2.5 N/A horsepower output

[4wheelspin]

Im new to the Subaru scene. I would like to know if people have built 200hp NA?
Thanks.

[MiniVanMan]

From my research, not with bolt-ons. You have to go into the engine, and heads. So, at the minimum, higher compression, and more aggressive cams.

Me personally, I'm looking to do a high compression motor, an E85 conversion, and a big valve job and port and polish. Add in some others like headers and cams. Expensive, but will be WELL over 200 hp.

If the price is right, then possibly a bore and stroke.

[4wheelspin]

I look at it this way. I dont like to install a used powertrain with 100 thousand miles on it. We all know that these engines have piston slap at these milles. I would like to rebuild the motor with a set of cams and a bit more compression.
Any good leads on some performance shop that already build these kind of motors with that kind of HP?
What other mods would be needed? Injectors? Tuner?...

[Desertrunner]

I have been playing with Subaru engine since 1974, currently playing with EG33 Subaru engines. What surprises me is that as regards NA engine there is this assumption that if you do a bunch of changes you are going to get a lot more HP when if fact its a simple maths problem NA engine develop torque at best equilvant to there litre size. So a Subaru EG33 well set up will generate about 330nm of torque if you are really lucky you may get 360nm, a subaru 2.2l is going to generate 220nm of torque if everything is done right and maybe a bit more. Given this fact the only way to get more power is to increase the peak power higher up the rev scale because Kw or Hp is calculated by using the rpm and the torque. I hear guys all the time saying I port the heads change the cams, put stronger pistons and rods and I will get all the amazing amount of power. It doesn't happen, NA engine are limited by the torque you have to move the engine up the rev range.

Don't take me wrong I am happy if some one can discredit what I say and provide example were the torque of a engine is 50% greater then the volume on any sort on normal NA engine.
Tony

[riptide motorsport]

I agree...it sounds like a classicx case of " theres no replacement for displacement"

[metalmaker12]

yea only forced induction

[Desertrunner]

I ran the calcs on a 2.5l NA engine and here is the numbers,

KW - Hp - Torque - rpm
79 - 105 - 250 - 3000
105 - 140 - 250 - 4000
131 - 176 - 250 - 5000
157 - 211 - 250 - 6000
183 - 246 - 250 - 7000
209 - 281 - 250 - 8000
236 - 316 - 250 - 9000
262 - 351 - 250 - 10000
288 - 386 - 250 - 11000

So what it tells you that if you can move the maxium torque up the rev range you will get 200 easy, you won't have to spend a fortune on the motor just a few simple things, like cams exhaust and maybe bigger injectors.
Tony