I have been collecting parts for awhile now. I'm thinking these heads will complement my top end build, but would appreciate some input from the experts on here.
​​​​​​https://www.performance-world.com/Cy...p/64180a-2.htm
My current parts list includes:
1. Extrude honed intake base
2. Edelbrock large tube runners
3. Ported stock plenum
4. 52mm Holley throttle body
5. Summit 8802 (hot cam clone cam)
My car is a low mileage L98, will keep it at the same displacement. This car will only see street duty. Additionally I have an s10 convertor, and corvette servo's in the otherwise stock transmission, and the rear is 3:23.
Thanks for the input, it's appreciated.

 

I missed the link to the aftermarket heads, should be decent for a nice cruiser, but I'd definitely do a different cam.

 

I have a hot cam w 1.6 RRs and fast burn heads. The heads you are posting about are not far off from fast burn heads spec wise. It's a good combo but wants to rev. Idk if that's gonna complement a tpi setup. I have a pro Flo xt intake and it really likes to rev w that cam. It really makes power up to 6200. IDK a lot about modded TPIs, will a honed one make power up that high? I'm sure there are people who know more about modded TPIs. The pro Flo systems work really well, with what you're planning on building I'd consider a more modern efi. I think you're gonna need a larger fuel pump(?)/injectors quickly also depending on what you do. I'm by no means an engine guru like a bunch of people here. That said. W my hot cam/fast burn heads and 9.6 compression I was starting to push my 29lb injectors. By the time your done buying all the parts to upgrade a tpi you could have a complete efi standalone system.

just a thought.

 

Yeah about 180cc heads would be good for hopped up TPI. I think you'd benefit from a custom cam grind, that cam seems wacky for TPI and probably a little heavy on the duration.

 

From 1985 to 2025 people have been trying to turn a sow's ear into a silk purse.

The Tuned Port Injection induction system IS NOT a high performance induction system. No. You can't turn it into a high performance induction system either.

I need to define what is a Tuned Port Injection induction system. When you pop the hood on a C4 Vette or 3rd gen it looks just like the TPI that came in there and it has individual Long Tube Runners.

What is my definition of a high performance induction system? One that will allow the engine to make at least as much horsepower as it does torque and to preferably allow the engine to do this at a RPM that is equal to or above the 5252 RPM torque and horsepower crossover point where horsepower at torque are equal.

A naturally aspirated Tuned Port Injection induction system, as I have defined it, can NEVER do this. I don't care if you had a billion dollar budget and the top people in Formula 1, NASCAR, and Pro Stock working of the project. It CAN'T be done. No one can cheat the laws of physics.

The only way to turn a TPI system, as I have defined it, into a high performance induction system is to turn it into something that is no longer a Tuned Port Injection induction system.

Can you make a lot of horsepower and torque with a TPI induction system? Yes. Are you going to make more HP than TQ? No. Are you going to do it above 4900 to 5100 RPM? No.

But so and so built and dyno tested a TPI engine and it made peak horsepower at 6100 RPM. No it didn't. Not in any real World would anyone rev an engine 1000 RPM to 1200 RPM more to gain 10 to 12 HP at that harmonic peak at 6100 RPM. The engine more or less flatlined for over 1000 RPM gaining and losing low single digit HP numbers along the way to hit that second harmonic peak at 6100 RPM. The engine peaked at 4900 RPM to 5000 RPM.

You can't turn Lead into Gold.

Well it turns out you can but it takes a particle accelerator to do it and to make 1 oz of Gold would cost more than all the money in the World to do so.

 

Particle acceleration:
https://www.thirdgen.org/forums/tpi/...be-runner.html

Not really even particle acceleration:
https://www.thirdgen.org/forums/engi...st-intake.html

Totally possible to make a 12 second TPI street car, that's about as fast as a stock modern v8 whatever.

 

What cam would you recomend?

 

I understand that. I'm not trying to make big power, just turn the "fun dial" up a notch or two. Like I said, it will always be a street car for me.

 

Sorry about my rant. I was kind of responding to @Firechicken82 and mostly just ranting because I've wanted to rant about this for sometime now.

The good news is that GM left a lot of meat on the table with TPI 3rd gens to turn up the "Fun Dial" several notches while still being a docile street car you could loan to granny for prayer meetings or to drive 3 states away to visit family.

The air induction system on our Firebirds suck and the exhaust system sucks even more. There are plenty of low hanging HP & TQ fruits on that tree without even turning a bolt, nut, or screw on the engine except for whatever is necessary to change the air induction and exhaust system. The falls flat on its face at about 4500 RPM feeling you get with an L98 Firebird will be raised a couple hundred RPM too.

The 90/92 TPI roller cam doesn't suck. It's not great, but it doesn't suck. It for sure could have used some more lift though even on a 100% bone stock car and damn sure could use more lift on a stock TPI Firebird with an uncorked air induction and exhaust system.

I'm tired of typing for now and don't want to risk something happening and my reply getting ate by the forum. So I will edit this reply later to add more information.

Just a tidbit for later on the #1 part you have in your list is the most important part to upgrade on a TPI induction system after the air induction and exhaust system have been took care of.

 

So, I think the moral of that story is, no the cam isn't gonna be good for a TPI!?!

 

Other than finding an extremely expensive used SLP intake box, what are people doing to improve the 90-92 firebird induction. I have a K&N filter in the stock induction, but i feel like that doesn't really do anything. I have Dyno Don Headers and dual cat ypipe waiting to be installed as well as Magnaflow cat back. Again, not looking for the highest numbers just a strong street car.

 

you could just build something like this. It was super easy.

 

Hawks Motorsports has made a reproduction of the 1991/1992 Formula Firehawk dual cold air induction system.

Surely they would sell components of that kit. All you would need is the passenger side air box assembly, EVAP canister relocation kit, and the parts of the installation kit necessary to do a single inlet cold air induction system.

Hawks Motorsports - Reproduction "SLP Style" Dual Cold Air Induction System - Third Generation F-Body Message Boards

 

I more or less got what you got:

Lingenfelter intake
58 mm tb (came with the car when I bought it, otherwise i'd pick 52 or keep the stock tb)
Dyno don headers
185cc 2.02/1.6 heads, 1.6 rr's
Fitech TPI
Stock converter and 3:23

except I chose the 8801 cam. My induction system supports more than I will ever need. My plan was build it for strong midrange (2.5 - 4 k rpm)

 

How do you like that cam? Any dyno results? I was told the 8802 might be too big for what I'm looking to do.

 

Correction! I run the 8800 cam and can't tell any difference from the stock 90-92 tpi cam (CPC 773). Im sure the dyno would show something but since I installed it together with new heads I can't tell what does what So why did I go with that cam? Well, the original plan was to optimize the shortblock, to let the stock bottom end (including the stock cam) breath as much as possible but while I was in there doing the heads I thought "might as well...". The 8800 is like 5% bigger than the original 773.

And, in reality I rarely have the car above 4500 rpm. It's the occasional on-ramp or straight country road that sees WOT, everything else is more or less city driving.

I like the character of the car. Very torquey.
I will dyno it next year.