and a aluminum intake and edelbroch carb. Looks like I make more power then the stock intake systems and my big cam should breath better too
your carb and the one used in this vid are two totally different carbs lol richard states the air foil yielded no gains on the efi but doesnt use 300-600 dollar street carbs
i would like to see what a throttle body injection would do on this engine.and I'm not sure the the fuel injection was optimized on these setups seem like the drop off in power at higher rpm's might be not enough fuel.
THE SHAPE OF THE POWER CURVE IS A FUNCTION OF THE RUNNER LENGTH
Dang that was a dramatic difference
Ok now repeat the test on a 383. I want to see how the airflow demand affects the comparison. Would the "LT1" intake overtake the TPI at a lower RPM? or would the TPI still dominate up to the ~4700 rpm wall?
WATCH THE BIG TPI TEST VIDEO (WITH A 383)
L98 is a torque monster but man once you hit around 4k all the power falls off. It’s a fun stop light to stop light engine though. 2-3k RPMs hits hard in the L98
S475 on the LT1 please
If you could test the Accel Super Ram TPI intake on the 4.3L L99 I think it would match the power of the carb intake if not exceed it!!!
SEE THE BIG TPI TEST
Disregard my last comment haha didn’t expect you to do the carb intake haha. I was right tho.... other than the torque of the tuned port. Richard this was an awesome video. This is why I still run carbs. Easy to tune and for some reason they just seem to always make power.
Be neat if there was a variable length runner setup like some of the imports have for this.
I'd use the dual plane carbed intake.
Put the aluminum lt1 heads on it and see what she does. Cool stuff! 😁
On the street the TPI would kill the LT1
There's one thing that has to be considered in why GM didn't put the TPI intake where the LT1 lived... does it actually fit in the applications where the LT1 lived? The throttle body is sitting quite a bit higher. I don't have the time to go hunting for hood profiles for various GM vehicles, but it may well be that they didn't want to change the stamping dies or it wasn't worth the unit cost for custom changes.
Can you modify a TPI manifold to accept a carb or something with similar runner length and carb for comparison? Probably not cost effective but would be interesting to see if it beats the fuel injection TPI.
its been done,it doesnt work well and looks ridiculous
very cool comparisons!
When do we finally get some more Coverage on the Gen 2 LT1 engines?
What about putting the the long runner tuned port on a vortec 5.7 liter and see what it does with a good cam.
I HAVE
A friend of mine did this. Stock van Vortec 5.7L. Home ported the bowls in the heads. Port matched Vortec TPI base. Stock un ported runners, plenum, and throttle body. Lunati street/strip hyd roller.
12.28@111mph in the 1/4 mile in a 1992 Z28.
The engine has loads of torque. Excellent street engine.
I have a 1996 Suburban with a 5.7 vortec engine. I have a rear mounted distributor and coolant runs through the intake. My engine must be a SBC correct? Were they still installing SBC engines 1992-97 in trucks but not cars?
yes they had 350 small blocks in 96 vehicles-
That LT1 intake is probably good for atleast 7k rpm with the right cam and heads.
So, a happy medium would be to go with bolt-on TBI? That's what I gather. Maybe that's what you should investigate next, Richard: Get a Sniper EFI TBI, and see where it takes you. ;)