Hi Guys,

I know there's been alot of Decat threads over the past months but I just want to clear something up.

I have currently have a standard exhaust system on my vRS and I want to purchase one of these 2 Piece 3" Decat's to replace my restrictive downpipe. (http://www.ebay.co.uk/itm/VW-GOLF-MK4-20V-1-8T-STAINLESS-EXHAUST-DECAT-DOWN-PIPE-/230663995948?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item35b4a5422c

)

I want to utilise the rest of the exhaust system until funds suffice, so is it a simple swap or is there more to it like cutting evolved?

Cheers again,

Marc

You'll have to get a reducer made as the standard system

Is prob only 2.25" and mate it to the 3" d/pipe.

I thought that but I noticed that the pipe shown has steps in the 2nd pipe, can you see it?

I thought that but I noticed that the pipe shown has steps in the 2nd pipe, can you see it?

I can now (phone playin up before). They could well be the steps and cut down to suit?

Mine was a single pipe so not sure on the 2 piece ones?

yup the 2 part ones if left should go on straight to the std system

yup the 2 part ones if left should go on straight to the std system

Right, cheers billy.

So if i get either an aftermarket 2.5" or 3" cat back system at a later date, will that fit too?

You could just buy the downpipe/de cat and milltek non res system that I'll be listing soon

You could just buy the downpipe/de cat and milltek non res system that I'll be listing soon

I'm not made of money you know

Right, cheers billy.

So if i get either an aftermarket 2.5" or 3" cat back system at a later date, will that fit too?

mmm

not exactly as the cat back might not reach back to the 2.5" part of the decat so youll prob have to find a custom place to either make the entire system or get the off the shelf stuff and then go to a place that can put the needed section in.

if that makes sence.

thats prob how it will fit

yeah makes perfect sense. cheers again!

Right, cheers billy.

So if i get either an aftermarket 2.5" or 3" cat back system at a later date, will that fit too?

In a word no.

As the std system fits differently. You will find the decats come to fit to std system. There are not long enough to hook up to a after market system. I extended mine with welding another piece on it. You can get sleeves to do the same. I did not like having different sections so opted to do it cleanly.

mmm

not exactly as the cat back might not reach back to the 2.5" part of the decat so you'll prob have to find a custom place to either make the entire system or get the off the shelf stuff and then go to a place that can put the needed section in.

if that makes sence.

+1 there Billy

how restrictive is the standard exhaust from the cat back? I would like a decat but dont really want to change the standard system at the moment.

Your the same as me then.

The standard downpipe is very restrictive, the cat isn't the problem but the bore of the downpipe is. After the cat the pipe work opens up a bit and continues at 2.25 bore for the rest of the system.

the back box is also a restrictive part as its a large funny shaped silencer and the popes are not connected. so the air comes in then has to find its own way out of the 2 exit pipes.

The car is a very restrictive part too. the DP is close but Id say second to the Cat as I used the std DP for a few years with a 200 cell cat and it was miles better and when I put the 2.5" dp on it only made a slight difference.

The cat isn't the problem but the bore of the downpipe is. After the cat the pipe work opens up a bit and continues at 2.25 bore for the rest of the system.

Sorry but the cat is restrictive too.

This is why the sports cat and downpipe are a good mod, a better flowing cat like a 200 cell and a better wider flowing downpipe are a good way to free up power and exhaust flow.

the back box is also a restrictive part as its a large funny shaped silencer and the popes are not connected. so the air comes in then has to find its own way out of the 2 exit pipes.The car is a very restrictive part too. the DP is close but Id say second to the Cat as I used the std DP for a few years with a 200 cell cat and it was miles better and when I put the 2.5" dp on it only made a slight difference.

+1 Billy.

Take it from the folks who have tried and tested this...

the back box is also a restrictive part as its a large funny shaped silencer and the popes are not connected. so the air comes in then has to find its own way out of the 2 exit pipes.

and this is why i've just ditched my back box and gone with a straight through section with a standard tail pipe trim on it, and boy what a difference it has made!!! so much more responsive and smoother.

oh and the noise

and this is why i've just ditched my back box and gone with a straight through section with a standard tail pipe trim on it, and boy what a difference it has made!!! so much more responsive and smoother.

oh and the noise

So effectively you just have a pipe going from the downpipe to the rear hmm what does that sound like, got any clips of it? I had contemplated getting a mufflerectomy but wasn't sure how loud it would be

i still have my mid box

quick tunnel vid

sounds louder due to the tunnel

sounds good, need some petrol though

no wont fit the bore is to wide even the thinn part it to wide for the bracket between the original parts

i know as gone to have 1 fitted today and couldnt do it

bit missleading as they do say octavia 1.8t 20v

but ive emailed them today same seller as you are looking at

they told me it wont fit the vrs

Edited 2 September, 201114 yr by lee1972

Thanks for telling us that Lee!

Think I'll just save for a full system, a blueflame or something.