De-catted exhaust system

Grant

Grant

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I've read of people having sports cats, but has anyone fitted a de-cat pipe on their S3?

One like the Supersprint one below:
325512.jpg


Come MOT time, how easy would it be to change back to the OEM cat for the emmission test?
 
I think Dave_Cav had the decat system fitted - and subsequently removed it beacuse of either DTCs or running problems.

As for installation, they can be a pain in the ***, as the bolts / nuts can rust together and then shear off.

As for MOT, thats fine, but there are now mobile emmission checks at the roadside which can identify "rogue" emmissions.

Still searching for that magic 300lb/ft??
 
[ QUOTE ]
David R said:
Still searching for that magic 300lb/ft??

[/ QUOTE ]
I have 299.9lb/ft - or so AmD say, but let's not get into that! /ubbthreads/images/graemlins/lol.gif
 
De-Cat pipes "should" be really easy to fit, not to sure about the S3 one but in general if they are good it should only be a case of 4-6 bolts. But obviously if you de-cat your car your engine management light will go on because your lambda sensor (wee sensor that tells all your fueling) will be going insane.

Imola if you are from Aberdeen I would advise that you take a trip to C&C Stainless Custom Exhausts in Hillington Industrial Estate (Glasgow), they have made all my exhausts and I would never go anywhere else. Top quality worksmanship, highly advise them, they would make you a full custom exhaust system for around £300, I think for a de-cat pipe to be made they would charge around £50.

Hope this helps /ubbthreads/images/graemlins/smile.gif

Pete.
 
My mate who has a Clio 172 has just fitted a JanSpeed decat pipe to his car. His decat pipe has 2 ports for the lambda sensors... one at the front and one at the back.

By looking at the pic of the Supersprint decat pipe, is it just me of does it look like there is a port on each pipe before it goes into the one larger pipe?

325512.jpg


So surely that would stop the engine management light coming on as it is just a direct replacement of the cats?
 
[ QUOTE ]
Imola S3 said:
My mate who has a Clio 172 has just fitted a JanSpeed decat pipe to his car. His decat pipe has 2 ports for the lambda sensors... one at the front and one at the back.

By looking at the pic of the Supersprint decat pipe, is it just me of does it look like there is a port on each pipe before it goes into the one larger pipe?

325512.jpg


So surely that would stop the engine management light coming on as it is just a direct replacement of the cats?

[/ QUOTE ]

THAT is why it will cause fault codes - Th lambda sensors measure before and after the cats..this way it can tell if the CAT is doing its job or not. If theres no cat there, the reading after will be far too high, and cause the engine management light to come on. On the earlier model A3's (not sure about S3), they only had 1 lambda sensor before the cat, so fitting a de-cat isnt a problem.

Make sense?

Rich
 
The lambda sensors would go into the ports on the decat pipe instead of the cat - therefore the ECU still gets the signal - no?

The Supersprint Sports cat has the same ports:
762602.jpg

 
Yes the sensors would go onto the de-cat pipe.

Your engine management light "will" go on, there is no question of this. Yes the ECU will get the signal but it will be getting the signal "oh my god look at all the [censored] flying through that exhaust" which is what will cause your management light to activate. /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

Pete.
 
[ QUOTE ]
Quik said:
Yes the sensors would go onto the de-cat pipe.

Your engine management light "will" go on, there is no question of this. Yes the ECU will get the signal but it will be getting the signal "oh my god look at all the [censored] flying through that exhaust" which is what will cause your management light to activate. /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

Pete.

[/ QUOTE ]

Spot on!
 
Quik and Rich,

Do you know this from personal experience or are you both presuming?

I had a decat pipe on a previous car and no warning lights came on. My mate's Clio 172 has a decat pipe with similar ports to plug in the lambda sensors and has had no warning lights and neither has anyone on the Clio Sport website.

This is a professionally made cat replacement pipe - not a cheap piece of tubing from someone like Powerflow.
 
Personal experiance with both my Bmw Mini Cooper and my mates Seat Leon Cupra and the same mates 380bhp escort cossie and 106gti

It doesn't matter how good or bad your pipe is the fact of the matter is your car will be way over the legal emmisions and therefor your lambda sensor will go on, if it does not then it has been disconnected or is not working. The job of the sensor is to warn you when you are giving off more emmisions and when you remove your cat thats what happens, hense the reason people remove their cat when they install a flamer kit (more petrol more fumes = more to go on fire)

This will be even more so because of the turbo also, when the turbo spools up obviously there is a mass rush of petrol to cope with the amount of extra power.

