De-cat downpipe and exhaust mod.

[mardon]

I’m thinking of getting a de-cat downpipe and my centre box taken out of my standard cupra TDI exhaust. Got a few questions:

1)Is this actually worth doing? Will there be any actual noticeable increase in power when combined with a green cotton filter?

2)Will it help the spool up time on the turbo and reduce lag?

3)Will the car pass emission tests with the de-cat

4)Will it sound any good? I don’t want it too loud but a bit of noise when booting it is always a bonus.

Seems like quite a cost effective modification if the gains are worth it.

I have a P-Torque remap now running 200bhp and will be getting an unrated clutch in the new year. Eventually I want to go for a custom remap combined with a turbo upgrade and clutch.

 

[deadeyejim]

In my experience.

1. I found it felt more torquey, but I've no evidence to back that up.
2. It does seem to spool faster than it did before.
3. Shouldn't be any problems whatsoever.
4. More turbo whistle and a bit more roar when the pedals in the carpet.

This was on an 07 plate FR with full milltek non res, green panel, and ptorque remap.

Just for comparison, here is the milltek DP and Decat pipe compared to the OEM pipe.

 

[mardon]

Time to start saving then

Thanks for that.

 

[Clone]

What about getting a miltek down pipe and then mufflerconomy if u have a derv?

 

[mardon]

Thats what I want to do. ShouldI take both boxes out or just the middle section. Recon the whole process inc the downpipe should cost more than £250 fitted.

 

[Altech]

I got both my boxes taken out and replaced with a straight 2.5" pipe into a custom R32 style exit. It sounds great, really nice roar when I floor it. However I left the standard downpipe and cat in.

 

[mardon]

How does it feel to drive?

 

[Altech]

The car revs a lot more freely than before. Also with the standard exhaust I couldn't really cruise at 30mph in 4th gear, the car always felt as if it was struggling. Now with the new system my car can easily cruise at 25mph in 4th!

The car does feel slightly more powerful, a bit more torque I reckon. Overall the car is easier to drive and also more fun as I love the noise. It's probably the best mod that i've done so far

 

[cheshire cat]

I got both my boxes taken out and replaced with a straight 2.5" pipe into a custom R32 style exit. It sounds great, really nice roar when I floor it. However I left the standard downpipe and cat in.

that's what I did, but with hind sight I would loose the cat and back box and keep the middle box which has no restriction anyway then 2.5" to the back -- in stainless and made to fit it was approx£100

 

[mardon]

Where did you get that done mate?

So your saying keep the exhaust tip (oval) but remove the rear box, then add a 2.5" stainless steel pipe back to the mid section and then from the mid section replace this with the de-cat downpipe??

 

[bbewekim]

Depends how far you want to mod your car, If you want stage 1 remap, keep standard exhaust and maybe just cut the backbox off and whack on a tip. Sound is good and is fine for stage 1 mapping.

Anything more than stage 1 you could look at a 2.5inch or bigger pipe going straight from the turbo back. But not really any point. Dervs dont get many gains from exhaust as aposed to petrol turbos which love it.

You could do any exhaust to standard car or remapped car mind, just dont expect amazing results without a custom map, some have even noticed fitting a bigger and better exhaust has lowered the bhp :O.

 

[mardon]

I want to reduce turbo lag, increase rev speed and add a little noise. Got 200BHP now so not too bother about adding loads of power. More after how the car will drive. I will be going for a stage 2 in the future though.

 

[cheshire cat]

Where did you get that done mate?

So your saying keep the exhaust tip (oval) but remove the rear box, then add a 2.5" stainless steel pipe back to the mid section and then from the mid section replace this with the de-cat downpipe??

only my opinion for what it's worth, there can't be much in it whichever way you go, I had mine done in Stafford think it was UNique Exhausts will check if you want--PM me

 

[mardon]

Ah i'm wirral. Little far for me. I'll check somewhere closer to home.

Thanks though.

 

[Ibiza 130 tdi]

Does make it sound a lot nicer! Smokes a bit though. But that is cos mine is pushing quite a bit on standard turbo.

Do it. Sounds cool and you'll love the smoke - works well. I used to hate it, now I love it.

 

[B3LSY]

should have a word with struggers1 hes got a straight threw pipe from turbo all the way threw sounds the nuts on his 200bhp derv

 

[mardon]

Yeah I guessed it might. There's nothing stopping all the soot at all when you remove everything. The map on my car is great though. It doesn't put out any extra soot ATM.