If you consider the era of the tpi, you need more torque at low rpm when limited to three and four speed transmissions. This was an effective way to make power and maintain excellent driveability. In modern times we have a lot more gearing options. An interesting test on tpi would be to create waves on the inside radius to ensure full use of the cross section at high rpm's.
I don't think that was the case. In fact, the first 4L60s that were behind the LT1s (short runner intakes) were the same transmissions. They just renamed them. 4 speeds were still coming behind LSs up through the 2000s. Gearing wasn't the rationale. I believe it was just a design flaw. GM was initially going to eliminate the 350s, but then they realized they obtained similar gas mileage with the 350. The TPI intake was originally designed for the 305 that was meant as the replacement engine. GM wasn't very good at fuel injection design either and their first speed density setups were awful.
Transmissions and gearing was not the problem. These motors always made the torque to overcome any gearing issues. Also by the time they had fuel injection, non overdrive transmissions were out. Back in the 50’s and 60’s they used 2 speed powerglides and little 283s in full size passenger cars. They didn’t need to worry about tpi 350’s and 700r transmissions
You probably get this a lot. But can you please get your hands on a first manifold and run the same tests as this and in the other vid. That’s what we all want :)
Me too, on my '88 Corvette. I love the low-end grunt for real world driving. I never go to the drag strip and really don't care about bragging rights at the Cars & Coffee gatherings. Horsepower is heroin, anyway. You need more and more to get your kicks.
Yes, yes it did. Just to compare.. my 2004.5 Cummins puts out 600 tq. This thing is in that area.... without the huge weight. Anybody build a low buck TPI for mpg and torque? My dad wants to go cross country in his 1988 305 (TBI) Caprice Wagon while pulling a small camper. The engine needs a rebuild. What would you guys do? 305 TPI? 350/383/400 TPI? 305/350 vortec converted to TPI? The goal is mpg AND tq.
Neat set of data. Loved the way the power hung in there on the 383. Now go the other way: fab up a set of LONGER runners for the TPI, and see how much low end torque you can make. Use the Helmholtz equation to calculate a runner length to move peak torque from 4000-ish down to 3500-ish. Yeah, it will suck for peak power, but this is for SCIENCE!
That's my interest, actually. I have a 99 Suburban that I plan to swap out the Vortec motor for a Gen. 1 TPI set-up. I've been playing with Comp Cams Desktop Dyno to see what camshaft, timing, headers, etc. will give the most torque below 3,000 rpm. With a close ration 6-spd manual trans the goal would be run strongest at 2,000 - 2,300 rpm at highway speed. So.... if the runner length can be increased a few more inches will it lower the torque curve sufficiently to make it a worthwhile project?
Have setup a TPI 400 in an 80 G30 dual rear wheel Shasta RV. Used a set of TBI 350 heads and a Comp High Energy 260 cam. It pulled a 4,500 lbs boat plus the RV uphill like a sports car.
I remember an aftermarket tune port injection unit that the runners were only slightly longer but they were larger in diameter by about 8% this made an amazing effect but I really believe the stock set up is just fine with headers
You may be thinking about the FIRST TPI manifold. They still make them believe it or not. They go for a little over $1000 which ain't bad considering it includes everything needed even injectors.
Thanks I am building a 383 TPI, this winter, THANKS FOR ALL THE GREAT INSTRUCTIONS. Wow over 500 lbs/foot From a 383!!! GM need this engine in Chevy Pick-up!!!!
Exactly the info I was looking for. As the blue cloud behind my IROC gets bigger I've been contemplating the best way to build the new engine to go a little faster while keeping it stock-looking. Seems to me the best way with a tpi is to add cubic inches and cam it to make peak power at 5,000. Then figure out how to make it hook up. I'm guessing the heads don't need to be that great and anything over about 230 cfm wouldn't be useful.
The tuned port intake is great for a daily driver,that 383 made 550 ft lbs of torque!!!That is crazy torque,a 383 Ls can barely do that na.Those TPIS parts sure added more power!Now I want to watch the next tuned port video 🤓
Thankyou Mr Holdener!!! This has always been an unanswered question!!!! "Experts" all claimed the smaller engines would develop peak hp&tq at a higher rpm with the tpi. Thank You Sir.
What experts ever claimed that in writing? Not to sound condescending but I am an avid reader, and follower of many performance industry experts. And nobody has ever said a small engine would develop peak hp and torque at super high rpm with a long runner intake. Runner length determines the curve and peaks. Perhaps you took their words out of context? If you don't mind posting a link to the experts you are referring to I would love to read what you are referring to dude.
@@shadowopsairman1583 actually a 4.005 by 3.800 with 196/206 cam with .431/.451 lift split and 9.1 compression. It is meant for torque and dynos at 400 lb ft from 2500 to 4000. Ideal for the rpm on the TPI manifold.