And you are saying that in your old car the light didn't go on, maybe the sensor is not as sensitive or something like that but it "should" have went on. But I can tell you this now, it will in an S3 /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

/ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif Hope this all helps m8, and seriously you should speak to C&C they are amazing.

heh just noticed I have a de-cat pipe for a mini sitting beside me.

Pete.
 
So by fitting the decat pipe, let's say the ECU warning light comes on - does that mean the ECU will alter fueling to try and recover the problem, therefore not delivering the same power?

I appreciate your commments Quik
 
Its no problem mate, more than happy to help /ubbthreads/images/graemlins/smile.gif

No it will cause no problems, the light will come on but it is nothing to worry about, just a bit annoying really.

Pete. /ubbthreads/images/graemlins/laugh.gif:D
 
OK...so you want a de-cat pipe?
Why?

To get a CEL?

To get more power...I doubt it.

Have any of you looked at a set of standard cats? You can see through them. Restriction? I don't think so. Not noticably so.

Milltek cars have even less inside...you can see straight through them...OK you'll pass the emissions test with them...but you will also get the occasional 'catalyst efficiency below threshold' DTC - but no CEL.
So if you get nothing by way of a power increase from fitting Milltek cats (no power, no torque...well, I got nothing anyway!) and they don't cause a restriction....why fit a de-cat pipe and risk getting humped by the feds for failing a roadside emissions test?
The standard cats are fine...no CELs, no restriction to speak of...why change them?

Everyone's always looking for cheap / free power.
Aren't we all...but this isn't some Micky Mouse, two bit, crap engine you know...it's been developed properly, and there aren't mysterious 10 BHP / 20 lb-ft gains to be found...especially by removing the cats.
Sorry to be so blunt...but it's a complete waste of effort in my book.

Oh, and modern EU compliant engines CAN enter a form of output limiting mode if they detect the emissions are way out...to remain within spec of the emissions.
So, it's possible that fitting a de-cat pipe COULD reduce engine output. Doesn't sound like aso much of a good idea now, does it?
 
Got that supersprint pipe and to be fair did feel a bit more free reving if that makes sense?? also sounded alot better cos i had a straight throw pipe made aswell , The standard pipe is very restrictive,

As for fitting it went straight on and off

And yes your engine managment light WILL come on

Its sat here if you want to buy it and try m8
 
Yea would actually say there is more of a chance of loosing power by removing the cat, results in loss of backpressure, and a little backpressure never hurts anyone /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif

Only reason I would really remove the cat is:

1. If you want it to flame
2. If you want it to pop and bang (mmm nice)

Pete.
 
Heheh I should be on commision from C&C really but I just think anyone that gets an exhaust should go to them /ubbthreads/images/graemlins/laugh.gif:D
They did a honda civic when I was there, and the guy went and got it dyno'd, 35bhp from an exhaust, now thats not bad at all, (before and after dyno on the same day)

And like I said, a de-cat pipe from them would only be around £50 and you wouldn't have to go to the garage to get it taken on or off come Mot time, it is a case of 6 bolts on the S3 and if its new they shouldn't even be difficult to take out, you could easily do it yourself.

To be honest I would just leave the cat in, get a straight pipe made with just a backbox and thats it.

Ess Three take a chill pill, nobody was having a go at you, wheres all the agrovation coming from. And remember other people have also been there and done it all, you are not the only person on here with tuning knowledge (may know more about S3's though /ubbthreads/images/graemlins/laugh.gif) I personally don't have any experiance with S3's but I have with Seat Leons which is basically the same car with a different chassis and many others. (Don't mean any of that in a bad way btw)

You were saying how a car cannot produce more than standard with nothing done to it, that is inaccurate, I have personally seen a standard 106gti have 30bhp more than it should and it ran a 14.9 1/4 mile (as standard)



Pete.
 
[ QUOTE ]
Quik said:
They did a honda civic when I was there, and the guy went and got it dyno'd, 35bhp from an exhaust, now thats not bad at all.....

[/ QUOTE ]

/ubbthreads/images/graemlins/laugh_roll.gif /ubbthreads/images/graemlins/laugh_roll.gif /ubbthreads/images/graemlins/laugh_roll.gif

Normally aspirated, 35bhp /ubbthreads/images/graemlins/laugh_roll.gif Dreaming... /ubbthreads/images/graemlins/snore.gif
 
[ QUOTE ]
Quik said:You were saying how a car cannot produce more than standard with nothing done to it, that is inaccurate, I have personally seen a standard 106gti have 30bhp more than it should and it ran a 14.9 1/4 mile (as standard)
Pete.

