Originally posted by Alan
I would think simply gutting your cat would be worse than just keeping it stock. It doesn't follow a smooth exhaust route, instead it creates turbulence in what was once the cat. I'd really like to see some dyno charts comparing stock, with a gutted cat, with a highflow cat, with a test pipe. Would be interested to see what yielded the best gains, and where exactly those gains were made on the torque curve.
i have seen this before... i will see if i can find the charts... but this is how it went...
Test pipe: best peak HP and decent TQ
High flow cat: best TQ and decent HP
Gutted cat: ok HP and ok TQ (nothing special)
Stock: just sucked all the way around
gutted did have some gains over stock... and with the high flow vs. test pipe that is really a "Pick your poision" kinda thing...
-Keith