Downpipe? sports cat?

[S3-Chris]

on a standard 2002 model s3- is it the downpipe that is most restrictful?
if so do i want to go to a 2.5" or 3"? and where can i buy one?
seriously wanting to upgrade the performance a little now!!!

 

[Mason-A3Sport]

Revolution motorsport is where i got mine, the restriction in your S3 will be in the downpipe and the catalyst, milltek do a very good system you can pick up the downpipe/Deacat or if you want to still pass an MOT go for the larage bore downpipe and high flow catalyst, I no if you go for the high flow catalyst you will also need to buy the milltek cat back system, quite pricey but i've got one on order ready for fitment on friday, hope this helps.

 

[ianysm]

Have you remapped the car already? If not then this is a starting place as you get most gains for you money (£350 ish)

Then get DP and cats (or full system but not necessary) and stage 2 map. Should see about 280bhp then. Just the DP will help if on a budget

 

[S3-Chris]

its already remapped, where can i buy a reasonable DP online from that will fit with no messing about?
also for the sports cat - does the s3 not have 2 cats?

 

[MartayMcFly]

its already remapped, where can i buy a reasonable DP online from that will fit with no messing about?
also for the sports cat - does the s3 not have 2 cats?

A Milltek downpipe doesn't split like the OEM one, and so mates to a single, larger cat. Not sure what happens when you want a big DP but standard cat...

 

[Kunit]

Blueflame or pipewerx are the best though you can get the pipewerx for 475 off eBay

 

[S3-Chris]

Blueflame or pipewerx are the best though you can get the pipewerx for 475 off eBay

are the pipewerx not the ones that are dodgy fitment? need to drill holes etc?

want something thats not gonna be hassle....

 

[Dani_B19]

No thats the cheap XS power ones.

 

[Kunit]

Blueflame are apperently a copy of pipwerx, mr pipewerx used to be at blueflame. I was informed the pipewerx one has a 200 cell cat, better material and a 3 layer flexi. Also the pipewerx one is waaaaay cheaper or should i say a more realistic price.

 

[Andrew@A.L.D]

I hope to get one later on for mine

Would sort of power do you guys think i'll get with my 2.1L, head work, big intercooler, N75J and DP and system? I think i'll need a stage 3 map?

 

[S3-Chris]

so if i buy the pipewerx ones, do i just need a cat back exhaust system? and also, will it pass an mot ok with the pipwerx cat, and will the engine management light stay out with the emissions of the different cat?
thanks

 

[Kunit]

Lad at work has the blueflame one with 100 cell cat and no eml on, made a big difference to how it drives and is not yet mapped. Im not going to bother with the rest of the exhaust till i have spare cash lying around. Andrew, are you not going BT with all that work?

 

[S3KO4]

I am in the same situation, pipewerx have a special deal for £300 but thats decat and DP. not sport cell. nevertheless its a good deal. oh its of ebay.

 

[Kunit]

That still makes only 175 extra for a 200 cell sport cat, cant knock that.

 

[Andrew@A.L.D]

Andrew, are you not going BT with all that work?

Not just yet but will do when i do get the cash

 

[S3-Chris]

whats better 100 cell or 200 cell?

 

[Kingston]

I'm getting a 3" downpipe and high flow cat a Blueflame one through Compbrake. I have seen the build quality and is really good. One item off my long list ha.

 

[S3-Chris]

I'm getting a 3" downpipe and high flow cat a Blueflame one through Compbrake. I have seen the build quality and is really good. One item off my long list ha.

how much mate if you dont mind me asking?

 

[Kingston]

how much mate if you dont mind me asking?

£536.42 plus vat and delivery it is that for the 3" downpipe and high flow cat.

They do it as a 3" downpipe with de cat which is
£280.98

Not bad price build is really good.

 

[JS1500]

whats better 100 cell or 200 cell?

I'd like to know people's (educated) opinions on this too.

Presumably 100 cell is more free-flowing but maybe has a higher risk of failing an emissions test?

 

[Kingston]

I'd like to know people's (educated) opinions on this too.

Presumably 100 cell is more free-flowing but maybe has a higher risk of failing an emissions test?

Good point well I have asked a few people and they said 100 cell will be fine to pass yet someone on here had problems getting a pass with a 100 cell. Was it just there car who knows. Think i'll take the chance.

 

[Sandip]

My S3 with its standard cats struggles when it comes to emissions, my dads A4 what has a full pipewerx system, turbo back with a 100cell cats goes through emissions straight away.
I think it all depends on the condition of your car. If you have a dodgy lambda, maf, breathers, temp sender etc all these things can effect your emissions.
I'm getting a pipewerx 3"downpipe and 100cell cat next year and every year i've struggled with emissions so once i get this system i'm looking forward to what happens m.o.t time

 

[Kingston]

My S3 with its standard cats struggles when it comes to emissions, my dads A4 what has a full pipewerx system, turbo back with a 100cell cats goes through emissions straight away.
I think it all depends on the condition of your car. If you have a dodgy lambda, maf, breathers, temp sender etc all these things can effect your emissions.
I'm getting a pipewerx 3"downpipe and 100cell cat next year and every year i've struggled with emissions so once i get this system i'm looking forward to what happens m.o.t time

Mine just failed on Mot with emissions with standard cat. They said it took ages to sort it. Had a split on one of my turbo pipes which caused loads of blue smoke when iddling for a few mins. That sorted now but think another pipe has split as the turbo sucks alot louder than before and the power has gone.

