Hey guys, just received my non-revup plenum, 5/16 Motordyne spacer, and OEM Z-tube from Jason at Riverside today. Will drop the car off in the morning to get it installed asap. My question now is, since countless threads about aftermarket exhausts have taught me that only minimal gains are to be had from their installation. I'm thiking that my mext two mods will be Stillen headers and Stillen hi-flow cats. What kind of gains have those of you that have added that combination experienced? I'll have the installation professionally done so, DIY knowledge or time consumed won't be an issue.

 

Without a tune, not that much. You'll definately have some gains, assuming you already have an exhaust (no use in hfc+tp's without an exhaust). But you will also be running lean, seeing how you already have a good number of breathing mods.

I highly recommend you go after an ecu reflash. The UpRev Osiris will do you just fine. You will see how much it awakens your car

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