[/ QUOTE ]

My 106Gti made 20bhp over standard awell

Ess Three No need for that last post whats your problem?
 
Glen

You have in the past given great advice and detailed product knowledge for example your time down at Star Performance.

However, there are times when your comments, especially your replies are a bit OTT when people challenge or disagree with what you say.

We all use forums to get a better knowledge of our cars and products that we have tried and tested and also to have a laugh. To say you don't give a toss what I spend my money on is very true as it is my money - but it is a little uncalled for and a wee bit chilidish.

I hope this is just a bad day in the life of Glen because you are usually a friendly, happy to help guy who is spot on with your advice!

Bring back the old Glen!
 
Heh seems to be common with 106 gti's we took my mates to GMC Motorsport, and they seriously know what they are doing with 106's and Saxo's, had about 25yrs experiance or something like that. Even they were surprised the extra power this lil thing had, they thought their machine was playing up and reset all the equipment and stuff lol.

Pete.
 
gmc really know there sh!t seen there supercharger kits??
 
[ QUOTE ]
Quik said:

Ess Three take a chill pill, nobody was having a go at you, wheres all the agrovation coming from. And remember other people have also been there and done it all, you are not the only person on here with tuning knowledge (may know more about S3's though /ubbthreads/images/graemlins/laugh.gif) I personally don't have any experiance with S3's but I have with Seat Leons which is basically the same car with a different chassis and many others. (Don't mean any of that in a bad way btw)


[/ QUOTE ]

Don't tell me to take a f'in chill pill!

This topic has been discussed at length on many occasions...as have the subjective 'gains' involved. Nobodys's having a go at anyone else...but this same old topic comes up time and time again, and we say the same old tired things...and the same old 'been on here 5 minute experts' go off and do the worthless mods, then whinge and whine about their lack of sucess and expect sympathy from other members.


As I previously stated, I couldn't give a toss if you or anyone else wants to waste their money on crap. But most people want value for money and actual gains...this is where advice comes from from those that HAVE actually tried it in the ACTUAL car in question.


[ QUOTE ]

You were saying how a car cannot produce more than standard with nothing done to it, that is inaccurate, I have personally seen a standard 106gti have 30bhp more than it should and it ran a 14.9 1/4 mile (as standard)


[/ QUOTE ]

Yes, yes...and I've been 1.4 Polos producion 25BHP more too...
But wait, was that 'Max Power' horsepower, 'Internet' horsepower, 'pie in the sky' horsepower, 'dreamer' horsepower or 'dyno operator fudging the figures' horsepower?
I wonder which...

It is bearly possible to get 30 GENUINE BHP out of a 106 GTI this side of a £3000 bill for serious headwork, cams, ITBs and standalone management. Certainly not from a standard car.
Believe me...we've tried.

As for 1/4 mile times...they are about as worthless as innacurate dyno plots.

There is a standard S4 on here ran a 13.1 1/4.
My best is a 14.5 1/4.
Funny that on the road, up to about 140MPH there is less than a car length in it.

No, but wait...that can't be...as his car does a 1/4 mile 1.4 seconds faster than mine, Or maybe less than a car length = 1.4 seconds (long car @ 100+ MPH)
Or maybe some timing gear is innacurate. Ah, no...that just can't be can it?
 
[ QUOTE ]
DaveCav said:

Ess Three No need for that last post whats your problem?

[/ QUOTE ]
No problem here...
The comments were warranted and I stand by them.

Is this what this forum has been reduced to?
 
[ QUOTE ]
Imola S3 said:
Glen

You have in the past given great advice and detailed product knowledge for example your time down at Star Performance.


[/ QUOTE ]

I'm glad you found it useful.


[ QUOTE ]

However, there are times when your comments, especially your replies are a bit OTT when people challenge or disagree with what you say.


[/ QUOTE ]

I don't believe so.
People can read my posts and make their own mind up.
Am I an argumentative fool? Probably.
Do I actually know what I'm commenting on? Probably.
Do I resort to being sacrastic to get people to admit to themselves that perhaps they are wasting theit money / time / effort? Probably.
Does that make me a bad person? No...I don't think so.

Everyone has a choice...read what you like, reply to what you like, buy what you like.

It doesn't affect me...but I'll not apologise for being somewhat abraisive if thet's what it takes to snap people out of the [censored] circle of missinformation that is the tuning industry in this country.

