TURBO TPI-BOOSTED TUNE PORT

[@cuzz63]

That TPI manifold is absolutely top 5 of the coolest intakes Chevy ever made.

[@backyardbuck6362]

Absolutely agree. I have my 89 firebird with it and think it would make good truck motor with all of that low end torque. Wood love to have an old Z71 with 4x4 and tpi.

[@bill2178]

number1 is the zr1

[@kennethrand1032]

I think it's awesome I changed my tpi to stealth ram I miss my low end torque but love being able to pull to 6k

[@terrypetty9822]

Unmatched torque.

[@joehudson3072]

@@backyardbuck6362 GM should have made the an l98 engine option in the in the trucks

[@CamaroRick]

Ive always love the look of the TPI intake.

[@wannabeetiger]

Me too. It looks very high performance.

[@ShawnStafford-1978]

I still love looking at my TPI L98 when I open my hood. It's still badass looking today

[@jamesbowman7963]

With TPI the tuned length is what it is, the idea is to keep the torque up without the drastic drop off at 4,700 RPM and when you do that you end up with a fast car that doesn't want to rev past 6K regardless. I had a 350 that would pull hard to about 5,600-5700 RPM but made tons of torque down low. Very fun to drive I assure you and stop light to stop light amazing. Also got 26MPG doing 75MPH with a T-56 behind it.

[@xmo552]

Could it tow?

[@twinsemi]

@@xmo552 It will if you don't mind replacing clutch discs and refacing your flywheel every few hundred miles. Towing is all about having the right cam. A cam that likes to rev over 5K is not that, no matter what induction system. I know because I towed with my TPI that has an XFI cam with 216/223 dur and destroyed my clutch in the process.

[@xmo552]

@@twinsemi I'd go automatic on this truck.

[@ryanwilliams1651]

The first car I ever built was a regal with a 305 TPI. fully polished, ported, match ported, larger injectors. I built a 700R4.i wish I had a turbo or two.. no training, just shade tree mechanics. Just books and alot of peterson publications. I was 19yrs. Old. Wish I still had that car. Thank for the trip down memory lane.

[@RT10Viperman]

I just picked up a 1989 Corvette Tune port that the guy took all apart and could remember how to put it back together. $1,800. I got all the machine work done and assembled the motor myself and have it back in the car..! That tune port looks cool and its light as heck...!!

[@theall-seeingpie8887]

Woo 4 in the morning... oh look a new Richard Holdener dyno video. Winning.

[@Fmandan77]

My 87 Formula 350 with a bone stock L98 / 700R4 drivetrain with very low mileage (less than 10K original) made 217rwhp on a dynojet. That's really respectable for a motor with a factory rating of 225hp and would indicate these engines were making a little more power than advertised.

[@dannoyes4493]

Another consideration is the intake plenum itself. It had two bridges behind the throttle body that seem to dynamically block intake airflow above 4400 rpm. I bought a new Corvette in '85 and with less than 50 miles on it, ground out and smoothed the intake of the manifold and installed 1.6 rockers - made a big difference in 1985, moving the peak up to nearly 5000 rpm

[@replica4132]

thanks for these tpi vids recently rich, very overlooked motors imo

[@mirage2991]

I owned two 85 irocs in the late 90’s... one stock 305 the other a 350, did the slp runners, ASM tb, slp base plate and the edelbrock headers/y pipe... talk about a walk down memory lane! I learned on the 350 cars that too much gears was about as bad as not enough... had 3:73’s, then switched to an Australian 9 bolts with 3:2x and gained 1 tenth and 1mph at the 1/4 lol... sold the car later and my friend did a carb swap with the “hot cam” but that tq was never the same...

[@wheezin_the_juice]

Had one for my highscool ride in the early '00s, modded right they're streetlight assassins LoL made alot of lunch monies against the fastless & furious crowds

[@darinr9424]

I went to a junkyard and bought a rear end. At the time i didnt know about the aussie 9 bolt. Thats what i ended up buyin.....

[@bryce1916]

I had a 1988 Iroc with the 305 and a 5 speed with the tuned port it was a torque monster as it never left me unhappy .

[@UnityMotorSportsGarage]

My Brother had a '89 GTA TransAm and we used to love to kill 5.0 mustangs back in the day!!! Brought back alot of memories!

