Years ago I did a TPI 350 swap into a 79 Firebird with a 3.42 rear and a TH350 trans with a 2500 stall converter. It wasn’t fast, but it was a lot of fun on the street, and that car was a ridiculous burnout machine!
Low RPM torque feels better in a street car. Making power at a higher RPM can actually make a car feel slower in most street use. More low RPM torque also gives better fuel milage. I love the TPI. Best looking production intake manifold out there IMO and I like seeing the solutions people have come up with to make power with it.
the tpi manifold looks nice but I like the SR as well, I would prefer more power although not sure about reliability. there is a max torque tradeoff so hard to tell which one gives better reliability
@@rotorblade9508 I assume you mean Steath Ram (?) which I like too. As long as you're not reving it too high it shouldn't hurt the reliability. I wouldn't be concerned about it.
Just imagine how the minds would had been blown if gm would have dropped the tuned port 350 in there pickup trucks I've always said that it would have been the best pickup engine gm ever produced
The TBI 5.7l in the pickup trucks ran extremely well. I had an 87 k2500 that I drove for 235,000 miles. 60,000 to 80,000 of that was pulling a loaded car trailer. Regular maintenance and a water pump were all that truck ever took. A GM certa transmission at 150,000 miles. 16.9 mpg on the highway in 2wd and tons of power.
Early 90s was a time where any HP gain was impressive so of course the TPI was impressive anyone remember the impressive CROSS FIRE I still remember laughing my ass off at my uncle when he bought his 82 firebird talking about how powerful it was
Excellent demo of the runner length calling the play...an l98 tpi motor in a truck would have been awesome for sure. For a heavy street car, drive in, foot brake et bracket car. I would go for the low end, the right cam, with a converter that would flash high, launch good make the converter do the work, when dialed in should be a very consistent combination that should last a long time...this is a street/strip foot brake et car...drive in drive out...not a 10:90- 9:90 bracket monster. With a od lockup trans, great mileage driving to the track too. My 75 Monza, would like this...hmmmmm!
The truck use comment is seriously an identical comment my buddy made about a year ago. He loved TPI Camaros and still believes in a truck they would have rocked!
Great post - Personally, as a 63 yr old cruising guy, I like the stock set up for the type of driving I do (`88 C4 L98 auto - no frisbee) For street driving I can jump out of the hole and hang with a lot of other rigs out there. Great post.
I'm a guy who builds for efficiency an low end to midrange torque for daily drivers. Most of what I build peaks the power band around 5000-5500 rpm. I've seen gains of double horsepower and torque from the late '70s carbed applications, with 30% mileage gains, depending upon application. Takes the right combo to do it... I was kinda surprised that carburetion vs efi alone was better for ultimate power. I always liked the feel of a carburetor over efi, but never tested them like Richard has. But then again, I spent many of my years debunking basic engine designs and "wisdom" from machine shops when they effed up my build..... nothing is more disheartening than to drop $5k on a nice efficient build, and have the machinist say it runs better than ever, and have it bog out in the low end. A friend had the same experience with a 383 K10, and bought a '79 f350 4x4 with a stock 400 that walked all over his "built" 383... It's pretty cool to see what works on the dyno, and what parts make what changes. I would like to see, though, more dyno graphs around the 1500 rpm and up ranges, where daily driving efficiency takes place!
I’d like to see an L98 build strictly for low end torque regardless of the top end power I’ll bet you could get nearly 550 foot pounds from a stroker tuned port build.
@@ocrapo9327 Your revolution is over. Condolences. The bums lost. My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me? The bums will always lose.
Always built low compression motors for the street ( max 9:1 or so). Built them for low and mid-range torque. Horsepower was nice but Low/ mid range torque busts the but best. In my day usually ran dual plane intakes with either two barrel Holley or small Holley four barrel. If I built one today I would definitely go with a Fitech or Holley throttle body fuel injection. I always kept lift on my cams at or below 0.550 with duration around 220-235 degrees. Lisa at or around 112 degrees. No experience with the tuned port but was pleased to see its torque production down low. Thanks for your tests. I really enjoy them. Your a great educator!
Richard, my son and I used a Comp 08-302-8 on a 355 Tpi. Stock cast iron l98 heads were reworked with a valve job and new ls6 blue beehive springs and roller rockers. Topped it off with long tube headers and 4 th gen Camaro cat back. It sounds good and pulls hard. This engine was from a GTA and replaced the stock 305 tpi. My son is very happy with the combination of this tpi engine and the t56 transmission. 3.91 gears are coming next!
Very well done. It was always hard to convince the pups that it's all about where you want to run your RPM range on a consistent basis. The TPI was designed to get optimum performance AND mileage! Can't do that with the carb. It's one or the other! (You couldn't make power AND meed EPA CAFE standards) Straight from the GM engineer in Detroit back in 86', (GM Training School) the 700R4 transmission was made to overcome the mileage loss due to the lower rear end ratios that were used to make you think the engines actually had power! You hit the nail on the head with the runners and the low end torque. It was part of that equation. Once you run out of HP (RPM), upshift and catch the torque band again! I once found a web page (20 years ago) that had the Chrysler data on their Cross Ram experiments showing where the torque/HP band was for a given runner length. Haven't been able to find it since! It was fascinating. I wish I would have printed it!
I just "finished" my small block 383 i am using a port matched blended holley stealth ram air system with the commander950 management with stock c4 corvette manifolds and made 358 wheel hp. Made 373 lb ft , on a mustang dyno, with one of the flattest torque curves that i have ever seen. Now i need to make a set of 1 5/8 long tube headers and make over 400 whp!
You think? There trick flow 195cc heads that i just did some gasket/ port matching on with all the tests that these guys do on 383s i didnt think that i was making all that much power
@@austindoud273 Ever seen the old combo engine/air compressor setups? Take a 351w or 302, take one head off, put a Reed-valve head on it, then boom... 4 cylinder self-contained air pump. AKA Monoblock Compressor. Is it relevant? Not really. But it does fall in line with air pump. Random info of the day for you.
Great Video! Love it! We can argue all day about the merits of both, but the looks and quirky cool factor of the TPI cannot be denied. I'm doing a buildup of my low mileage of my 87 Corvette. For me, there is no choice. The TPI system (mine is ported), along with the "Atari" dashboard IS the identity of the C4 Vette.