You (everyone this is) can always choose to ignore me, if you want.



[ QUOTE ]

We all use forums to get a better knowledge of our cars and products that we have tried and tested and also to have a laugh. To say you don't give a toss what I spend my money on is very true as it is my money - but it is a little uncalled for and a wee bit chilidish.


[/ QUOTE ]

Your view, not mone.
I respect it...I stand by my comments.

Being an Aberdonian, I would have expected you more than anyone to want value for money!



[ QUOTE ]

I hope this is just a bad day in the life of Glen because you are usually a friendly, happy to help guy who is spot on with your advice!


[/ QUOTE ]

Actually this is one of the best days of my life...for many reasons I shall not document here.



[ QUOTE ]

Bring back the old Glen!


[/ QUOTE ]

The old Glen has never left.
The old Glen is very passionate about tuning cars...
Very passionate about people receiving quality information and being able to make informed choices.
Very passionate about the way we in this country are fed miss-information which bluntly, amounts to fraud.
I'm not going to apologise for treating each and every menmer of this forum as a freind, and wanting MY freinds to get value for money and not waste their hard earned wages on unsubstantiated rubbish, if I can pervent them from doing so.
But that's just me...

Same old Glen...I am argumentative, always will be...but that's my way.

I don't mean to offend, but occasionally sarcasm or mild offence is the best way to make people actually think about things. If I suceed in doing that but am seen as being argumentative...fine. I can sleep at night knowing that.

Today is a good day...
 
Now I wanna know why today is a good day /ubbthreads/images/graemlins/smile.gif
 
[ QUOTE ]
cybrey said:
Now I wanna know why today is a good day /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

It's not automotive related in any way...

But, I shall ellaborate:

12 months ago the company I worked for were taken over.
6 months ago the take over company announced they no longer wished to employ Staff Technicians offshore....we are all being made redundant and will have to apply for our own jobs with the incumbent contract company.
Then comes 6 months of unknown, rumour, low morale etc...
3 weeks ago I find out I have not been sucessful in securing a job with the incumbent contractor.
Damn. Not good.
2 weeks ago I hear that, in actual fact, I have been sucessful in securing a job with the incumbent contractor.
Excellent.
Yesterday I signed my redundancy aggreement with my previous employer who is chosing to pay me handsomely for the privilege od severing my contract.
Great stuff!
I then hit the pub with the rest of my shift (who have all also been made redundant)
We enbark on a final - for all times sake - bender.
Even greater stuff!

Today...I wake up with no hangover (remarably), the sun is shining, my g/f has a day off, the money just keeps on coming, I have the next two weeks off, and a decent job waiting...
This is a good day...

I am on top of the world... (my world anyway)

Today could be a good day to go collecting brochures of potential future automotive delights...we'll see! /ubbthreads/images/graemlins/smirk.gif
 
Congrats..

My Dad was just took voluntary redundancy at 57, been working for the company for 25 years.. so got a whopping pay off of just over 150K /ubbthreads/images/graemlins/smile.gif not bad if you can get it.
 
Audi obviously gave it 2 cats for a reason...to make it as free flowing as possible while staying inside EU limits.
I honestly cant see them being THAT restrictive in standard or even chipped state. Sure the Millteks may be a little more free flowing, but doesnt always mean more power...maybe just slightly faster spool up. maybe if you going to big turbo route, then the millteks may then come into their own, but i guess until its proven we wont actually know.

I spoke to a customer the other day..he has a APR chipped Seat Cupra, and fitted a milltek cat and system exhaust (remember the cupra was the 180 variant so uses a K03S and single cat), and he had before and after dynos done at star performance, and got 15bhp from the full upgrade. I would tend to believe this as only being a single cat meant for 150/180 applications, 225bhp is a pretty big increase.

Rich
 
Very true if you are talking about NA then 3k is a very accurate figure for the work that would be needed for "guaranteed" results.

Been here for longer than 5 mins so I guess the cap don't fit anymore /ubbthreads/images/graemlins/tongue.gif

A rosette, would rather a blue peter badge if you have one /ubbthreads/images/graemlins/smirk.gif /ubbthreads/images/graemlins/smirk.gif

About the whinge, fair enough you have been here far far longer than me, people probably do whine all the time, I have had plenty of experiance with that on other boards.

