MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Jons1001 on January 20, 2021, 05:22:09 pm

Title: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 05:22:09 pm
Hi all, really need some help trying to source an OEM exhaust. Currently have 3inch downpipe with sports cat, 3 inch straight pipe and OEM backbox. I added the sports cat today to help pass mot but also try and reduce noise, however it's as loud as before (ASBO loud). Called into euro car parts and asked if there system brings anything up, they gave the following part number for OEM middle section with silencer;

VW608Q

Does anyone know if this will be the correct one? Reason I ask is I heard that the middle section/backbox were all one piece. Thanks



 
Title: Re: Stock exhaust help h
Post by: G-olf on January 20, 2021, 06:27:26 pm
Hi,
The standard exhaust is one piece from end of downpipe back. They corrode where the pipe joins the central silencer and then where the flat section is as the exhaust passes between the rear arms.
The replacement central silencer is available.
The original system is cut and the replacement centre section has a slip joint on the end. The original system is 63.5mm I think.
Have a look on you tube there is a guy opening up the original system to show you what’s inside.
Are you sure it’s all exhaust noise? What about induction?
What cat did you go for 200cell? And was it ok with emissions
Title: Re: Stock exhaust help h
Post by: G-olf on January 20, 2021, 06:51:06 pm
Can’t help with the e c p part but here’s the number for the genuine replacement centre section which they should be able to cross reference 1K0 253 209BP

Hope this helps 👍
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 07:21:29 pm
Hi,
The standard exhaust is one piece from end of downpipe back. They corrode where the pipe joins the central silencer and then where the flat section is as the exhaust passes between the rear arms.
The replacement central silencer is available.
The original system is cut and the replacement centre section has a slip joint on the end. The original system is 63.5mm I think.
Have a look on you tube there is a guy opening up the original system to show you what’s inside.
Are you sure it’s all exhaust noise? What about induction?
What cat did you go for 200cell? And was it ok with emissions

Hi thanks for your help. It does have a ramair induction kit on it but I'm pretty sure it's just the exhaust. Yes it was a 200 cell magnaflow cat, not took it for the mot yet so not sure on emissions.

I know I will be ok joining to the backbox as it's original but I'm worrying about connecting to the downpipe, obviously I will need a 3 inch to 2.5 inch reducer but will any do? Don't want to mess the length up.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 07:39:33 pm
Can’t help with the e c p part but here’s the number for the genuine replacement centre section which they should be able to cross reference 1K0 253 209BP

Hope this helps 👍

The part number on the diagram they gave me is 1K0 253 209AQ
Title: Re: Stock exhaust help h
Post by: GVK on January 20, 2021, 08:09:34 pm
https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/center-muffler-assembly/1k0253209aq/

part number ending AQ looks like that

BP is for a BYD (EDITION 30)

https://volkswagen.7zap.com/en/rdw/golf+variant+4motion/golf/2009-625/2/253-253090/
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 09:08:07 pm
Here is the diagram they showed me

https://ibb.co/Y2WPsTX

Only thing is the downpipe I have doesn't look as long as the stock one in the diagram, unless it's just not to scale. The downpipe I have seems to have a much shorter horizontal section.
Title: Re: Stock exhaust help h
Post by: GVK on January 20, 2021, 09:16:20 pm
Just a poor diagram I expect.

If you search for VW608Q it brings up pattern part exhaust on ebay etc.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 09:35:58 pm
Just a poor diagram I expect.

If you search for VW608Q it brings up pattern part exhaust on ebay etc.


Thanks, here are some pics of my exhaust (before the sports cat was welded in).

https://ibb.co/f943xxV
https://ibb.co/tDC8FzZ
https://ibb.co/8xqVBCp

Does the middle section (with silencer) go in after the clamp in the second pic, towards the rear?

Edit : Just seen that it does go here.

Do you think this will reduce the loudness by a lot or will most of the noise be coming from the 3 inch downpipe?
Title: Re: Stock exhaust help h
Post by: G-olf on January 20, 2021, 10:06:12 pm
The second picture shows the downpipe reducing in size 👍
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 20, 2021, 10:12:29 pm
The second picture shows the downpipe reducing in size 👍

Yes so an OEM centre silencer should slot straight onto here correct? Sorry I know I sound thick lol just want to be 100% sure after the trouble I've had so far!
Title: Re: Stock exhaust help h
Post by: G-olf on January 20, 2021, 10:39:08 pm
In theory yes, although the standard downpipe/centre joint normally has the tubes both the same size which just butt together then a longer double clamp or sleeve goes over both.