Awesome information. The old Ramchargers Drag Team had some really interesting home brewed intake manifold designs back in the early 60's on the Dodge and Plymouth stuff. They did a ton of experiments with intake runner length. Thanks for the continued education. I learn something new every single time I watch your stuff. I really look forward to it. Thanks. Dig the shirt too, by the way. Great kids come from great parents.
Built a 350 to put the tpi on with tons of research, Cam, compression, Injector size, gearing, power ranges rpm and this one video was a pretty good summary of most of it.
This video answered several of my questions regarding tuned port vs dual plane. Thanks. Putting that video of dyno tests on several tuned port systems sound great! BTW that mild cam caught my attention. I had a 208/208@.050" with 108 LCA and dual plane manifold with long tube headers and super free exaust 40 years ago. It shocked a lot of people. I cut the transmission cross member into 7 pieces and rewelded it so the exaust humps were lined up with the collectors. I also had to rest the weight on the cross member, remove the seats and beat the floorboards with a 5lb maul to ceate a clearance for the cross member. I always wondered what a tuned port injection would do on that set up.
I also remember people throwing in high lift cams in these engines back then. I guess that wasn’t the best way to go with the Long port runner. Needed these videos 20 years ago! :)
Maybe modern carbs are better at this now, but in the '80s it was wonderful to just walk out to the car whether it was 0 deg or 100 deg outside and just turn the key and have the engine start, first time, every time. Plus that low end torque never fails to put a grin on your face.
I find it funny that if anyone even mentions the L98 aluminum heads on a forum the immediate response is "Buy some AFR's or TFS heads". When you're 16 years old, it's 1993 so aftermarket heads are not near as prevalent or cheap, and an older student working at a junkyard says they can score you a set of 113's for $500.... You jump on them. After a little port cleanup and on top of a 10.5:1 327 with a healthy cam, those heads will support more than enough power for any 17 year old to be driving around on the street in a lightweight '69 Nova. My HS autoshop teacher pulled some strings to get the engine on a friends dyno. It put down similar numbers to the carbed L98 you tested(360 something) and the car ran mid 12's at E-town.
Great video..! My neighbor has the long tube TPI in his old 78 silverado with th350 trans and 33" tires.. The power comes on like a light switch, but does not like to rev at all.. (maybe 4200 rpm and feels asthmatic - a lot like the 6.2L non turbo chevy diesel)...
The car had a 4000 converter and a trans brake. 11.14 in good air. 4.11 gears .3300.00 IROCK.Z STOCK COMPUTER. TRICK FLOW heads. And alot of people looking and pointing. Lol.
I like the TPI for the street and have 2 vettes with them. One is a large tube lingenfelter engine and the other is stock. As you indicated the modified engine just amplifies the stock power curve. The LPE engine is around 400 CHP and still gets 30 MPG. My carb'd 350 is lucky to get a 1/3'd of that. So on the street the TPI is such fun with excellent response and it indeed feels like a bigblock. I take mine to the drag strip from time to time and it usually leaves me disappointed since the RPM range shifts much higher than the street. The cars low end torque makes it hard to launch with street tires and the 60' times are critical in a RPM limited car.
Since boneyards are full of TPI setups that no one wants combined with the availability of aftermarket ECUs and the SBC still being the cheapest to build, this makes me want to build a TPI setup for my tow pig and replace the vortec TBI.
Thank you for your unbiased well informed experiments. TPI all day for daily driving. Less rpm less spring pressures and lower rpm for less possible ware and tare. It’s hard to pick one. Maybe average numbers would give a better idea. Also I believe a lot of guys have the shifting points incorrect for the tpi. Hurts quarter times extremely. For instance my tpi 350 tries to shift upwards of 4800 rpm which I think 4.3-4.4k is probably more in the max power range. .
I had a FIRST fuel injection system about 10 years ago. I wish I still had the dyno test from it. Mild camed 350 w/ 389hp & 413 torque. I'd like to say that toque started to really pick up at 2300 rpm and maxed out at 4800. I had to sell it becuase of life before I was able to install it. Would of been an awesome dd /cruiser. I would love to see the tpi test you did in the past.
I have a dyno DB with a list of people running FIRST Fuel Injection intakes. My notes say you had a 9:1 comp 355 SBC running 1st Gen Twisted Wedge Heads 212/224 .487/.552 lift and ended up with 380 HP @ 5,000 RPM 430 ft lbs @ 4,300. The Super Chevy Stealth Mode TPI article ended up with 458hp @ 5,800 RPM; 534 ft lbs @ 4,000; a 383 with Comp XR 264HR. RCS Racing Engines: Sells a 460 HP @ 5,200 RPM; 520 ft lbs @ 4,000 RPM 383 crate engine now. I've built a 350 10.2:1 CR, Profiler 195cc heads, Mike Jones 227/228 @ 0.050 0.600" lift intake with 1.6 RR; Lightly touched up and port matched First (Felpro 1206 gasket) that should EASILY clear 400hp; controlled by Holley HP EFI w 58x crank trigger, Vortec Truck cam sync, and LS ignition coils. -Waiting to get it back in my car. Just finishing up AC conversion while I have the engine out.
Agree 100% on your truck comment. I had a 1992 C1500 5.7 5 speed, 3:73 posi SCSB. I swapped an L31 Vortec crate motor from Scoggin Dickey, Edelbrocks MPFI vortec intake system. GM is always stingy on trucks and messed up for decades. The crappy TBI then the spider intakes on Vortec trucks.
Good test. I have a similar build I'm working on right now. Except the L98 heads I have, are flowing up there with stock cathedral port heads. Can't wait to see what it comes out to.
That is what makes the variable geometry intakes Ferrari uses so cool. Pulling out all the stops is also why there 6.5L can make 789 net HP on 89 pump and still be clean enough to legally sell. That's impressive power from only 396ci all motor being a V12 just makes its sexier.
I'm running TPI so i made the choice. The plan was to add a turbo but that would only worsen traction issues. Went there after running a small displacement with rump rump cam. The torque is much more fun.
You read my mind Richard, a TPI style manifold on the Vortec 350 would’ve been fantastic, I’d also like to see an original TPI system on a 327, I feel like the smaller displacement would allow it to rev a little higher and maybe carry the torque curve a little higher in the rpm range.
