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Model specific boards => Golf mk3 => Topic started by: twistedblack69 on 23 January 2013, 21:07

Title: GTI decat.
Post by: twistedblack69 on 23 January 2013, 21:07
Am I right in thinking that the bore on a decat pipe would be the same for 8v, 16v and VR6?
Title: Re: GTI decat.
Post by: Wayne on 23 January 2013, 21:18
16v and VR are bigger bore against an 8v.
Title: Re: GTI decat.
Post by: boneybradley on 23 January 2013, 21:47
on the cat back end they are all the same, although they do differ at the other end!
Title: Re: GTI decat.
Post by: tweed on 23 January 2013, 21:55
No they are same. I fitted a 55mm decat pipe on my 8v with a 50mm cat back system
Title: Re: GTI decat.
Post by: twistedblack69 on 25 January 2013, 13:40
Anyone have any recommendations? I can get a Milltek one for just under £80 or an ebay special for £50.
Title: Re: GTI decat.
Post by: tweed on 25 January 2013, 14:01
Nothing wrong with the eBay ones. That's what I got. It's good quality and I got a flexi join too. Cut a 100mm section out the pipe slide the two ends in the flexi and weld it up. That was still cheaper than a milltek and its only a pipe at the end of it. Nothing special just the name price. 
Title: Re: GTI decat.
Post by: dom on 26 January 2013, 23:38
No they are same. I fitted a 55mm decat pipe on my 8v with a 50mm cat back system

Yeah, they are all 55mm before the cat, the 8v reduces to 50mm after the cat.
Title: Re: GTI decat.
Post by: Migz on 28 January 2013, 11:41
You say it reduces after the cat? Where after the cat? Directly after?
As in one side of the cat is 55m and the other side is 50mm. Or are both sides 55mm but just after the cat it reduces down to 50mm?
As I've got a catback exhaust for 16v/vr6, so want to know if its going to go straight on or if it needs some adapters.
Title: Re: GTI decat.
Post by: boneybradley on 28 January 2013, 12:14
both sides of the cat are 55mm - exhausts by bosal etc have a small connector piece between the cat back end and downpipe (8v goes 55mm - 50mm and 16v is 55mm both ends)
Title: Re: GTI decat.
Post by: Migz on 28 January 2013, 12:57
Ok brilliant thanks, seems like my exhaust should go on then. May just wait another week or two and order a decat pipe aswell to get it all done at once, then that way i can also check to see if it'll fit before i put it onto the car.
Title: Re: GTI decat.
Post by: tweed on 28 January 2013, 13:01
The cats are the same as we said. It changes after the cat, not on the cat. I believe the mid pipe is what reduces the diameter.