Z4-forum.com

I have the same downpipes in my car

Just to confirm they are difficult to fit

I'm going to order the Chinese pipes.
I'll report back on quality/fit after fitting.

Smartbear wrote: ↑Fri Jan 12, 2018 8:28 am

flybobbie wrote: ↑Thu Jan 11, 2018 11:04 pmCould take the existing off and just smash out the mesh?

I think that's what twinturbo on here did to get a catless downpipe, not sure how he got it tested at MOT time?

Rob

Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

Nick9one1 wrote: ↑Sat Jan 13, 2018 5:33 pm

Smartbear wrote: ↑Fri Jan 12, 2018 8:28 am

flybobbie wrote: ↑Thu Jan 11, 2018 11:04 pmCould take the existing off and just smash out the mesh?

I think that's what twinturbo on here did to get a catless downpipe, not sure how he got it tested at MOT time?

Rob

Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Smartbear wrote: ↑Sat Jan 13, 2018 5:52 pm

Nick9one1 wrote: ↑Sat Jan 13, 2018 5:33 pm

Smartbear wrote: ↑Fri Jan 12, 2018 8:28 am

I think that's what twinturbo on here did to get a catless downpipe, not sure how he got it tested at MOT time?

Rob

Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Ah I didn't realise it was a 2.0 you were talking about. I'n that case you're probably correct!
Maybe he had a 'friendly' MOT station..

Nick9one1 wrote: ↑Sat Jan 13, 2018 6:46 pm

Smartbear wrote: ↑Sat Jan 13, 2018 5:52 pm

Nick9one1 wrote: ↑Sat Jan 13, 2018 5:33 pm Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Ah I didn't realise it was a 2.0 you were talking about. I'n that case you're probably correct!
Maybe he had a 'friendly' MOT station..

Twinturbos car was a 28i but runs the same engine & exhaust as the 20i
Rob

Smartbear wrote: ↑Sat Jan 13, 2018 5:52 pm

Nick9one1 wrote: ↑Sat Jan 13, 2018 5:33 pm

Smartbear wrote: ↑Fri Jan 12, 2018 8:28 am

I think that's what twinturbo on here did to get a catless downpipe, not sure how he got it tested at MOT time?

Rob

Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Good to know, MOT failure if that's the case so il definately leave that mod alone then

JimsZ wrote: ↑Sat Jan 13, 2018 7:40 pm

Smartbear wrote: ↑Sat Jan 13, 2018 5:52 pm

Nick9one1 wrote: ↑Sat Jan 13, 2018 5:33 pm Smashing the insides out shouldn't be any different to fitting a stainless downpipe.
There are two ways you can fail - visual removal (after Googling I think this might only be Diesels) and the emissions test. Most cars only need one set of cat's to pass, either front or rear (ours have 2 sets).

I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Good to know, MOT failure if that's the case so il definately leave that mod alone then

Here's the link to what happened to me when I took my 35i (with newly decatted downpipes), to the MOT...

viewtopic.php?f=23&t=99202

I include the exhaust emission stats in that post too.

stijohnny wrote: ↑Sat Jan 13, 2018 8:27 pm

JimsZ wrote: ↑Sat Jan 13, 2018 7:40 pm

Smartbear wrote: ↑Sat Jan 13, 2018 5:52 pm
I’m pretty sure the 20i only has the one cat in the downpipe, the middle box is only a silencer
Rob

Good to know, MOT failure if that's the case so il definately leave that mod alone then

Here's the link to what happened to me when I took my 35i (with newly decatted downpipes), to the MOT...

viewtopic.php?f=23&t=99202

I include the exhaust emission stats in that post too.

Good news for the 35, mines a 28i 4 pot. My previous turbo'd car had a primary and secondary CAT so after removing the downpipeCAT it still passed an MOT. If I read Smartbear correct the 4 pot only has 1 CAT..?

willgill wrote: ↑Thu Jan 11, 2018 6:09 pm

NeilMick wrote: ↑Thu Jan 11, 2018 5:59 pmWhere are VRSF made?

Hudson, Massachusetts

Wrong, China, pond dredging indeed, AR Design or Supersprint all the way

NeilMick wrote: ↑Sat Jan 13, 2018 10:15 pm

willgill wrote: ↑Thu Jan 11, 2018 6:09 pm

NeilMick wrote: ↑Thu Jan 11, 2018 5:59 pmWhere are VRSF made?

Hudson, Massachusetts

Wrong, China, pond dredging indeed, AR Design or Supersprint all the way

busted.
Could even be the same manufacturer!

JimsZ wrote: ↑Sat Jan 13, 2018 9:09 pmHere's the link to what happened to me when I took my 35i (with newly decatted downpipes), to the MOT...

viewtopic.php?f=23&t=99202

I include the exhaust emission stats in that post too.

Perfect!
Any issues with it throwing codes? - looks like it has o2 sensors both sides of the cat (usually to check if the cat is working correctly).

Nick9one1 wrote: ↑Sat Jan 13, 2018 10:43 pm

JimsZ wrote: ↑Sat Jan 13, 2018 9:09 pmHere's the link to what happened to me when I took my 35i (with newly decatted downpipes), to the MOT...

viewtopic.php?f=23&t=99202

I include the exhaust emission stats in that post too.

Perfect!
Any issues with it throwing codes? - looks like it has o2 sensors both sides of the cat (usually to check if the cat is working correctly).

That was stjohnny's comment not mine, I have a 28i

Slightly off topic I've been reading up on the super sprint website. Some good reading but it's 28i related sorry!!

https://www.supersprint.com/ww-cn/full- ... 4-28i.aspx

Also shows some impressive gains in hp and nm.

wow, and I thought the VRSF pipes were overpriced...



I like how they have the sprung joints, probably makes fitting a little easier.

This line confirms my suspicions on the o2 sensors.

CAUTION ECU tune compulsory to avoid the Check Engine Light. Alternatively it's possible to extend the lambda sensor wires and plug the sensors after the secondary OEM cat or the Supersprint sports cats

Nick9one1 wrote: ↑Sat Jan 13, 2018 10:43 pm

JimsZ wrote: ↑Sat Jan 13, 2018 9:09 pmHere's the link to what happened to me when I took my 35i (with newly decatted downpipes), to the MOT...

viewtopic.php?f=23&t=99202

I include the exhaust emission stats in that post too.

Perfect!
Any issues with it throwing codes? - looks like it has o2 sensors both sides of the cat (usually to check if the cat is working correctly).

Nick - no probs at all. It had a stage 2 remap on a rolling road when the downpipes were swapped out, I think they corrected the settings so no error codes.