Miltek decat or sports cat on Cupra TDI

[Gazb]

Well its time to take the plunge and start spending some money on my Cupra.

First on the list is a Miltek exhaust which from what I've read if I only get the cat-back system I'd have to cut cut the original exhaust and weld on the miltek.

As I really want to cut up the original pipe I'd rather get either the decat pipe or the sports cat so it'll connect to the downpipe and require least time with not cutting and welding.

So the question is which to go for. Usually I'd just say decat and be done with it, but as the tdi can be a smokey little fellow I was thinking maybe the sports cat will help reduce the smoke abit but still help it spool up and sound better.
The downside ofcourse is the price of the sports cat which is quite alot.

The Decat is alot cheaper but I don't want it sounding too much like a tuck and smoking like one aswell.
I'm pretty certain I remember reading somewhere having a cat helps keep some back pressure to increase torque but I could be wrong. (can't find the post where I read that).

 

[devonmikeyboy]

Well its time to take the plunge and start spending some money on my Cupra.

First on the list is a Miltek exhaust which from what I've read if I only get the cat-back system I'd have to cut cut the original exhaust and weld on the miltek.

As I really want to cut up the original pipe I'd rather get either the decat pipe or the sports cat so it'll connect to the downpipe and require least time with not cutting and welding.

So the question is which to go for. Usually I'd just say decat and be done with it, but as the tdi can be a smokey little fellow I was thinking maybe the sports cat will help reduce the smoke abit but still help it spool up and sound better.
The downside ofcourse is the price of the sports cat which is quite alot.

The Decat is alot cheaper but I don't want it sounding too much like a tuck and smoking like one aswell.
I'm pretty certain I remember reading somewhere having a cat helps keep some back pressure to increase torque but I could be wrong. (can't find the post where I read that).

To keep it quick;
Sports CAT total waste of money on diesel as it serves no real perpose other then to empty your pocket. Diesel tuning is different to petrol tuning.
You have to cut the original exhaust to remove it as it has no joioners to unbolt. Seat must fit the exhaust first then the rear axel i guess.
You don`t need to wield a new exhaust on as you should use exhaust clamps.
A CAT has very little to do with removing noise of the car as it is designed to remove/change exhaust particles not noise, it`s the back box that controls the noise as that is what it is designed and fitted for.
N/A engines need back pressure not turbo diesels. Your appling petrol tuning to diesel tuning again.

 

[Gazb]

To keep it quick;
Sports CAT total waste of money on diesel as it serves no real perpose other then to empty your pocket. Diesel tuning is different to petrol tuning.
You have to cut the original exhaust to remove it as it has no joioners to unbolt. Seat must fit the exhaust first then the rear axel i guess.
You don`t need to wield a new exhaust on as you should use exhaust clamps.
A CAT has very little to do with removing noise of the car as it is designed to remove/change exhaust particles not noise, it`s the back box that controls the noise as that is what it is designed and fitted for.
N/A engines need back pressure not turbo diesels. Your appling petrol tuning to diesel tuning again.

Thanks bud, quick and simple.

As you probably guessed I was trying to read as much posts on here as possible about it but got abit confused so made this thread.

Simplest option be to just buy the miltek cat back and decat pipe (maybe even source one of these second hand).

 

[Gazb]

Anyone in northern ireland bought their miltek from east coast customs?
According to miltek's site ECC are the distributers for them over here, handy as its only 4mile from my house.

 

[Ibiza 130 tdi]

A CAT has very little to do with removing noise of the car as it is designed to remove/change exhaust particles not noise, it`s the back box that controls the noise.

Although saying that - when I had my backbox changed, it didn't make much noise difference. It went from the standard biggish backbox to this one:

Which is quite small. So I then had the cat removed and it made quite a difference to noise........and smell..........and smoke.......

 

[Gazb]

Although saying that - when I had my backbox changed, it didn't make much noise difference. It went from the standard biggish backbox to this one:

Which is quite small. So I then had the cat removed and it made quite a difference to noise........and smell..........and smoke.......

Damn, that looks seriously small compared to the standard one.

 

[Ibiza 130 tdi]

Damn, that looks seriously small compared to the standard one.

