CATs or No CATs???

[M12maniac]

I've upgraded quite a few bits on my GTO 3 and I'm wanting to put a Hayward and Scott system on, once I've sorted some niggles.

You obviously get more performance with a de-cat pipe, how much more performanc? Plus, does it devalue the car when you remove them?

[Gadgeroonie]

it might be a bit louder

also - it will fail an mot (unless you know a friendly tester)

[TuxMan]

You get better flames with no cats

[funkybmx1]

TuxMan said:

You get better flames with no cats

[node]

is it necessary to re-map the engine if you de-cat the car?

[M12maniac]

I've always been jealous of your flames Tux!

How does no CATs affect the value of the car?

[YellowShed]

[quote=M12maniac
How does no CATs affect the value of the car?
[/quote]

Depends on the CAT - CAT A, CAT B, CAT C etc!!!!

It shouldn't be necessary to remap the car after de-catting, but people usually do to take advantage of a performance exhaust that usually goes with it and upgrade to the latest mapping as well as having something bespoke to their car.

YellowShed

[Lakelord]

Other thing to consider is whether you wish to track the car. I have a Rousch decatted zorst and have been turned away from a few tracks. You should be OK on 105db events but not if they're very fussy.

[BobE]

With the Haywood and Scott system you can hace a single cat that replaces a straight pipe for MOT purposes. Just make sure the tester puts the probe into the correct exhaust pipe....

[markrichards]

De-cat on an Alunox exhaust is 100.6db which should get you into most tracks. Rather new exhaust though so will likely get louder with time. Definitely recommend a "Trevor special" re-map post a new exhaust. I was mis-firing all over the place without it.

[R0162]

no cats + yellowshed map = big flames ... put some heavy tail pipes on and the noise will be reduced greatly.