Depends on the day maybe, once on HRPT my small block in a 72 mailbu was accused of BBC after a couple rolling start races on the interstate, that day I was very pleased to have all I could on top. Thinking back on those wins just makes a guy smile.
Haha ... I'm wearing the same shirt right now as what you had in the video :o) Daughters are awesome (at least that's who gave me mine!) You showed me some great information here. I've put together an L98 which is on the cusp of first fire up. What's kewl about your video for me is I was able to pick up a Holley Stealth Ram for it, with the 58mm TB. The cam in it is a Comp Cams 08-305-8 (.544"/.554" lift, 220/229 duration, 114LSA on 1.6:1 roller rockers). I have a set of aftermarket aluminum heads which flow 250cfm @ .550" lift. I'm shooting for 400WHP and I think the numbers you've shown with stock heads and a bit of a milder cam than what I have should put me in that ball park. I'm really looking forward to getting this thing fired and on the road.
Wheel or engine dyno 400 hp engine dyno I believe with nothing hooked up to the engine wheel closer to 300 hp 330 tq I would like to see wheel dyno smoothing 5 they just don’t breath
On a 385 (bored .040 with a 3.75" stroke) and a 224/230 cam, I made 342 rwhp and 335 lb-ft of torque. It was choked by the 1 5/8" shorty headers with a necked-down collector, probably would've made 360-375 rwhp with better headers.
Around 1989 Ford offered all kinds of support for the 5.0 pushrod Mustangs. Cams, heads,headers, rpm extenders, "off-road" catless h-pipes, everything. GM offered zero support, unless you were scca firestone/firehawk road racers. It was a curious time for sbc 3rd gen cars. A bunch of high$ companies selling junk that barely made gains. Throwing away the tpi for a carbed rpm airgap would have made good sense
I used to have the factory TPI intake on a 400 in my '94 Silverado. Good power but ran out of air flow too soon. Switched to the Stealth Ram and love it. I still have the TPI intake and plan to use it on a 302 or 327 for an S-10. Should be awesome for the smaller inch engines
I personally think the TPI intake is the coolest looking intake setup ever. I've been very tempted to swap to a TPI setup in my 67 Camaro just to have something different than all the big blocks or LS swaps I always see.
Your combination of energy, know how and curiosity is amazing! The amount of theory and combinations dyno tested by you generates a wealth of information! I can’t help but wonder how a TBI set up and an Accel super ram intake would perform on this exact L98. Thank you for all the hard work in the dyno room.
I just got my old IROC that I drove in the 90's back on the road. Loving the TPI torque, but could be a little faster. Keep the TPI vids coming. I like the idea of an optimized long runner setup, maybe with a little cam and some vortec heads. These parts are getting harder to find and expensive.
tempted to put a variable runner length intake manifold on my daily driver to improve the overall powerband. that and some variable valve timing would be nice.
I love the way you talk in this intro! i can't stand the stop and go way you do it in your other vids, this way is sooooo much better! Keep it up please!
Gee, thanks mate, very interesting, the thing is this,,, i have never been a fan of rev the crap out of something, WHEN, you can get serious grunt at a lower RPM, my 89 vette is SUPPOSED, to be 240 hp 340 t at low RPM, i dont know if anything has been changed Int, but it has A/M runners and from the runs i have had on the street, it goes way better than those figures.... So to keep the grunt where it is,,,, a PUMP AT 25 PSI, is what its getting.. thanks again for TPI stuff. Eddie Sydney Australia.
I'd put a Centrifugal supercharger in the motor with a TPI manifold. Low down torque for street driving, rising boost curve with RPM to get top end power
Cool stuff! Definitely one of the greatest channels I have watched involving my favorite engines. The Chevy 350 Gen 1& 2 rollers. My other favorite is the Chevy 305. Why? Get this....It's actually because of the way the Box Chevy Caprice 305's would idle so soft and quietly. My late Grandfather had a 1982 that would blow cold A/C and was so quiet you didn't even know the car was idling! Why I love the Chevy 350 is a no brainer....This is probably one of the only motors that I know off that will give Hot Rodders and Muscle Car Guys something to due on the weekends when there is nothing to do, because you can always add to it or try new stuff or combinations out. 2 thumbs up !!!
Being a product of the 80's and 90's, I have a natural affinity for the TPI setups. I have owned a a 1985 Corvette and a 91 Camaro Z28 5.7, both obviously with TPI. Always loved the that low end power, and they would light the tires up with a blip of the throttle at a stop light. I would love to get back into a C4 or 3rd Gen F-body with TPI. I know any new muscle and even today's V6 Camery's and Accords would probably be as quick if not beat a stock TPI car, but just to have that feel- that low end instant grunt. Since I don't race every person I see or at a stop light (anymore, grew up from that :) ), I don't need the high winding power. I would pick TPI. There doesn't however seem to be any support for them anymore and with good reason, I know that LS tech has gone a long way. Still, a properly cammed TPI would feel soooo good as a daily driver.
You brought up so many great points especially why GM didn't use the TPI engines on their trucks with the vortec cylinder heads. Can you please do a video comparing the l98 with the LT1?? That would be a great comparison.
This channel is excellent at disproving all the stories with facts! I am in the medical field, and we do many studies, your methods are comparable to our methodology. Everything is proven by Dyno results. Please do the stock intake vs. “cold air intake” and prove these don’t work! Biggest ripoff in motor sports.
If it was me I’d take the perks of EFIs reliability and drive ability along with the extra torque. If I was going to build a race car, it would be a different story. But I drive my stuff to work and to the store, bangin through the gears on occasion
You must be reading my mind. I want to get the 383 HTE crate motor and put TPI on it for my 1992 GMC sierra. I also have a 400 SB out of a 1980 one ton commercial van that I think would be a perfect truck motor with Vortec heads and TPI
I would definitely go with the dual plane intake but go with a self learn EFI setup !!!! And no stealth ram!!! Looks cool and was cool if you had one in the 90’s on your vette or Iroc!!!!
When I see this stuff it always reminds me of the thought of what GM was thinking with the trucks... Here's a truck engine that would have blown the TBI junk out of the water for torque.... and does. They could have even run the swirl port heads with it lol. Even better... release the Vortec head in 1996 and then literally put the worst intake and fuel injection system they ever created on top of it. Would have been better off doing a sequential setup with TPI until the release of the LS.
