Yea, I figured the headers would sacrifice torque without a tune. Still debating about getting them.
NISMOZ, did you leave your headers alone and simply tune with HFC and exhaust?
Berk HFC is under my desk and mid-June ETA for my F.I. exhaust. Tony at F.I. is experimenting with different configurations than the G37 like eliminating the H pipe and going for true dual at the mid section (I think). More variables there...
From your posts, it appears you've had significant gains from HFC and exhaust. That's all I'm thinking about doing besides debating about headers and keeping the stock airbox... last is UPREV.
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