@@Dr_Reason I watched these videos when they came out. Today my dad was talking about fixing up his old 1988 305 tbi with 700r4 Caprice wagon. I told him to run the intake that's on my brother's 1988 iroc, go 305 tpi. I think it's the best combo of mpg and torque. I really don't know how the 305 tbi does. 🤷♂️
@@xmo552 The 305 TBI makes about 170 Net at 4200 with 255 Net torque. I have one with a chip from TBI CHips. This helps the bottom end torque by adding timing under load. I have a 93 caprice with 2.56 gears and 4L60. It runs quite nice and can get out of its own way. I think the cam in the TBI is the same cam as the "peanut cam" TPI so if you can get the manifold, I am sure TBI chips can help you out and you can keep your computer. I think you would get 205-215 HP net out of this setup with great torque. Also great gas mileage.
id love to see a 406 with good heads and the AS&m siamesed runners used with the extrude honed base and plenum used in the tpi mega test. a nice 500 foot pounds off idle. even if the hp peak was 460 and flat. that would make a fun street engine
An idea perhaps? A single episode to demonstrate the relationship between WOT manifold vacuum against Power and Torque peaks. Small carb to large carb etc.
The problem with the TPI intake not being able to pull at pull to higher rpm is not so much the runner length as it is runner design. The fact the the runner turns 180 degrees and the fact the the roof of the runner is the short turn radius (opposite of an LS1 where the roof of the runner is the long turn radius) is the main reason the TPI has such high velocity flow at low rpm, thus limiting higher rpm.
@@richardholdener1727 Lingenfelter designed the SuperRam, which is the EXACT same base as a TPI and half the TPI tube runner length, thus reducing the total runner length by only 3-31/2". Your own dyno test (as well as thousands of other) shows the TPI flattening out starting between 4600-4800 rpm. However, the SuperRam usually shows peak rpm at 5600-5800 rpm. THERE IS NO WAY 3-3 1/2" in going to make 1000 rpm difference by itself, but taking out half of the 180 degrees bend will. Here is an LS1 intake comparison where 20 different intakes had runner lengths that varied from 12" (LSX) to 5 1/2" (Symbol Performance). Between all of the intakes, the peak rpm ONLY varied 200 rpms (6900-7100) yet the runner length changed by 6 1/2" in length. www.hotrod.com/articles/20-ls1-intake-manifolds-tested/ Like I said, the TPI runner design is more of an issue than the length of the runner in limiting rpms.
Could it be the interaction of the pressure waves in the plenum chamber, dictated in magnatude and frequency by the No. of cylinders and the length of the inlet tract. One way to prove the point would be to try the same inlet dimensions on a v6 to see if peak power accures 25% higher or lower in the revs 👊😂 The more you learn, the more you need to know😣
I HAVE TESTED RUNNER LENGTH ENDLESS TIMES-IT DOES THE SAME THING ON EVERY MOTOR, REGARDLESS OF DISPLACEMENT OR NUMBER OF CYLINDERS-ORGAN PIPE THEORY PREDATES THE INTERNAL COMBUSTION ENGINE
Just change the intake to a LT1 and your done, all from a 1994 z28 and up, your right change the intake to quick air flow, The lt1 is the choice option to go, Just keep your old parts and don’t get rid of them, i case u sell the car, u have all the stock parts in the garage,
I have a 350 crate motor ; very mild cam; big tube runners; and a period correct; passenger side mounted paxton. Runs like a top! Don't really care about hp; more interested in reliability! Tpi motors; to me; very reliable! If I wanted hp. I wouldnt do an l98.
I ran carburetors on TPI manifolds five years ago and and I didn't do no dyno testing but the engines ran fine I even did a dual quad TPI manifold and it ran awesome on a 350 and a 406 I know what you're talking about their fuel ratio but everything works fine for me in fact I got it on a trans am GTA in my driveway right now with a single carb1850 holley TPI manifold and it runs flawlessly in fact they run stronger than the fuel injection ever did and gets 18 miles and a gallon on the highway anyhow I'm glad to see someone else did it good luck, 🙂
@@anthonyangotti5484 I know what you mean. I argued with someone the other day. I told him I've seen it done and it works. Also, Holdener did it the other day on this channel, it works.
@@anthonyangotti5484 ah so your running twin quads? Richard only ran a single hence why i think your setup works and his didn't. However without dyno and or 1/4 times before and after we don't know if its actually any better
1988 corvette L98 stock motor , 2500 stall, wrapped headers ,150 shot of nitrous on a controller , this is what i am running , pulls like a bull out of hell.
Here's a thought for the 4.3L V-6: Locate & Z-cut an Accel-Ram intake, like I've seen done with a SBC tunnel-ram for use with a 4.3L V6 in an Econo-rail in the day. ;)
The siamesed connector tubes are supposed to eliminate the runner length issue. But you still cannot make any serious top end power with this setup, because of the overly restrictive intake runners...
If the runners are fully siamesed then the you can possibly run to 6500rpm. Been done before, check out the thirdgen.org forums. Lots of work involved but it can be done.
@@RSChris666 I've seen it done before, but haven't tried it myself. It didn't look that hard, but the lower manifold restrictions just negate any other efforts, so I went in another direction.
looks like the the power curve reflects perfectly the power rating. I mean for example @11:28 we have 400hp power stock 383hp and you would rate it a 400hp engine. Well, you can benefit from all horse power as opposed to an engine that males peak power at the end of the rpm range. you would have say 500hp and rate it 500 but you won’t be able to use all that power while accelerating. In other words this is the fastest possible 400hp engine or whatever is rated. for example the 350 l98 is the fastest possible 250hp engine.
