MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: nezquick on January 22, 2012, 07:36:05 pm

Title: downpipe, decat and sports cat question
Post by: nezquick on January 22, 2012, 07:36:05 pm
I am interested in getting myself a downpipe soon (3") and need so ask for some advice. the deal includes a decat but my car is a daily driver with mitor way trips bi-weekly.

Which would be the best option to avoid in cabkn drone (excessive) particulary around motorway speeds. Avoid failing my m.o.t (shouldnt be a problem as mechanic is froend and doesnt mind swapping but if pulled and tested i dont want to fail miserably or for them to think im "taking the piss".

So is it better to run with the decat that comes with it, run it with just the downpipe, run it with 200cel sports cat.

A remap is going to be done soon so hence the downpipe.

Also if i aas to just run the downpipe and mate it to the stock exhaust will that be noticable kncrease in bhp and reponse and sound or barely worth it? i do hae a resonated miltek rear and centre (bought with the car)

Thanks in advanced  :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: Janner_Sy on January 22, 2012, 07:40:41 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered
Title: Re: downpipe, decat and sports cat question
Post by: nezquick on January 22, 2012, 07:49:26 pm
So you think just take it to a chop shop and get them to whack just the downpipe on with the stock. i love the burble and a little bit of pop but really dont want anything excessive or attention seeking. especially when im coming back late did yours throw a check light when you installed the downpipe?
Title: Re: downpipe, decat and sports cat question
Post by: sub39h on January 22, 2012, 07:56:43 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

hmm so could i theoretically have a Milltek DP with sports cat mated to my OEM middle and rear sections? the Milltek website states that you HAVE to have the cat back if you have their downpipe
Title: Re: downpipe, decat and sports cat question
Post by: nezquick on January 22, 2012, 08:08:41 pm
I think fhey put that if your to get the quoted or stated increase figures and if you dont then you cant complain to say it hasnt done what it claimed. The more iv been reading the power comes more from the downpipe. i guess so long as you have a reasonable exhaust or sport cats then your more likely to get better resukts.
Title: Re: downpipe, decat and sports cat question
Post by: Janner_Sy on January 22, 2012, 09:51:13 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

hmm so could i theoretically have a Milltek DP with sports cat mated to my OEM middle and rear sections? the Milltek website states that you HAVE to have the cat back if you have their downpipe

Miltek will say that because they are trying to make cash.  

yes you can, you just need a reducer to connect the two.  I had the pipewerx downpipe which didnt even need the reducer as it was built into the pipe already.

This isnt the one i had but you can see the reducer builtinto it

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fwww.awesome-gti.co.uk%2Fshopimages%2Fproducts%2Fnormal%2Fpwerx6.jpg&hash=7010dfac6e9b794c0355289a9d9c0a15cce62378)
Title: Re: downpipe, decat and sports cat question
Post by: bulak on January 22, 2012, 09:58:49 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

just wanted to know what cat back did you have? i actually have a downpipe and decat brand new blueflame but never been fitted
currently got blueflame suitcase delete and was thinking of adding the downpipe and sell the decat

but i dont want any drone  :fighting:
Title: Re: downpipe, decat and sports cat question
Post by: gazon69 on January 22, 2012, 10:09:28 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered
i was in the same boat. Had 3" decat and full milltek non res, sounded evil on throttle but m/way driving just did my nut in. Gone back to standard cat back now. Sounds ok but pondering on whether to go for the suitcase delete in the way of the blueflame but leave in the standard res box
Title: Re: downpipe, decat and sports cat question
Post by: fab5freddy on January 23, 2012, 10:26:53 am
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

just wanted to know what cat back did you have? i actually have a downpipe and decat brand new blueflame but never been fitted
currently got blueflame suitcase delete and was thinking of adding the downpipe and sell the decat

but i dont want any drone  :fighting:

What's a suitcase delete?  :confused:
Title: Re: downpipe, decat and sports cat question
Post by: bulak on January 23, 2012, 11:36:42 am
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

just wanted to know what cat back did you have? i actually have a downpipe and decat brand new blueflame but never been fitted
currently got blueflame suitcase delete and was thinking of adding the downpipe and sell the decat

but i dont want any drone  :fighting:

What's a suitcase delete?  :confused:


removes the exhaust (suitcase)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2Foldexhaust.jpg&hash=a1bd90b6d5ed3c68edd769c03585fbd475c561e0)

and replace it with this

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2FGOLFMK5TAILS1.jpg&hash=b9af5a772df5fa19f76f6f1a8b09c665363a477a)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2FIMAG0014.jpg&hash=30a00d2ce6fcbea94794c413775c0e59e8e666aa)

very big mod in America
Title: Re: downpipe, decat and sports cat question
Post by: GTImike on January 23, 2012, 12:17:54 pm
I was pondering on this question as well, I ended up buying a Milltek 2.75 inch DP and 200 cell sport cat for my ED30 off ebay (cheap as chips), I only realised it was 2.75inch when it arrived as I was more worried about the turbo flange being correct for the K04 rather than K03. Others have confirmed that the flange is the same and someone was recently advertising one on here had stated that the 2.75 inch actually makes better torque over the 3 inch but less out right power, but not sure if that's true??