What's worse is it's not like they didnt have the parts laying around.. typical corporate decisions Im sure, cant seem like youre lowering 'performance car' tech to the hordes of unwashed truck buyers. lol.
Spider was horrible not to mention one little piece failed the whole thing had to be changed instead of a 100 dollar fuel injector a 600 dollar spider system what garbage
Daniel Hoffman Never had issues with my 92 TBI. Fixed other people’s spiders. A TBI is essentially a carb that meters out the fuel electronically, and now there’s relatively cheap ecu replacements to be able to flash tunes. I’m all for port injection, but I’d take a Vortec headed TBI over the spider intake on those heads.
The TPI on a 350 truck motor and slightly higher compression ratio. And 1.6 roller rocker. Does in fact have more torque down low. The only thing left is an RV roller cam. Later when is time for my truck to be rebuilt. I will install an RV cam.
I have taken mine pretty far. On a V6 mind you. Ported heads with a matched manifold. COMP cam, 1.6 roller rockers. I was able to use the ECM from another vehicle which surprisingly nailed the fuel delivery which I can see on my wideband gauge. I still have my eye on the Holley Sniper 2bbl unit. I wan't to change the manifold and possibly supercharge it and the stock unit simply won't handle it. The Holley would also clean up the unsightly stock wiring harness and allow me to mess with timing and fuel any time I want.
I have a 1987 corvette, I can’t speak for the other engine but I love my L98. It has fun responsiveness and heavy torque that makes the ride enjoyable. The power is manageable and not over the top either.
I would pick the L98 injection for my usage case because anything I build would be just a street driver or daily. So i'd benefit from the easy cold starts, throttle response, more precise instrumentation and on the fly fuel trim adjustments. Unless i'm really ringing the car/truck out on the street for some reason it won't really see much time above 5000rpm. If I were building a track car that spends most time high in the rev range then of course the carb wins.
Hello Richard.... great content... I remember the L98 TPI... my very first fuel injection car... 85 Corvette’s came standard with the L98. Even though it was Rated at 245 hp and 340 foot pounds of torque...... the L98 felt like a beast with that intake manifold form Idle to around 4000 RPMs. The dyno shows a disappointing top end power output.....but on the street the L98 with the right gears feels like a more powerful engine then what the dyno graph shows.
Richard I watch your videos from beginning to end these are some of the most informative videos I've seen yet.. I can't wait to watch when you break down and analyze the LT1 and LT4 engines...if possible please let us know your factual opinion on the torque-head ignition control system vs the optispark system
Had an 89 L98 Corvette....insane throttle response.
Those ole L98's were tire stredders... they were fun from red light to red light
Years ago I did a TPI 350 swap into a 79 Firebird with a 3.42 rear and a TH350 trans with a 2500 stall converter. It wasn’t fast, but it was a lot of fun on the street, and that car was a ridiculous burnout machine!
Low RPM torque feels better in a street car. Making power at a higher RPM can actually make a car feel slower in most street use. More low RPM torque also gives better fuel milage.
I love the TPI. Best looking production intake manifold out there IMO and I like seeing the solutions people have come up with to make power with it.
How much time do you spend over 5k rpm anyway?
Yesss!!! TPI was (and still is) a great street setup!
the tpi manifold looks nice but I like the SR as well, I would prefer more power although not sure about reliability. there is a max torque tradeoff so hard to tell which one gives better reliability
@@rotorblade9508 I assume you mean Steath Ram (?) which I like too. As long as you're not reving it too high it shouldn't hurt the reliability. I wouldn't be concerned about it.
@@ちくてぬしくけて Red light to red light or windy back roads. m
My 91 Vett is an absolute blast to drive! So yes it's a street car lovers motor IMOP.
Thank you for doing L 98 engine
Love the tq of the tpi. Especially from a cruiser.
I agree the tuned port injection combined with the Vortec heads would have been a great truck engine.
Just imagine how the minds would had been blown if gm would have dropped the tuned port 350 in there pickup trucks I've always said that it would have been the best pickup engine gm ever produced
I did in a 92 k2500 instead of the tbi system
The tune port motors were never all that great they ran out of rpm fast and the LS and LT motors are light years ahead of them.
Thanks the joke the Corvette and F body guys say that we have the best truck engine ever made in our cars, lol.
The TBI 5.7l in the pickup trucks ran extremely well. I had an 87 k2500 that I drove for 235,000 miles. 60,000 to 80,000 of that was pulling a loaded car trailer. Regular maintenance and a water pump were all that truck ever took. A GM certa transmission at 150,000 miles. 16.9 mpg on the highway in 2wd and tons of power.
Early 90s was a time where any HP gain was impressive so of course the TPI was impressive anyone remember the impressive
CROSS FIRE I still remember laughing my ass off at my uncle when he bought his 82 firebird talking about how powerful it was
TPI is great for the street. Low end torque allows you to run a higher gear.
Tuned Port was awesome stoplight to stoplight action! Those L98 engines were absolute torque terrors.
Excellent demo of the runner length calling the play...an l98 tpi motor in a truck would have been awesome for sure. For a heavy street car, drive in, foot brake et bracket car. I would go for the low end, the right cam, with a converter that would flash high, launch good make the converter do the work, when dialed in should be a very consistent combination that should last a long time...this is a street/strip foot brake et car...drive in drive out...not a 10:90- 9:90 bracket monster. With a od lockup trans, great mileage driving to the track too. My 75 Monza, would like this...hmmmmm!
The truck use comment is seriously an identical comment my buddy made about a year ago. He loved TPI Camaros and still believes in a truck they would have rocked!
Great post - Personally, as a 63 yr old cruising guy, I like the stock set up for the type of driving I do (`88 C4 L98 auto - no frisbee) For street driving I can jump out of the hole and hang with a lot of other rigs out there. Great post.
I'm a guy who builds for efficiency an low end to midrange torque for daily drivers. Most of what I build peaks the power band around 5000-5500 rpm. I've seen gains of double horsepower and torque from the late '70s carbed applications, with 30% mileage gains, depending upon application. Takes the right combo to do it...
I was kinda surprised that carburetion vs efi alone was better for ultimate power. I always liked the feel of a carburetor over efi, but never tested them like Richard has.
