Found it!

https://www.miataturbo.net/diy-turbo...-doesnt-62045/

 

Oddly enough I've read through those 2 threads in the last couple weeks while searching about cracked downpipe.

I might order the FM 3" brace and see if I can get it to work with my setup... I dont think it could be that far off.. Might have to re-bend it or add washers, etc but at least it'll be a starting point

 

It's been years since I last saw it, but there's a another thread out there where bbundy shows how the exhaust clamp made crimps on his exhaust piping.

He also posted pictures of a clamshell clamp (I can't remember the exact name but it has something to do with sea life) which has more surface area so the denting doesn't occur.

 

I believe you are referring to this one...

https://www.miataturbo.net/flyin-mia...t-brace-43572/

There was a link to that in the link that aidandj posted

 

2nd page in my link he shows his setup.

 

I support the addition of poly exhaust hangers. I think they might make a big difference in the amount of stress on the downpipe. Old rubber hangers allow a lot of sag and movement over bumps, while the poly hangers do not. I also agree that they suck to install, but are totally worth it.

 

I plan to make the move to poly hangers. I actually replaced my old hangers with new ones from advance auto and they seem much stiffer. I took a ~250 round trip on Sunday for a Miata meet and the downpipe survived! Very happy about that!

 

poly hangers can technically increase stress.

 

/\ This is what I always thought too, but don't really have any actual data to support/refute. Your drivetrain moves, your chasis doesn't. Restricting the movement of exhaust parts bolted to the moving drivetrain tells me you'll putting more stress on them

 

One thing about the frear of crimping the tube. If done correctly, the support clamp should be installed with prevailing torque nuts that do not depend on being tightened to remain in place. The objective is to let the pipe acutally slip axially in the clamp during expansion and contraction with temperature; and to only hold the pipe radially (vertically). So, you don't really want to make the clamp real tight.

 

Poly hangers might cause more stress if you're pulling hard on the exhaust to make the connection, but if your connections are neutral, the benefit is in the reduced movement in bumps/loads (as mentioned).

fwiw- These are worth every penny when it comes to exhaust hanger bushings.

 

+1 They are most excellent. I borrowed a pair from Gesso and I keep forgetting to give them back.

 

this.