M635 Exhaust Restore

jdb · Post by **jdb** » Fri Aug 30, 2013 3:43 am

Previous work to add Cats. and poor choices by other owners left me with a mess of hacked headers and mufflers.
The crime of substandered EPA/DOT work to euro BMW's brought into the U.S. that had no factory cats. has been a issue with all 3 of my beloved euro's.
This is to show what it took to restore headers that had the flanges cut off and cats. welded right to the headers and this M635 had a U.S. 635 rear muffler. I ceramic coated the headers after making and welding on new flanges that involved also taking a 2" pipe 14 ga. and turning it to 50mm O.D. as finding 50mm exh. pipe in the U.S. did not happen.
The car ran like s**t with no acceleration untill...
It now runs as it should!!
Just wanted to share, thanks for looking

Jeff

Da_Hose · Post by **Da_Hose** » Fri Aug 30, 2013 5:12 am

This is a great share. Very nice job.

Jose

jpr210 · Post by **jpr210** » Fri Aug 30, 2013 6:59 pm

That looks great, what did you do with the rest of the exhaust, supersprint all the way back?

Jpr

ericono · Post by **ericono** » Fri Aug 30, 2013 7:40 pm

Great job! I'm in the same boat you were in. Where did you get your headers coated? And what coating did you get? Do you have a picture from further back that shows how the 3" back tips look on the car?

Again, nice job.

Eric

rmorin1249 · Post by **rmorin1249** » Fri Aug 30, 2013 8:02 pm

Very nice. I am also interested in the rest of your exhaust system as I am considering an upgrade to a Supersprint system but I am not running any cats so I am curious as to whether or not I need all of the Supersprint components as they offer a front, a middle and a rear muffler. Surely, I don't need all 3. Any assistance is appreciated. Thankfully the PO of my car had a complete German system installed with the correct pipes after it came out of EPA/DOT certification. It has been on the car for many years so I need to have it fully inspected to see what kind of shape it is in. I don't like the look of my exhaust tips as they look too small and are a bit beat up.

Pod · Post by **Pod** » Fri Aug 30, 2013 11:07 pm

Nice work!

hornhospital · Post by **hornhospital** » Sat Aug 31, 2013 12:17 am

Wow, that ceramic coating is just stunning! Mind telling how much that cost? And how durable is it?

jdb · Post by **jdb** » Sun Sep 01, 2013 12:20 am

Thanks for the kind words.
I used the comlpete S.S. system, and the price kept going up. I don't care for the comunication when I was waiting for these 3 different parts to be avalible again, they never told me when they were avalible and the cost went up $350.
It is a bit quieter than I would like, but I have a Split Second with MAF and a K&N filter so the music from the intake blends just right with the exh. note.

I used Performance Coatings out of Washington. Price was $195. plus shipping. The coating is nice and easy to clean becouse it is glossy, but it is tough to break it in correctly. You have to heat it in cycles getting hoter each time before you just drive hard. I used a infared heat gun to moniter the temp. If you get it to hot to fast you will loose the gloss but the coating will not come off. It will scratch when reinstalling so be cafeful, I wraped each header with thin foam packing to be safe.

I also DO NOT LIKE the Super Sprint rear muffler hanger, to use it makes installing/removing a real pain and I think you could scatch the valance.
I used the stock hanger, cut and welded to fit the S.S. housing with a section that comes out of the middle..see picture.

The rear tips do not extend enough to move the exh. out the back and will just slime the rear bumper, so.. I used high quality 2" stainless steel lap clamps so I could then not install the rear muffler pipes as far into the 2nd muffler allowingthe tailpipe to be about 3" further out the back.

Hope this shows what you wanted to see.

Jeff

rmorin1249 · Post by **rmorin1249** » Sun Sep 01, 2013 1:26 am

jdb wrote:Thanks for the kind words.
I used the comlpete S.S. system, and the price kept going up. I don't care for the comunication when I was waiting for these 3 different parts to be avalible again, they never told me when they were avalible and the cost went up $350.
It is a bit quieter than I would like, but I have a Split Second with MAF and a K&N filter so the music from the intake blends just right with the exh. note.

I used Performance Coatings out of Washington. Price was $195. plus shipping. The coating is nice and easy to clean becouse it is glossy, but it is tough to break it in correctly. You have to heat it in cycles getting hoter each time before you just drive hard. I used a infared heat gun to moniter the temp. If you get it to hot to fast you will loose the gloss but the coating will not come off. It will scratch when reinstalling so be cafeful, I wraped each header with thin foam packing to be safe.

I also DO NOT LIKE the Super Sprint rear muffler hanger, to use it makes installing/removing a real pain and I think you could scatch the valance.
I used the stock hanger, cut and welded to fit the S.S. housing with a section that comes out of the middle..see picture.

The rear tips do not extend enough to move the exh. out the back and will just slime the rear bumper, so.. I used high quality 2" stainless steel lap clamps so I could then not install the rear muffler pipes as far into the 2nd muffler allowingthe tailpipe to be about 3" further out the back.

Hope this shows what you wanted to see.

Jeff

Looks great. Do I understand that you used all 3 of Supersprint's sections, front, middle and back and also retained cats? When I called Supersprint they didn't seem to know how many sections I should order when I told them my car was a Euro model and did not have catalytic converters. I don't want my car to drone at highway speeds but also don't want to buy any parts that I don't need. I am thinking that the center section and the rear muffler should be all I need. Would appreciate your insight. Thanks.

jdb · Post by **jdb** » Mon Sep 02, 2013 5:24 am

I did use all three sections of the super sprint system for the M635.
I wanted to not use all of it becouse of the cost, but to make any part of the system myself with mandel bent would have taken more time and the headers took alot of time to restore.

I have no cats on this car.

The system has no drone and is very well thought out with the exception of the rear hanger and that I had to move the rear muffler back a few inches for my taste.

Stock parts are still available for non cat M635
rear muffler 18121309004 64 in the fatherland
front muffler 18122225082 35 in the fatherland
The sleeves that conect the pipes and the rear muffler tips and NLA

Jeff

rmorin1249 · Post by **rmorin1249** » Mon Sep 02, 2013 1:09 pm

jdb wrote:I did use all three sections of the super sprint system for the M635.
I wanted to not use all of it becouse of the cost, but to make any part of the system myself with mandel bent would have taken more time and the headers took alot of time to restore.

I have no cats on this car.

The system has no drone and is very well thought out with the exception of the rear hanger and that I had to move the rear muffler back a few inches for my taste.

Stock parts are still available for non cat M635
rear muffler 18121309004 64 in the fatherland
front muffler 18122225082 35 in the fatherland
The sleeves that conect the pipes and the rear muffler tips and NLA

Jeff

Thanks, Jeff. Do you have the Supersprint Part numbers? What source did you use to get your parts?

Added: Seems the North American distributor for Supersprint is now in Quebec, Canada. I have an inquiry in to see if I can buy direct. The other option is a Billy Boat. I had one on my '88 635Csi and it had a nice mellow sound with no droning at highway speeds. However, the car had cats on it so without them I am expecting the sound to be much louder and this is my main concern with a B&B rear muffler.