Yer it is! sounds nice though.

 

[fatcatman]

I am also just starting to mod my car and was wondering the same kind of thing-

What do the Large bore Downpipe and Cat Replacement pipe, and Hi-flow Cat & Downpipe actually do?
i.e. what are the differences between them, why would you get one instead of the other?

If i was eventually intending on getting the Allard intercooler and stage 2 remap done is it ok to just get the catback system?

 

[devonmikeyboy]

I am also just starting to mod my car and was wondering the same kind of thing-

What do the Large bore Downpipe and Cat Replacement pipe, and Hi-flow Cat & Downpipe actually do?
i.e. what are the differences between them, why would you get one instead of the other?

If i was eventually intending on getting the Allard intercooler and stage 2 remap done is it ok to just get the catback system?

Large bore down pipes are for if you fit hybrid turbo`s. Your stock down pipe will flow plenty enough exhaust gasses for the stock turbo even when remapped.
CAT replacement pipes; You can either replace the whole down pipe and CAT with just a pipe like a Milltek system or just cut the CAT out and wield a new piece of pipe in it`s place which any garage should easily be able to do for £50.
Hi flow CAT where first made for petrol cars as they have censors in the CAT and different MOT regs to pass. There is no real reason to spend £200 + extra on a sport CAT for a diesel. You will not fail your MOT or break any laws by removing your CAT and driving on the road in England, other countries are different.
So basically to answer your question a CAT back system would be fine on your car with a FMIC and remap.

 

[devonmikeyboy]

Although saying that - when I had my backbox changed, it didn't make much noise difference. It went from the standard biggish backbox to this one:
QUOTE]
The size of the back box doesn`t determine the amount of noise it makes. Internal design,packing used,tail pipes used etc are what matters. Removing the CAT will increase the noise since the CAT is bound to get in the way of the noise vibrating down the exhaust but i stand by what i posted above as the CAT is designed to remove/change particles and agsses not noise like the back box. I have messed about with several exhaust systems on diesel cars and never noticed that much difference in noise/smoke/smell etc by removing the CAT.

 

[fatcatman]

Cheers for that, exactly what i needed to know

 

[devonmikeyboy]

Cheers for that, exactly what i needed to know

Well i could confuse the situation and tell you that with the Milltek system all you are getting is basically a free flow back box as the rest of the exhaust system is the same as your stock system within 1-2mm which makes sod all difference so if you wanted to uprate your exhaust system all you basically got to do is change the back box for a free flow version which would cost £150ish tops fitted....

 

[fatcatman]

Cheers for that, exactly what i didnt need to know.
I think i will go with the Milltek cat back and then can add the down pipe if i mod it further

 

[devonmikeyboy]

Milltek exhausts are very good and well made, i have bought them for my last three diesel cars so i am not knocking them as such just there are lots of ways to mods a car exhaust,engine etc just comes down how much money you are willing/have to spend plus the quality of the end result that you want to go for.

 

[Ad Lav]

I have a cat-back non-resonated on my Ibiza TDI, sounds the nuts above 3k rpm!

Well worth the money, looks so much nicer too.

 

[bbewekim]

this thread is useless without videos or sound clips! There seems to be a lot of talk about having no boxes at all though? just running pipe straight from the cat...?

 

[Gazb]

Milltek exhausts are very good and well made, i have bought them for my last three diesel cars so i am not knocking them as such just there are lots of ways to mods a car exhaust,engine etc just comes down how much money you are willing/have to spend plus the quality of the end result that you want to go for.

Yeah, I'd rather spend abit more to get something I know is of good quality.

 

[Ibiza 130 tdi]

this thread is useless without videos or sound clips! There seems to be a lot of talk about having no boxes at all though? just running pipe straight from the cat...?

Ask Ad Lav for the video of his! Been waiting ages for it! Really curious to hear what it sounds like!

Mine with Powerflow decat and backbox as shown earlier in the thread:

 

[Ibiza 130 tdi]

It actually sounds a lot meatier on the worse quality video!

 

[Ad Lav]

Its on its way, just keep forgetting or watching the rugby!