Originally Posted by Jordo!

What kind of dyno and correction factor?

If you picked up someone's Factory nismo exhaust it has an H-pipe -- very curious to see if it outperforms the S-tune, which has the Y. My guess is it just moves the gains around a bit...

I have mixed feelings on the HPS tubes... they give you a little bit of gain, but barely enough to make it worth the cost and hassle to install. Still, every little bit helps, and that plus the K&N panels should give you essentialy the same gains as any of the aftermarket intakes. I've yet to see any dynos that convince me any of them out perform the panel filters (with or without the HPS tubes).

Without a doubt, test pipes or HFC's will net the biggest gains -- best bang for the buck bolt on you can do. Factory cats are really restrictive.

Good luck -- let us know how it does. Post the dynos