Obviously would need GIAC software to control the turbo and the intercooler - any thoughts from the Subie guys?

I'm estimating the following:

GIAC - $500
K04 Turbo - $1,000
Intercooler - $800
Shop work - $300

Total $2,600?

 

What is this, "Shop Work"?

 

I'd want to see some dyno pulls with that combo before spending money on it. Has anybody even pushed the stock turbo yet? A turbo swap changes the character of the car....bigger power usually means sissified lower RPM performance in exchange for top end numbers.

 

I agree with PGT. Bigger turbos generally mean loss of low end, gain in top end. Yes more hp and tq, but generally higher up in the rpms.

I believe only fireballed (not even positive though) and Alta have experimented with bigger turbos so far.

 

Not to mention Turbo Lag!

 

what about if it's a twin-scroll turbo?

 

twin scroll is just more efficient. it doesn't overcome the spool time. a bigger turbo needs more exhaust gas to spool. there are ways around this but none are good for a daily driver.

honestly, if it was my car, I'd want to see how far things go with the stock turbo. the other option is to order the larger OEM turbo from the JCW car that's inbound.

With all choices, it also comes down to tuning. You can put a larger turbo on and not get the benefit without a proper tune.

I had a VF40 on my Legacy. It didn't have the top end of the STI's VF39, but it spooled much earlier and smoother. A bellmouth downpipe, headers and tune and there was a ton of power....260ish whp and 280+ in tq at the wheels.