Former VWDieselParts.com Forum

Last summer I had my local muffler shop fabricate the exhaust for my TD conversion. Now it's cracked.
Does it need to be supported as it comes off the turbo? It's mounted to the turbo side engine mount and then to the body at the tailpipe.

Johann

Since it is cracked, I think you should move your flex joint to where the crack it. That area seems to be where the vibration is worse. Regards.

You could clamp the engine side of the exhaust to some thing that moves with the engine (ie motor mount) and be sure the flex joint is not far from there.

So I had it repaired by the same guy. Not exactly what I would have done. Now it's cracked again.
My exhaust man is proposing a longer flex joint in place of the original.
There doesn't seem to be room in the curve where the original cracked to put the flex there.

Looking at your bend, it appears to have been made by a muffler bending machine. I can see the crimp in the wall of the radius. I would suggest buying a "mandrel bend" and having it in place of the one from the exhaust shop. You can purchase stainless bends for a reasonable price. Also, the support added could have contributed to the failure. It might have been better to have the support welded to an exhaust "c-clamp" and then bolted to the pipe. You'll get it figured out. Regards.

I wonder how close you can put the flex pipe to the turbo?
Can you brack the exhaust to one of the bolt holes on the back of the block?
Using the exhaust to support itself doesn't seem too wise.

Replace the stumpy flex with a longer one and move it as close to the turbo as possible. Right now you have a long, rigid "lever" extending away from the engine center - vibrations will only be amplified as you move away from the crank centerline...

Also by mounting part of the exhaust to the body, you've effectively rigid mounted some of it while the rest is constantly shaking and vibrating with the engine. Without a lot of flex pipe to isolate these two sections, cracks are guaranteed.

You'd be best to mimic the OEM mounting where the entire exhaust is attached inboard of the engine mounts and will then all shake and vibrate in unison.

It's also a good bet that all that tubing in the area that keeps cracking has been work-hardened and will continue to crack no matter what you do to correct things.

Chris

With all that hanging out there; I'm surprised it hasn't busted some exhaust studs.

I had the crack welded while I wait for the guy who created this can of worms to come off his vacation.

I appreciate that it's a long lever away from the engine, but it's mounted on rubber in two spots. The first is at the stock LS engine mount (inboard of the rubber) and the second on the right side near the tailpipe where it's mounted to the frame. It seems to be able to move OK, although when I manhandle the pipe the whole engine moves.

Anyone got a pic of working, custom TD exhaust? I want a good plan when I next go to the muffler shop.

I had the exhaust reworked today. So far so good. I brought in some pictures of really nice stainless exhausts that others had made up, mounted to what looked like factory brackets, at least on the engine side of the rubber. I also duct taped my camera to the bottom of the bumper and went for a short drive to show him how much it all moves.

Well he got the idea and when I came back to pick it up, he had replaced the cracked part with a much nicer U, like in the first pic I posted, apparently not mandrel bent but without the crimps like in the second pic I posted. He made up a piece for the stock oilpan mount points which although not as nice as the original piece I have seen in pics, should be serviceable.

So it's all mounted to the engine now and he painted it all black to boot. If you don't hear back on this topic, it hasn't cracked again.

Thanks for all your comments and suggestions

Johann

mind showing some pics of the new work?

I was having the same problem as jolotter... Here are some photos for those that may be interested in the future;
http://billwildenberg.shutterfly.com/vwvanagon/192

Here's some example photos I used when having this exhaust made;
http://billwildenberg.shutterfly.com/vwvanagon/113

Helpful links;
http://my.tbaytel.net/guskers/exhaust.html
http://members.shaw.ca/albell/exhaust_3.html
http://www.familycar.com/store/item/Vol ... 55262.html
http://www.thesamba.com/vw/forum/viewto ... t=#3710300
http://www.stainless-specialties.com/products2a.htm
http://www.hanksvillehotrods.com/Produc ... fault.aspx

Here's some pics, a year later. The exhaust has been reworked and while not fixed, it seems to be failing slower.

The new u-bend off the turbo



Left side rubber mount made from piece of tire



Right side mount



Crack on the lower side of u-bend off the turbo. There's a matching crack on the top of the bend


If I stiffen up the rubber parts, which are made from a piece of tire, maybe it'll keep everything moving together more. Like maybe heavier tire or another ply.

Is there a mount to the turbo like i think there might be on the Jetta/golf? Maybe a muffler clamp welded to a bar that bolts to the turbo housing. (Credit to rsxsr for that idea)

How about putting in one of those toilet bowl sockets like on the golf?

Thats a really nice install wildenbeast. I wish I had seen that before i started. You are mounted really solidly before the flex joint. I'll see if I can get mine shored up similar to that. I'm in too deep to modify mine to come down first like yours but i can probably find somewhere to mount to.

I didn't see any support before the flex joint.
I think it should be supported to the block before the flex joint.