Evo vs. STi

Discussion in 'Modifications & DIY how-to' started by Deke, May 22, 2007.

  1. Deke

    Deke Active Member

    So this is something I've been wondering about for a while. Maybe this isn't really the case, but it seems to me that there are a lot more Evos putting out ridiculous horsepower than there are STis. Is the boxer engine a stumbling block with big horsepower? Are our cars just more expensive to build? What's the deal?

    I'm not looking for examples of STis that are ridiculous either. I know that they are out there. I'm just saying that it seems much more common to hear about an Evo putting out 500+ hp than it is a Suby.

    Maybe this should be in the noob section...
  2. calmnothing

    calmnothing Shlimp Flied Lice Supporting Member

    It's just a lot easier to make big power on an evo from what I hear. The 4g engine has been around forever so tuners know exactly what to do to it. It's also a forged iron block so it's strong. I noticed the same thing. We've got a bigger block and have to put in more money in order to achieve the same thing.
  3. techlord

    techlord Active Member

    I was tuned the day of a EVO dyno day and did not see one that made 500awhp, in fact I only saw one that made over 400. Guess we will see this weekend...
  4. bomjoon

    bomjoon Active Member

    evos are the shit thats why. LOL j/k.

    i think evos are easier to mod and take the mods well and hae plenty of history behind the engine.
    thats one of many reasons.

    i know of many evo owners that got the car cuz its sooo easy to achieve 400+awhp out of the car.

    hell with $1000 you can achieve 110 more awhp over stock.
  5. miloman

    miloman Retired Admin

    I think the length of piping the exhaust gas has to go through to get to the turbo affects the output power as well.
  6. EJRex

    EJRex Member

    Sorry double post.. please delete.
  7. EJRex

    EJRex Member

    True in the case of spool time, but the basic reason you can achieve more power out of the 4G63 vs. the EJ20/25 is because the 4G63 has 8.8:1 compression, vs. 8:1 in the EJ20, and 8.2:1 in the EJ25. The blocks are also stronger as someone stated.
    It's simple really... a higher compression engine will always make more power when equally modded against a lower compression engine. Plus the EVOs have a better stock turbo.
  8. fast shadow

    fast shadow Member

    With stock turbos in place the Evo can make a pretty good amount of power. Once the stock turbos are off then IMO all bets are off and it's pretty much even.
  9. bomjoon

    bomjoon Active Member

    well if everything was about same sti would have more advantage cuz of the bigger displacement.
  10. schneid

    schneid Member

    well isnt the 4G63 a solid iron (closed deck) motor?

    and the boxers are open deck?

    If Im right, I think thats the big reason there. Easy to make more power when your stock motor loves 25 to 30 psi
  11. Deke

    Deke Active Member

    This sounds like a pretty likely reason to me.

    I want someone from Battleground to chime in on this one.
  12. this is something I had been wondering about for a while as well, I had the same suspicions about mod friendliness, and compressions, but I had forgotten about the open vs. closed deck posibilities. i thought the 2.5 was a closed deck and that is why it makes so much more power than the 2.0 (other than size differences).
  13. miloman

    miloman Retired Admin

  14. bomjoon

    bomjoon Active Member

    good info on the comparison.

    nice pics and a good explanation on both.

    its simple really i guess cuz evos run higher boost than the sti's
    i run 23 psi

    more boost = more power.
  15. mamock116

    mamock116 New Member

    i believe the legecy engine is a closed deck
  16. mamock116

    mamock116 New Member

    i belive the legecy engine is a closed deck
  17. EJRex

    EJRex Member

    Yeah, but that's the old EJ22 90-94 SOHC engine. It was a closed deck with aluminum head iirc.
  18. monk

    monk <b>The Kitchen Ninja!!!!</b>

    i thought closed-deck engines ultimately ran into cooling issues though, which is why subaru went with a semi-closed deck...?

    ARNOLDWRX Member

    do not forget the cylinder head!!!

    the 4g63 is proven power. and the cyl head off the evos and the gen 1 gst/gsx are great flowing heads.

    i almost sold my suby for this very topic. but then i was on my bike and witnessed an sti pull off so hard and storng form a stop light shooting fire out the exhaust brought me back down to earth.

  20. slowwrx

    slowwrx Supporting Member

    The 4g63 is a great platform plus its been around forever.

    OOPs got to go more later
  21. bluetwo

    bluetwo Active Member

    Both cars are cool. To me it's all about who is crazy enough to add enough boost to blow the shit out of thier engine. If you got it like that and just go buy another car or something, if money is not object then make huge HP all you want.

    To me it's these kinds of guys who are making the huge power. Where money is no object or at least not as big an object as for some of us. I'll never try to make huge HP with my car because I want the engine to last a long time and to be honest, anything close to 250 HP and 320 ft. lbs. on a 3,000 lbs. car is more than fast enough to get you in trouble on the streets.

    May not exactly be track material but when you're talking about racing you have to go right back to that money thing.

Share This Page