SubieNate--The lower the compression the more you can get away with. A 205 at 14psi is no comparison. Those are much quicker. Boosting an older Subie nowadays involves a swap or working with what you've got on the cheap. The nice thing is that you could put just a 2.0L short block under old school heads and keep everything you just built.
You always end up doing some kind of maintenance anyway. It's best to do what you know you're going to need to do first. Turbo pipes can make the passenger rear cam seal a real pain. I have to do a kitchen sink very shortly at 105k. Maintenance bites everyone eventually.
I was thinking of the ej20 wrx motor specifically. I have yet to see those 2.0L high compression pistons, but I'm pretty sure they are unboostable. Maybe you could get away with 5-6psi, but I don't really know.
1993 Impreza L (1.8L SOHC Dual Port) SWAPPED to a 2.2L SOHC Dual Port from a 1990 Legacy...just used the 1.8 I/M and plugged the EGR line.
M90, mounted in place of the airbox.
TMIC from a WRX(stock TB location)
Now, will my 1.8 ecu handle a M90 on 5-6psi?
What wiring is involved?
More importantly...will my 200k 2.2L bottom end hold up to 6psi?
If so, will it make it 50k miles or 3k miles?
Lastly, how do I adjust timing on a car that doesn't have a knock sensor and has a coil pack?
I understand low charge temps/ cold plugs/ oil cooler...But what about running a Meth/Water injection kit on that TMIC? Will I increase my motors odds of longevity?(assuming the meth/water doesn't crap out at 6k rpm under 6psi)
any help would be greatly appreciated...
"The caterpillar cannot understand the butterfly" -Timothy Leary
02+--why you shouldn't do it and you're on your own from here...
Simply put, 2002+ N/A engines have pistons that can't handle much boost. Those of you that have managed to get them to live are all under that strict 8psi limit and managed to fool the electronics just right. 4-6psi is about all you can really get at safely. That's less of a return for the effort. I got out of boosting older Subarus around 2002 because of it. Who wants to repair all those failures? It's best to just NOT boost these. That doesn't mean other avenues aren't open like E85 and nitrous.
I'll always advocate a fuel swap for 02+ N/A cars. They respond better to the E85 fuel change than older cars because of their higher compression and aggressive timing curves. Get a Walbro and rrfpr OR 440s and you're good for E85.
Is this pertaining to a > 2001 RS with a phase I EJ251 compared to a phase II? DOHC vs SOHC? Did subaru decide to cheap out on na pistons post 2002?
I've read about the ej251 having "glass pistons", and was just wondering if the prior years really do have better pistons...