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I was wondering if and roughly how much power I will make over the stock with installing JDM wrx heads. They have the same size combustion chamber so my compression ratio will be the same. My supporting mods will be 3" catless turbo back, custom short ram intake, and 06 wrx TMIC.

The point behind the 20G/K heads is that the valves are larger making flow better. On a regular 2.2T heads, you start to lose power at about 5300 ( this was dyno proved on my car) The G/K heads will allow flow way beyond that point. So instead of me shifting at 5300 ( peak power point) I could push the car to say 6500 rpms.

As for how much will you gain: it depends on the car and mods. But without a larger turbo, you will not see a major improvement, as the stock turbo is set-up to work with the stock heads. ( better power down low)

The G/K engines also have a higher redline than the 22T. So with some EM you could have an even wider powerband.

AWD_addict wrote:The G/K engines also have a higher redline than the 22T. So with some EM you could have an even wider powerband.

Not by much, unless they are STi engines.

The reason the Ej22T has the 6500 rpm redline that it does is that the head ports (and not the valve) restrict the air flow to the point that it's pointless to rev any higher. It just won't make power up there because it won't flow.

That said, given the powerband of a the Ej20G heads you don't suffer by using the stock Ej22t 6500 rpm redline. The JDM WRX only revs a couple of hundred rpms higher and over the years they've brought the redline back down to 6500 on our US cars.

Even with better flowing heads, the stock turbos (vf10 or td04) just don't push enough air to warrant going higher. High RPMs get treated like they are some magic pill. Rev higher = more power. Not true. It's only true under the right circumstances.

93GCsedan,
You'll probably pick up 30+chp by changing the heads and fiddling around with your boost a bit. This assumes that you are already or will be getting intercooled. You've got to change manifolds to do the heads, so if you can get the Ej20G injectors at the same time do it. Your stock ECU can run them fine even though they about 12% more than stock. If you install a FCD you can turn your boost up to about 1 bar and you'll be a really happy camper with that head swap. You'll be making stock WRX power in a car that weighs hundreds of pounds less.

^this is the fastest, cheapest formula that I have used, except I used a td-05 16g and 560 yellow injectors. What Evo?

so if i put some jdm sti head on 2.2 block forged,i got a good combo?

Yep, check out some of the builds on this forum... The ones who actually have built motors make pretty damn good power.

Forged 2.2T + DOHC Headswap + right turbo = damn fine engine.

Forged pistons are not even necessary unless you suck and tuning and plan on detonation

We all suck at tuning at first. If you read alot of different forums, alot of 'pros' apparently suck at tuning too.

PhyrraM wrote:We all suck at tuning at first. If you read alot of different forums, alot of 'pros' apparently suck at tuning too.

I should have clarified, I meant at the power levels we are talking about here (Stock WRXish power)

Ah, Nick... okay, now that you clarified, that makes sense...

I was gonna say, Dave (non-forum person... ex-rallitek tech) rocks at Tuning, and he uses and swears by forged pistons.

Yes, forged are typically tougher than cast pistons, but its only necessary when you are pushing enough air to warrant them. Untill you move past a VF39 or 16g on a 22T you aren't there yet.

Even then, not all forged pistons are created equal. There is a reason CP pistons are almost twice as much as Wiseco's.

Thanks for the replys guys. I am wanting to run a vf39, STI yellows, a custom fmic, and run about 17+psi, with the supporting mods, ie fcd with a piggyback. I am wanting to run about 250-275+ hp to the wheels, is that resonable?

It might be tough without full control over your ECU.

What about the e-manage ultimate, it is almost a standalone in it's self. Does anyone have any experiance with this unit? Any thoughts.

I'm not saying it cannot be done with a piggyback. It's just that not having full control over timing handicaps you. You want to ask a VF39 for everything it has, and without the ability to control everything like you can with a standalone or a modern ECU with open-source tuning, you will have a tough time doing so reliably.


Piggy-back units like the e-manage, PP6, Maf T Pro, etc, are not standalones, and aren't even close. The software may be there, but you are still dependant on the factory ECU for ignition and injector drivers, among other things. Therefore, you cannot call any piggyback an almost-standalone.






In no way, shape or form am I trying to dog you or sway you from a piggy back. I'm just trying to bring everything to your table in reality.



If you can make it happen, I say more power to you.

megasquirt

^ Has anyone installed one without using an EDIS wheels and matching sensors?

This is so frustrating trying to find some management with good control, there is also the concern of trying to find someone that would be able to tune it.

A good tuner can tune something no matter what brand of EM it is. Fuel is fuel, and timing is timing. If they say they only do AEM or something like that, stay away.



Its not hard to find management with good control. What is hard to find is cheap management with good control.