80's era L98 tpi

[absintheisfun]

I honestly think that this TPI set up is the most attractive fuel injection system out there.

Does anyone know how much horsepower this setup can handle? I know that the aftermarket makes 58mm throttle bodies for them, but does that make a big difference?

I'm toying with the idea of putting one of these on a 350. My goal is between 400-500 hp. Can these handle that kind of power? stock, they barely had 200, so I don't know if the system can support over double that power.

Pre 87 or post 87 makes no difference. As crazy as it may sound, I'll build the motor around the TPI (like I said...I think it is a beautiful intake)

So, can they handle the power? Anyone know? Anyone tried?

Thanks!

[TPI Monte SS]

You can make a 400hp 350 pretty easily, but it'll need good heads and a fairly stout cam that makes peak HP well north of 5K rpms. The problem is that TPIs really don't breathe beyond 5K rpms, so 400hp will be tough to get. There is some aftermarket support; Edelbrock makes a baseplate and large-tube runners that can be ported, you can get the aftermarket 52 or 58mm TB, but the problem is the runners are soooooo long that they rob upper RPM horsepower. If you said you wanted 500 ft/lbs of torque, that's much easier to accomplish with a TPI motor.

That being said, look into the FIRST intake - www.firstinjection.com - it looks like a stock TPI, but it's huge, and can support the high-HP numbers you're looking for.

[MonzaRacer]

Use the LT4 HOT roller cam kit, orderup some AFR185s and you can make very near or over 500hp.
I use them with AFR 185 or 195s and generally get in the 475 to 500 range.

[Samckitt]

I agree that that intake system looks pretty cool, but maybe the super ram intake made by Accell/Lingenfelter will help you with some HP.

Super Ram:




Also there is a guy on www.montecarloss.com that has an SLP T-Ram intake used on the Firehawk for sale. Too much money if you ask me though, he wants $2000 for it.

Tunnel-Ram intake:

[SatisTraction]

the short answer is no. the TPI can not support 400-500 ho. check out
http://www.thirdgen.org/techboard/tpi/
for more info.

i just swapped a 92 model transam engine and tpi into my 85 chevy truck. they make great truck engines

[absintheisfun]

Okay, the truth comes out...

Plan 1:
ZZ383 with a holley stealth ram
http://holley.com/91504201.asp

I figure with the correct gearing, 425HP is going to be plenty for what I want--a street friendly weekend car that isn't going to shy away from anything attempting a challenge on the street...


OR
Plan 2:
Rebuild my current 350...in very good shape, and before the rebuild started, it probably put out about 375-400HP (the last time I drove it, I was 18---12 years ago, so my memory could be off!
Rebuild it with low compression, an 80's era TPI, and a cheap turbo kit like this:
http://cgi.ebay.com/ebaymotors/CHEVY...spagenameZWDVW
I am fully awarre that this would be more for the *BLING* effect, but I can't help but think that it would get me more than the desired amount of HP, and cost about the same.

The way I see it, I know absolutely nothing about either fuel injection, or turbos...but up until about a month ago, I didn't know anything about body work---turns out I'm not too bad of a teacher.

I'm giving myself two years to comlete the project (have about 1.5 years left!)...so plenty of time to go back and forth on this one

THANKS to all for the input

[dusterbd13]

we are running a TPI based setup in our track car.
88 L98 block, lunati forged crang, h-beam rods, weisco pistons. actual displacement is 385CI. were using reworked pro-topline heads (full P&P), and a pretty stout hydraulic roller. everything in the motor is coated. the stock TPI was swapped for a TPIS miniram, and a 58 MM throttle body. at 100% duty cycle on the injectors, the car made 430RWHP at 5600RPM. has a lot more in it with bigger injectors and a more agressive tune. thats also through a stock C4 intake tract. theres more to this build than i can remember right now, but the particulars arent what's important. the thing is, with well chosen parts you can make a TPI based motor scream.
Michael

[SatisTraction]

yes you can but he wants a stock TPI intake.

[dusterbd13]

oh. well, then ignore my post.
sorry for the confusion.
Michael

[Texas Hotrod]

Stock TPI systems are pretty maxed out at 300HP.
That's why GM introduced the LT1, for capabilities of 300+ for the Corvette. The Grand Sport and the Firehawk had even more w/the LT4 opt'd engines.

The TPI is a cool looking intake, even though the tubular intake runners look wimpy. I swapped in a set of SLP runners on my 88 C4, and I like how they look. The car runs good for what it is, it has no problems turning 6K RPM.
I've heard that a TPI system makes for excellent turbo induction.

[Zed]

I was originaly going with a tpi setup on my car so I have looked into this. Breathability is the restricting factor on the TPI. These are the largest runners available for the intake.

http://www.azspeed-marine.com/19latuinru.html

Combine those with a larger throttle body and a hogged out plenum and you should be able to have the look of the stock intake and breathability to support whatever engine you build. If you really want torque, put a 400 block under that system.

[absintheisfun]

Stock TPI systems are pretty maxed out at 300HP.
That's why GM introduced the LT1, for capabilities of 300+ for the Corvette. The Grand Sport and the Firehawk had even more w/the LT4 opt'd engines.

The TPI is a cool looking intake, even though the tubular intake runners look wimpy. I swapped in a set of SLP runners on my 88 C4, and I like how they look. The car runs good for what it is, it has no problems turning 6K RPM.
I've heard that a TPI system makes for excellent turbo induction.

Okay, so as inefficient as it may be...would it get me some power if I hooked up a twin turbo?
Maybe a bigger set of runners and 58mm throttle body? I understand the limitations of the system, but would forced induction kind of "overlook" that?...or should I say, bulldoze through the restrictions?

[Texas Hotrod]

I have kicked around the idea of building a turbo system for my C4. I scored a sb400 a while back, so it could be a turbo'd 406 in the future.
I never even considered running the TPI system. I plan on building a fuel injected Victor Jr for part of my induction system. I'd fab up an intake adapter (a big elbow) and mount a Vor Tec throttle unit facing forward (like the TPI's). The Victor Jr. flows more than enough air for a stroker and the big 1 barrel throttle plate will be a lot less restrictive.

Add a turbo to the system and it will be capable of big power. It would have to be low-balled to save the rest of the running gear.
A TPI would be ok, with the correct tuning and matching of parts, but why settle for that when there's something so much better (and easier to service).


This Camaro was TPI'd with a 383 at one time. It ran really good, below 4500 rpm. Though now it is a 406 w/a Victor Jr, I did a Holley conversion. At 10psi, it's good for around 800hp, 1K+ with more boost.
Click on the pic, for more pics and a short vid.