Richard, I have heard you many times say that you wish to try the TPI manifold on a Vortec 350... so what's holding you back? You not only have the base manifold, but now, also the better-flowing runners & throttle body, which were made for the factory TPI 350 to begin with! Not to mention you also have 1.6:1 rockers, which along with a Ram-Jet 350 cam, were suggested for use in a build of a Vortec 350 to create better low-end torque... which is what you've been wanting to see done with one in the first place!! So what's holding you back?! Do it... DO-it! We're all waiting to see you make one. Especially me, who wants to make my Astro mini-van able to pull a stump... while going uphill! ;)
we really need to see effect of runner sizes on these engines stock runners and base is 1.5 next up would be an aftermarket base and slp runners at 1.55 after that accel cast and tpis runners at 1.66 and finally a first tpi unit 1.8
Throw a set of twins on it with the right ar and a 2.41 gear and go for a land speed record. 5000rpm and a 6 speed show 290mph give or take with a 29 in tire lol
@@AndyR1982 The Vector W8 supercar in 1990 had the unofficial top speed world record with a twin turbo-charged FIRST TPI-based SBC: th-cam.com/video/bNAkfdno3u8/w-d-xo.html You can see the FIRST TPI intake with a polished plenum @ 28:42 in Doug DeMuro's video of the Vector W8: th-cam.com/video/3WEhsS9ybwk/w-d-xo.html
Alright, I believe I have everything gathered to build a 302, standard hydraulic roller 350 block, L99 crank, L98 heads, tuned port, and a ZZ-4 cam. Throw a turbo on this combo 🤷
Well... I wonder if a 400+ cubic inch motor would gain any horsepower over the 383 or just hit that 400 hp mark sooner. I know you have test the TPI a bunch but... 🤷🏼♂️
Was it easier to tune the smaller displacement engines? It seems the intake manifold pressure/vacume variations would be smaller in the small displacements so the airflow signal would have less false signals from reversion of flow through the throttle bodies. How about the Keglodon, was that easiy to tune? That had a huge plenum/displacement ratio which might buffer the pressure varitions at the throttle body.
But, Richard, the guys at cars and coffer told me that the tests you ran are on a different dyne than theirs and they can get more power everywhere when they......
and yet for some ridiculous reason GM never used their TPI system in the trucks...maybe it was the same genius who decided that the 4.3l V8 belonged in a full sized sedan
It was explained to me that the 85 tuneport actually had a smaller diameter runner tubes than the 1986 tuneport. I do have a strange request, can you run a crossfire 82-84 intake and the renegade intake?
Thank you for this video. I have custom built car with 383 stroker. I have a complete 1986 TPI set up from a 1986 Corvette but no electronics in a box I'd like to use. What ECM and what injectors would you recommend? Would the stock injectors from the Vette be sufficient? Thank you for your help 🙂
Another AWESOME set of informative tests! I'm currently assembling the parts to build the following for my 91 6 speed Corvette and would love to see a test on a combo like this: E-bay "assault racing" 205 CC Vortec style heads, Crower .525/.545 221/230 114 ICL hydraulic roller (peak power is supposed to be at 5800 rpm), will end up at 10-10.25 compression, for emissions reasons using LT1 shorty headers and for the intake I'm wanting to use either the Holley 300-263 single plane EFI manifold with a 4150 style throttle body or the FIRST Fuel Injection TPI setup. Those 2 intakes are quite different and I'd LOVE to see you do a test with those two.
The single-plane manifold will only make more power than the TPI manifold above 6000 rpm, and will lose a lot of torque from 3500-5000. Since your cam is only supposed to go to 5800, I think the TPI is the better choice.
@@richardholdener1727 Yep, very familiar with that one. I ended up buying the Holley intake yesterday. I really don't want a flat power curve in the upper rpm's.
@@andyharman3022 The manifold is rated for 2500-7000. With the 6-speed and 4.10's I'm really not worried about low end. I'd rather lose a little torque and hook up better than spin tires. And the cam is rated for peak power at 5800, max useable rpm is 6300.
Interesting that the 350 had 1 5/8" headers and yet the 305 had 1 3/4" headers. Yet the L99 proved the smaller motor liked the smaller headers much better. Ys, I know "why" but it is something to consider for future combo's? though I have never even seen any LS 1 5/8" full length headers for sale, shorties yes, Long tubes Nope!
Hello Richard I own a 89 Camaro irocz. What heads and cam would you recommend? It has the stock l98. tuneport engine, the only upgrades are short tube headers, exhaust, 58mm throttle body, big mouth tpis intake and slp runners. Thank you.
Back in the days where people still believed in magic. Took complete 85 Firebird 2.8 MPFI engine and a Paxton @ 8#, to a 86 Cherokee. Has .040 over factory pistons, 3.4 V6 rods and main caps, 3.1 crankshaft and Crane cam, which I cannot remember at moment. Tried many injectors and actually settled on 3.1s. The 5.0 injectors were fantastic at top end but without fuel map changes sucked off idle to mid range. Others were too small or too large. With no available support back then, 25 years later still running strong! Made a huge difference compared to the original 2.8 2V! The first upgrade to the OEM 2.8 was to install a Dual port Offy w/Holley 4V. That helped but going EFI and blown on the now 3.2 changed everything.
Where is our first fuel injection, boosted or sprayed see what torque monster with ok hi rpm , there is 8 second tpi cars out there, easy. Low gear rear, get all torque down. So much torque it would of been a crazy truck motor.