But then again, I spent many of my years debunking basic engine designs and "wisdom" from machine shops when they effed up my build..... nothing is more disheartening than to drop $5k on a nice efficient build, and have the machinist say it runs better than ever, and have it bog out in the low end. A friend had the same experience with a 383 K10, and bought a '79 f350 4x4 with a stock 400 that walked all over his "built" 383...
It's pretty cool to see what works on the dyno, and what parts make what changes. I would like to see, though, more dyno graphs around the 1500 rpm and up ranges, where daily driving efficiency takes place!
I’d like to see an L98 build strictly for low end torque regardless of the top end power I’ll bet you could get nearly 550 foot pounds from a stroker tuned port build.
we did that with a 383
It was built stock strictly for low end torque.
@@unicornsteaks6769 yeah, but... there is so much more low end to be had than stock as well....
13 dislikes? Must be Ls swap guys....Great video Richard.
LS, Low Spirits swap
@@ocrapo9327 Your revolution is over. Condolences. The bums lost. My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me? The bums will always lose.
Lool
This video really makes me change my mind on building my 85 vette.
Low end Torque is always the way to go for the street !
Thanks again for a awesome comparison 👏
Always built low compression motors for the street ( max 9:1 or so). Built them for low and mid-range torque. Horsepower was nice but Low/ mid range torque busts the but best. In my day usually ran dual plane intakes with either two barrel Holley or small Holley four barrel. If I built one today I would definitely go with a Fitech or Holley throttle body fuel injection. I always kept lift on my cams at or below 0.550 with duration around 220-235 degrees. Lisa at or around 112 degrees. No experience with the tuned port but was pleased to see its torque production down low. Thanks for your tests. I really enjoy them. Your a great educator!
I love the tuned port intake for a street car. Wicked torque under street driving conditions and looks wicked good to boot
Richard, my son and I used a Comp 08-302-8 on a 355 Tpi. Stock cast iron l98 heads were reworked with a valve job and new ls6 blue beehive springs and roller rockers. Topped it off with long tube headers and 4 th gen Camaro cat back. It sounds good and pulls hard. This engine was from a GTA and replaced the stock 305 tpi. My son is very happy with the combination of this tpi engine and the t56 transmission. 3.91 gears are coming next!
Very well done. It was always hard to convince the pups that it's all about where you want to run your RPM range on a consistent basis. The TPI was designed to get optimum performance AND mileage! Can't do that with the carb. It's one or the other! (You couldn't make power AND meed EPA CAFE standards) Straight from the GM engineer in Detroit back in 86', (GM Training School) the 700R4 transmission was made to overcome the mileage loss due to the lower rear end ratios that were used to make you think the engines actually had power! You hit the nail on the head with the runners and the low end torque. It was part of that equation. Once you run out of HP (RPM), upshift and catch the torque band again! I once found a web page (20 years ago) that had the Chrysler data on their Cross Ram experiments showing where the torque/HP band was for a given runner length. Haven't been able to find it since! It was fascinating. I wish I would have printed it!
I just "finished" my small block 383 i am using a port matched blended holley stealth ram air system with the commander950 management with stock c4 corvette manifolds and made 358 wheel hp. Made 373 lb ft , on a mustang dyno, with one of the flattest torque curves that i have ever seen. Now i need to make a set of 1 5/8 long tube headers and make over 400 whp!
you must have some sick heads(or l31 vortecs)
You think? There trick flow 195cc heads that i just did some gasket/ port matching on with all the tests that these guys do on 383s i didnt think that i was making all that much power
Amazing demonstration of runner length. Very informative! The best channel ever!
Even better:
xtremecarzone.com.au/STORAGE/ARTICLES/GM/TPI/ComparisonOfTPIintakeOptions.pdf
I enjoyed my L98 Corvette, had a auto with 3.08 gears, torque was amazing, but my 93 with a LT1 6 speed was the best
٤٥٥٤٤٥٥٤٥٤٤٤٥⁴٤٤٤٤٥٥٤٥٥٤٤٤ص٤٥٥٤٤٤٤٥٤٤٥٤٥٤٤٤٤٤٤٤٤٤٤٥٤٤٤٤٥٤٤٤٥٥٤٤٤٤٤٤٤٤٤٥ض٤٤٥٤٤ص٤٤ض٤٤٤
What was the rear gear in the LT1?
I suspect that if the L98 had the six speed, and a 3.43 rear, the gap between the two would have been much smaller.
@@johntempest267 3.45 with the 6 speed, no way the L98 can match a LT1
Imagine the odd feeling one gets when theres a sense of relief that it's a SBC test rather than an LS test
on this channel-we test it all
Who cares an air pumps an air pump
@@austindoud273 Ever seen the old combo engine/air compressor setups? Take a 351w or 302, take one head off, put a Reed-valve head on it, then boom... 4 cylinder self-contained air pump. AKA Monoblock Compressor.
Is it relevant? Not really. But it does fall in line with air pump. Random info of the day for you.
@@austindoud273 How does an air pump an air pump?
@@richardholdener1727 I know, it was mostly in jest. Definitely more diverse set of tests than other masters of engines
I loved the look and potential of the TPI system that I converted my 92 RS 305 from TBI to this. That was all the way back in 2000.
Would really like to see a vortec test with the stock intake
This would be cool. If we could get the Vortec and then do exactly the same compression/ cam for a 5.7 vs 6.0 rods also.
tbi already runs out of flow on stock heads. it would onlybget worse with vortecs. 350 tpi dead by 4500-5k. stock tpi
@@darinr9424 none of those intakes are vortec
Great Video! Love it! We can argue all day about the merits of both, but the looks and quirky cool factor of the TPI cannot be denied. I'm doing a buildup of my low mileage of my 87 Corvette. For me, there is no choice. The TPI system (mine is ported), along with the "Atari" dashboard IS the identity of the C4 Vette.
Awesome information. The old Ramchargers Drag Team had some really interesting home brewed intake manifold designs back in the early 60's on the Dodge and Plymouth stuff. They did a ton of experiments with intake runner length. Thanks for the continued education. I learn something new every single time I watch your stuff. I really look forward to it. Thanks. Dig the shirt too, by the way. Great kids come from great parents.
