Im having the cats replaced on my 91 tt import (40,000) is it better to have straight through sections or small silencers put in?

 

many thanks all

 

Jim.

Depends if you want the sound increase

not to bothered about sound increase as long as its not stupidly loud! im more concerned with flow, also it it better to vent the recirculating thingeys?

 

thanks mate

 

JIm

some comments would be greatly appreciated as im having this done tommorow lads??

 

JIM:confused:

I would suggest straight through pipes. There are three boxes on the standard system as well as the cats, so there is plent of room to fit boxes to quieten it down if required

 

If by "venting the recirculating thingys" you mean the AIV pipes, I am reliably informed that they make no real difference and can be removed from the pipe, and IIRC the engine end should be left open.

 

You will also find two connections in the cats themselves, these are heat sensors (for when the cat is overheating) and can be removed, I cut them off (in my case they were a braided steel covered wire) and tucked them out the way. It is my intention to trace them and remove them at source, manyana.

 

The guy who built my exhaust asked me what sound I wanted (loud and sporty, rumbling, or quiet (I went for rumbling)) and he made it happen

 

Hope this helps.

I thought the AIV pipes should be blocked off?? :confused: Anyway, that's what I did, stuck big bolts up the tubes to block them and had no problems.

 

HTH

James

 

PS Pretty sure AIV's worked on pulsing of the exhaust to creat vacuum, limiting the air to be re-cycled. If you leave it open it'll be sucking air all the time as the Aiv's have a vacuum pipe from the engine running to them.

ps this is just my basic understanding from what I've read around the place and I could be completely wrong!

 

Please someone correct me if that's the case :)

Thanks lads for the replie im off for cat removel now!!

 

JIM