If you didn’t want to be stealthy, for a balls-to-the-wall street motor. What would you change on the 383 to maximize its power? I know you used a mild cam on it and the stock 113 aluminum heads with some porting. Is there anything you’d change? I have a 1988 C4 Corvette I use for weekend driving I’d like to beef up. (Sorry forgot to mention, while keeping TPI
@Richard Holdener how did you get it custom modified? And after getting it modified will it on any size chevy engine block within the 305-400 engine size ? Thank you
If you consider the era of the tpi, you need more torque at low rpm when limited to three and four speed transmissions. This was an effective way to make power and maintain excellent driveability.
In modern times we have a lot more gearing options.
An interesting test on tpi would be to create waves on the inside radius to ensure full use of the cross section at high rpm's.
I don't think that was the case. In fact, the first 4L60s that were behind the LT1s (short runner intakes) were the same transmissions. They just renamed them. 4 speeds were still coming behind LSs up through the 2000s. Gearing wasn't the rationale. I believe it was just a design flaw. GM was initially going to eliminate the 350s, but then they realized they obtained similar gas mileage with the 350. The TPI intake was originally designed for the 305 that was meant as the replacement engine. GM wasn't very good at fuel injection design either and their first speed density setups were awful.
Transmissions and gearing was not the problem. These motors always made the torque to overcome any gearing issues. Also by the time they had fuel injection, non overdrive transmissions were out. Back in the 50’s and 60’s they used 2 speed powerglides and little 283s in full size passenger cars. They didn’t need to worry about tpi 350’s and 700r transmissions
You probably get this a lot. But can you please get your hands on a first manifold and run the same tests as this and in the other vid. That’s what we all want :)
HOW MANY OF THERE ARE YOU?
I love that you are doing all these TPI test. I have a 85 Vette and refuse to get rid of the Tuned Port.
I have a 88 iron 305 TPI and a 85 gmc tow truck 400 TPI. Luv em. And possibly a jeep.
Me too, on my '88 Corvette. I love the low-end grunt for real world driving. I never go to the drag strip and really don't care about bragging rights at the Cars & Coffee gatherings. Horsepower is heroin, anyway. You need more and more to get your kicks.
@@Michael_Lorenson
I just got off work and I was just defending the TPI and LT1 vs the LS.
TPI ALL THE SBCs!!
TPI is the COOLEST looking intake of all time.
And for the street, it puts power where you use it for everyday driving @weskirkland5850
That 383 TPI was making 530TQ
😎
It will get you to the picnic in a hurry
Hauling the effing mail!
alot of 383 are Tq monsters.
Yes, yes it did.
Just to compare.. my 2004.5 Cummins puts out 600 tq. This thing is in that area.... without the huge weight.
Anybody build a low buck TPI for mpg and torque? My dad wants to go cross country in his 1988 305 (TBI) Caprice Wagon while pulling a small camper. The engine needs a rebuild.
What would you guys do?
305 TPI?
350/383/400 TPI?
305/350 vortec converted to TPI?
The goal is mpg AND tq.
Definitely build a 400tpi. Itl just fatten the curve even more. And make it a torque monster😎
TPI was the best overall intake system made for Gen 1 small blocks in my opinion. I love my L98.
And absolutely the coolest looking intake of all time.
I’d love to see a TPI test using the Scoggin Dicky lower that adapts the TPI to vortech heads.
Neat set of data. Loved the way the power hung in there on the 383.
Now go the other way: fab up a set of LONGER runners for the TPI, and see how much low end torque you can make. Use the Helmholtz equation to calculate a runner length to move peak torque from 4000-ish down to 3500-ish. Yeah, it will suck for peak power, but this is for SCIENCE!
HELMHOLTZ IS NOT RUNNER LENGTH-THAT IS THE RESONATING FREQUENCY OF THE PLENUM VOLUME (AND ASSOCIATED PORTIONS)
@@richardholdener1727 Why are you yelling, bud? Turn off the Caps Lock, lol.
That's my interest, actually. I have a 99 Suburban that I plan to swap out the Vortec motor for a Gen. 1 TPI set-up. I've been playing with Comp Cams Desktop Dyno to see what camshaft, timing, headers, etc. will give the most torque below 3,000 rpm. With a close ration 6-spd manual trans the goal would be run strongest at 2,000 - 2,300 rpm at highway speed. So.... if the runner length can be increased a few more inches will it lower the torque curve sufficiently to make it a worthwhile project?
I would love to see a TPI on 400ci motor.
My 85 GMC tow truck is getting a 400 tpi when the 350 needs a rebuild.
@@xmo552 Hell yeah brother... Torque to spare.
@@sportsmansparadice42
That's the plan
Have setup a TPI 400 in an 80 G30 dual rear wheel Shasta RV. Used a set of TBI 350 heads and a Comp High Energy 260 cam. It pulled a 4,500 lbs boat plus the RV uphill like a sports car.
@@chrisreynolds6520
Did the ecm need any work?
I remember an aftermarket tune port injection unit that the runners were only slightly longer but they were larger in diameter by about 8% this made an amazing effect but I really believe the stock set up is just fine with headers
You may be thinking about the FIRST TPI manifold. They still make them believe it or not. They go for a little over $1000 which ain't bad considering it includes everything needed even injectors.
