87 300SDL - 2 3/8" exhaust pipe OD? - PeachParts Mercedes-Benz Forum

sixto · #1 10-28-2005, 11:10 PM

Can someone confirm that the 87 SDL exhaust downpipe section is made of 2 3/8" OD pipe?

Thanks,
Sixto
87 300SDL

sixto · #2 10-28-2005, 11:24 PM

Reason I ask, I'm thinking of using something like this -

http://www.jcwhitney.com/autoparts/ItemBrowse/c-10105/s-10101/p-100000174754/mediaCode-ZX/appId-100000174754/Pr-p_CATENTRY_ID:100000174754

to bypass the cat. I say bypass but you know what I mean

Might require a matching stainless steel flange downstream. I can use a 2 3/8" ID sleeve to clamp the plain steel downpipe to the stainless steel flex section.

Thoughts?

Sixto
87 300SDL

boneheaddoctor · #3 10-29-2005, 10:58 AM

Actually I think its a Metric dimension tube...but you can tweak a english dimension tube to work...but I would avoid that flexible tubing you linked...

dieseldiehard · #4 10-29-2005, 01:33 PM

I have been thinking of this too. I measured the pipe using a wire, you wrap it around the outside of the pipe, cut to fit, then divide its length by Pi to get the OD. The material is approx .0625 (1/16) thick so deducting twice that you get the ID. It is a little less than 2.5 in. If 2 3/8 I'd not be surprised but I can't locate my calculations but I do remember that 2.5 pipe is what is closest because I called a exhaust place that said they will make a "bypass" in 2.5 pipe. http://www.bobsmuffler.com/ for my '87.
The old style downpipes are extinct! BTDT can't find any anywhere

I asked what about a complete new line in 3.0 in they said no problem, custom made and mandrel bent of course. I wouldn't mess with anything other than mandrel bent. Click on Portfolio and take a look at the pictures of some truck exhausts they have made. Lots of truck owners out there in the valley who want their trucks to sound like a hot rod with the Flowmaster sound

The exhaust they put on a Camaro is really sweet too. I think they to put a Mercedes picture on there

About that 2.375 flex pipe. Anything that is not perfectly smooth on the inside it will add back pressure. I would avoid it! Use a smooth pipe with flanges if necessary. A good muffler shop can use a pipe that flared larger to fit over the adjoining sections and welded in place and should hold up very well with no extra back pressure.
If I get to Bob's I plan to ask them if they can make up a few bypass pipes, for members. If anybody's interested maybe I'll put it to the top of the wish list.

Brian Carlton · #5 10-29-2005, 04:21 PM

Quote:

Originally Posted by dieseldiehard

If I get to Bob's I plan to ask them if they can make up a few bypass pipes, for members. If anybody's interested maybe I'll put it to the top of the wish list.

The SDL has no cat but the downpipe is shot and needs to be replaced. As you mentioned, the dealer and the aftermarket do not offer this pipe anymore.

So, I'd be interested in a replacement downpipe, mandrel bent, if they are able to do this without the vehicle.

I'm not positive that the '86 and '87 are identical. Maybe the shop can confirm???

dieseldiehard · #6 10-29-2005, 06:28 PM

Brian, if (and when) I get to Bob's I will see if they can fab several of them, the flanges are going to be one item they might have a problem with, as I doubt they stock a bunch (if any) of the MB style flanges (I could be wrong tho!)
I wanted stainless, too if you think thats ok. Bob's said they have a flex section but I doubt it is identical to OE, it probably uses a wire mesh. What do you think about the one below? What does a MB flex section look like inside?

I tried looking for flanges locally but the wrecking yards around here don't keep them and the ones that have a car with one on it won't pull it, I guess they figure they can't get enough $$ for that. One told me no, they don't have any downpipes or exhaust stuff to sell when I know I saw one on a 300CE in their lot. go figure.

Brian Carlton · #7 10-29-2005, 10:26 PM

Stainless would be fine. But, it's probably less costly to get it here:

http://www.timevalve.com/cat/us/p15c.html