[@brianpeacock9444]

OH YEA? My cousin in West Tennessee bought/ordered a brand spank new 1989 TURBO TRANS AM 20TH ANNIVERSARY INDY PACE. Had our own 1/4 mile spray paint lined across an old 2 lane road between the cotton fields rite outside of town. So we SMOKED EM ALL PRETTY MUCH back then[stangs, vettes, u name it!! LOL!

[@ChristopherGaul]

It seems like a TPI setup on a 383 would make a great combo for a truck or other application where you want lots of low speed torque. Even a street motor in a heavier car. Would love to hear your thoughts Richard. I'd also love to see that setup tested. GM's HT383E long block/heads with its stock RV cam mated to a Corvette TPI with a Scoggin-Dickey Vortec TPI intake base. Then add turbo. I'll bet the result is a killer street/truck motor.

[@richardholdener1727]

lots of truck guys running that intake-works well

[@thetriode]

Go look up "how long until it grenades" on The Turbo Forums. Bring a drink and a snack you'll be there for a while in awe of what a TPI can do when you wring every last solitary half ounce of power from it.

[@xmo552]

@@richardholdener1727 Have you got any experience or knowledge on draw thru turbo stuff possibly on a SBC? I know GM and Ford experimented with this shortly in the late 70s and early 80s... as well as aftermarket RV kits. Currently I know the aircooled VW guys use that tech successfully. I'm kind of wondering if low psi boost could help me.

[@xmo552]

@@richardholdener1727 You tuned most of these with a Holley XFI, correct ?

[@TurboTPI]

Great video! I did my turbo TPI setup back in 05! I never had my car dynoed, but full weight Third Gen Firebird running 130mph in the 1/4 mile. Has to be making pretty good power. Still have it today. I beat up on many LS cars

[@Stabilityx2]

I have a 5.7 85 vette any info on how I can start a turbo build?

[@rkstewart9585]

I've followed your work for years in the magazines and it's completely awesome to see you on youtube and getting to try all this crazy stuff and bring back some really cool articles. Thank you for the content!

[@Fernandogomez-wy7ul]

Good morning Mr Holdener! I must admit that I love your videos because you make a lot of technical things easier to understand, and you're also making it very very difficult for me to not BOOST the crap out of my 1987 corvette L98 🤣! I just purchased it and im thinking maybe a mini ram intake and cam for now. Maybe boost later 😎

[@4BillC]

I've just recently got a Boosted vehicle. Fell in love instantly and just wanted to say that you are correct. Boost makes everything better!

[@edwardcold7431]

I like how you got back around to how these are slightly underrated from factory whilst giving lots of info lol cool

[@Michael_Lorenson]

The power is awesome, especially for an engine essentially unchanged since 1955, but I hate turbo under-hood heat and plumbing challenges. But damn that's a lot of power from a low budget setup. Lot of power. Lots and lots 'o power... And in future news: "C4 Corvette Owner Rendered Completely Insane By Attempted Turbo Installation."

[@fryloc359]

Yeah trying to turbo the TPi in my corvette is not going to be easy.

[@Stabilityx2]

Look up beckers garage 😉

[@BadassBarney452]

Thank you for what you do. Can't wait for each days video drop. Patiently awaiting some 351 windsor love !

[@davejackson3680]

You should try out the First Performance TPI Intake and do a dyno run with one of those

[@RJGPG]

TPI cars did awesome donuts

[@jamescameron7633]

Thanks for all your hard work testing bro great work

[@harveybrown5654]

loved the content chief, keep up the great input and the classic we all wonder about, the tpi was a camaro jewel but gen 2 sbc 350s bring on the crank, cam, aluminum heads and every boost system available chief

[@idriwzrd]

Love the TPI motors. Best truck motor GM ever put in a Camaro. Takes me back to the days as an inexperienced (dumb) kid, tried to make my own siamesed runners for more top-end power. Luckily I had another set of stockers to put on.

[@niagrasprings]

I have a dyno test that says those siamesed TPI runners do produce more power ........

[@idriwzrd]

@@niagrasprings I believe it. But making your own doesn't always go well. Especially when you're inexperienced with welding aluminum.

