How much HP can the stock motor handle?
 

Hey sorry if this question already exists in another thread, but I was wondering if anyone knows, with a good amount of certainty, what the the stock motor can handle HP wise before you should start considering internals? I've read the suburu did a better job with this boxer over the previous EJ so I'm curious what is "better"? Thanks for any and all feed back .

415.25 WHP

Its a complicated question. How much does it take and for how long? You can build a 1000 hp monster to last 2 dyno pases. Did it take it? Sure. But how long...


So having said that, FBM are currently at 600 + whp. I'd say that its crazy to think that will last years, but it is holding for now. Don from Accelerated Performance pushed 400+ whp and Daily Drives it. I believe Dynosty is at 500+ whp.

Giving me personal opinion, 300 whp should last years (of course taken with a grain of salt, because years of 10-12 track day events and years of 0-1 track events are very different animals).

It will all be based on use, maintenance, heat management, track duty, etc. I still say, a DD who spiritedly drives, has rare track days, 300 is a good number.

Heat mangment, tune quality and how its driven make huge variables.

Alot of the E85 guys are at 400 without issues and FBM has torture tested their car on over 200+ dyno runs/street runs at anywhere from 300-600

Long term its hard to know, maybe they will have issues in 40k? or 10k? This question will be alot easier to anwser in 2-3 years. But at 300whp on a good tune and cooling I could see it lasting quite some time.

Don's is now built I believe...But he was still pushing over 400+ for quite a while including several 1/4 mile passes.

I'll correct my post, you are absolutely right.

Thanks @sportsguy...I should have been more specific i'm looking at a quasi DD eventually with some mild track use in the future...my power goals are probably going to hold at 325whp max so i just wanted to know stock engine capacity with a decent amount of longevity bc i want to make a more informed decision with regards to my turbo selection and its max efficiency vs. spooling and all that goes with that...

BC if stock was only good for 350 or something along those lines i wouldnt worry about maybe getting a slightly larger turbo than the one im currently looking at

...and i plan on getting all the good supporting mods to help with longevity..ie cooling(oil, radiator if needed) fuel pumps and good fuel

Thanks for all the feedback very helpful...still in my R&D phase ;)

is that give or take 1HP? i appreciate the specificty down to the decimal...WOW

That was done on a RhynoJet dyno. Those are accurate to the decimal point.

i say long term reliability i would stay under 350 for 93 pump. i think the transmission, CV, Clutch will go out before the engine.

How long do any of u guys think a 350-375 whp scion frs would last? No racing just for daily driving and no track (maybe a trackday once a year)

These posts are so freaking pointless. No one knows how long a completely stock engine will last. There have been cars with less than 5k miles and completely stock put big holes in the side of the block.

Longevity will depend entirely on the owner and how he treats the car, how well the components are selected, and what if any defects made it in from the factory.

^ Lol true story!

Background story from me to you. Originally when I bought this car I ended up putting a Greddy turbo kit in and had a really nice 300whp (E85) tune done with FBM. After 600-700miles the engine decided it didn't like one of it's piston rods, broke in a prefect straight line and punched a hole on the top side of the engine. A nice and clean hole that looked like a perfect "H." LOL...

With that said, in my opinion--and I'm sure many of our senior forum members will agree--it's a gamble. You will be safer at lower power but not guaranteed your components will last. But honestly, a safe 7-8psi 91/93 octane tune with any reputable turbo maker should be safe for this engine, especially with kits out there that have a standardized tune (as long as your components don't deviate too much from the tuner's recommendations).

Hope this helps and enjoy :)

Edit:

Also, if you go E85 just be cautious that E85 blends can change in certain geographical areas (winter areas). So you will need to watch you boost levels when running this type of setup. Otherwise E-85 will allow you to get to the levels you'd like on a stock engine.

along the lines of HP i understand from what im reading you can possibly do up to 400-500 but with boost could you push 400-500 with only 7 psi because from ive been seeing and hearing running over 7 psi at 330 is good for longevity. But what about in terms of running 400-500 with the 7 psi?