on another forum i saw a post from a guy about his friend's 500hp 87 IROC with a pic included. it was VERY stock looking and i sort of called him out on it. i asked if the pic was taken before the mods but he said that it was a recent pic and that all the work was "done under the heads" and they wanted to keep the stock TPI unit on.

is it just me or is it really possible to get 500hp out of a stock L98 with the stock TPI unit???

here is the pic the guy included:

i just don't see 500hp out of this and thought somebody here might get a kick out of it.

 

Pretty easy really...

All it takes is 150-200 HP of nitrous. Most people's motors would need closer to the 200 mark, or possibly even more than that.

 

A stock TPI wouldnt be enough to handle 500hp would it?

But if the guy isnt running juice, i think chances are slim that he is pushing 500hp...

 

Disregarding gobs of N2O.... No. The amount of air that can flow through TPI, has been shown time and time again to not be able to to make much more than 450, with everything ported. With juice, anything is possible with a strong bottom end.

If it is an unported TPI. There is no way in hell.



Tell him thats like saying you can flow I fire engine hose amount of water out of a straw. No matter how smooth and "tunned" that straw is, it is never gonna flow enough to put out a fire.

 

That's a little ..... optimistic.

Chances are ZERO.

TPI's runners are acoustically tuned to reinforce the cylinder fill event, at 3600 RPM. They have little effect below that, produce this HUGE bump in torque in the 3500-3800 RPM range, and then DE-INFORCE cylinder fill events above that. TPI's torque falls below that of an otherwise identical motor with a non-restrictive carb or other FI setup at about 4300-4400 RPM, and begins to crater seriously at about 4500. Output is negligible above 5000 RPM (REAL RPM, not factory tach RPM).

All of those RPMs are based on THE RUNNER LENGTH. If you don't change the runners somehow, that's the RPMs that these things occur at, PERIOD. It's a consequence of a LAW OF PHYSICS, namely, the speed of sound (pressure waves in air).

So quite simply, in case it wasn't obvious from my first post, the guy is lying. Or, to be a little less blunt, he's running off at the mouth.

Let him show us a time slip down in the 11s, and we'll start taking him seriously. Meanwhile, if he's up in the mid 13s with the rest of the well-modded 350 TPIs, we'll know his engine builder did it right. Anything slower than about a 14 flat, he'll need more than a 200 shot to reach 500 HP.

 

i knew you guys would enjoy this one

i just made a quick reply telling him to have his friend come here because there would be a lot of people interested to see how he throws down 500hp on the stock TPI and stock everything else.... i hope he shows

 

Yea, this guy... my friend... he has an 87 Iroc and it has like 500hp. Its really fast.

 

Using measured data to answer the question, see here:

https://www.thirdgen.org/forums/tpi/...feb-super.html

For a 383 with a hot cam and good heads/exh, you'll see what kind of TPI-type intake is needed, and what kind of rpms are needed to get to 500 fwhp. In a 350, the rpms would have to be 10% higher to make up for the smaller displacement. For a 305, the rpms would have to be 25% higher.

If memory serves, they got to 410+ fwhp with the stock intake. Using any of the other 9 intake types tested, the power was in the 430-505 hp range depending on which one chosen. Even the single-plane type manifold (non TPI) did well (490+ fwhp).

Of course, if the engine used a blower, it would be a lot easier to get to the number. But N/A, no way. HTH.

 

I would never say anything is impossible. As soon as you say "that's impossible" some maniac goes out and does it.

I will say this without qualification.... I could not do it myself. I doubt anyone on this board could, either, and there's some pretty smart and experienced TPI guys running around here.

 

Ok then... Its Impossible!

Now someone go out and do it!

 

"Work was done under the heads" No way in heck. He would need some killer AFR Heads and big A$$ cam to get to even 425ish

 

350 with fully modded TPI is doing realllly good if its making 300whp. thats heads/cam/fully modded big tubed TPI and good tune. 383 might beable to make 300whp with same setup alittle easier with its extra cubes.

stock TPI tho is around 270whp with same above setups. with a big shot of juice then yes, i can see 500 motor hp or close to 400whp. but its gotta be a 200shot more than likely.

but i think he's just BS'ing

 

Hey now I'm at 330rwhp through stock runners.

 

Blah! WTF, not even one god damn sticker

 

My car makes 511hp at the wheels with the AC on and the stock air box and filters, I have a 9in APC exhaust tip, pro whatever heads and the cat cut off, thats all it takes Geez guys, my civic has 500 stickers on it and it's at LEAST 600hp, 1hp per sticker and 100hp for the 1.75in catback. Seriously, take a look at that setup there's no POSSIBLE way he's flowing 500hp through those runners and that intake it's been proven on these boards. The kid probably went from 210hp to around 250 and it blew his mind, seeing as he's young he probably doesn't know what 40 real horsepower feels like so yeah, be kind to this poor guy and tell him that he may want to quit saying that before someone with a stock TPI and a shot of juice walks the dog on him. Tell him to take it to a chassis dyno if he really wants to know what it's putting down.