[@niagrasprings]

@@idriwzrd My male parent never taught me anything about working on cars, because he did not know anything. I had to pick it up myself, any way that I could. One of my first major successes, at age 16, was switching the two barrel manifold and carburetor on my 1969 Nova to a quadrajet set up. It was a major undertaking for a 16 year old with no substantial support, and something that my male parent was counting on me NOT to be able to do, because he wanted my car to be slow. Then there is all of the stuff that I messed up --like the horrible paint job that I put on the same car, because I just did not know much about paint, which I still can NOT do, and avoid because its so toxic. I became a machinist, a mechanic, and a welder, mostly so I could know how to work on cars ......now there is a huge electronic aspect to it too. How far along in welding aluminum were you when the attempt was made on the TPI runner tubes?

[@xmo552]

@@niagrasprings Father, the word is father aka daddy.

[@randywilliams4325]

I own a 87 4+3 Vette . I runs good but I have a 5.3 ls motor going in there . But thanks for posting up what the old tpi motor is doing .

[@RoyBrown1794]

Your the best Richard I’ve been asking about Holset turbos for some time now because I have so many laying around and don’t know what to do or how to size them BUT!!!!

[@K1LL3R_M1LL3R]

I have a big one!!! Came off a 12.1 liter diesel, military equipment

[@TheDude2111]

You just need to learn how to read a compressor map. Reading a turbine map helps too. Any displacement engine at a given volumetric efficiency at a specific rpm will use a specific amount of air per psi. Now weather you measure total air in cfm (like Garrett) or in kg/min (like Mitsubishi) changes your calculations. A good baisic rule of thumb for me is turbo on engine a spools x psi at x rpm. Engine B displacement multiply by given rpm. Take total and divide by engine B displacement equals engine B spool rpm roughly (different engine shave diffent VE). As long as you don't choke the engine with the compressor or turbine this works pretty well.

[@philipwade5559]

Boost makes everything better. I love it! Really needs to be on a shirt!

[@uncletevan]

Is it possible that you meant 'Shirt' ???....

[@philipwade5559]

@@uncletevan oops!!!🤣 thanks for catching that!

[@kwik440]

ANOTHER GREAT video ! Thank you Richard !!I was always curious about the tuned port intake, I worked at G.M. dealership most of my life,and never got to dyno a tuned port motor

[@jesseison-bowman3964]

Cool! Makes me feel even better about my build plan for my Frankenstein themed K5. It's an 84 GMC Jimmy with dana 60 feint corp 14 bolt rear axles from military CUCV square body, a zz4 sbc long block, built late model 700R4, rebuilt NP205 transfer case, and refurbished TPI system which bolts right up to the aluminum heads on the zz4. I think the long intake runners on the TPI and small intake volume of the zz4 heads will make a great truck engine. Perhaps I will go ahead and get twin turbos for it since I dont have headers or exhaust yet!

[@king0cans]

Tuned port swaps were the shit in the 90's

[@jaydubb71]

Chevy swaps have always been the shit. From carbed SBC's to TPI's to Gen 2 LT1's to LS... Cheapest, easiest and most reliable way to go fast. I'm just waiting on Gen V prices to drop...

[@niagrasprings]

@@jaydubb71 my FIL 's Ford Deuce coupe had a 1955 Chevy V8 in it......so as soon as there was a Chevy V8, one was put in that Ford car.

[@brianjacobsen5762]

So we're funky paint jobs.

[@robsorgdrager8477]

So was mountains of cocaine

[@ztwntyn8]

Just the fact that you said “he shit” tells me you are 90s

[@TheSlim93gt]

Do a mid 90's LT1 build next. Stock, then HCI, and off course boost it to cap it off.

[@redtesta]

i think this is the sleeper motor. Minor tweaks to the 90's LT1 , drop it into an early c4 (L98) But then an LS2/3 would be a nice drop in but you can grab a full trans , motor and loom for so cheap for an LT1.

[@aaronnoyb]

TPI = Torque Producing Intake. Great setup in 4X4's like Landcruisers etc, in the days before LS's.

[@lucasmullins5100]

For stock heads on a Tune Port that's decent numbers. It would be a riot to drive be in a truck.

[@bartpang]

They make great truck motors with all of that torque.

[@cmcbunch]

I've said for years the TBI should have been the hp application and the trucks should have had the TPI. I've done plenty of street cars and trucks with TPI with a mild cam, portmatch, and tight headers for good fuel economy and torque. great for towing. did one 383 that had almost 600 ft lbs.

