What was your TQ? My car dynoed around there with that cam so dont think that you are alone.

 

When you start making more power and you try to push it through the cats they become more of a restriction. The 18-24rwhp loss is probably about correct on a HC car. Figure around 5-15rwhp on a bolt on car.

 

No, not really.

I have a mild HC setup with nothing special. T1 cam, heads, headers, ls6 intake, no pulley/tb/meziere/cutouts or anything like that. 410rwhp through the factory 2.5" cats.

I wouldn't expect to gain more than 5-10rwhp with a HC car losing the factory cats.

Dope

 

Take Off Your Cats And Install Cutouts And That Should Get Your Numbers Up To Par.

 

I personally gained 18-24RWHP with the ORY vs dual 3 inch highflow carsound cats on my 360ci motor.
I didnt retune however. Timing etc needs to be changed with cats on the car...