Okay, I'm getting bit ahead ahead of myself here I know, but I'm starting research the pros and cons of a hybrid build vs. just throwing a built sti motor in the car. looking for input from any and all that have gone this route. basics what I'm looking at..... pnp wrx heads 2.5 block with upgraded internals (pistons, bearing, etc.... still researching) I'm planning to start compiling parts this winter and complete the build next year at some point, hopefully spring) thoughts, advise, feedback??? the end result is to have a motor that can push 400-425 at the wheel. this will not be a daily driver, but I'm sure I'll drive it a ton. why do it want to do this? just because I want to....:biggrin:
IMHO, you are better off going with a 255/257 longblock as opposed to a hybrid build. Much of the torque gains over the 2.0 block is directly linked to AVCS. Plus, the 16-bit ecu for the 2.0 flat out sucks when compared to the 32-bit ecu used with the 255/257. Then there's the whole tuning issue with a hybrid -- there have been all kinds of problems with phantom knock due to the knock logic of the 16-bit ecu being tuned to listen for knock frequency characteristics of a 2.0 block. Basically, the best way to go with a hybrid is with a UTEC. Then on top of your build, you gotta remember that you'll probably end up doubling your build cost when you realize that 400whp is going to totally trash your gears. IMHO, just move to an STi if you want to make real power.
Tom, thanks for your input. I already plan to "go big" with a tranny. I've thought about the easy route and just buying an STI, but where's the fun in that. I want to build a car. I take a ton of pride in my cars and being able to say "I built it!" As always, I will pay for the build with commissions from my job and not touch my credit cards. I don't want to buy an STI and have another car payment, I'm already taking over Sarah's wrx next year for the daily driver and she is buying a newer car like a forester turbo. those are my thoughts today...who knows, tomorrow could change everything I haven't heard of the knock issues, I'm going to research that a bit more
I say you keep an eye on those new gears sets that are coming out for under 2500 bucks. I can find the link over at nasioc. Edit: found it, http://forums.nasioc.com/forums/showthread.php?t=1327207 I say you just buy a stock 257 block and drop some forged pistons in it and call it day. Cheap and very effective. Look at my setup, cheap and made good power and it held up to abuse. I would also suggest keeping an eye on Full-Races top mount, rotated twin scroll turbo kits. Spendy but it should be a sweet kit. UR also makes a good top mount rotated kit, single scroll. That's my advice, and what I plan to do to the wag0n
If you are budgeting at all, you would be wise to stick with the heads you already have as sourcing a set of STi heads will set you back considerably. My set sold for 1400 and I was just trying to get rid of them. If you already have a set of functioning heads, I'd suggest just using the WRX heads instead. 400 whp is easily attainable, there are lots of options for cams and such, and you can still use your WRX ECU. Yes, Tom is correct that the WRX ECU isn't the greatest, but it does offer alot of aftermarket tuning ability via Ecutek, AccessPort and Enginuity. UTEC is nice too, but not as adaptive since it pretty much forces the ECU to do what it says. (Fixed timing) The other benefit of the 257+WRXheads setup is that with the cometic gasket for the STI, your compression ratio runs around 8.75:1. Lots of streetable torque. A GT30R setup or some sort of twinscroll 30R setup would likely net you the 400whp you are looking for, and with the twinscroll you'll likely have a nicer torque curve.
It all depends on what tuning route you want to go, IMO. I'm an advocate of the standalone. They aren't that hard to install, especially on a WRX, and generally they will support any sort of hybrid you can dream up. Also, you usually end up with several extra outputs to use as you please, such as IC spray, meth/water, or anthing else you can dream up. Like Jorge told me, fuel is fuel, timing is timing. The 257 shortblock is reasonably priced and effective. Hard to argue with that. As far as heads go, I'm a fan of the 2.5 DOHC heads. They outflow WRX heads stock for stock, and have plenty support as far as cams, valves, and springs go. You can find those EJ25(D?) motors that are for parts for pretty cheap. If you spend more than $450 on a longblock, you didn't look hard enough. They are easy to source coolant and oil from, also. I'f you were planning on using the chassis you have, you could get decent scratch for for your WRX longblock to help offset your build cost, a little. But as many have told me just as much as I've said it myself, take what you think your build will cost and double it. Then you'll be in the ballpark. Good luck.
he's hungry for more power I would suggest an ej255/257 with avcs =D also, as piddster said, the standalone would be really nice to go with the setup
Well, if you keep your AP, I wouldn't worry too much about the knock stuff. With the newest firmware update, there are LOTS of cool new items that will help that out. Then you can also run a 3 or 5 bar map sensor, so say hello to 35+ psi with ecu control. Russ
35+ PSI say hello to blowing your car to pieces or blowing a head gasket.....not like I would know :ugh:
^^na, not really spraking any interest to be honest. Great option, just not one I want to pursure. Why? No reason, just don't.
One thing to consider is that right now there are very few people making aftermarket AVCS cams for STis. however there are alot of different sets in the works. perhaps by the time you are ready to build there might be some ready to go. AVCS might allow you to gain some extra hp over the stock wrx heads.
My Link Plus G2 will control AVCS, but the tuning can be very complicated. Link themselves recommend not messing with it.
But you needed a d-tec to do it. The ap and a map sensor adapter will allow the ecu to do it, so no gameboy is needed. Russ
no duh. however it is possible to make it work. and some of these new cams which can make full use of avcs might make for mow powa.
EJ257 series 703, drop in some Mahle pistons and your done. I have made over 500 whp on that type of bottom end. This way you can reapply the remaining money to the heads and cams where it is really needed.
