Pipewerx 3" Downpipe - My View

hendo#1

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All information here is based on my 2003, BAM engine, face lift S3. Parts and prices quoted are from TPS. Use any information / part numbers at your own risk.

I’ve been busy working away fitting my 3” Pipewerx DP and de-cat to my 2003 BAM S3 over the last few nights.

Before doing it I did quite a lot of research into it. So I’ll add my experiences in here for future reference for anyone else who may search for this in future. This is not a guide; there are no pictures, just what I learned.

I’ve only driven the car about 40 miles since fitting. It’s slightly louder than stock but not overly. Turbo spools up much, much quicker, and most of the extra noise you hear is the turbo. There does seem to be a bit more resonating in the noise but nothing that’s bothering me. And I do not like noisy cars. The car feels noticeably better to pick up on the throttle. My **** on the seat dyno is saying good things.

The fitment is very, very good. I would definitely recommend the Pipewerx down pipe. I’ve mated mine up to the OEM Audi cat-back system. No fitment issues anywhere, it all went on nicely and nothing touches anything else. The flexi joint on the downpipe is just ever so slightly touching part of the heat shield under the car. Unfortunately there is no space behind the heat shield to push it up away, but as it is only just ‘kissing’ it I’ve decided to leave it for now and keep an eye on it. The whole set-up sits nice and high under the car too.

Pipewerx 3” DP and decat - £300 (£450 with the sports cat).

I used new nuts to bolt it to the turbo – N903 690 01 £5.47 each. You need 3.

I used a new gasket DP to turbo – 8L9 253 115A £7.22

I used a new clamp to mate it to the OEM cat-back system – 8L9 253 115A £31.60

Notes on fitting –

I have access to a good, big garage (my Dads) and tools. I installed it on axle stands as high as I could get them. A lift would have been a god-send. You could do it on your drive but I wouldn’t like to. I spent a few hours each night, over 4 nights doing it. My car isn’t a daily driver so I had no rush in doing the job. If yours is a daily driver and you will need it the next day, think carefully before you start, as a snapped bolt or something could bite you in the ****.

You WILL need to lower the front sub frame as far as you can get it on the bolts. The bolts are stretch bolts and should be replaced (100NM + 90 degrees). Taking the dog bone off will give you much needed wiggle room with the engine. Your dog bone mount WILL need to be poly bushed.

I didn’t touch the steering rack.

You WILL need to remove the driver’s side driveshaft for access. The big bolt on the hub is 240NM + 90 degrees.

You WILL need to unbolt the prop-shaft and move it out of the way (3 bolts). You will need a 12 point socket for this.

You WILL need a very good selection of sockets, extension bars, wobble bars etc, deep sockets etc.

You WILL need to sacrifice an old 17mm spanner by cutting it in half to allow you to undo the turbo to DP nuts. I got 2 of the nuts from the top of the engine and one from underneath the car. These nuts should be tightened to 40NM but there is no chance of getting a torque wrench in.

You WILL need a reciprocating saw, with some good metal blades. Once you have the CAT off, you need to cut the downpipe. I accessed and made the cut from underneath. I cut it just after the flexi joint. The bottom half came away from under the car, the top half through the driver’s wheel well.

You will probably need a 4” grinder to get the CAT bolts etc off.

After all that the new DP slots in from underneath. It’s a tight fit and takes some moving about, thinking about and jiggling about but it does go, and once it’s in, its plain sailing from there. One thing I will say is get the prop shaft bolted back on BEFORE you tighten the DP nuts as a bit of play here helps you get the prop shaft on.

Summary –

The Pipewerx gear is very good and fits well. It’s a complete **** job to fit but the results so far seem worth it. It’s one of those jobs that I could now probably do in half the time, but honestly, I just wouldn’t want to do it again. Not without a nice 2 post lift anyways.

As Ive had the subframe unbolted, and the ball joint (undone by the 3 bolts) to get the driveshaft out, I'll also have to get the car re-tracked. Something else to think about.

I just need to get the car in with R-tech again now.

Hope this helps somebody.
 
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Can anyone comment on the de-cat I have fitted and any problems it may give me? I have the post CAT sensor still in place but after 40 or so miles I still havn't had a light come up on the dash yet.