Tpi setup would been great on truck engines. All that low end torque would really help with towing and pulling in there trucks and suvs.
Thanks
I am building a 383 TPI, this winter, THANKS FOR ALL THE GREAT INSTRUCTIONS.
Wow over 500 lbs/foot
From a 383!!!
GM need this engine in Chevy Pick-up!!!!
The 383 TPI has a great torque curve, lots of fun on tao there.
I had an 84 Z-28 that we swapped in a 350 TPI from an 89 and it was fun as hell. Would fry the tires on launch and spin the first 2 shifts.
A set of Siamese runners, like those from SLP from back in the day, would help push the power further out into the RPM range.
SEE TPI TEST
Exactly the info I was looking for. As the blue cloud behind my IROC gets bigger I've been contemplating the best way to build the new engine to go a little faster while keeping it stock-looking. Seems to me the best way with a tpi is to add cubic inches and cam it to make peak power at 5,000. Then figure out how to make it hook up. I'm guessing the heads don't need to be that great and anything over about 230 cfm wouldn't be useful.
The tuned port intake is great for a daily driver,that 383 made 550 ft lbs of torque!!!That is crazy torque,a 383 Ls can barely do that na.Those TPIS parts sure added more power!Now I want to watch the next tuned port video 🤓
Great data. I love the TPI system. Archaic enough to be old school, new enough to still tinker with.
Thankyou Mr Holdener!!! This has always been an unanswered question!!!! "Experts" all claimed the smaller engines would develop peak hp&tq at a higher rpm with the tpi. Thank You Sir.
What experts ever claimed that in writing? Not to sound condescending but I am an avid reader, and follower of many performance industry experts. And nobody has ever said a small engine would develop peak hp and torque at super high rpm with a long runner intake. Runner length determines the curve and peaks. Perhaps you took their words out of context? If you don't mind posting a link to the experts you are referring to I would love to read what you are referring to dude.
The takeaway 500 ft pounds of torque at low RPM is incredible for a small block!
I would love to see an HT 383 crate motor with a TPI. In a Caprice.
I’d buy one
Ok a stroked 350...
@@shadowopsairman1583 actually a 4.005 by 3.800 with 196/206 cam with .431/.451 lift split and 9.1 compression. It is meant for torque and dynos at 400 lb ft from 2500 to 4000. Ideal for the rpm on the TPI manifold.
@@Dr_Reason
I watched these videos when they came out. Today my dad was talking about fixing up his old 1988 305 tbi with 700r4 Caprice wagon.
I told him to run the intake that's on my brother's 1988 iroc, go 305 tpi. I think it's the best combo of mpg and torque.
I really don't know how the 305 tbi does. 🤷♂️
@@xmo552 The 305 TBI makes about 170 Net at 4200 with 255 Net torque. I have one with a chip from TBI CHips. This helps the bottom end torque by adding timing under load. I have a 93 caprice with 2.56 gears and 4L60. It runs quite nice and can get out of its own way. I think the cam in the TBI is the same cam as the "peanut cam" TPI so if you can get the manifold, I am sure TBI chips can help you out and you can keep your computer. I think you would get 205-215 HP net out of this setup with great torque. Also great gas mileage.
id love to see a 406 with good heads and the AS&m siamesed runners used with the extrude honed base and plenum used in the tpi mega test. a nice 500 foot pounds off idle. even if the hp peak was 460 and flat. that would make a fun street engine
I think it’s time to run a First, would love to see it on a 305,350,383. The world of TPI needs to know.
An idea perhaps?
A single episode to demonstrate the relationship between WOT manifold vacuum against Power and Torque peaks. Small carb to large carb etc.
TPI is the coolest looking intake any american small block ever had.
A good build would be a TPI on a 400 small block would be a great truck motor
The problem with the TPI intake not being able to pull at pull to higher rpm is not so much the runner length as it is runner design. The fact the the runner turns 180 degrees and the fact the the roof of the runner is the short turn radius (opposite of an LS1 where the roof of the runner is the long turn radius) is the main reason the TPI has such high velocity flow at low rpm, thus limiting higher rpm.
IT'S RUNNER LENGTH
@@richardholdener1727 Lingenfelter designed the SuperRam, which is the EXACT same base as a TPI and half the TPI tube runner length, thus reducing the total runner length by only 3-31/2". Your own dyno test (as well as thousands of other) shows the TPI flattening out starting between 4600-4800 rpm. However, the SuperRam usually shows peak rpm at 5600-5800 rpm. THERE IS NO WAY 3-3 1/2" in going to make 1000 rpm difference by itself, but taking out half of the 180 degrees bend will.
Here is an LS1 intake comparison where 20 different intakes had runner lengths that varied from 12" (LSX) to 5 1/2" (Symbol Performance). Between all of the intakes, the peak rpm ONLY varied 200 rpms (6900-7100) yet the runner length changed by 6 1/2" in length.
www.hotrod.com/articles/20-ls1-intake-manifolds-tested/
Like I said, the TPI runner design is more of an issue than the length of the runner in limiting rpms.
I love these tests and my 85 Vett Anyway you can run a first tpi set up They claim 320cfm on those and are still making them
Oh really will look into this!
Check out the horsepower on the 383! It peaks at 4700 but instead of falling off it stays flat all the way out to cutoff.
I'm really loving these videos. Keep up the great work!
Nice big block torque with tpi 383.love it.
