at the dyno rates by me, i've better off buying my own dyno jet. but judging by all the posts i've read and all the pictures i've seen, i can't imagine anything but gains from mid-upper powerband. down low power is tought to say with shorty headers, but i believe the design intentions were to maintain back pressure as well.

 

You will really enjoy the benefits of those headers. I picked up 17hp and 28lbs of torque from my testing. The torque is what really wakes up the car. Several thousand miles so far and nothing but good things too report. Sucks it is not a direct fit for you but this allows you to really put in a nice custom exhaust.

https://www.clublexus.com/forums/sho...=197918&page=2

Lee

 

I agree completely with Pearl power...Gains are made with the deletion of those down pipe cats too...THe only draw backs I can think of is the headers create alot more outside engine heat so your intake may suffer abit for some...Also the heat is really felt radiating from outside the car when you exit.....You lose a tiny bit of lowend power too, really not noticeable unless you have a true high performance exhaust system throughout like I do...Noise levels are good and you need not worry...maybe 10% louder then stock...Oh and also the check engine light remains on all the time...