Westech ran one of the Dodge intakes on the dyno-amazing stuff
Those intake and exhaust systems they used to run were crazy😁 some cool history
Built a 350 to put the tpi on with tons of research, Cam, compression, Injector size, gearing, power ranges rpm and this one video was a pretty good summary of most of it.
This video answered several of my questions regarding tuned port vs dual plane. Thanks. Putting that video of dyno tests on several tuned port systems sound great! BTW that mild cam caught my attention. I had a 208/208@.050" with 108 LCA and dual plane manifold with long tube headers and super free exaust 40 years ago. It shocked a lot of people. I cut the transmission cross member into 7 pieces and rewelded it so the exaust humps were lined up with the collectors. I also had to rest the weight on the cross member, remove the seats and beat the floorboards with a 5lb maul to ceate a clearance for the cross member. I always wondered what a tuned port injection would do on that set up.
TPI on a 383 with a mild cam = torque monster. Seems like it'd be an awesome setup in a pickup or suv
Just run out of the air sooner on the RPM curve.
For a drag or track car, TPI is a no no, but for the common sports car on the streets, it's a torque monster.
I also remember people throwing in high lift cams in these engines back then. I guess that wasn’t the best way to go with the Long port runner. Needed these videos 20 years ago! :)
Maybe modern carbs are better at this now, but in the '80s it was wonderful to just walk out to the car whether it was 0 deg or 100 deg outside and just turn the key and have the engine start, first time, every time. Plus that low end torque never fails to put a grin on your face.
People just realized that phenolic spacers are a thing?
@@theeoddments960 They have been around forever. Look at a Thermoquad carb
I find it funny that if anyone even mentions the L98 aluminum heads on a forum the immediate response is "Buy some AFR's or TFS heads". When you're 16 years old, it's 1993 so aftermarket heads are not near as prevalent or cheap, and an older student working at a junkyard says they can score you a set of 113's for $500.... You jump on them.
After a little port cleanup and on top of a 10.5:1 327 with a healthy cam, those heads will support more than enough power for any 17 year old to be driving around on the street in a lightweight '69 Nova. My HS autoshop teacher pulled some strings to get the engine on a friends dyno. It put down similar numbers to the carbed L98 you tested(360 something) and the car ran mid 12's at E-town.
Great video..! My neighbor has the long tube TPI in his old 78 silverado with th350 trans and 33" tires.. The power comes on like a light switch, but does not like to rev at all.. (maybe 4200 rpm and feels asthmatic - a lot like the 6.2L non turbo chevy diesel)...
the long runners are designed to make power lower in the rev range
The car had a 4000 converter and a trans brake. 11.14 in good air. 4.11 gears .3300.00 IROCK.Z STOCK COMPUTER. TRICK FLOW heads. And alot of people looking and pointing. Lol.
I like the TPI for the street and have 2 vettes with them. One is a large tube lingenfelter engine and the other is stock. As you indicated the modified engine just amplifies the stock power curve. The LPE engine is around 400 CHP and still gets 30 MPG. My carb'd 350 is lucky to get a 1/3'd of that. So on the street the TPI is such fun with excellent response and it indeed feels like a bigblock. I take mine to the drag strip from time to time and it usually leaves me disappointed since the RPM range shifts much higher than the street. The cars low end torque makes it hard to launch with street tires and the 60' times are critical in a RPM limited car.
Since boneyards are full of TPI setups that no one wants combined with the availability of aftermarket ECUs and the SBC still being the cheapest to build, this makes me want to build a TPI setup for my tow pig and replace the vortec TBI.
Right? He makes a really good point about the TPI in a tow rig.
ive got a full tpi setup with ecu and wiring for a 350,come get it...need a long block,got a couple of those as well.
even easier,get a vortec tpi base and add tpi at your leisure
@@trillrifaxegrindor4411
I need one, for a 1984 Chevy 1/2 ton.
What is the price??
Thank you for your unbiased well informed experiments. TPI all day for daily driving. Less rpm less spring pressures and lower rpm for less possible ware and tare.
It’s hard to pick one. Maybe average numbers would give a better idea. Also I believe a lot of guys have the shifting points incorrect for the tpi. Hurts quarter times extremely. For instance my tpi 350 tries to shift upwards of 4800 rpm which I think 4.3-4.4k is probably more in the max power range. .
Carburetor and manifold been around for a long time look how successful they are at the racetracks
I had a FIRST fuel injection system about 10 years ago. I wish I still had the dyno test from it. Mild camed 350 w/ 389hp & 413 torque. I'd like to say that toque started to really pick up at 2300 rpm and maxed out at 4800. I had to sell it becuase of life before I was able to install it. Would of been an awesome dd /cruiser.
I would love to see the tpi test you did in the past.
I have a dyno DB with a list of people running FIRST Fuel Injection intakes. My notes say you had a 9:1 comp 355 SBC running 1st Gen Twisted Wedge Heads 212/224 .487/.552 lift and ended up with 380 HP @ 5,000 RPM 430 ft lbs @ 4,300.
The Super Chevy Stealth Mode TPI article ended up with 458hp @ 5,800 RPM; 534 ft lbs @ 4,000; a 383 with Comp XR 264HR.
RCS Racing Engines: Sells a 460 HP @ 5,200 RPM; 520 ft lbs @ 4,000 RPM 383 crate engine now.
I've built a 350 10.2:1 CR, Profiler 195cc heads, Mike Jones 227/228 @ 0.050 0.600" lift intake with 1.6 RR; Lightly touched up and port matched First (Felpro 1206 gasket) that should EASILY clear 400hp; controlled by Holley HP EFI w 58x crank trigger, Vortec Truck cam sync, and LS ignition coils. -Waiting to get it back in my car. Just finishing up AC conversion while I have the engine out.
Agree 100% on your truck comment. I had a 1992 C1500 5.7 5 speed, 3:73 posi SCSB. I swapped an L31 Vortec crate motor from Scoggin Dickey, Edelbrocks MPFI vortec intake system. GM is always stingy on trucks and messed up for decades. The crappy TBI then the spider intakes on Vortec trucks.
I prefer the TPI intake manifold for my trot line weights.
Good test. I have a similar build I'm working on right now. Except the L98 heads I have, are flowing up there with stock cathedral port heads. Can't wait to see what it comes out to.
that's a lot of time spent with a die grinder,shame the combustion chamber sucks
That is what makes the variable geometry intakes Ferrari uses so cool. Pulling out all the stops is also why there 6.5L can make 789 net HP on 89 pump and still be clean enough to legally sell. That's impressive power from only 396ci all motor being a V12 just makes its sexier.