Could it be the interaction of the pressure waves in the plenum chamber, dictated in magnatude and frequency by the No. of cylinders and the length of the inlet tract.
One way to prove the point would be to try the same inlet dimensions on a v6 to see if peak power accures 25% higher or lower in the revs 👊😂
The more you learn, the more you need to know😣
The easier way to test that theory is to use an individual runner manifold. Then no cylinder's intake pulse will directly effect another's.
Or, locate & Z-cut an Accel-Ram intake, like I've seen done with a SBC tunnel-ram for use with a 4.3L V6 in an Econo-rail in the day. ;)
I HAVE TESTED RUNNER LENGTH ENDLESS TIMES-IT DOES THE SAME THING ON EVERY MOTOR, REGARDLESS OF DISPLACEMENT OR NUMBER OF CYLINDERS-ORGAN PIPE THEORY PREDATES THE INTERNAL COMBUSTION ENGINE
@@richardholdener1727 Wise words
Learned so much! Thanks so much!!
Don't hate me for asking but it would be interesting to see what a cut down TPI intake would produce on a 4.3 V6. Thanks for the vid sir.
GM did almost that. The earlier 4.3 Vortec engines with CPI had a variable length, long/short runner intake setup.
I hate you for asking that. 😂😉
@@donellmuniz590 Really??? Why make a looser comment??? Donnell you must have not been hugged enough as a kid.
@@adampatterson707 Of course not, silly. Don't ya know a joke when you see one??
The 😉 and the 😂 should have clued you in. Nobody has a sense of humor anymore.
Just change the intake to a LT1 and your done, all from a 1994 z28 and up, your right change the intake to quick air flow,
The lt1 is the choice option to go,
Just keep your old parts and don’t get rid of them, i case u sell the car, u have all the stock parts in the garage,
the LT1 intake won't bolt onto the L98
I have a 350 crate motor ; very mild cam; big tube runners; and a period correct; passenger side mounted paxton. Runs like a top! Don't really care about hp; more interested in reliability! Tpi motors; to me; very reliable! If I wanted hp. I wouldnt do an l98.
Really liked this post by the way! Makes me really wonder about the FIRST stuff and if can actually even do what they claim?
I ran carburetors on TPI manifolds five years ago and and I didn't do no dyno testing but the engines ran fine I even did a dual quad TPI manifold and it ran awesome on a 350 and a 406 I know what you're talking about their fuel ratio but everything works fine for me in fact I got it on a trans am GTA in my driveway right now with a single carb1850 holley TPI manifold and it runs flawlessly in fact they run stronger than the fuel injection ever did and gets 18 miles and a gallon on the highway anyhow I'm glad to see someone else did it good luck, 🙂
Did you mount it up top on the plenum ?
@@xmo552 yes on top
Yes just like looks just like a tunnel ram, I got two velocity stacks sticking out of the hood
@@anthonyangotti5484
I know what you mean. I argued with someone the other day. I told him I've seen it done and it works. Also, Holdener did it the other day on this channel, it works.
@@anthonyangotti5484 ah so your running twin quads? Richard only ran a single hence why i think your setup works and his didn't. However without dyno and or 1/4 times before and after we don't know if its actually any better
Lol 😂 how about a TPI setup on swirlport head 350 or 400 and a truck cam. Would be interesting to see what kind of torque numbers could be produced.
I wonder what MPG that TPI 4.3L would make in a little S10 with a good transmission seems like a great setup
Just grab a 262
Or a Ranger with a 255 V8 4.2L with a T5 for efen better mpg than any of the 4 cylinders
Moot now, since most folks would just use a 4.8 or 5.3 boneyard LS.
Prob 14 mpg still lol. MPG is all about vehicle vs air flow. Motor can only be optimized for those things
1988 corvette L98 stock motor , 2500 stall, wrapped headers ,150 shot of nitrous on a controller , this is what i am running , pulls like a bull out of hell.
I think GM should have used the TPI manifold on the Vortec 305 and 350's. Would have been an excellent factory combo in the trucks.
Love all the information i get from these videos. Your a great guy and very helpful
Awesome. Just what I've been looking for. I've had questions from the latest videos.
Here's a thought for the 4.3L V-6: Locate & Z-cut an Accel-Ram intake, like I've seen done with a SBC tunnel-ram for use with a 4.3L V6 in an Econo-rail in the day. ;)
I remember the edelbrock runners helped a lot on the tpi engines
THEY DID VERY LITTLE ON MY TPI INTAKE TEST
Hope there will be an episode with the FIRST tpi intake with a procharger setup. Or just the Intake 😅
The siamesed connector tubes are supposed to eliminate the runner length issue.
But you still cannot make any serious top end power with this setup, because of the overly restrictive intake runners...
If the runners are fully siamesed then the you can possibly run to 6500rpm. Been done before, check out the thirdgen.org forums. Lots of work involved but it can be done.
@@RSChris666 I've seen it done before, but haven't tried it myself.
It didn't look that hard, but the lower manifold restrictions just negate any other efforts, so I went in another direction.
SEE THE TPI INTAKE VIDEO-WE RAN SIAMESED RUNNERS
Finally, this will get impressive view numbers,TPI my huffy.
Thank you. Great information.