[@crw3673]

I would love to see more information on tpi versus tbi? Because these tune port injection engines, made great torque down low. Surprise you didn't see these intakes in more truck applications.

[@thebigpicture2032]

People didn’t care so much about modding their trucks back then plus they were needed for work. Whatever came from the factory was generally good enough. Very few “fools” were building their new truck in those days.

[@MrOgre1110]

Boost makes everything better! Also have a question, was there really something before KZbin!? Lol great content including everything not just ls'.

[@fryloc359]

Just magazines, and maybe a cable tv show.

[@stanmack1]

@@fryloc359 and books.

[@THatChevyguy91]

Hot rod magazine and motortrand had alot of things going on before youtube

[@jacobnicoletti1235]

Ive always loved these TPI intakes and ive dreamt of putting one on a 350 for awhile now. I finally own a 96 K1500 that came with a new-ish goodwrench 350 and my plan is to manual swap the truck with a brand new SM465, and swap in a mild cam, some new lifters, springs and rockers, a TPI intake with Vortec base and then give it a nice tune. Should be a really nice truck to drive in my opinion. Super torquey for off road and mild street driving.

[@patlandymore7035]

Really enjoyed this video despite me mainly being a BBC and LS guy. On the note of someone else’s suggestion...please consider offering a small batch of Decals and T-Shirts for sale. I‘d love to own both and don’t think I’m the only person. Cheers 🍻

[@ijmodified]

Same, WE NEED HOLDNER MERCHANDISE

[@ijmodified]

Same, we need holdener merch

[@stevenwinnen9155]

I loved this video! I have a ‘91 camaro with a TPI L98 and I want to drag race with it and so this is amazing to see. Even with just tuning it made over 300hp so thank lord I have hope lol love the vids keep it up!

[@docsmallblock6584]

I just like the gen 1 sbc! More people have had more tire smoking fun with a gen 1 sbc than all other motors(engines) combined!!! I still run N 010 block to this very day!

[@nedaCFilms]

Oh yes, RPO code B2K lol. I just uploaded a video of a B2K TPI on the drag strip from 1988. It ran mid 13s spinning. The B2K Vettes could get in the 12s.

[@JohnJohn-kv4xy]

I wish I could post pics, I just put a turbo 89 l98 tune port in a 1976 Toyota land crusier. Didn't know if it was even possible but made it work

[@redtesta]

wow, came across this and so memories hit me. I was the grey mustang gt at "mustang Dynamics" back in the day ( name is john shop was in anaheim off of la palma ave and lakeview) when we were the early tweakers of the 80''s mustangs. Sure, there was bbk, steeda and kaufman but actually putting supercharges and building motors we were doing that at MD (remember Saleen was down the street) You had that black hatchback and was one of the first , back then, truly racing the mustang. Rich "speed" holdener if i remember correctly. Good seeing you still in the game.

[@richardholdener1727]

THAT IS FROM BACK IN THE DAY

[@redtesta]

@@richardholdener1727 yes it is. Remember it well!!

[@xmo552]

@@redtesta Are you still doing ford 302 5.0 stuff?

[@redtesta]

@@xmo552 i haven't after working at mustang dynamics, back in the day and a few years later i got into corvettes after getting completely destroyed all around by one at the track LOL. I actually wanted to get (hold onto your hats) a 95/96 Mustang SVO and fully update it. That car had all the suspension and brakes the GT didn't and the GT had the motor the SVO didn't LOL. I was disappointed with the 4th gen mustangs (had a 1995 convert almost sold that thing within months with is detuned and monstrous 215hp barely 5hp more than my amazing 1985 GT 10 years prior). Last stang i had was a 1999 with the 265hp, just did some gears , pulley and exhaust (the status quo back in the day before all the options now) . I did have it along side my vettes at the time but sold it. I will always have a place in my heart for Ford especially during the 80's :) Rich, did you run the silver state back then? I m trying to remember one day you were in with the black hatch and prepping it and i could have sworn it was for silver state?)

[@xmo552]

@@redtesta Those years are nice. I have a mark 8 and I'm building a 56 f100 with another Mark 8 donor.

[@darwinfridgeseals741]

Thanks Richard, stay healthy and safe.

