A2 1.4TDI AMF BHC Downpipe - what is the ultimate design - buy or make?

It sounds like it may well be the law but unenforceable in practice. I know MOT stations won't pass petrol cars without a CAT or diesel cars without a DPF, but CAT's on TDI's seem to be overlooked.
 
It sounds like it may well be the law but unenforceable in practice. I know MOT stations won't pass petrol cars without a CAT or diesel cars without a DPF, but CAT's on TDI's seem to be overlooked.
That's only because measuring emissions, apart from smoke, is not part of the diesel MOT because the presence of a catalyst is assumed. Let it be on your conscience (and possibly your wallet). It's certainly not unenforceable; all MOT stations already have a CO/HC monitor.

RAB
 
Rab I can appreciate that you feel passionately about this, but this is turning quite threatening and I don't appreciate the tone. I don't have a de-catted TDI, I drive a petrol with a CAT, I was merely commenting with my understanding of the situation.
 
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I hope it is OK that I make a 540 deg turn and heading back to what this thread suppose to be about.... ;)

Anyone know of what kind of power increase one can expect ? ? ????
 
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I hope it is OK that I make a 540 deg turn and heading back to what this thread suppose to be about.... ;)

Anyone know of what kind of power increase one can expect ? ? ????
I'm following a post on fb with a guy who said hes got 125 hp out of his 1.4tdi ... still waiting for him to tell us the mods but I'm not going to hold my breath ?
 
I'm following a post on fb with a guy who said hes got 125 hp out of his 1.4tdi ... still waiting for him to tell us the mods but I'm not going to hold my breath ?

That’s quite achievable with just a larger intercooler, hybrid turbo and a custom remap.

The 90’s can get 150-160 with similar mods.

37AFFDA4-D431-4F2C-AA45-2AD3CE8E6695.jpeg


Here’s one of my old project 90’s that was around 160hp.
 
Many thanks @spike ? ?
Tried to progress my downpipe yesterday and ended up burning my thumb... (now I have 9 left) so now I needed a kind of motivation, 3hp is not a lot, but it is motivation :) Lessons learned - TIG welding require regular practice.... sofa -hours does NOT count ;)
 
Replaced my cat with this to keep the noise down at least;

IMG_20210102_154539.jpg

The Registration office of vehicles is aware of this, the registration form has a remark on it; no pollution filtering system (cat) present...... Which was a lie, because they made an error when the car was imported: The cat was there for sure!

It now pulls more "freely" when going from 100 to 120 km/hr, and sounds more quietly (? Is that a correct sentence) at motorway/speeds.
 
A small mini "how too" for changing the downpipe flex.

Since the downpipe flex is one of the few parts that has a "limited" life on our A2s I thought to share how my latest flex failure was repaired.
Mine had cracked both in upper and lower end.
The following parts are needed: 50-54mm clamp joint, 2"x 8" flex with weld ends, exhaust compound and turbo outlet gasket.
Tools needed: 13mm spanner/socket for the 4 bolts against turbo flange,17mm spanner to tighten the clamp joint, 5" angle grinder with thin cutting disk and MMA or MIG welder.
Do not forget your PPE :)

1 Place the car on two or four good and stable stands
2 Apply solvent to the 4 nuts/studs on the turbo outlet flange
3 Cut the exhaust pipe 4" / 100mm after the cat.
4 Unscrew the four 13mm nuts on the turbo outlet flange
5 Release the two rubber retainer rings carefully while supporting the downpipe assembly
6 Make a simple jig as shown below to be able to weld in the new flex with correct length and angles referenced to flange, bracket and rear exhaust.
7 Measure the C-C (centre to centre) distance of the existing flex welds, and cut in the middle of each weld
8 Trim the length of the new flex to the length you measured on the existing one
9 Assemble parts into the jig and tack weld them together and do a fit test, adjust if necessary, and complete welding when fit test is ok
10 Open up the clamp joint and push it onto the rear part of the exhaust and fit the turbo flange gasket
11 Carefully, manoeuvre the downpipe assembly into correct position and torque up nuts and fit the rubber retainer rings
12 Apply exhaust compound to the last 2" after the cat and the first 2" of the rear part. Then pull the clamp joint so the clamps length is equally divided onto the two ends. let it rest for 20min and tighten the nuts
A2 downpipe jig s.jpg


A2 downpipe jig s b .jpg


A2 downpipe jig detail rub hang.jpg

A2 downpipe jig detail end stand.jpg

All my A2s are longrunners and when I maintain and service them I have in mind that I do what I can to get maximum mileage out of them...
Therefore, I use long nuts in A4 or A2 quality on the turbo exhaust outlet flange to reduce problems with corrosion and i weld with AISI304 or 316 consumables.

Cheers
dieselfan[

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That is pure magic love your ingenuity!

Can I ask where you sourced your parts and part numbers be good to have a "fitting kit" to enable quick order! The long deep nuts is a great idea I sometimes double up to prevent corrosion on the threads!

Well done that man!
 
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