Well hope it just one of the pipes.
Link to the down pipe i'm getting.
http://compbrake.co.uk/shop/product_info.php?products_id=4170

 

[ash3435]

just been looking on eBay and came across this downpipe.what is every1 opinion.item no 230414287860

 

[Dani_B19]

Woudlnt bother mate, save up and get something decent.

 

[Andrew@A.L.D]

just been looking on eBay and came across this downpipe.what is every1 opinion.item no 230414287860

Thats for K03 turbo engines

 

[Ess_Three]

Then get DP and cats (or full system but not necessary) and stage 2 map. Should see about 280bhp then. Just the DP will help if on a budget

Not a chance! Not genuine power anyway.

It takes more than just a stage 2 map and cats to get 280BHP...
I finally got mine up to 275-280 BHP and the Cats made no difference what so ever at that sort of power...so they aren't restrictive.

Saw a 'miracle' set of downpipes loose power too, on an S3 making 270ish BHP.

 

[Ess_Three]

Revolution motorsport is where i got mine, the restriction in your S3 will be in the downpipe and the catalyst, milltek do a very good system you can pick up the downpipe/Deacat or if you want to still pass an MOT go for the larage bore downpipe and high flow catalyst,

On an S3?
I tried std and 100 Cell Cats - no difference.
The 2nd owner went to 200 Cell Cats...no difference.

Saw a car dyno's at Star with fancy downpipes on...and it lost power...significant power.

S3s do not need uprated Cats/exhaust/downpipes at under 270BHP.

Above that, if chasing every last psi from the K04, you may see a BHP and a few lb-ft...but you'll be heat-soaking like hell, so spending the money on a FMIC will prolong the power you have, and give a better overall gain than ANY exhaust...been there, done that.

you may see a BHP or so...but not 10. To get above 270ish you need better charge air cooling - bigger more efficient intercoolers, which allow more ignition advance.

An exhaust does neither...

The restriction on an S3, is the turbo manifold!


As for a Milltek exhaust for an S3...it's utter cack.
The tailpipes sit squint of the box sits square, the box sits squint if the tailpipe sits square, it adds none of the power they tell you it does...and it knocks like hell on the rear Haldex carrier when the exhaust is hot.
Milltek were un-interested in rectifying for the 2 1/2 years I moaned about it.
If that's your idea of a 'very good' system, then be my guest.

 

[ash3435]

ive got all of the above.fmic, miltek,decat,filter,tip,forge007p,stage 2 revo.im looking to gain that extra bhp from the down pipe.so what you saying dont waste my time

 

[Ess_Three]

I would doubt you'll see much...maybe a few BHP with another map...but in all honesty, you've got all the basics covered.

The K04 just isn't big enough to move enough air, and the manifold is struggling.
To get a meaningful gain over what you have, you will need a slightly bigger compressor, or a better manifold...or both!

But from my experience of downpipes on S3s, I seriously doubt you'll see much by fitting them...as I say...maybe a slight gain, along with another re-map...but in percentage terms next to nothing.

You need to move more air, if you want to see real gains.

Personally, I wouldn't bother...

 

[Kunit]

My downpipe and cat have made a significant difference to an un mapped car, along with 007p and fmic which I previously fitted so to a mapped car it'd be worth it. I know the manifold is a problem but removing any restriction after the turbine will help in many areas.

 

[ash3435]

ok thanks for your opinion.

 

[ash3435]

what do you think bount the manifold off ebay.item no 230414287860.spoke to him and he said it will fit a ko4

 

[Ess_Three]

My downpipe and cat have made a significant difference to an un mapped car, along with 007p and fmic which I previously fitted so to a mapped car it'd be worth it. I know the manifold is a problem but removing any restriction after the turbine will help in many areas.

What's a significant difference?
How much of a gain, power & torque?

With regard to the other bits...the DV makes no difference at all as long as the original isn't broken...an at standard boost, a FMIC is of little gain. The charge air doesn't get hot enough to need better ICs as the compressor is well within it's efficiency curve.

I fitted my exhaust & 100 Cell Cats to a standard un-mapped car...and it made no difference at all - Dyno proven.

I can't understand how it made a significant difference to yours, when fitting downpipes to a 270 BHP S3 made no difference.

I agree that removing any restriction after the turbine will help...but if you see the size of the ports on the manifold, and compare to the area of the downpipes, it's clear that after the turbine is vastly bigger than before it...so the restriction is pre-turbine...not after.

I've yet to see concrete proof that anyone has a good gain from changing the downpipes...but would love to see some, if it exists?

 

[Dansmith]

Do you think the down pipe would help with the amount of lag around 3,000 revs? I'm running a revo re-map at the moment and there always seems to be a hold before the power hits in! On cold days it feels dangourus and throws me forward a little in the seat!

 

[Ess_Three]

I think it's a function of having the torque spike to give huge urge and big torque figures.
Mine was the same...it went from making around 100 lb-ft to 330 lb-ft in 700RPM or something equally silly...proper old-school turbo shove.

Not much you can do I don't think.