[@richardgilmore856]

With the 1.6 rockers and the cam it comes to 629 total lift for a every day driver within lsa of 109..in a 1994 Chevy Silverado yes it got a lift kit ..

[@larrytemen4789]

Of course it works. There was a guy that lives by me that was one of the first to do it and be on a magazine cover running 10’s I think? In a 3rd gen f-body. I can’t remember his name.

[@TurboTPI]

Larry Temen where are you from? Lol. My turbo TPI car was in GM High Tech magazine. And runs mid 10’s

[@jodypierson3137]

Cool to see this, currently waiting on a new distributor for a guys 89 Pontiac GTA, lost spark and car died at 100 mph,he said scared the hell out of him with no power steering at that speed, old distributor looked like it was from the bottom of a salt lake , guts come apart in it.

[@cuzz63]

I swapped in a late 80's TPI 5.7 into my Camaro. I dont know what the numbers were but it pulled great at the low end, would spin the tires on the first 2 gear shifts on a built 700r4.

[@Ugrasrava]

"Will a turbo work on this motor" is like asking "will a Mikes go down well right now." Yes. Of course it will. Just don't overdo it or you might find things you wanted inside make their way outside.

[@camaromustangmods3327]

Congratulations Richard. I subscribed when you had around 10000 subs. Watched this video and just noticed you have over 40000 subs and growing. The variety on your channel is amazing and right to the point with no fluff. Thank you for what you do.

[@narmale]

where is the set of SLP or Edelbrock runners?! :3 i love the old TPI manifolds... man seeing 600+ lb/ft of torque tho ... noice!

[@jackpinnell3204]

Now you've done it Richard.............lol. You've given me an answer to a problem I've been working on for......well....a LONG time. My 1989 K1500 (stock) is anemic to say the least and on top of that, it pulls some heavy loads every day since it's my work truck pushing 300k on the clock. Had thought of swapping a 5.3LS into it, but wasn't looking forward to the time it would take with ECM and wiring AND I wasn't looking for a lot of HP, just more torque. And guess what!?!?! This video is the answer!!! 400 foot pounds of torgue N/A is exactly what I need! I didn't have any idea the TPI motors were so strong on the torque side. You duh MAN!!!

[@richardholdener1727]

lots of guys running these in trucks

[@jorgealvarado3512]

I have learned so much watching your videos. Thank you keep them coming bro.

[@johnparrish9215]

Damn good Truck engine.

[@jeffreymceloryjr4155]

I would LOVE to see an update with a more modern style intake manifold. Maybe a modified LT1 or Mini Ram or RamJet, etc. I’d love a big bang too. Haha

[@yourcarsucks3259]

Awesome! Had TPI in my 86 IROC. Was such a cool setup back in the day.

[@7passu]

383 w tpi, siamese runners, ported lower intake, 500+ lift on cam shaft finished off with a centrifugal supercharger tuned with a Holley/fast setup. Maybe even on AEM

[@terrypetty9822]

I'd LOVE to see the same TPI testing with NO2 instead of turbo, I think that will break your mold and show a different curve.

[@timothybayliss6680]

With the right size turbo, I can only imagine how little lag there would be. When your only trying to make 400 horsepower from 5.7l you could probably spool the turbo at idle. If it's a 67mm turbo, it's huge for this at this boost level. Hx52 turbos are relatively common and have the benifit of a T4 flange. Still, depending on who you believe it can flow more than 80lb/m and at this power level you need about 44lb/m.

[@thetriode]

You're still too big. You need like an HX40 or a small turbine TP38 or a 60-1. On a 4.6L or 5.0 Ford they're good for about 425 to the tire and that would be on a stone stock 350.

[@varmastiko2908]

One thing you can do here is to use a huge turbo like this but run a full stock engine with regular fuel. When your turbo is way oversize and consequently you'll be running very low boost pressure for the airflow, it's much less stress on the engine due to reduced heat load and you'll also be easier on your entire power train due to peak torque coming in at higher rpm and in a smoother manner.

[@TurboJohn74]

This is my Cars & Coffee in the morning!

[@K1LL3R_M1LL3R]

Mine too

[@richardholdener1727]

there is more coming this afternoon-brunch!!

