hey all, came across a great deal on a APS SR40 turbo and was wondering if it would be a worthwhile upgrade over my VF48 from a 2012 STi
I have a better bellmouth dp, tial 44mm ewg, grimmspeed uppipe, apexi catback I'm going to have installed so adding a turbo isn't an issue
07 wrx TR
EJ255 w/ 2012 sti vf48
STi TMIC & manifold
HKS catless downpipe
turboXS midpipe into STi axleback
grimmspeed pulley & ECBS
tuned by EFI logics in CT 298 whp/318wtq (open source)
I'm very happy with how the car drives but I can get a screaming deal on the APS SR40, so even if it's only marginally better I would still be interested. I need to get retuned as well anyway with the ewg.
I know I'll get some gains from the less restrictive exhaust and ewg and but I want to keep whp/wtq around 350 due to reliability and longevity being top priority. this is my daily
I should be able to run on the stock injectors right? I have some 850cc ones from a friend I can use as well...
Yeah. honestly the stock injectors are probably maxed out and holding you back now with your current setup. Pick up a set of ID1050x's and go from there.
I am not familiar with the sr40 turbo. So I don't want to say if it is or isn't an upgrade for the VF48. That would be another good question for your tuner who I am sure has knowledge about the turbo you are asking about.
Even if it turns out that you keep the vf48 on your car, I would still invest in the injectors mentioned above then get retuned.
SR40 is equivalent to like an OG 20G turbo on the Subarus (~44lbs/min).
You're already maxed out on your injectors, so even with the VF turbo, you'll want to upgrade them by the time you get retuned, even if it's just for the EWG / new catback. Add a bigger turbo, and you'll be downgrading if you don't upgrade the fuel system.
As for the downpipe, keep the HKS one; there is no benefit to upgrading when you hold the wastegate shut for EWG. Had I known how quickly I'd add an EWG to my setup, I'd have never flipped the HKS downpipe I had. Sell the downpipe and put that money towards injectors / EL manifold / TMIC. Those would be much better ways to invest in terms of power than a bellmouth downpipe that is going to do nothing.