It should also be a simple job for one of the custom exhaust shops to add a silencer, not sure how much though.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 21, 2021, 08:36:08 am
In theory yes, although the standard downpipe/centre joint normally has the tubes both the same size which just butt together then a longer double clamp or sleeve goes over both.

It should also be a simple job for one of the custom exhaust shops to add a silencer, not sure how much though.

Thanks again. So I may end up short with the pipes having to overlap? Is there any easy solution to this?

I take it when you say exhaust shop to add silencer you mean to weld one in to the downpipe/middle section? I did think of this but trying to keep costs to a minimum and I can get the original middle silencer for about £65. Just really want to bring the noise level down as it's mega loud. Hoping a middle silencer will do this otherwise will mean changing the downpipe which I've just spent £200 getting a cat put on it. What a hassle lol.
Title: Re: Stock exhaust help h
Post by: Jb55 on January 21, 2021, 12:28:57 pm
I’d get the car to the mot station and see if it passes with the cat you’ve put on before spending more money adding a silencer.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 21, 2021, 01:45:30 pm
I’d get the car to the mot station and see if it passes with the cat you’ve put on before spending more money adding a silencer.

Hi, i want to reduce the noise regardless though as it's just too loud. Just want to be sure what I'm doing will definitely reduce the noise as i was told by a few people that adding a sports cat would but it hasn't made any difference.
Title: Re: Stock exhaust help h
Post by: G-olf on January 21, 2021, 05:28:04 pm
I suspect a stainless silencer would be close to that without fitting.

If you buy the standard centre it should just need the sleeve clamp on downpipe end and a regular u bolt type for the joint to back box.

As JB said, just run the car into the mot station and ask them to put it on the emissions machine to see if your cat has done the job.  Make  sure car is warm/ oil temp is high enough so the cat has enough heat in it.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 21, 2021, 06:26:41 pm
Cheers, yes i will call in the mot centre this weekend and ask if they can test emissions before mot or if not first thing as part of mot. If cat is no good I'll probably throw more money at a standard downpipe (which equals even more as map will probably need changing). Failing that may see whether the tester likes £20 notes.

Thought i had an alright deal by knocking off £500 asking price to sort the exhaust but current cost £210, plus silencer, plus potential remap @ £££ and i still don't know if it will pass an mot!

What are people's opinions on what the sound should be like with 3" downpipe and sports cat into standard middle silencer and rear, surely still not going to be mega loud?
Title: Re: Stock exhaust help h
Post by: G-olf on January 21, 2021, 07:32:40 pm
Lots of people on here have that combo, it should be just a bit louder than standard.

They always make more noise on cold start, then settle down.
You’re probably getting a bit of extra induction noise because of the filter too

If the tuners map is the same for sports cat or de cat then it should be ok. Something to perhaps check out once you’re up and running
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 21, 2021, 08:41:34 pm
Lots of people on here have that combo, it should be just a bit louder than standard.

They always make more noise on cold start, then settle down.
You’re probably getting a bit of extra induction noise because of the filter too

If the tuners map is the same for sports cat or de cat then it should be ok. Something to perhaps check out once you’re up and running

Cool, i could live with that level of noise. Yeah I'm unsure on the map, they said they'd want £150 to tweak the map but didn't say in what way it needed to be tweaked. If it's just lost a few bhp then i don't care but what I don't want is it to damage the car in anyway obviously or cause it to use more fuel etc. Another more local tuning company with great reviews said they can't see why it would need altering.
Title: Re: Stock exhaust help h
Post by: ahsan82 on January 21, 2021, 09:16:14 pm
have you thought about taking it to a custom exhaust place to have a centre box added to reduce the noise?
Title: Re: Stock exhaust help h
Post by: fakie1977 on January 21, 2021, 09:32:25 pm
have you thought about taking it to a custom exhaust place to have a centre box added to reduce the noise?
Yeah this is what I would do - getting someone to add a resonator/silencer shouldn’t be that expensive.


Sent from my iPhone using Tapatalk
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 22, 2021, 12:12:05 am
have you thought about taking it to a custom exhaust place to have a centre box added to reduce the noise?
Yeah this is what I would do - getting someone to add a resonator/silencer shouldn’t be that expensive.


Sent from my iPhone using Tapatalk

Do you mean getting a resonator/silencer welded in where the OEM one would be? What would be the reasoning behind this over OEM, better sound/less restriction etc.? If it was nearly as cheap then I would go for it but I'm looking at £80 for new centre silencer fitted. The exhaust company that quoted to weld in my CAT wanted £150 and that's with me supplying the part so I'm guessing it will be the same for a silencer plus the part so looking at £250?
Title: Re: Stock exhaust help h
Post by: pudding on January 23, 2021, 12:41:19 am
The original system is 63.5mm I think.

