TDI Exhaust Setup

[ChrisGTL]

Done lots of searching about TDI exhausts and I'm still no clearer as to TDI exhausts.

1) I've labelled up (in red) the picture below, is this correct?

2) Whats the reason for a CAT on a TDI if TDI's don't get tested for emmisions on a MOT?

3) Is the CAT/Downpipe very restrictive for a mapped 150? (200BHP)

4) If I took my car to a exhaust specialist and they say 'straight through pipe' what is meant by this? Chop the CAT out and have a straight pipe going from downpipe to backbox?

5) Would a resonated or non-resonated system sound best (by best sound I mean no stupid booming, nice suttle grunt when giving it beans)


I like the OEM look of the twin pipe exhaust on my TDI, thats not the reason I want to uprgrade.....its basically to push a couple more BHP out of it, and to give it a hint of noise when booting.

I know I could go for a Milltek and people like them very much, but they are expensive, I think the 'brand' Milltek bumps up the price by £150..

Any views/opinions on what to do..

Petrol exhausts I've played around with so i'm quite farmiliar but as this is my 1st TDI i'm into the unknown.

 

[brad1]

hi mate
i belive that to be for the mk2 leon, not the mk1

 

[ChrisGTL]

hi mate
i belive that to be for the mk2 leon, not the mk1

Yeh sorry, I should of said that pic is just for illustration purposes.......I think its from a MK5 golf.

 

[brad1]

thats ok mate, ive changed my exhaust and been under the car and it looked nothing like mine lol

 

[olaf]

Jonjay and Slick both have straight through exhausts, cost in the region of £100, just means they have a straight pipe instead of a back box.

Have a search through Jonjays posts and sure you can find some more info!

 

[jonjay]

This has been discussed on quite a few occasions however for the record. With dervs it to do with restriction and exhaust temperature. The less restriction you have the quicker the turbo will spool up and the easier it will be to release unwanted gases hence you will get a performance increase. As for the removing the CAT argument as Olaf kindly stated I and Slick have straight through to cat exhausts, no backbox. Removing the CAT is only worth it if you have the following,

Bigger downpipe
A big turbo.

Otherwise there is no point. You might gain 1 bhp but a hell of a lot of noise.

 

[ChrisGTL]

I like the sound of £100

So basically don't remove my cat as its not really restricting unless i get bigger turbo or bigger downpipe (both of which I dont plan doing)

So I want a straight through pipe from the cat to the tip? No box at all?


I rang powerflow at Leeds today and told him about my car etc, he suggested cutting the cat out and connecting a 2 box system with my choice of TIP for £280+VAT.

Or he said if I was on a tighter budget I could do the same as above but with 1 box only, costing about £240+VAT.

How do these straight through system sound? Subtle or LOUD?

I'm gonna read through jonjays posts......try pick up on some more info

 

[ChrisGTL]

p.s - Is this what is known as a mufflerectomy?

 

[jonjay]

Not a full mufflerectomy. Mufflerectomy would be removing both backbox and Cat.

So I want a straight through pipe from the cat to the tip? No box at all?

Thats correct.

£240 for what you want sounds very expensive. Should cost you no more than £150. Buy the tip you want separately and shop around.

 

[devonmikeyboy]

How load do you want your system as removing the back box will make it very load when motorway driving and at tick over it tends to make a diesel car sound more like a tractor. A CAT is in the exhaust to remove/change exhaust particles the back box is fitted solely to lower the noise of the car. Personally i don`t like the sound of a diesel car with no back box and there are some on SCN that have removed the back box only to replace it again like Unclefester. If you just want to get a few bhp plus make the car sound a bit more "sporty" plus maybe change the rear pipes just remove your stock back boxes and fit a free flow back box from a good local exhaust place with the tail pipes you like. Twin round pipes are more quiet then a single oval as well. At the end of the day it`s your money and you need to choose which you want to do as there is no single right or wrong way of doing this sort of thing really.

 

[ChrisGTL]

I dont want it very loud, just want it to give a nice sound at higher revs.

Cheers.

 

[devonutopia]

If you watch my dyno run video, (in sig) thats what a straight through exhaust sounds like. That's a 2.5" custom downpipe off a big turbo, mating to a 2.25" pipe which goes straight out the back, with an oval tail on it.

 

[noblem14]

i have a straight through system and its very loud. ive scared people standing behind when i start the car