You realize the 383 you have there would be a great boat engine, you could run 5000 RPM for a long time without harming the engine.
looks like the the power curve reflects perfectly the power rating. I mean for example @11:28 we have 400hp power stock 383hp and you would rate it a 400hp engine. Well, you can benefit from all horse power as opposed to an engine that males peak power at the end of the rpm range. you would have say 500hp and rate it 500 but you won’t be able to use all that power while accelerating.
In other words this is the fastest possible 400hp engine or whatever is rated. for example the 350 l98 is the fastest possible 250hp engine.
AWESOME WORK
would be cool to see a big block comparison with the chevy 366 and 396 vs other engines
Richard, I have heard you many times say that you wish to try the TPI manifold on a Vortec 350... so what's holding you back? You not only have the base manifold, but now, also the better-flowing runners & throttle body, which were made for the factory TPI 350 to begin with! Not to mention you also have 1.6:1 rockers, which along with a Ram-Jet 350 cam, were suggested for use in a build of a Vortec 350 to create better low-end torque... which is what you've been wanting to see done with one in the first place!!
So what's holding you back?! Do it... DO-it! We're all waiting to see you make one. Especially me, who wants to make my Astro mini-van able to pull a stump... while going uphill! ;)
the base manifold that was modified for the l99 wont work on vortec heads different bolt pattern and vortec has taller ports
THE VORTEC AND LT1 ARE DIFFERENT-I WANTED TO TRY THE TPI ON THE LT1 (L99) AND DID
Had GM put the tpi in the trucks they would of had done torque monsters, but either way still love that ole tpi intake.
we really need to see effect of runner sizes on these engines stock runners and base is 1.5 next up would be an aftermarket base and slp runners at 1.55 after that accel cast and tpis runners at 1.66 and finally a first tpi unit 1.8
TPIS large runner TPI on a 412ci in my 89 TA with a 5 speed was a lot of fun. :)
I'm planning a 400 tpi in an 85 GMC tow truck when the 350 needs a rebuild. Did you have to do anything to the ecm to run larger cubic inches?
The header pipe arrangement going to the collector is relevant to the firing order, why isn't the intake set up the same way?
should run the bigger base runners on the smaller engines to see what gains can be had
What about de-stroking a TPI 350 & use high compression????
Get rid of that TPI and use the Edelbrock ProFlo intake manifold. Make some real power. TPI manifold is highly restrictive.
530 ftlb out of a 383 at 4000 rpm. That’s a serious amount of cylinder filling!!! That would be a tire frying machine.
Throw a set of twins on it with the right ar and a 2.41 gear and go for a land speed record. 5000rpm and a 6 speed show 290mph give or take with a 29 in tire lol
@@AndyR1982 The Vector W8 supercar in 1990 had the unofficial top speed world record with a twin turbo-charged FIRST TPI-based SBC: th-cam.com/video/bNAkfdno3u8/w-d-xo.html
You can see the FIRST TPI intake with a polished plenum @ 28:42 in Doug DeMuro's video of the Vector W8: th-cam.com/video/3WEhsS9ybwk/w-d-xo.html
Gday Richard another great video keep em up.
Alright, I believe I have everything gathered to build a 302, standard hydraulic roller 350 block, L99 crank, L98 heads, tuned port, and a ZZ-4 cam. Throw a turbo on this combo 🤷
I would like to see the tpi on a small block 400 with a truck cam that's made for low end torque and power.
I have that exact set up for my 1985 tow truck but I haven't ran it yet.
I'm thinking the TPI manifold base might be a good starting point for an ITB setup. 😉
It wouldn't, you would still have a terrible angle to the port.
Well... I wonder if a 400+ cubic inch motor would gain any horsepower over the 383 or just hit that 400 hp mark sooner. I know you have test the TPI a bunch but... 🤷🏼♂️
My hunch would be that it hits roughly the same hp, just sooner. The tq might be slightly more.
I would love to see a dyno run on a FIRST TPI type intake.
ME TOO
Right on
Was it easier to tune the smaller displacement engines? It seems the intake manifold pressure/vacume variations would be smaller in the small displacements so the airflow signal would have less false signals from reversion of flow through the throttle bodies. How about the Keglodon, was that easiy to tune? That had a huge plenum/displacement ratio which might buffer the pressure varitions at the throttle body.
the tune was identical with and without the Kegalodon
The 383 TPI would be great for my K5
I take it... It wouldn't do well on a SBC 400?
Very sad you didn't use the FIRST TPI. I assume it would be similar to the tpis numbers but I'm really curious.
But, Richard, the guys at cars and coffer told me that the tests you ran are on a different dyne than theirs and they can get more power everywhere when they......
He is at sea level with very good tuning abilities, this is a junkyard engine he used. Not a fresh to spec engine with no miles on it.
I'd like to see that manifold on a 434sbc tow truck motor 😂 or is there a manifold with even longer runners?
I'll never understand why GM didn't put these intakes in their trucks in the 90's instead of that garbage TBI and spider injection.
Agree! A much better fit for trucks, van, and the likes. Not light vehicles like cars.
Perfect for trucks and perfect for twin turbos lol.
Tuned Port rules all.
Any info on emissions comparison? Want to build a beefed up TPI Iroc. Live in California & they have strict smog & emissions laws.
nope
That base manifold is begging for a Holdener built adjustable length cross ram using two stock throttle bodies and dual stock injectors per cylinder.
