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$Cost to make reliable 400 whp 2017 STI?

109387 Views 53 Replies 14 Participants Last post by  XJman
I'm thinking about buying a new 2017 STI. I'd really like it to make more power but would not want to have to worry about something going wrong since the warranty will obviously be compromised. So if I wanted 400 wheel horsepower or more what's the best safest route and how much would it cost?

I know all the basic parts evolved when tuning these cars for more power. But I want reliable power. So aside from all the bolt-ons like downpipe, upgraded fuel pump, exhaust, injectors, blah blah blah etc etc.

For reliability would it be necessary for forged pistons and a closed deck block? Or would the pistons be good enough? And what would the typical cost be for 400hp? I know for 300hp to the wheels stage 2 it's about $2900..
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If you want 400whp, here:

ID1000 Injectors
Walbro 255lph pump
GTX3572R rotated manifold turbo
Killer-B ELH + rotated EWG UP (does this exist yet?)
E85 flex-fuel kit
Tuning solution (obviously)
TGV deletes
Parallel fuel rail mod
IAG fuel damper kit
Snow performance Water/Meth injection (you'll need all the det-resistance you can get)
Catless DP
Speed-density conversion
Killer-B Oil pan, baffles, and pickup (you'll need the extra oil capacity for cooler oil temps)

That should make 400whp on most dynos. The motor may last 100,000 miles or 1,000 miles. At these BMEPs, the motor could go at any minute.

Sure, you could build the motor for another $8,000-10,000 and it MIGHT last another 50k miles, but built motors rarely last as long as stock OEM motors.

At the end of the day, you might have an Impreza that cost you $65,000 and resells for $25,000. Or you could have a $40,000 Camaro SS (with 400+whp mind you) that resells for $38,000.
very nice into have a 2011 wrx its stock and quick but learning quick just how much money it cost crazy. dam srt-4 neon 1600 buck bolt on 50trim 500hp untune lol. subaru cant even put on intake on without a tune lol.
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