I'm sure I measured it at 70mm outside diameter last time I messed with the exhaust. I could be wrong though, was a while ago. Ze Germans love their odd ball metric sizing.

It's a strange system.  Massive turbo outlet, which then immediately throttles down into a tiny crimped section for gear cable clearance after the cat, and then bores up again to 70ish mm back, and then squashed down again for floor/subframe clearance at the back.

Having said that, I've not noticed a 'seat of the pants' gain in fitting a 3" downpipe.  Maybe 10hp at the top end, tops.  In spite of the physical evidence and intuition of restrictions and narrow bore....the net result isn't actually that restrictive.  Voodoo gas flow dynamics at play.  Plus the engine is physically and electronically tuned for said restrictions.  In the same way binning the R32's cats absolutely kills the bottom end torque.
Title: Re: Stock exhaust help h
Post by: pudding on January 23, 2021, 12:49:59 am
Lots of people on here have that combo, it should be just a bit louder than standard.

They always make more noise on cold start, then settle down.
You’re probably getting a bit of extra induction noise because of the filter too

If the tuners map is the same for sports cat or de cat then it should be ok. Something to perhaps check out once you’re up and running

Cool, i could live with that level of noise. Yeah I'm unsure on the map, they said they'd want £150 to tweak the map but didn't say in what way it needed to be tweaked. If it's just lost a few bhp then i don't care but what I don't want is it to damage the car in anyway obviously or cause it to use more fuel etc. Another more local tuning company with great reviews said they can't see why it would need altering.

As per my comments in your other thread, you don't need a map tweak to fit a sports cat in terms of engine performance.  It will tune itself automatically for mild alterations like that.  What they might mean is turning off the downstream O2 sensors to stop the EML coming on.  That is a simple on/off byte change in the map, hardly £150 worth of work. 

The reason why the EML might come on with a sports cat or decat is because gas flow through both is much faster compared to an OEM cat, which the secondary O2 detects as a catalyst efficiency fault and stick the engine light on the dash.  The best thing to do is run the sports cat for a while and see if the EML comes on.  If it doesn't, all good.  If it does, worry about shifting the EML some other time.  It doesn't do anything to the engine.  It's just an EU emissions law to flag a cat fault.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 23, 2021, 10:11:21 am
Lots of people on here have that combo, it should be just a bit louder than standard.

They always make more noise on cold start, then settle down.
You’re probably getting a bit of extra induction noise because of the filter too

If the tuners map is the same for sports cat or de cat then it should be ok. Something to perhaps check out once you’re up and running

Cool, i could live with that level of noise. Yeah I'm unsure on the map, they said they'd want £150 to tweak the map but didn't say in what way it needed to be tweaked. If it's just lost a few bhp then i don't care but what I don't want is it to damage the car in anyway obviously or cause it to use more fuel etc. Another more local tuning company with great reviews said they can't see why it would need altering.

As per my comments in your other thread, you don't need a map tweak to fit a sports cat in terms of engine performance.  It will tune itself automatically for mild alterations like that.  What they might mean is turning off the downstream O2 sensors to stop the EML coming on.  That is a simple on/off byte change in the map, hardly £150 worth of work. 

The reason why the EML might come on with a sports cat or decat is because gas flow through both is much faster compared to an OEM cat, which the secondary O2 detects as a catalyst efficiency fault and stick the engine light on the dash.  The best thing to do is run the sports cat for a while and see if the EML comes on.  If it doesn't, all good.  If it does, worry about shifting the EML some other time.  It doesn't do anything to the engine.  It's just an EU emissions law to flag a cat fault.

Thanks this is reassuring. The light didn't come on the other day when I had it fitted but I didn't run the car for very long at all. Because they had mapped out the eml with the decat you would think it would come on with the sports cat either.

Now my other problem is the noise! Do you think putting the middle silencer back in will make a big difference? Watching YouTube I can't make up my mind. Even peoples videos where they have same as me (3 inch decat/sports cat into middle delete into standard backbox) it just doesn't sound as raw as mine, it has at least some tone to it where as mine is just LOUD. And it def. Isn't leaking either. Will have to try and do a video to see what people think.

