decat or not

Hey people,just wandering about the decat thing,at the moment i have a zigen5 zorst and was told by the previous owner the cats ares till there,the car is very very quiet just a little whistle on boost and hey i quite like it,but!!!! been thinking what kinda money would i be looking at to decat and also what kinda power gains do ya get from a decat?oops yea do they sound nice?

sorry but kinda new here

kind regards keef

My decat cost £400... money well spent. Got an HKS Hiper cat back and its nice and loud. The power gain is significant. Removing the first cat is more tricky but it is this one that is more restrictive, so you'll get better returns on it.

Anyone who asks if they should decat should be shot and put out of their misery!! Dont ask, just do it!

btw Patrick, £400 does sound excessive to me..

Remember also if your going for full decat then you'll have to also think about getting a Fuel Cut Defensor and a Boost Gauge (either manual one or an electronic one).

Boost creeps up once the CATs are removed.

The decat pipes are approx £120 - £150 each and the second cat is easy to do and can be done on axle stands the first cat is a real pitter to get at.

It also depends if you are J-Spec or UK/US spec, if you are UK/US spec then just remove both and then get some form of boost control and wind it up for some great fun, if you are J-Spec then you either need to leave one cat in or fit a restrictor ring, the latter is better as the cats stop alot of exhaust heat escaping.

yea mines a j spec mate,so the decat pipes should fit my 5zigen system?or will i have to get in touch with zigen for there pipe?also how do i fit and where do i get a restrictor ring???

thanks guys

Get in touch with Chris Wilson, he can sort out all your de-cat and restrictor ring needs.

It shouldn't take you long to find a post of his, do a search for 'de-cat'...

The cost included CW fitting them and also replacing some bolts that sheared off... and maybe one other small thing. I guess it would have cost £350 for just the pipes and fitting!

Yesterday I had to fit my mid cat back in to get ready for an up and coming MOT. My boost has dropped around 3 psi.

Normally I run 17 psi on full decat with a resrictor ring, without the ring it creeps up to 20 psi, which I'm not happy running on stock Jap fuel/turbos etc.

It's not so much the drop in boost that effects the performance, it's the way the turbos spool up. I was amazed how just putting one cat back in how sluggish the car feels to full decat.

Speak to Chris Wilson about a restrictor ring if you go full decat, I told him what bar/psi I wanted to run and he got it dead on.

hey keef,

thanks for postage a message in my thread.

but seeing you started one here might as well mention here.

but yea, im in same situation, got a 5 Zigen exhaust.

call me stupid guys (not litterally ), but how do i know if my car has been decat, or both decatted. what are they infact, all i know they are long metal tubes that run across the bottom of the car.

any useful pics will be helpful cheers

If you remove just one cat will it still pass MOT? and is it worth doing ?

Originally posted by cookie

If you remove just one cat will it still pass MOT? and is it worth doing ?

Yes it will pass. I passed with just the front cat in last year.

Yes it is also worth doing, makes the car sound great and will raise your boost up by about 2-3 psi.

As mentioned above you will need an FCD. When I first got my Supra it had only the 1st cat in, it was around summer time, so I was getting away without an FCD, then the winter came and a drop in temperature and I started to hit fuel cut.