Sure.
Until you shell out $8k for a first service tune up at 5k miles.
(If it stays out of the shop that long)
I'm running TPI so i made the choice. The plan was to add a turbo but that would only worsen traction issues. Went there after running a small displacement with rump rump cam. The torque is much more fun.
Always liked the look of the Holley Stealth Ram intake.
You read my mind Richard, a TPI style manifold on the Vortec 350 would’ve been fantastic, I’d also like to see an original TPI system on a 327, I feel like the smaller displacement would allow it to rev a little higher and maybe carry the torque curve a little higher in the rpm range.
Depends on the day maybe, once on HRPT my small block in a 72 mailbu was accused of BBC after a couple rolling start races on the interstate, that day I was very pleased to have all I could on top. Thinking back on those wins just makes a guy smile.
Looking forward to getting my 1966 El Camino TPI 357 in for a dyno test 😊
I sooo look forward to these videos everyday 😁
Richard you should do a test the TPI on all the Gen1 small blocks 283 to the 400..... Awesome video
Richard looks a lot calmer than usual, it caught me off guard for the first minute 😂
Haha ... I'm wearing the same shirt right now as what you had in the video :o) Daughters are awesome (at least that's who gave me mine!)
You showed me some great information here. I've put together an L98 which is on the cusp of first fire up. What's kewl about your video for me is I was able to pick up a Holley Stealth Ram for it, with the 58mm TB. The cam in it is a Comp Cams 08-305-8 (.544"/.554" lift, 220/229 duration, 114LSA on 1.6:1 roller rockers). I have a set of aftermarket aluminum heads which flow 250cfm @ .550" lift. I'm shooting for 400WHP and I think the numbers you've shown with stock heads and a bit of a milder cam than what I have should put me in that ball park. I'm really looking forward to getting this thing fired and on the road.
Wheel or engine dyno 400 hp engine dyno I believe with nothing hooked up to the engine wheel closer to 300 hp 330 tq I would like to see wheel dyno smoothing 5 they just don’t breath
On a 385 (bored .040 with a 3.75" stroke) and a 224/230 cam, I made 342 rwhp and 335 lb-ft of torque. It was choked by the 1 5/8" shorty headers with a necked-down collector, probably would've made 360-375 rwhp with better headers.
This is Awesome! Some Classic TPI love
Around 1989 Ford offered all kinds of support for the 5.0 pushrod Mustangs. Cams, heads,headers, rpm extenders, "off-road" catless h-pipes, everything. GM offered zero support, unless you were scca firestone/firehawk road racers. It was a curious time for sbc 3rd gen cars. A bunch of high$ companies selling junk that barely made gains. Throwing away the tpi for a carbed rpm airgap would have made good sense
How about 1996 - 2000 Vortec fuel injection vs carb?
I used to have the factory TPI intake on a 400 in my '94 Silverado. Good power but ran out of air flow too soon. Switched to the Stealth Ram and love it. I still have the TPI intake and plan to use it on a 302 or 327 for an S-10. Should be awesome for the smaller inch engines
I personally think the TPI intake is the coolest looking intake setup ever. I've been very tempted to swap to a TPI setup in my 67 Camaro just to have something different than all the big blocks or LS swaps I always see.
Your combination of energy, know how and curiosity is amazing! The amount of theory and combinations dyno tested by you generates a wealth of information! I can’t help but wonder how a TBI set up and an Accel super ram intake would perform on this exact L98. Thank you for all the hard work in the dyno room.
Absolutely love all these videos and real world motor scenarios, and keep the “OTHER GUYS” videos coming
Power down low= Red light racer👍
I can attest to this. Took a 97 skyline gtt for a run up to 150kmh from a dig in my stock 87 GTA
I knew a guy that did a 350 TPI swap on a GMC Sonoma. That little bucket was sooo crazy 🤙🏾😂.
I just got my old IROC that I drove in the 90's back on the road. Loving the TPI torque, but could be a little faster. Keep the TPI vids coming. I like the idea of an optimized long runner setup, maybe with a little cam and some vortec heads. These parts are getting harder to find and expensive.
tempted to put a variable runner length intake manifold on my daily driver to improve the overall powerband. that and some variable valve timing would be nice.
I love the way you talk in this intro! i can't stand the stop and go way you do it in your other vids, this way is sooooo much better! Keep it up please!
Another great set of tests.
Gee, thanks mate, very interesting, the thing is this,,, i have never been a fan of rev the crap out of something, WHEN, you can get serious grunt at a lower RPM, my 89 vette is SUPPOSED, to be 240 hp 340 t at low RPM, i dont know if anything has been changed Int, but it has A/M runners and from the runs i have had on the street, it goes way better than those figures.... So to keep the grunt where it is,,,, a PUMP AT 25 PSI, is what its getting.. thanks again for TPI stuff.
Eddie
Sydney Australia.
I'd put a Centrifugal supercharger in the motor with a TPI manifold. Low down torque for street driving, rising boost curve with RPM to get top end power
Oh smart
Yep totally awesome combo- I have one too
Congratulations on over 70 thousand subscribers Richard. 👍
Many thanks!
@@richardholdener1727 👍
Cool stuff! Definitely one of the greatest channels I have watched involving my favorite engines. The Chevy 350 Gen 1& 2 rollers. My other favorite is the Chevy 305. Why? Get this....It's actually because of the way the Box Chevy Caprice 305's would idle so soft and quietly. My late Grandfather had a 1982 that would blow cold A/C and was so quiet you didn't even know the car was idling! Why I love the Chevy 350 is a no brainer....This is probably one of the only motors that I know off that will give Hot Rodders and Muscle Car Guys something to due on the weekends when there is nothing to do, because you can always add to it or try new stuff or combinations out. 2 thumbs up !!!
I agree with you Richard. It would of been amazing if they put a tuned port manifold on a truck. Like the early 90's ss 454.