I believe the post CAT sensor can be coded out during mapping?
 
Excellent write up there pal, the only problem you will have with the de cat is when you come to mot the car, unless you know the tester it will fail on the emissions, and yes the eml light can be mapped out
 
The EML light has now come on after a few more miles.

There's an MOT tester in the family, got that base covered!
 
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I get an EML light with a CAT after fitting my 3" DP and 200 cel cat, its a common fault
 
I get an EML light with a CAT after fitting my 3" DP and 200 cel cat, its a common fault

Its not actually a fault...

Most sport cats need a lot of warming up to reach the desired efficiency (particularly prior to an MOT to pass emissions)... std cats warm up more quickly and are generally over the mapped threshold by the time the map is past cold start

This value can mapped out to stop the EML from coming on

<tuffty/>
 
thanks tuffty, another comment to take with me when it is ready for a new map, along with DIS snowflake reduced turbo boost.:)

so, is this the same issue as the thread owner's issue with a complete decat?
 
Post CAT lambda's purpose in life is to monitor CAT efficiency... CATs need warming up to work effectively, no CAT will always end up throwing a fault and EML as to the ECU the CAT (that isn't there) is no longer efficiently catalysing exhaust gases...

Sports CATs can give similar faults as by design they flow better and therefore take longer to get up to an effective temperature to work as a CAT...

If the ECU sees the measured value from the post CAT lambda is below this threshold regardless of if you are OE/sports/de cat then the EML will come on

<tuffty/>
 
thanks tuffty, another comment to take with me when it is ready for a new map, along with DIS snowflake reduced turbo boost.:)

so, is this the same issue as the thread owner's issue with a complete decat?

Whats the snowflake thing all about then?
 
When the car starts in the cold and the snowflake is visible in DIS (< 5 degrees) then I don't get any boost above actuator pressure (6psi), Bill said most remaps remove the restriction. if I drive half a mile and restart then I get full boost again, it happened all through the winter.
 
Great write up @hendo#1

This is a mod I'm still considering.

Do you think the sports cat version would be quieter with the standard cat back exhaust?

Did you have any map adjustments after fitting the 3" down pipe?

Any negatives now you've lived with it for a while?

Thanks.
 
Had my pipewerx downpipe and decat on for a good 3k miles or so I don't think my eml wil come on now.
My car is a s3 8l 53/03 bam.
The car is over fueling which wil get sorted I've got a load of dibs to do with the car first..
 
I had a pipewrex downpipe and sports cat fitted bout start of November and everything has been fine since fitting. No warning lights on cause of the sports cat.
 
Great write up @hendo#1

This is a mod I'm still considering.

Do you think the sports cat version would be quieter with the standard cat back exhaust?

Did you have any map adjustments after fitting the 3" down pipe?

Any negatives now you've lived with it for a while?

Thanks.

Hi.

The sports cat would definately be quieter IMO, any restriction will make the exhaust quieter.

After the 3" downpipe & de-cat (along with other required mods) I took it for a stage 2 tune at R-Tech where it made 282BHP and 300ft/lbs. It definately makes a difference.

The car now has a full pipewerx 3" turbo back system on it (de-cat) so the noise is a moot point really. I am also running the Badger5 hybrid set up. The chinafold exhaust manifold must be in an ever so slightly different position to the OEM as Ive been back to pipewerx a couple of times to have it altered slightly.

Other than that, no issues. Pipewerx is good quality stuff, I wouldn't bother using cheaper gear. Its a **** job to do, you definately don't want to be doing it twice.
 
Anyone passed or had issues passing an MOT with a pipewerx sports cat ?
 
I have a decat Fock it someone will take an extra drink


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Any 200 cell “sports” cat, high flow, etc. Should..... pass an MOT. Just need to make sure there’s enough heat there, to better your chances ask if you can take the car out for a good run just before they do the emissions test.

Alternatively find a “friendly” mot station.


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I had a 200 cel sports cat from pipewrex and never had any bother with any of my last 3 months its had with it.
We dont have the option here to find a friendly mot tester would have been handy now I'm running a de-cat