My import zed has a nice after market exhaust on but the previous owner must have hit it a few time and the one silence on the passenger side after the cat is well dented and the weld on the other box is cracking.As the rear silencers and the cats are ok, what is anybodys thoughts on cutting out the middle silencers and replacing with straight pipes?? will it be too noisy or will back pressure probs arise? also where is the supposed restricter in jap exhausts before or after the cats. Cheers Guys

Jeff TT

The main restrictor is after the cats. If you're playing exhaust games then you may as well dump the cats - your car does not need them for an MOT.

Just out of curiosity, what is the cut-off year for cars to be allowed on the road without CATS?

 

Cheers,

 

Danny

1992

 

Sept/Oct I think?

That's for UK models, but if your car is not EXPLICITLY listed in their book, then the rule is they use the test for cars without cats. This is documented on their web site.

Backpressure isn't an issue - your turbos give all the backpressure that is needed at low revs - any extra is undesirable !

 

The legality thing is a bit comples. If a car was fitted with cats before the date from which they were mandatory then strictly it is illegal to remove them.

 

Good luck finding an MOT tester who actually knows AND cares though !

 

Dave

 

As far as I remember, the middle box isn't a silencer at all, it's just a cross-link for the 2 systems.

 

The restrictors are in the middle section immediately behind the flange where the cats bolt on. It only take 10mins to remove them with an angle grinder.

 

I took the cats off mine and ground the restrictors out and the car does feel much more responsive. Did fit a Blitz filter at the same time though.