Some people mention having a silencer put in, still not sure if they mean welded in or those things you put in the exhaust tips? Any further advice welcome, main aim is to reduce noise significantly while having a little effect as possible on the map. And all for the cheapest price possible, not asking much am I  :grin:
Title: Re: Stock exhaust help h
Post by: brian_badonde on January 25, 2021, 03:51:04 pm
Best bet is to go to a decent exhaust place and ask for their opinion I think. A middle silencer/resonator will definitely make a difference, hard to say by how much. What back box is on there at the moment? Is it the stock one? My (limited) understanding is that the back box is there to primarily reduce the overall volume whilst the resonator aims to avoid resonant frequencies that give you a drone in the cabin, although obviously as they're another restriction they also reduce volume.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 25, 2021, 05:43:46 pm
Best bet is to go to a decent exhaust place and ask for their opinion I think. A middle silencer/resonator will definitely make a difference, hard to say by how much. What back box is on there at the moment? Is it the stock one? My (limited) understanding is that the back box is there to primarily reduce the overall volume whilst the resonator aims to avoid resonant frequencies that give you a drone in the cabin, although obviously as they're another restriction they also reduce volume.

Hi mate, yes it's the original backbox. I've ordered the standard middle section so hopefully get that fitted later this week. I've taken a video today but not sure how I post it. Worryingly lots of black smoke on first rev but I'm hoping that's just where it's been sat for weeks as it didn't smoke before.

I've booked it in for an emissions test tomorrow at my mot place so crossing fingers it will be ok.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 25, 2021, 05:51:10 pm
https://streamable.com/tnucue

Try this, black smoke is bad! But like I said this was the first time I started it in a week or two and also since the new downpipe was put on (only ran it for a few minutes when fitted). Hardly revved it either as I didn't want to upset the neighbors.
Title: Re: Stock exhaust help h
Post by: G-olf on January 25, 2021, 06:41:36 pm
Don’t forget they always make more noise on cold start it will settle down as it warms up.

Black smoke may just be lots of stop/starts?? Fuel??

Who welded in the sports cat and did they do a good job? How much was it?

Interested to see how you get on with emissions test.

Good luck 👍
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 25, 2021, 07:09:01 pm
Don’t forget they always make more noise on cold start it will settle down as it warms up.

Black smoke may just be lots of stop/starts?? Fuel??

Who welded in the sports cat and did they do a good job? How much was it?

Interested to see how you get on with emissions test.

Good luck 👍

Yes to be fair after a minute it was idling pretty quiet with no smoke. Hoping the black smoke is like you say stop starts rather than running rich/lean. It's been sat for weeks now with only odd start, not driven.

The cat was welded in by a bloke working out of his front garden in the roughest area of town lol. He did have excellent reviews online and was cheap at £60. Wasn't entirely happy though as he didn't smooth off the end and so it wouldn't fit back together meaning my mechanic had to get the grinder out, cost me another £20. No leaks though once on.

Yes will update tomorrow, was thinking of putting some liqui moly in then taking it for a little run first, worth a try?
Title: Re: Stock exhaust help h
Post by: brian_badonde on January 26, 2021, 09:15:09 am
I could be completely wrong but hearing it on the video I reckon a resonator will make a big difference and hopefully tone down the ASBO factor for you.

Finger's crossed for your emissions test today  :happy2:
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 26, 2021, 09:48:03 am
I could be completely wrong but hearing it on the video I reckon a resonator will make a big difference and hopefully tone down the ASBO factor for you.

Finger's crossed for your emissions test today  :happy2:

Cheers, any thoughts on black smoke? Hoping it's just where it's been sat for a while but worrying it might be bad cat/overfueling due to map not being right for new cat.
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 26, 2021, 02:59:10 pm
And the results are in!

You might find this hard to believe after seeing the video earlier with plumes of black smoke coming out of the exhaust but it passed with zero emissions! haha  :surprised:

I did put a bottle of liqui moly in and gave it a good ragging beforehand (15mpg  :laugh:) but all good, and mot booked for Monday.
Title: Re: Stock exhaust help h
Post by: Jb55 on January 26, 2021, 03:45:24 pm
That’s great news
Title: Re: Stock exhaust help h
Post by: G-olf on January 26, 2021, 07:24:51 pm
 :happy2:
Title: Re: Stock exhaust help h
Post by: brian_badonde on January 27, 2021, 08:42:42 am
 :congrats: superb, glad to hear it!
Title: Re: Stock exhaust help h
Post by: Jons1001 on January 27, 2021, 09:21:42 am
Cheers was definitely surprised the reading was zero. Here is the sports cat btw;

https://ibb.co/d6D7wtC

Not the cleanest job lol, my ex welder work colleague said 'did a bird sh*t on those pipes?!'

But for £60 (plus £100 for the cat itself) it's done the job so can't complain. Just hoping putting the resonator back in will sort the loudness/drone out now, what exhaust setup have you guys got?