New De-cat Pipe

Skipton01

Skipton01

Admin Team
Today saw the latest chapter in the upgrade of Tank - a fully stainless, 2.5 inch diameter hi-flow de-cat front pipe - custom made and installed by Pipewerx (www.pipewerx.com).

So far, although I've only had a quick run back home along the M6/M62/M60, but the performance seems somewhat more spritely.

Overall power has probably not increased much, if at all, but what is obvious is that the engine (which revved very freely) will go round the dial in double quick time now - the turbo spools up unbelievably quickly now.

Here are links to a couple of photos of the new front pipe:

http://i19.photobucket.com/albums/b163/skipton01/De-cat01.jpg

http://i19.photobucket.com/albums/b163/skipton01/De-cat02.jpg

You can see immediately, the new pipe is much less restrictive and less convoluted, giving the exhaust gasses a quicker route away from the engine. The second photo shows the sleeved section which will be replaced with the original cat (actually a particle filter) should it be necessary in the future. I've kept the cat and Pipewerx can simply re-insert it should legislation make it needed. Even if it's replaced, the new front pipe will mean that the engine can still breathe easier anyway.

Cheers,

Mike
 
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Hi Mike
That's a nice piece of kit. The quality of the fabrication and welding is superb.
When all the mods are complete, maybe you should run another competition to guess Tank's new power and torque figures.

Cheers Spike
 
Yes, Ian who built the pipe is superb at his job and I may well have him fit a full 2.5" system in place of the Milltek.

He has a few tricks up his sleeve, which should improve Tank a fair bit, not that the Milltek is a shabby piece of kit.

So, I may have a full exhaust for sale soon, which may be of interest, especially as they are no longer available.

Cheers,

Mike
 
Does this mod result in the car is no longer being street legal? If so, will be a real pain having to revert to standard for every MOT session.
 
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alanm said:
Does this mod result in the car is no longer being street legal? If so, will be a real pain having to revert to standard for every MOT session.
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Absolutely not - as long as the car in question is a diesel.

Diesel A2s do not have catalytic converters, they have particulate filters, which take excess soot from the gasses, but it comes out eventually, either whenyou'give it the beans' or when the ECU tells the car to purge the filter.

For a healthy diesel, this lack of a filter is no problem and indeed, I haven't seen any extra soot coming from the back.

For a petrol however, taking the catalytic converter will immediately make the car 'illegal' in terms of emissions, so don't do it.

You can get a free-flow sports cat, but they are really not worth it for the A2, even for the FSi.

Cheers,

Mike
 
At last something, I know about!!

Some diesel cars have both catalytic convertors, and particulate filters as a 2 brick, or 1 brick exhaust treatment solution. The company I work for is the worlds largest supplier of these items, and we supply VAG with most of there exhaust treatment solutions. I am not sure what the A2 is fitted with. I would guess that the older 1.4 75bhp models have a simple oxidation catalyst (to get rid of carbon monoxide and unburnt fuel) whilst the very last models may have that technology combined with a DPF (diesel particulate filter). I have attached a link to our companies public website where you can learn all about the chemistry!! DPF's were only commercially available in 2005/06 and I know that the A4/Golf were the first VAG models to get the full treatment. If you have any more questions I am happy to try and help!

David

http://ect.jmcatalysts.com/technologies-diesel.htm

The link may refer to heavy duty diesel engines (larger than 3l) but the technology is the same, just a bit smaller!
 
David - so where does that leave the legality issue re. compliance with exhaust emission regulations if you remove this gizmo from the exhaust system?
 
Mike would you say the difference in the new cat pipe was more noticable than when you changed to the Milltek exhaust ....Nice job by the way ...:D
 
alanm said:
David - so where does that leave the legality issue re. compliance with exhaust emission regulations if you remove this gizmo from the exhaust system?
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I've yet to hear of a de-catted diesel that fails an emission test, simply because they don;t have them - all they are subject to at MOT time is a smoke test, and and healthy TDi will pass this easily, even without any exhaust.

Carl, it's quite subtle, but I'd say it's AS noticeable as the Milltek.

Cheers,

Mike
 
Good question!

The car manufacturer has to guarantee certain tailpipe emissions over 100,000kms of operation. These figures (including CO2 g/km) are published after independant testing and form the basis for car taxing and which emmssions band the car falls in. All cars now produced have to meet Euro IV standards, but their individual CO2 figures will vary signifcantly.

CO HC+NOx NOx PM
Euro III Jan. 2000 0.64 0.56 0.50 0.05
Euro IV Jan. 2005 0.50 0.30 0.25 0.025

CO = Carbon monoxide, HC = hydrocarbon (unburnt fuel), NOX = nitrogen oxides, PM = Particulate matter

These figures are for diesel cars only. My A2 (2002 MY) is Euro III compliant. Some older engine designs required a particlualte filter to meet Euro IV, whereas most TDi engines don't need them to get below 0.025 g/km PM. In Germany there was a VAT rebate if the car had a PM filter fitted, even if it didn't need it!! So some Euro IV cars have PM filters.

It is a bit of a minefield!!

The easy answer is when it comes to an MOT test. The dealer garage can not do a full rolling road driving simulation, so does an idle and fast idle tail pipe analysis. This gives them CO levels and HC+NOx levels. Most well maintained cars will pass this test with any sort of catalystic convertor installed. This is how performance exhaust systems are legal, they have some degree of catalyst installed that does enough conversion to pass the MOT test, but not as much as the manufacturer intended. Since the performance exhaust people are generally not guaranteeing emmsions limits over 100,000km!

I can only speak as well informed scientist :)o) and don't know enough about the A2's system to know whether removing the close coupled catalyst brick will result in an MOT failure, but I am sure Mike will have got this sorted.

I guess the MOT test will get tighter as Euro regs get tighter, so in the future the degree to which you can mods the exhaust will narrow. But it is a small price to pay for still being able to drive!! esp in an A2

Hope this was helpful,

Dave
 
Skipton01 said:
...and I may well have him fit a full 2.5" system in place of the Milltek.
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Hi Mike,

nice pieces of metal!

Please let us know some (eer I meant all :)) details of your future full 2.5“ exhaust system.

Should be interesting to get a direct dyno comparison - pre and post install...
 
From what I've been told, it'll be a non-resonated system, that will leave plenty of room for a Haldex unit!!;)

The unit will still have to be joined over the rear axel, but the sliencer will be in front of the axel - go figure!

Offers on the Milltek anyone? I'll give it a full mirror polish before selling.

Cheers,

Mike
 
re. "Offers on the Milltek anyone?"

V. interested but would be helpful if could know:

1. Is it single tail pipe?
2. What sort of number have you in mind?
3. Any idea how much to remove orig system & replace with the Milltek?

Cheers - Alan
 
alanm said:
V. interested but would be helpful if could know:

1. Is it single tail pipe?
2. What sort of number have you in mind?
3. Any idea how much to remove orig system & replace with the Milltek?

Cheers - Alan
Click to expand...

It is a single tailpipe, hidden behind the rear valance in exactly the same way as the original.

The number begins with a 2 and ends in a 0!

As to how much, it takes about 30 minutes and Stealth did mine (actually, Robin did it for mates rates!).

Cheers,

Mike
 
And you have one back.

Just in case someone thinks the Milltek is for sale at £20, it's not - there is a digit in between the 2 and 0

And it'll be available mid -February, unless someone needs it really urgently.

Cheers,

Mike
 
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