Euro M exhaust project

[Badgas]

I was finally able to pick up a nice set of used headers. I spotted a tread over on BCG pointing to a CL post in San Francisco. I called and emailed the guy. He sent pictures, I committed to buy on the spot. Turns out he works at Dinnan so when I picked them up I got a tour of the facility including the engine assembly area, machining area and a peak into the dyno room. They had a 12 cyl Ferrari on it at the time.

On to the project. The existing exhaust system consists of a "Federalized header" (6 into 1), single pipe to a cat from some model BMW, then a single pipe to a pretty new Magnaflow header I had installed.

My plan is to meet a local guy Tuesday that has a mandrel bender to talk about fabricating a system from the header back. I have a picture of the unit made by Ireland engineering for the US models. I am assuming they will not fit up to the euro headers.

I have the support bracket that mounts off the bell housing. I'm gathering gaskets & studs then
I'll have the old system off and install the headers. Then a short but exciting drive between shops with the system uncorked.

Tips and sugestions welcom. I am wondering about the ECU. There is an O2 sensor connected now, so I am thinking it should be ok. The new header is fitted with a sensor after the collector. Sugestions on Cats?

[e24mpwr]

I was finally able to pick up a nice set of used headers. I spotted a tread over on BCG pointing to a CL post in San Francisco. I called and emailed the guy. He sent pictures, I committed to buy on the spot. Turns out he works at Dinnan so when I picked them up I got a tour of the facility including the engine assembly area, machining area and a peak into the dyno room. They had a 12 cyl Ferrari on it at the time.

On to the project. The existing exhaust system consists of a "Federalized header" (6 into 1), single pipe to a cat from some model BMW, then a single pipe to a pretty new Magnaflow header I had installed.

My plan is to meet a local guy Tuesday that has a mandrel bender to talk about fabricating a system from the header back. I have a picture of the unit made by Ireland engineering for the US models. I am assuming they will not fit up to the euro headers.

I have the support bracket that mounts off the bell housing. I'm gathering gaskets & studs then
I'll have the old system off and install the headers. Then a short but exciting drive between shops with the system uncorked.

Tips and sugestions welcom. I am wondering about the ECU. There is an O2 sensor connected now, so I am thinking it should be ok. The new header is fitted with a sensor after the collector. Sugestions on Cats?

I put a Magnaflow hi-flow low-profile on mine. Got it from Jeggs. Had it put in my swappable setup.

[Roku35]

25+ year old cars still need CATs in CA? We don't need no stinking CATs Hahaha.

[Zack01GC]

I still need a cat on my car. I am still subject to emissions in PA, everything after 1975 is, unfortunately.

[DaHose]

Here is what I am running on my 1987 M6 with Euro headers.

2-1 stainless collector
to
3" SS high flow catalytic
to
Moroso Spiral flow muffler
to
18" long, 3" ID resonator
to
3" pipe curving around suspension
to
3" ID, Magnaflow straight muffler







When I got the car it was already fixed up with a mediocre 2-1, before the 02 sensor. However, the catalytic had been cored and it only had the resonator and straight muffler. At 2500 RPM or so, the drone completely drowned out the stereo and I couldn't really speak to my passengers. Once I added in the bullet catalytic and the Moroso, the drone was GREATLY reduced and I really like the end result. I also used a stainless V-band clamp to join the rear section (resonator back) to the front section (catalytic forward). I did all the work myself, including taking a 3" piece of SS curved tubing, flaring one end to 3.5" and hand working it into an oval that would match up into the SS 2-1 collector section I scavenged from the original setup.

Jose

[Alex E24 E30]

I still need a cat on my car. I am still subject to emissions in PA, everything after 1975 is, unfortunately.

Same way in my home county, so I claimed residence where I go to school



...I'll probably keep the cat's in though...Hadn't decided yet, plus I'm not at the point to spring for an exhaust setup yet.



Alex

[Layne]

Personally I plan to go with a single 3" pipe as well, but with a dual outlet muffler to keep it looking stock. Given the same internal area, a single pipe will flow better than 2 pipes so I can't see a reason to do all the work twice.

Just because you have an O2 sensor doesn't mean it's connected to anything. Check your ECU, if it's the stock 055 there is no O2 input on it, and the wire is just a dead end.

[Badgas]

I put a Magnaflow hi-flow low-profile on mine. Got it from Jeggs. Had it put in my swappable setup.

Thanks for the source. Now that I've started looking, I'm running into "no longer legal in California" on a number of cats. Looks like it's going to narrow my search a little.

Here is what I am running on my 1987 M6 with Euro headers.

2-1 stainless collector
to
3" SS high flow catalytic
to
Moroso Spiral flow muffler
to
18" long, 3" ID resonator
to
3" pipe curving around suspension
to
3" ID, Magnaflow straight muffler

When I got the car it was already fixed up with a mediocre 2-1, before the 02 sensor. However, the catalytic had been cored and it only had the resonator and straight muffler. At 2500 RPM or so, the drone completely drowned out the stereo and I couldn't really speak to my passengers. Once I added in the bullet catalytic and the Moroso, the drone was GREATLY reduced and I really like the end result. I also used a stainless V-band clamp to join the rear section (resonator back) to the front section (catalytic forward). I did all the work myself, including taking a 3" piece of SS curved tubing, flaring one end to 3.5" and hand working it into an oval that would match up into the SS 2-1 collector section I scavenged from the original setup.

Jose

That's quite the system. I like the idea of going to a single 3" pipe. Not sure about a resonator and two mufflers though.

Personally I plan to go with a single 3" pipe as well, but with a dual outlet muffler to keep it looking stock. Given the same internal area, a single pipe will flow better than 2 pipes so I can't see a reason to do all the work twice.

Just because you have an O2 sensor doesn't mean it's connected to anything. Check your ECU, if it's the stock 055 there is no O2 input on it, and the wire is just a dead end.

Thanks Layne. I'll check on the ECU. I am having similar leanings on the 3" pipe with a dual outlet muffler.