[@williamhorvat8224]

@@richardholdener1727 , Love your engine videos, they are top notch, especially the intake manifold comparisons. NASA quality testing. 👍 😎 Were you writing articles and racing Mustangs back in the mid 90 to late 90's ? Your name looks familiar from Super Ford, Hot Rod and Muscle Mustangs & Fast Fords magazines. I made a mistake and sold my 1990 5.0 Mustang back in 1998. 😭😢😲

[@joshtheking1772]

Centrifugal Superchargers are phenomenal with Tuned Port Injection. Unbelievably fun to drive. I do have to say one thing though about what you said about "Artificially" moving the torque and hp curves. When you use TPI you ARE tuning it according to sensors, data sets, A/F ratio, RPM dependent values. So in essence, you are not using "Artificial" anything. Its just a different means of tuning.

[@richardholdener1727]

the rising boost curves artificially forces the peak power past the effective rpm of the cam or reflected wave of the intake runner length (the rpm where the combo would make peak power in na form or turbo form with a constant boost curve)

[@TurboJohnRacing]

Wow, no wonder I could kill my buddies trans am back in the day. He was tuned port, I had carb and dual plane intake. Motors about the same. He would normally get me a car length out the gate, but I would run back by him at half track on! Didn’t know they were that dead above 5000rpm. Thanks

[@richardholdener1727]

I have a TPI vs Dual Plane test coming up

[@rattdog777]

MOST AWESOME VIDEO !! KEEP THE SBC ALIVE !! THANKS RICHARD !!!

[@richardholdener1727]

We will!

[@bennyfactr6122]

Ran a 383 with the old lt4 hotcam kit and tpi in my 88 formula 350 for 15+ years. With a b&m holeshot 2400, it was a torquey driver. That intake designed made 1st gear in the 4l60 useless under wot.

[@andysteele4056]

2 tuned port vids in a week? You just got a new subscriber!

[@Misterfairweather]

I can only think of one cooler looking intake used by GM and that is on the LT-5 in the ZR-1. I just never should have worked on an LS motor because everything is easier with them. Really cool to see this stuff thanks for doing the video!

[@richardholdener1727]

we have one of those too

[@K1LL3R_M1LL3R]

Wow. That is a very small camshaft. You didn't really go over the head flow, or the intake flow?! You're right, the tuned port intake looks so cool. My friends always thought that intake would flow so well, but I always explained that they are just for low and mid range torque. They are all finished by 5k.

[@rongravel4585]

That’s awesome. I’m impressed. That thing was a torque monster. Had to be fun to drive in whatever it went into. Hopefully it made it to a chassis. I always liked those engines back in the day.

[@kickermatice8249]

I got a cam from comp its a 232/234@50 594/600 lift on a 115° lobe sep on a 0° off set for my turbo tpi peek tq was 512 at 3100rpms and carried it to 4700rpms before it droped. This was with factory l98 heads decked 10 thou on pump gas on 8lbs of boost. Bottom end was built ran it on the dyno at Tom bailey's pre-party in 2018.

[@richardholdener1727]

that is a lot of cam for a tpi motor

[@viciousrap700]

So here's something on my mind, Richard. I'm not sure exactly what the difference in runner length is between for example an LS6 Intake and a TPI intake but clearly LS motors have the ability to rev even with long runners. Clearly we have efficiency differences here but if we optimize OUR TPI manifold with porting and plenum porting or even a first manifold and good heads can we cam this thing to rev out? I really would like to see what it would do with the turbo and some RPM around 6500. Now I know there are much better manifold options than to just optimize the stock intake, the HSR from Holley for example of the Miniram from TPIS but I'd kinda just like to see how far we can actually get the stock TPI manifold to rev, maybe even with a better set of runners on it. These TPI engines we just don't see much of so it would be cool to see just what we could get one to do and let's get rid of that wimpy freaking cam man, geez, let's get into atleast a Comp 503 with some 1.6 rockers or something. Wanna see more from this engine and c'mon Richard get us a freaking LTX!!!! I've been begging for months for an LTX build!

[@clintonmaurer5758]

I still have two TPI set up's, they are probably going on Marketplace. Hard to beat the LS engines... Awesome Video though!!

[@xmo552]

Where are you

[@juancamaney3562]

Love that engine

[@randallslocum5252]

Love to Watch your videos but still waiting on the dodge 4.7 L Big bang to find out what works, what helps and what doesn’t.

