Replacing the exhaust manifold

[BLAAK]

Any opinions concerning headers with 2.5" outlet into a 2.5" high flow cat down to 2.25" flange to refit onto my original exhaust line?

Has any of you guys seen a difference in performance on the fact that I'm choking the exhaust air?

I'm getting some mixed reviews.

Thank you for replying.

[Dave_B]

Any opinions concerning headers with 2.5" outlet into a 2.5" high flow cat down to 2.25" flange to refit onto my original exhaust line?

Has any of you guys seen a difference in performance on the fact that I'm choking the exhaust air?

I'm getting some mixed reviews.

Thank you for replying.

Well... I think I understand what your asking. The question is you have a 2.5" header collector, and 2.5" cat. Your wondering if your 2.25" exhaust is "choking" the exhaust. If that is your question, then yes.

However, what mods do you have? If just header and cat, I wouldn't say it's doing enough to really make a difference, however if it's a pretty decent build, that would be my next thing to replace. If you want quiet (and is why you kept the stock exhaust) I would look into either a Mugen Twin Loop or Hytech Twin Loop. Both a pricey, but quality pieces.