I was toying with just getting this fitted to my standard system and a remap to suit, I'm not bothered about stage 2 plus or chasing big big power as I can't be bothered with the hassle of the HPFP and far worse MPG etc. Does anyone know what diameter the std cat back exhaust is, so that I can order a reducer? I'll just be happy with a solid 300 bhp (planning on a CAI as well, then that's it engine mods wise). There was a Scirroco R in VW Driver the other month with similar mods that had a rolling road output of around 320bhp.

In a nutshell, the Milltek should surely be a better bet than the std DP and cat currently fitted to mine shouldn't it?? :confused: :stupid:
Title: Re: downpipe, decat and sports cat question
Post by: fab5freddy on January 23, 2012, 12:46:42 pm
Mine hadthe 3"DP mated to stock exhaust which made a lovely deep burble.  this iis where 99% of the bhp gains are

After a year or so I fitted the cat back as well and hated the drone and wished id never bothered

just wanted to know what cat back did you have? i actually have a downpipe and decat brand new blueflame but never been fitted
currently got blueflame suitcase delete and was thinking of adding the downpipe and sell the decat

but i dont want any drone  :fighting:

What's a suitcase delete?  :confused:


removes the exhaust (suitcase)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2Foldexhaust.jpg&hash=a1bd90b6d5ed3c68edd769c03585fbd475c561e0)

and replace it with this

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2FGOLFMK5TAILS1.jpg&hash=b9af5a772df5fa19f76f6f1a8b09c665363a477a)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fff451%2FAbubacker_Lakhanpal%2FIMAG0014.jpg&hash=30a00d2ce6fcbea94794c413775c0e59e8e666aa)

very big mod in America



 :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: stu_no_1 on January 23, 2012, 04:53:36 pm
For the mot id just find a more friendly mot tester and tell them its decatted save you the hassle of changing it every time
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 23, 2012, 05:24:32 pm
Have you considered the BCS Downpipe and oversized 100 cell cat. It's FIA approved and fully road legal, with the flow rate of a de cat pipe. Also has the adapter pipe which will allow you to go to full 76mm when upgrading to the full system without using any step down pipework.
It also runs a 1d bend of the turbo which means it wont hit the tunnel heat shield or put undue stress on the flex, and utilises the longer 200mm 76mm twin core ILOK Flexible decoupling joint (so no cracking).
Power gain is massive even on the stock map.
Cheers
Nige
 :happy2:

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi66.photobucket.com%2Falbums%2Fh269%2Fnigeblueflame%2FRACECAT.jpg&hash=2263d066799ad0874ae959f4529d9bd3e3900982)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fnigeblueflame%2FVW%2FBCSFlexcomparison.jpg&hash=aef1358d19c002b1dc7ca3c5d0c2d446e3e5610a)
Title: Re: Re: downpipe, decat and sports cat question
Post by: Marshall on January 23, 2012, 10:00:28 pm
I had a milltek catback on my cupra R with standard downpipe and have removed it and sold it due to the noise was too much at motorway speeds.
Anyway I've spent the money on a Pipewerx down pipe with sportscat to mate to my original catback and it has made the exhaust a bit noisier but not boomy but the greatest thing is the extra power and larger powerband.
Well made and great pipe I wouldn't opt for catback again.
Waste of time and money only for looks. Sports downpipe is the only way to go.

Sent from my HTC Sensation XE
Title: Re: downpipe, decat and sports cat question
Post by: nezquick on January 26, 2012, 02:07:35 pm
Have you considered the BCS Downpipe and oversized 100 cell cat. It's FIA approved and fully road legal, with the flow rate of a de cat pipe. Also has the adapter pipe which will allow you to go to full 76mm when upgrading to the full system without using any step down pipework.
It also runs a 1d bend of the turbo which means it wont hit the tunnel heat shield or put undue stress on the flex, and utilises the longer 200mm 76mm twin core ILOK Flexible decoupling joint (so no cracking).
Power gain is massive even on the stock map.
Cheers
Nige
 :happy2:

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi66.photobucket.com%2Falbums%2Fh269%2Fnigeblueflame%2FRACECAT.jpg&hash=2263d066799ad0874ae959f4529d9bd3e3900982)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fnigeblueflame%2FVW%2FBCSFlexcomparison.jpg&hash=aef1358d19c002b1dc7ca3c5d0c2d446e3e5610a)

Does it matter what cat i run? for example could I just pick up a universal sports cat and have a shop mate it to the downpipe? or is there a specific size I'd need?