[@wirebrush]

To this day, a Calloway twin turbo C5 is the sexiest sounding street car I've ever heard.

[@josephcottone9613]

I wonder if a progressive boost curve could flatten the torque curve. I’d imagine you would need a good wastegate and obviously an electronic programmable controller. .....andddddd you just mentioned it in the video, as I’m watching lmao! Great video!! 👍🏻

[@Averagegunenthusiast]

Based on the power curve I think it did have the factory cam. I like the look of TPI too and I think it would have made a great system for a truck where you want low end power.

[@benji7001]

Right on Man. I have a 86 Iroc z and love the TPI

[@normalbikeguy2658]

I’ve always loved tuned port. Back in the 90’s I lost my license for having too many speeding tickets so I hand polished the TPI on my 3rd gen. All the mullets. A younger me always thought it would be cool to add throttle plates to the runners that could open at 3800rpm when those motors start falling on their face. Kinda like an on demand itb setup....aka quadrajetpi

[@xmo552]

Thats what newer cars do

[@gmcnelly2468]

best truck motor gm ever produced. whole bunch of fun on the street!!

[@robc7812]

that was only ever in corvettes and camaros... trucks had tbi

[@lilibethdoherty295]

I just figured my C4 made only 240 HP so the 700 R4 would last till the warranty was expired !

[@michaelangelo8001]

I have a pile of these intakes... I liked the "Cross Fire" fuel injection also. Like you said, they are probably the best looking factory intake system ever made. However, the reason they fall off in HP at the top, is more related to intake runner size, than the length. Inside the manifold, the runners are pretty tiny. And if you look at your graph, you can see the boosted curve is not identical to the NA. It falls off faster at high rpm, because it can't handle that much air. I believe they are probably the perfect truck manifold though... Also, regarding the possibility of building a turbo C4 Corvette... Have you ever looked under the hood of one? There is just no extra room at all. I think a Procharger is a much more practical option, and even *that* is a very tight fit...

[@cbr1thou]

Take a long non ferrous ball grinder thingy and open up the plenum lower until a 3/4" socket goes through each runner.

[@seaniemcp2887]

Thank you for making this 👍🏻. Shame there was no video of this thing running. Must say the TPI has the weirdest power curve of any engine. No top end.

[@niagrasprings]

the TPI has tons of top end ......compared to a flat head.

[@jarmominkkinen9409]

I have First big Alu runners 75mm trotel body Roller cam Dart Heads 190 volym Twin Turbos K27 Vems EFI Custom build Turbo Hedders 50mm wastgstes Build this abaut 95-96 Still standing in The garage In May Corvette uppradade Rear and 12 bult Toms axels strång...Hope i have 500 Whp...Street Car...RPM 6500 That no problem...

[@brockhouse3857]

Thank you so much for the l98 build!!!

[@bluecollarhotrods9781]

I have a soft spot for these engines and the cars they came in. I had a few TPI F Body cars over the years, mostly in the mid to late 90s. They were cheap back then.

[@kevinjohnson9372]

Those motors were very torquey mh friend had an 87 gta and for being stock it was an animal off the line

[@Z06RFan]

I know this was done 3 yrs ago. I have always like the TPI's as well. Do you think you could get more RPM with some of the Modern Aluminum heads and cam selection? It is great that you experiment with these combinations.

[@richardholdener1727]

tpi still determines effective rpm

[@jamest.5001]

I know my ws-6 formula firebird, even with the 5.0 tpi was decent for a 305, I swapped everything to a 355, with aluminum heads, it ran good then, with T-5 and 3.45 gears, I'd like to swap a 4.8/5.3 in it now, with boost, maybe 600 tire,

[@ja5435]

I’d love to see you try making power with a Oldsmobile 307ci 5.0 V8 that was used in a ton of cars back in the 70’s and 80’s in Buick Regal’s Oldsmobile cars.

[@austinhicks9989]

I second the motion I'd love to see an early 5a head 307 with the vin9 HO cam .440 196/210@50 109lsa or something bigger like the comp OL-xe250H-10 run on the dyno you've shown the ford and chevy 5L some love dont leave us Olds guys out in the cold

[@xmo552]

I did a 403 swap and never looked back.

