exhaust upgrade

[scottish pug estate]

what i was wanting to know,is if i fit the GTI-6 MANIFOLD,to my estate you need to fit the cat for that car as well,now my exhaust will need replacing shortly and i went to get a quote for a full stainless system from the maifold back and it was a dammed good price £250+vat i am also going to have it with a de-cat pipe,so would it be possible to have my standard cat for the MOT,as the pipes will be custom made anyway or would i still need the 6 cat

[jameslxdt]

where will the cat go if your getting a custom system from the manifold back, if i was you, get them to cut the cat section up and weld it into the custom system, a decat will looose you power, trust me, and it will be far faaaar toooooo loud

[scottish pug estate]

thanks for responding james,its prob me that hasn"t explained things right ok by the way have you still got your manifold for sale,am going to try to get one locally first,here goes,i was going to get a de_cat pipe fitted so that i can fit the cat when needed AHEM!! coughs,so what i wanted to know is do i still need to use the GTI 6 cat with the system or could i get the system made up and use my standard 406 cat with the system,is it some special way the cat is fitted to the GTI 6 manifold or is it part of the manifold

[Welly]

I agree with James, be very careful with the stainless jobbie and no CAT it will be very loud.

You can loose back pressure with these exhausts which effects exhaust gas scavenging/pulses in the system and you end up loosing Torque.

I must admit though, De-Catting usually results in freeing up the engine at higher revs as long as the exhaust is properly designed.

I had one made for my Honda VTEC and it was a dissaster. They put the next size up in the tubing at 2" instead of 13/4" and I had a de-cat pipe. It was incredibly loud and I lost a lot of low down Torque. It had no knowledge here and trusted them with it, the exhaust only lasted 1 month and then I had to buy the proper Honda one from Japan at great cost. The car was then fine again and I learnt a lesson.

In general people can think their car is faster with a straight through stainless system but in reality it only really sounds faster

If it's a Turbo'd engine it's a different story as these respond well to exhausts and they won't sound too farty either as the Turbo interupts the sound pressure.

[jameslxdt]

the gti6 cat is special as its a high flow stainless cat you dont have to use it but its a waste not too, its very different to the 406 one, the guys over on 306gti6.com loose a hell of a lot of torque, most people put the cat back on not long after removing it as it has such a negative effect, and even some people have lost top end power, it was only like 1 or 2 bhp but why pay to loose power
if you butcher your cat basically cut the two ends off you could just weld it in and it would be fine, but it will save you time and money if you use the gti6 cat

[niz406]

Get your custom stainless and then a Miltek Sports CAT.... will cost you Circa £400ish but the cat has like silly warranty and the exhaust lifetime and they can fit the cat at time of install and all will be good in the hood !

[scottish pug estate]

thanks guys the place who i was going to get to do the job also offer a sports cat,so by the sounds of it i will need to get one,i got the price for duel tailpipes and it was quite a bit dearer cos of that ,i really wanted them,but i could go back to just a single exhaust and that would give some money back to get the sports cat as i was doing this to improve it over standard as the standard exhaust would be a bit cheaper but not much,once again thanks