Cheers
Title: Re: downpipe, decat and sports cat question
Post by: vRS_Pagey on January 26, 2012, 08:04:35 pm
One option would be to firstly remove the pre-cat material from your OE downpipe, then have a garage cut out the cat and replace it with a straight pipe, but heres the clever part, they weld flanges to all the ends so you can swap it back in 15 minutes to pass your MOT......?
Title: Re: downpipe, decat and sports cat question
Post by: nezquick on January 27, 2012, 09:51:20 am
One option would be to firstly remove the pre-cat material from your OE downpipe, then have a garage cut out the cat and replace it with a straight pipe, but heres the clever part, they weld flanges to all the ends so you can swap it back in 15 minutes to pass your MOT......?

Yeah I've read a few forums where this tends to be the case, but I don't really want to have drone in the car. Especially as I do a motorway trip regulary I don't fancy ending up hating every minute when I should be enjoying it. Does this cause a lot of drone? I don't quite fancy swapping my exhaust every few weeks for motorway travel although I guess I don't mind a little drone in the low revs.

Title: Re: downpipe, decat and sports cat question
Post by: Ducky76 on January 27, 2012, 03:53:41 pm
Just ordered the blueflame suitcase delete off e bay 150£ so gunna fit that and knock out pre cat , so would that make exhaust good enough for stage 2 or is it just the cat that makes ALL the difference ?? Seen 200 cell cats on e bay for 100£ 2
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 10:47:03 am
Don't want to worry you but price is directly proportional to the loading of precious metals on the cat monolith.
Most cheap cats have a miserly 5gram loading - in certain cases enough to turn the cel off - however, the durability of the cat will be crucially dependent on the loading.
Nothing worse than getting to you MOT guy and failing due to the PM's having burnt off, and then confronting the manufacturer who will squirm out of it by saying - it only has a one year guarantee, or is the car mapped as this invalidates the warranty or we only allow the warranty if you use our map.
And all the other B--- ---t excuses for ripping you off in the first place.
My advice is save up for a while longer and buy proper kit - trust me the wait will be worth it in the end.
Cheers
Nige
 :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: Upperoilcan on January 28, 2012, 11:17:19 am
Nige,do you guys do a suitcase delete ?
Title: Re: downpipe, decat and sports cat question
Post by: Ducky76 on January 28, 2012, 11:51:00 am
Ok cheers il start saving then ,that new fence might have 2 wait :smiley:
Title: Re: downpipe, decat and sports cat question
Post by: Janner_Sy on January 28, 2012, 12:14:04 pm
That double size 100cell race cat option seems very appealing to me.

Im currently running a decat and my map has been setup with that in mind, so i putting a 200cell cat on would slow the flow down alot.  Whats tthe going rate on a double size cat downpipe setup; well a rough guide.  ie normal 200 cell downpipe is around £500
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 01:39:47 pm
Nige,do you guys do a suitcase delete ?

Well TBH we've never done one, it's going to be achingly loud - we get over this by inserting into our system the oversized front silencer. This then provides the perfect balance of tone and power.
However, notwithstanding this we could make one on your car for you no problem.
Cheers
Nige
 :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 01:42:23 pm
Ok cheers il start saving then ,that new fence might have 2 wait :smiley:

Sensible choice  - one that will definitely pay you back in spades
Cheers
Nige
 :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 01:52:40 pm
That double size 100cell race cat option seems very appealing to me.

Im currently running a decat and my map has been setup with that in mind, so i putting a 200cell cat on would slow the flow down alot.  Whats tthe going rate on a double size cat downpipe setup; well a rough guide.  ie normal 200 cell downpipe is around £500

Hey - thanks for the enquiry.
The downpipe and 100cell oversized cat is £561.00 inc vat (this includes the connecting pipe to take it back to the oem cat back - this can be removed if the system is later upgraded to our full 76mm system)
Cheers
Nige
 :happy2:
Title: Re: downpipe, decat and sports cat question
Post by: Janner_Sy on January 28, 2012, 06:14:04 pm
Still pass emmissions?

Do you offer any sort of heatwrap or zircotec coating?
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 07:48:03 pm
Still pass emmissions?

Do you offer any sort of heatwrap or zircotec coating?

Hi there
Yes we can wrap it for you no problem.
To have it ceramic coated will cost in the region of £125.00
Cheers
Nige
Title: Re: downpipe, decat and sports cat question
Post by: Janner_Sy on January 28, 2012, 08:06:20 pm
When i get back from Afghan i think ill take you up on that actually, i was going with the piper one but im reluctant as my last one was to loud
Title: Re: downpipe, decat and sports cat question
Post by: Powervalve Nige on January 28, 2012, 09:33:04 pm
Hey - many thanks for considering us.
Get in touch when your ready - I'll look after you.
Stay safe
Nige
BCS