How far can you push the stock engine 540+whp?
 

I've previously run a stock engine at 1 bar on GT2560's to push 519whp.
We switched to a pair of GT2871r's and ported the internal wastegates to stop boost creep. Ended up with 440whp at 7psi. Which we've now bumped to 540whp (DIN) on 12psi.
It's about as high as I'm comfortable at with the stock rods. However saying that the configuration seems to push this HP easily with low IAT's and not a hint of detonation.

Wondered if there was anyone else who's pushed the stock engine this hard?

Specs
Stock untouched engine.
Fuel, E30
Custom dual throttle body, high rise intake manifold.
Straight, 3 into 1 exhaust manifolds.
GT2871r's with ported internal wastegates.

think one other person but cant remember, sometimes get a decent engine but its a far cry from a reliable combo. not to mention engines arnt close to the prices of old school small blocks(or i imagine hondas), at least not here in the states so its a expensive proposition.

the general acceptable limit, which can easily be found with the search button, is 450 to the wheels and i think 500 on the hr

As far as you want but how long it will last is another story

Yea. What engine? De or hr ?? I don't see the de pushing 500 w stock block for that long at all.

It's a DE.
We ran a stock block for a season and a half at 519whp and ended up running a bearing with bad oil control.
We then ran a Cosworth DE for a half season before we lost the external filter adaptor, dumped it's oil, ran a bearing and lost most of the engine internals.
We've run this stock block for well over a season with no issues to date on 440whp. It seems comfortable at 540whp having no issues on the dyno. However given the general reservations seen in this group I'll leave it there until such time as we decide to put the Cosworth back in the race car. At which point we may as well find out just how far we can push the stock engine.

I believe Phunk and George@GTM, pushed their stock blocks just as hard..

Thats insane. Id love to have 450-500.

Too many variables, not enough [Search].
A mass produced engine does not have sufficient QA/QC on every component to ever answer a question like this with any reasonable certainty.

Blocks have blown up with less than 400whp. You're rolling the dice any way you look at it. It's not a matter of if, it's when.

The more power, the shorter the lifespan. There's probably a line graph in some engineering lab somewhere that shows this.

Pics of your custom dual throttle body intake manifold?:pics:

Elevation is going to play a part in this too. I know guys out in Co. usually run higher whp numbers and when brought closer to sea level they Dyno significantly lower.

Like mentioned, you are certainly pushing the limits for a DE, but there have been some lucky members that ran those kind of numbers without hurting the motor.

What kind of racing are you doing with the car? Is the care being raced at the 540whp or 440whp number? Wayyy to many variables IMO.

i read that title and all i pictured was a rod flying out

rods could still be curved right now and car would still make good power.

I can speak up on this post. I think you have a time bomb on your hands. My car made 539whp on 11.8psi before SNAPPING the larger HR connecting rod. I drove it at that power level for several months. Even doing a 1/2 mile drag racing event with at least 6-8 passes. check out my thread "Pop goes the HR." I have pictures. By the way, i think my rod was curved before it finally snapped.

This is exactly why I'm not going the built motor route...don't have time and patience to ruin a built motor.

:worthless:

Would a curved rod affect compression reading for that cyl in a noticeable way?

Overall stroke would remain, but the combustion chamber would now be larger... should show up in compression test if its bent with any significance?

ive been thinking about it a little bit lately. My 370z is down on some power and I cannot figure out exactly where it went. I have no signs of engine damage at all, but I havent done a leakdown/compression on it yet. ive been wondering if i may have a bent rod or a few.

Most shops shops in CO use pretty high correction to "Make up" for the altitude.

I'm not down on power but I have increased bearing wear evident in UOA even with no boost for an entire oil change. A curved rod could cause streaking on the bearings I would think. That's why I was wondering if there's any other way to know if a rod is bent aside from a teardown.