Being a product of the 80's and 90's, I have a natural affinity for the TPI setups. I have owned a a 1985 Corvette and a 91 Camaro Z28 5.7, both obviously with TPI. Always loved the that low end power, and they would light the tires up with a blip of the throttle at a stop light. I would love to get back into a C4 or 3rd Gen F-body with TPI. I know any new muscle and even today's V6 Camery's and Accords would probably be as quick if not beat a stock TPI car, but just to have that feel- that low end instant grunt. Since I don't race every person I see or at a stop light (anymore, grew up from that :) ), I don't need the high winding power. I would pick TPI. There doesn't however seem to be any support for them anymore and with good reason, I know that LS tech has gone a long way.
Still, a properly cammed TPI would feel soooo good as a daily driver.
At points in time I had GTA and IROC both with TPI ..... loved those engines .... great torque and long legs
yep,thats something you do not get rid off.thankfully i took my own advice
You brought up so many great points especially why GM didn't use the TPI engines on their trucks with the vortec cylinder heads. Can you please do a video comparing the l98 with the LT1?? That would be a great comparison.
I hope he does this video!!!. L98 vs lt1 engine comparison
This channel is excellent at disproving all the stories with facts! I am in the medical field, and we do many studies, your methods are comparable to our methodology. Everything is proven by Dyno results.
Please do the stock intake vs. “cold air intake” and prove these don’t work! Biggest ripoff in motor sports.
hot air from these aftermarket "intake systems" immediately make them too loud,too hot of an intake charge and lower performance.
Kegaladon! Best intake ever!! You better get a patent on it! It is going to look awesome sticking out the hood of My S10!!
If it was me I’d take the perks of EFIs reliability and drive ability along with the extra torque. If I was going to build a race car, it would be a different story. But I drive my stuff to work and to the store, bangin through the gears on occasion
You must be reading my mind. I want to get the 383 HTE crate motor and put TPI on it for my 1992 GMC sierra. I also have a 400 SB out of a 1980 one ton commercial van that I think would be a perfect truck motor with Vortec heads and TPI
In the first test, there wasn't much loss of torque, but the gain of horsepower was generous. I'd opt for the carb setup due to the cheap gains.
I had good luck with the stlith ram. Replacement.
I would definitely go with the dual plane intake but go with a self learn EFI setup !!!! And no stealth ram!!! Looks cool and was cool if you had one in the 90’s on your vette or Iroc!!!!
When I see this stuff it always reminds me of the thought of what GM was thinking with the trucks... Here's a truck engine that would have blown the TBI junk out of the water for torque.... and does. They could have even run the swirl port heads with it lol. Even better... release the Vortec head in 1996 and then literally put the worst intake and fuel injection system they ever created on top of it. Would have been better off doing a sequential setup with TPI until the release of the LS.
What's worse is it's not like they didnt have the parts laying around.. typical corporate decisions Im sure, cant seem like youre lowering 'performance car' tech to the hordes of unwashed truck buyers. lol.
Spider has its limits - but it's not worse than TBI.
@@wereexpertstoo3795 spider sucked because those bastards were brittle AF.
Spider was horrible not to mention one little piece failed the whole thing had to be changed instead of a 100 dollar fuel injector a 600 dollar spider system what garbage
Daniel Hoffman
Never had issues with my 92 TBI. Fixed other people’s spiders. A TBI is essentially a carb that meters out the fuel electronically, and now there’s relatively cheap ecu replacements to be able to flash tunes.
I’m all for port injection, but I’d take a Vortec headed TBI over the spider intake on those heads.
I would take the low speed torque just because everything I have is a daily driver
Exactly what I was going to say
for some reason i saw fat thor, took me by surprise. love the shirt. going to watch the rest of the video now.
its been a long quarantine-don't judge Fat Thor
The TPI on a 350 truck motor and slightly higher compression ratio. And 1.6 roller rocker. Does in fact have more torque down low. The only thing left is an RV roller cam. Later when is time for my truck to be rebuilt. I will install an RV cam.
This may not be popular but I'd like to see some kind of GM TBI build. Just to see what can be done. Turbo? Cam? Heads? Just curious.
I have taken mine pretty far. On a V6 mind you. Ported heads with a matched manifold. COMP cam, 1.6 roller rockers. I was able to use the ECM from another vehicle which surprisingly nailed the fuel delivery which I can see on my wideband gauge. I still have my eye on the Holley Sniper 2bbl unit. I wan't to change the manifold and possibly supercharge it and the stock unit simply won't handle it. The Holley would also clean up the unsightly stock wiring harness and allow me to mess with timing and fuel any time I want.
I have a 1987 corvette, I can’t speak for the other engine but I love my L98. It has fun responsiveness and heavy torque that makes the ride enjoyable. The power is manageable and not over the top either.
ive got an l98 with the proflo 4 carb efi and i love it
I would pick the L98 injection for my usage case because anything I build would be just a street driver or daily. So i'd benefit from the easy cold starts, throttle response, more precise instrumentation and on the fly fuel trim adjustments. Unless i'm really ringing the car/truck out on the street for some reason it won't really see much time above 5000rpm. If I were building a track car that spends most time high in the rev range then of course the carb wins.
Cool. Got an l98 vette I'm gonna carb as soon as I can
It’s like you read my mind. I was wondering what direction to go with my l98 iroc
Horsepower and torque, I want it all right now.
Richard Holdener Dude I absolutely LOVE that shirt!!!!! I actually have the Othala rune on my arm for ODIN. SKAL BROTHER!!!!!
Hello Richard.... great content... I remember the L98 TPI... my very first fuel injection car... 85 Corvette’s came standard with the L98. Even though it was Rated at 245 hp and 340 foot pounds of torque...... the L98 felt like a beast with that intake manifold form Idle to around 4000 RPMs. The dyno shows a disappointing top end power output.....but on the street the L98 with the right gears feels like a more powerful engine then what the dyno graph shows.
In my zf6 vette a have a crane compucam an a lingenfelter manifold , was looking for higher rpm horsepower ,that worked well👍
I have a 1986 Ttsns Am that I am building and L98 TPI to put in.
Richard I watch your videos from beginning to end these are some of the most informative videos I've seen yet.. I can't wait to watch when you break down and analyze the LT1 and LT4 engines...if possible please let us know your factual opinion on the torque-head ignition control system vs the optispark system
I like EFI connections system, since It's utilizing GM components. You can can get replacements easily from any parts store if needed.
@@allanb3222 thank you so much I'll definitely look Into it