I thought your mod job was advice on tuning by the name of your title, but if its not then cool /ubbthreads/images/graemlins/laugh.gif

Ok I don't know for a fact that 3k would get me 350bhp but I am pretty damn sure, only because I can get hold of half a Garrett T3 kit for £500 though, got one sitting in the house awaiting my S3 if I ever can get insured. But in all honesty I don't know enough about the strength of the S3 running gear to have said that really, for all I know at 325bhp might need stronger diffs, uprated clutch etc etc etc. But I am pretty positive I could, we shall wait and see though /ubbthreads/images/graemlins/laugh.gif

The nonsense statement was with your talking about "max power" figures which I totally agree with people doing all the time, but I am just saying it is possible for a car to produce an extra 20-30bhp without any modifications. Because I have seen it happen personally.

I would never say that you should resign your post as moderator because you clearly are into the subject hense the reason you can get pretty argumentative just like me. I thought your mod job was to do something different which you explained /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

Pete.

 
[ QUOTE ]
Quik said:

Been here for longer than 5 mins so I guess the cap don't fit anymore /ubbthreads/images/graemlins/tongue.gif


[/ QUOTE ]

Fair enough...but don't replace it with a Burberry one, will you?
Or we'll have to ban you!


[ QUOTE ]

A rosette, would rather a blue peter badge if you have one /ubbthreads/images/graemlins/smirk.gif /ubbthreads/images/graemlins/smirk.gif


[/ QUOTE ]

I have a gold Blue Peter badge. I got it off eBay...
I will send you it for being such a worthy adversary.


[ QUOTE ]

I thought your mod job was advice on tuning by the name of your title, but if its not then cool /ubbthreads/images/graemlins/laugh.gif


[/ QUOTE ]

I think I'm still only a Moderator of the Tech / Tuning section...perhaps I'm not trusted to be let loose with the rest?


[ QUOTE ]

Ok I don't know for a fact that 3k would get me 350bhp but I am pretty damn sure, only because I can get hold of half a Garrett T3 kit for £500 though, got one sitting in the house awaiting my S3 if I ever can get insured. But in all honesty I don't know enough about the strength of the S3 running gear to have said that really, for all I know at 325bhp might need stronger diffs, uprated clutch etc etc etc. But I am pretty positive I could, we shall wait and see though /ubbthreads/images/graemlins/laugh.gif


[/ QUOTE ]

Getting a suitable manifold will be a problem (cheap that it)
Getting it mapped...

The S3 bottom end will take 350 BHP and about the same in torque with no issues.

Beyond that there are problems with Haldex units, clutches and the usual breakables.

Research it...you'll find plenty to form your own opinion...


[ QUOTE ]

The nonsense statement was with your talking about "max power" figures which I totally agree with people doing all the time, but I am just saying it is possible for a car to produce an extra 20-30bhp without any modifications. Because I have seen it happen personally.


[/ QUOTE ]

And I have seen far more ludicrous dyno charts than standard engines making way over standard power.
At the end of the day, you can make a dyno show anything you want.

Some companies do...
But the less said about that, the better.


[ QUOTE ]

I would never say that you should resign your post as moderator because you clearly are into the subject hense the reason you can get pretty argumentative just like me. I thought your mod job was to do something different which you explained /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif


[/ QUOTE ]

I like you Pete....you can't whack a decent discussion...
Today just gets better...

 
Hehe cheers, always good to meet people who can talk technical and debate about it without getting moody /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

Keep the burberry away from me, get enough of that in Glasgow, especially working in Govan /ubbthreads/images/graemlins/tongue.gif

Yea some companies can be pretty "over-zealous" with their rr's, AVA in Glasgow area is a perfect example. I actually saw a new model rolling road a little while back though that veilside were using on their drag skyline, was 4 podiums that poles from the wheels were inserted into. Supposedly is a very very very accurate atw figure (the skyline in question got 1200atw btw). Would be good to try if I had the kind of money that veilside can throw away

Hmm think my friends at c&c should be able to give me a hand with that manifold problem but its the mapping that I am worrying about more than anything, was told Jabbasport or Revo would be my best bet, but after looking about over the last few days AMD seem pretty promising. Might be going for the piggyback ecu option as well as maybe adding a few little extra toys.

Oh Ess, is it a 3 bar map sensor that the S3 has btw??

Me and one of my mates will be about aberdeen soon, he is currently putting 2 turboed Hiabusa engines in his original mini (got an R1 engine in it just now) if you want to take a look at it /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif 700bhp 4wd mini his little project (in theory if it doesnt tear in 2 when he starts it which I think it might hehe)

Heh I am having a pretty good day as well, company joined forces with guiness, and thats never a bad thing... Maybe manage to scam myself some free drink lol. /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif

Pete.
 
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