Hi All.

 

Im going to be upgrading my standard exhaust soon, and would like to remove the CAT's. I understand there are several ways to do this, i.e replacement pipes, straight thu pipes..... My car is a 93 UK TT. Any ideas/advise on what to do, and/or changes once removal has been carried out.

 

Also, what realistic increase in power can be expected?

 

CheerZ

 

p.s MOT is not an issue

I just did this on my '92 auto import, so yours may be slightly different.

I got the complete front pipes from Johnny at GPS, with the inbuilt straight though silencers where the cats used to be. Not sure how much difference the silencers make, but at least they won't disrupt the airflow much. The cat temp sensors can just be unscrewed and tucked up out of the way (don't cut them off). I didn't have any recirc valves built into the front pipes, but some cars do. Also, I didn't have any pre-cats and I don't think you will either.

The power gain should be around 20bhp, or so I'm told, but the greatest difference is in the spoolup speed of the turbos.

I Cut my cats out. Replaced them with piping.

Sounds a whole lot better.

Power gain, im not so sure.

 

I ran same figure on dyno before and after.

I suspect a case of louder exhaust makes car sound faster.

It does get better spool up though.

Being a 93 I think legal you need to have Cats fitted to pass the MOT

Is there a difference in the CAT setup, pre and post 1993?