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?

You are replying to a thread that is 2 years old plus the OP hasn't posted since 03-14-2016.

i dont pay attention to these things but thankyou

Actually, this is a great time to resurrect this thread and ask the guys who have been pushing it for several years how they are doing and any probs they have had.

300+ HP for 3+ years guys- well?

Hey a quick FYI: PSI on 1 turbo will not make the same power at the same PSI level of another turbo. I am currently running 10 PSI and I would guess I am 280-300whp. I have had it up to 13psi for a day and it lived. Tuned on 94 pump

I thanked some old posts so they will check :lol:

I think the current record is 693 HP

I wouldn't put anymore than 300 on the motor. And thats only getting into your turbo every once in a while. . I think I'd feel pretty safe at 275 which is what I'd like to have

I'm running near 300kW on stock motor (2015) and stock transmission. Still using the stock 215/45/17 tyres so they are the first thing to give out. And run varied boost from 14.5 to 18 PSI.

All depends on driving habbits etc etc. I don't boost past 4th gear. Mayyyybe 5th if high RPM and speed. Turbo comes in nice and slow to maintain rods etc.

Turbo/boost/torque coming in slower I get.
Not using power in 4th or higher makes no sense to me at all...

You rev the engine to say 6k with 14psi in 3rd, but won’t do that in 4th... why?

This is a really fun read...

http://mywikimotors.com/subaru-fa20/

Skip to the bottom

"To receive 350+ horsepower, you need the new fuel pump, fuel injectors, pulley and water/methanol injection. Don’t forget about transmission cooler and aftermarket radiator.
Instead of supercharger kit, you can install turbo kit on the basis of Garrett GTX3076R. Such kit is possible to install on stock internals and to receive 400 ++ WHP, and even up to 500 WHP (sport fuel).
FA20 stock internals keep more than 500 WHP, and if you use sports fuel and adjust ECU correctly, than over 600 horsepower."

What!

Do they mention expected life of 400-500-600hp FA20 with stock internals? :)

It said you can keep them not that they would last.


https://cdn.noths-static.com/system/...ker-basket.jpg

I think he was including 4th, and referring more to building boost at low RPM in 5th and 6th, which is indeed a terrible idea.

Let me rephrase. I don’t load the shit out of the engine with high boost in the higher gears. For example cruising in 5th on highway, I won’t just plant it and put large load on the engine.

And sorry I meant beyond 4th, so 5th and 6th.

Im making 320 whp with a jrsc and a flex fuel kit with new injectors and fuel pump. I daily drive it and have never taken it to a track, but it has been boosted for 15k miles and still has had no issues. Getting catless headers and a catless front pipe soon and will be getting dyno tuned at delicious. I have a jrsc HBP, but im not sure if i want to put it on because i would most likely make 400+ whp and really dont have the funds to blow up my engine and have to rebuild it. Yet again, i think TJ Hunt has stock internals and is making 420 whp. Decisions, decisions :help:

TJ Hunt has forged internals on his BRZ. His 420HP is on a heartbreaker so I'd be careful comparing his car. Not saying it is a unicorn, but he has put some funds into it to make sure it doesn't grenade.

What is a heartbreaker in this context? I already know women can shatter a man's heart ha ha HA HA HA :brokenheart:

But how reliable is it for day to day use?

It's not