Sounds like a pretty good truck engine setup.
and yet for some ridiculous reason GM never used their TPI system in the trucks...maybe it was the same genius who decided that the 4.3l V8 belonged in a full sized sedan
It appears the best upgrade for the TPI is higher flow runners ..power gains with no sacrifice at lower RPM's.
It was explained to me that the 85 tuneport actually had a smaller diameter runner tubes than the 1986 tuneport.
I do have a strange request, can you run a crossfire 82-84 intake and the renegade intake?
Thank you for this video. I have custom built car with 383 stroker. I have a complete 1986 TPI set up from a 1986 Corvette but no electronics in a box I'd like to use. What ECM and what injectors would you recommend? Would the stock injectors from the Vette be sufficient? Thank you for your help 🙂
stock injectors are likely too small-we ran a Holley ecu (others will work)
Thank you 😁
Another AWESOME set of informative tests! I'm currently assembling the parts to build the following for my 91 6 speed Corvette and would love to see a test on a combo like this: E-bay "assault racing" 205 CC Vortec style heads, Crower .525/.545 221/230 114 ICL hydraulic roller (peak power is supposed to be at 5800 rpm), will end up at 10-10.25 compression, for emissions reasons using LT1 shorty headers and for the intake I'm wanting to use either the Holley 300-263 single plane EFI manifold with a 4150 style throttle body or the FIRST Fuel Injection TPI setup. Those 2 intakes are quite different and I'd LOVE to see you do a test with those two.
The single-plane manifold will only make more power than the TPI manifold above 6000 rpm, and will lose a lot of torque from 3500-5000. Since your cam is only supposed to go to 5800, I think the TPI is the better choice.
PLEASE SEE THE TPI INTAKE TEST
@@richardholdener1727 Yep, very familiar with that one. I ended up buying the Holley intake yesterday. I really don't want a flat power curve in the upper rpm's.
@@andyharman3022 The manifold is rated for 2500-7000. With the 6-speed and 4.10's I'm really not worried about low end. I'd rather lose a little torque and hook up better than spin tires. And the cam is rated for peak power at 5800, max useable rpm is 6300.
Great testing, 👍
Interesting that the 350 had 1 5/8" headers and yet the 305 had 1 3/4" headers. Yet the L99 proved the smaller motor liked the smaller headers much better. Ys, I know "why" but it is something to consider for future combo's? though I have never even seen any LS 1 5/8" full length headers for sale, shorties yes, Long tubes Nope!
what is causing the odd big dip at the beginning on the 350 and 383? it seems especially bad on the 350.
Can you please do a video on siamesed TPI runners?
THAT VIDEO IS UP-SEE TPI INTAKE TEST
@@richardholdener1727 Thank you
or how about maybe fabing up a varible vane set up like the 2004 mercedess class that goes from long runners to short runners with a vacum can
Just saw a guy exactly like richard on Netflix Fastest car
THAT WAS ME
Hello Richard
I own a 89 Camaro irocz. What heads and cam would you recommend? It has the stock l98. tuneport engine, the only upgrades are short tube headers, exhaust, 58mm throttle body, big mouth tpis intake and slp runners. Thank you.
afr or tfs heads, mild cam 212/218 duration
@@richardholdener1727 thank so much! 195cc?
@@richardholdener1727
Btw love the channel, Keep them coming! Hope to see a vid, using a first tpi setup if you ever get your hands on one.
Lets see a 93-95 Camaro 3.4l with a 2.8l intake from a s10 punched out to accept a 4.3l throttle body injection. Then work your magic !
Back in the days where people still believed in magic. Took complete 85 Firebird 2.8 MPFI engine and a Paxton @ 8#, to a 86 Cherokee. Has .040 over factory pistons, 3.4 V6 rods and main caps, 3.1 crankshaft and Crane cam, which I cannot remember at moment. Tried many injectors and actually settled on 3.1s. The 5.0 injectors were fantastic at top end but without fuel map changes sucked off idle to mid range. Others were too small or too large. With no available support back then, 25 years later still running strong! Made a huge difference compared to the original 2.8 2V! The first upgrade to the OEM 2.8 was to install a Dual port Offy w/Holley 4V. That helped but going EFI and blown on the now 3.2 changed everything.
Where is our first fuel injection, boosted or sprayed see what torque monster with ok hi rpm , there is 8 second tpi cars out there, easy. Low gear rear, get all torque down. So much torque it would of been a crazy truck motor.
What parts did you use to put a tpi on the 4.3l I want to toi swap my 283 to put in my 1949 buick super
a custom lower intake from TPIS
You love 4.3 8v I do
I dont shift with my eys.
I shift with my inner ear.
If you didn’t want to be stealthy, for a balls-to-the-wall street motor. What would you change on the 383 to maximize its power? I know you used a mild cam on it and the stock 113 aluminum heads with some porting. Is there anything you’d change? I have a 1988 C4 Corvette I use for weekend driving I’d like to beef up. (Sorry forgot to mention, while keeping TPI
tpi will always be the limiting factor-boost helps
How did you get the TPI manifold bolt up to those engines I thought it only bolts up to the stock 305 or 350 engines that came in the camaros?
custom modified lower tpi intake
@Richard Holdener how did you get it custom modified? And after getting it modified will it on any size chevy engine block within the 305-400 engine size ? Thank you