dump pipe vs turbo back

[alphabeatsco]

does a dump pipe with catback = turbo back?

i know catback doesnt gain any performance....
so does that mean, for stage 2 tuning, dump pipe is all i need?

[Lucas_R]

Correct - the stock dump pipe is horribly restrictive with 2x dense cat convertors.

The dump pipe is a necessity, whereas the cat back is optional for looks/extra noise.

[alphabeatsco]

in that case, i might as well keep the stock exhaust.
i avtually prefer no noise...just pure performance.
next question is... what size is stock gti piping size? do i need to get a dump pipe that fits?

Correct - the stock dump pipe is horribly restrictive with 2x dense cat convertors.

The dump pipe is a necessity, whereas the cat back is optional for looks/extra noise.

[Lucas_R]

Stock exhaust diameter is 2.5inch. All the dump pipes are 3inch and then taper down to 2.5inch to join up to the stock catback.

[alphabeatsco]

does that mean it requires modifications?

[tigger73]

does that mean it requires modifications?

If you change the DP you will need a new tune.

Depending which DP you get most will fit up to the existing stock exhaust (unless it's specifically designed to fit to a custom exhaust).

What sort of modifications you were meaning?

[Lucas_R]

If you replace the dump pipe and dont change the tune, you will get a CEL (check engine light) because the free flowing catalyic convertor will tell the ECU that something is wrong with the exhaust/emissions system.

So you should get a tune to accompany a dump pipe and the tune will code out the CEL.

[alphabeatsco]

i actually mean tmodifications to make it fit with stock catcback.
i dont wanna weld the exhaust...i want a dump pipe that is bolt fitted to the existing catback...

If you replace the dump pipe and dont change the tune, you will get a CEL (check engine light) because the free flowing catalyic convertor will tell the ECU that something is wrong with the exhaust/emissions system.

So you should get a tune to accompany a dump pipe and the tune will code out the CEL.

[Tim]

What car do you drive?

Most aftermarket downpipes will mate to the stock cat back as you can see here by our SPM GTI DP. It comes with a reducer section

As for sound. That depends on the car you drive. A GTI wont be much louder with a DP but a Golf R generally will be.

[alphabeatsco]

Since I can't see a flange on that end. Does that mean it needs to be weld? I have gti mk6