e39 Exhaust Query

[stubobby]

Exhaust Query.
So – it begins. My restoration (rather light overhaul and upgrade) of my 2001 e39 530i SPORT.

With a bit of patience and perseverance – 2 trolley jacks and several axle stand – my full centre, middle and rear exhaust is down. It is one piece on this car.

So now I have some options and what I am going to do to replace. Now I would love to get a full Supersprint system - but the manifold is over £2k and the centre with racing CATs is also over £2K. So my intent is to leave the OEM manifold and OEM CATs in place and the use a 785532 and then a 785903. (I already have a backbox – 785926).

https://www.supersprint.com/ww-en/supersprint-perf...

So this presents a slight problem – if you look at the following

https://www.realoem.com/bmw/enUS/showparts?id=DT52...

You will see that the “diamond” flanges are very close to the LAMDA probes – and these are quite corroded. They are also welded to the pipe on an internal weld.

So my intention is to carefully grind the internal weld off and leave a clean straight pipe and then fabricate a section to go from the new SS centre section to my OEM down pipes.

Questions

Any comment on my plan?
Has anyone done this before and has anyone got any alternative options?
Finally – how do I ensure my OEM headers and CATs are in good condition and working order and this plan will be ok? It is 20 year old car – but “only” done 70000 miles?
Thanks.

[Ltd Slipper]

Have you looked on EBay ? There are plenty of options of exhaust flanges or joining pieces . I found this , it’s even stainless

https://www.ebay.co.uk/itm/2-25-57mm-304-Stainless...

[d_a_n1979]

stubobby said:

Exhaust Query.
So – it begins. My restoration (rather light overhaul and upgrade) of my 2001 e39 530i SPORT.

With a bit of patience and perseverance – 2 trolley jacks and several axle stand – my full centre, middle and rear exhaust is down. It is one piece on this car.

So now I have some options and what I am going to do to replace. Now I would love to get a full Supersprint system - but the manifold is over £2k and the centre with racing CATs is also over £2K. So my intent is to leave the OEM manifold and OEM CATs in place and the use a 785532 and then a 785903. (I already have a backbox – 785926).

https://www.supersprint.com/ww-en/supersprint-perf...

So this presents a slight problem – if you look at the following

https://www.realoem.com/bmw/enUS/showparts?id=DT52...

You will see that the “diamond” flanges are very close to the LAMDA probes – and these are quite corroded. They are also welded to the pipe on an internal weld.

So my intention is to carefully grind the internal weld off and leave a clean straight pipe and then fabricate a section to go from the new SS centre section to my OEM down pipes.

Questions

Any comment on my plan?
Has anyone done this before and has anyone got any alternative options?
Finally – how do I ensure my OEM headers and CATs are in good condition and working order and this plan will be ok? It is 20 year old car – but “only” done 70000 miles?
Thanks.

Replied to your thread over on the 5 forums

[wsn03]

stubobby said:

Exhaust Query.
So – it begins. My restoration (rather light overhaul and upgrade) of my 2001 e39 530i SPORT.

I thought I was the only person in the world who was restoring one. Prices are so low it makes no sense, but its the best all rounder I've ever driven.

Im putting mine back on the road as a keeper. The 3.0 is the best engine im sure

[rayyan171]

wsn03 said:

I thought I was the only person in the world who was restoring one. Prices are so low it makes no sense, but its the best all rounder I've ever driven.

Im putting mine back on the road as a keeper. The 3.0 is the best engine im sure

Same here, I am restoring a E39 528i once all this blows over and I can actually leave the house/secure parts.

[wsn03]

rayyan171 said:

wsn03 said:

I thought I was the only person in the world who was restoring one. Prices are so low it makes no sense, but its the best all rounder I've ever driven.

Im putting mine back on the road as a keeper. The 3.0 is the best engine im sure

Same here, I am restoring a E39 528i once all this blows over and I can actually leave the house/secure parts.

BMW 5 SERIES forums is a useful source of information.

Lots of parts are available pattern and even new thanks to BMWs ongoing heritage parts scheme.

I think the e39 will be a popular long term classic. A friend of mine has a cousin who changes cars every 4 years in Sweden for example, but she kept her E39, had a garage built for it, and uses it every summer.

Mine was my business car, but I never found anything I liked as much once it became impractical. It will be run on the weekends for pure pleasure

[rayyan171]

wsn03 said:

MW 5 SERIES forums is a useful source of information.

Lots of parts are available pattern and even new thanks to BMWs ongoing heritage parts scheme.

I think the e39 will be a popular long term classic. A friend of mine has a cousin who changes cars every 4 years in Sweden for example, but she kept her E39, had a garage built for it, and uses it every summer.

Mine was my business car, but I never found anything I liked as much once it became impractical. It will be run on the weekends for pure pleasure

The forums are rather useful indeed. There is high parts availability although BMW themselves are rather expensive to use, but it is good to know they still sell the parts. We have had ours in the family for nearly 18 years and plan to use it as a third car in the household.