[@89-IROC-Z28]

Haven't seen the video yet, looking forward to the results. Been wondering about boost on TPI. Edit: finished video, impressive numbers for a stock L98 with a cam. Anyone have experience with the "FIRST TPI" intake? Was thinking about building a 383 with that intake considering it's probably the largest TPI style intake available. Although if I just port a few things and add boost, maybe that's a better route. Great video as always!

[@cadillacwrench]

I have a 383 full forged TPI with a comp cam .444. Lift and like 228 duration. With a set of GM fast burn heads. With A Vortech V-1 supercharger I built in 96' when i was in The Isuzu/GM Program in College to Replace the Blown TPI motor in My El Camino. Which i put the TPI in 1994.

[@cbr1thou]

Its old news really

[@timothyevansjr7100]

Love to see Similar camshafts one a nitrous cam shaft and one a turbo cam and one na cam on the motor of your choosing with same set up on boost also same about of boost back to back

[@JohnDiMartino]

They should have put the tuned port injection engines in pickups , I had 2 of them , both 350s in F. Bodies, an 89 Formula 350 and an 89 Iroc 5.7 , they are absolute torque monsters...I did an Accel SuperRam on the Camaro with a nice roller cam and TFS heads,SLP headers and exhaust and it Really woke up! A built 700rR and swapped to 3.42 gears ,it would break the tires loose from a 60 roll punching it .

[@jade9396ify]

I have a question? I have to start off by saying I'm nowhere near a mechanic I learn things from KZbin as I go. I know this is an old video l enjoyed watching it just now! My question is I noticed the turbo was far away from the engine. Even though I'm not a mechanic I just notice unique stuff. I see a lot of tests on KZbin like this when the turbo seems far away from the engine. It seems like it will get more power or a different reading if the turbos were closer to the engine as if they were in a car distance wise/placement. I saw some of your other videos I noticed you like to see if something will work or not. I'm assuming you might already know the answer to my question I'm just wondering myself.

[@richardholdener1727]

the only thing that turbo placement with possibly change is response rate (power will be the same)

[@MotocrossPS]

Richard, anyway you could give me a call, I believe I own the first l98 car HP performance built, it was a blue 85 vette. The pictures of the turbo setup in this video by HP performance is the exact, and I mean exact setup in mine. Even have the HP performance badge on it still. It’s as built around 2005. Holset turbo tial waste gate, 42 pound injectors. Custom headers and borla exhaust. Turbo is located where the battery originally was

[@MotocrossPS]

Just talked to Jimmy, he confirmed this was the first prototype car they built

[@richardholdener1727]

VERY COOL-DID YOU HAVE A QUESTION-JIMMY IS GOOD PEOPLE

[@MotocrossPS]

@@richardholdener1727 having problems with the fuel system, injectors, and pump need replaced if you want I could send you pictures of how it sets currently, so awesome to see the history of this car

[@tommywicker1432]

The tune port is a good looking gm piece.

[@Turbo_Todd]

Trucks would love that curve for hauling

[@tomcampbell4414]

That’s a sexy looking engine!

[@richardholdener1727]

agree

[@xmo552]

@@richardholdener1727 Start with low timing Adjust the air fuel. Same for everything, correct ?

[@petersingh4825]

Would love to see how it would respond to a Ported upper and lower base and runners Also that Holley mini ram!! With boost of course

[@richardholdener1727]

I have TPI intake shoot out coming

[@gregblau8082]

Richard Holdener have you ever seen an accel intake that looks like the factory one? I bought an l98 for the long block and haven’t had much luck researching it. One guy said maybe it’s from a lingenfelter

[@michaelangelo8001]

@@gregblau8082 The Accel looks a lot like a crossram.

[@TK-eg7eg]

@@richardholdener1727 Do you have a miniram to test? I've had one since '95!!

[@zachkuby87]

@@richardholdener1727 please do the FIRST tpi set up too.

[@tjkilshot]

I'm ready to boost my L98 Corvette but I have no idea who or where to go to for tuning! NC/SC and DMV area please!

[@georgeeconomos6042]

With the ls craziness I like watching older stuff.. working on a 4gen Lt1 .. like to see what u can do with that motor.

[@darinr9424]

Good gawd. Low boost and that much tq and good hp. Could ya imagine a camaro with 3.27 or 3.42 gears and a open highway? Fuuun