After doing some thinking Ive come to realize that my car is going to end up going way way way futher then i ever expected it to go as in performace wise. I was pretty happy with it before the knock of death so of course I step up to the bigger block which mean in time ill be stepping up to a bigger turbo (Thinking rotated kit) which leads me to ask what about my heads will they flow enough for high horsepower applacations? What should i do to make it better? I was thinking maybe the Helix kit that Gruppe-S offeres but ive read some bad things about it and very few good things. But i was read a thread on NASIOC which means I was digging thourhg all the crap to find the good information. So what is your oppion on this. I have head that after about 450whp the heads become pretty restrictive (sp)
The biggest problem with the 2.0 liter heads is the cams. If you do a simple port job, meaning just clean up the casting marks and such, you shouldnt have any problem getting to 500hp. Matt
I Think im going to shoot for over 500 but ill be happy with 500. Hopefully next weekend ill get my daily driver and I wont have to drive it everyday and i can start saving the money needed for this.
If you plan on going over 500 you might want to go ahead and swap the pistons too...the stock sti pistons are not forged, they are hypereutectic pistons and are not very stable for any type of det or knock due to the high silica content. Forged pistons give you a bit more of a safety margin as they are not as brittle.
Yea im doing new piston as well once i get everything for the complete build together. but this time i will do i9t by myself and not pay a soul to mess it up....
WRX heads are IDENTICAL to STi heads as far as the casting goes. The cams and valves are a little different.
eh...not so much identical...wrx heads are 51cc and sti heads are 58cc...that is where the extra compression comes for. I think they also have some different oil passages for the AVCS right?
Outside of the AVCS then yeah. If you port the WRX heads then they are virtually identical. That isn't a lot more flow per say.
Just found out yesterday that using Sti cams in Wrx heads is a bad idea for low and midrange power. Turns out that the cams have a built in amount of timing retard in them and that unless you have the AVCS to control them they actually hurt low end and midrange power in comparison to the Wrx cams. The AVCS has the ability to advance the cams during the low and mid then switch to the retarded timing profile for high end power. Christian at Cobb explain this to me as I mentioned the possibility of Sti cams in the future. Just thought I would share.
264's work well from what I understand. I don't know if SS has any experience with cams on a hybrid but I would be interested in his input.
They said that any of the cams built for the wrx can work well, they said that they used regrinds for a long time with a lot of sucess but are now in the process of making their own complete cams. The only problems they said they ever had with the regrinds was when oil pressure dropped off (oil superheated at road track and no oil cooler was a common culpret) or an oil pump failed these cams went out quick and saw super fast wear. They said if doing regrinds to make sure and get an oil cooler and upgrade the cooling system in general if you are doing any heavy track work or hard core driving. That was on my list of things to do anyhow. Have seen regrinds for as little as $65 per cam from some very reputable shops.