Engine mounts & Exhaust damage - can they be too stiff?

[TomD 0]

Hi all! Seasons greetings!

 

I need some help!

 

Last year I fitted a G-werks 4 branch too my car, along with a BBM solid front mount, G60 rear engine mount and VR6 gearbox mount (also supplied by G-Werks) so the the 4 branch wouldn't get any flex and crack - The car already had a Miltek decat pipe and exhaust on it.

 

6 Months or so ago the exhaust started blowing so checked it out and the weld that holds the bit of metal plate that goes from the pipe to the back edge of the can (on the decat pipe) had come away at the end where it attaches to the can.

 

The engine mounts did have a lot of play before fitting the new stuff so I assumed that it must have been damaged before and given up the ghost since.

 

Managed to find a new miltek decat pipe from JMR (Thanks to Neil G60!) and fitted it in October, but car started blowing again this month - finally got underneath it today and there's a hole in exactly the same place where the weld used to be.

 

There's absolutely no play in the engine mounts and the exhaust rubbers are fine - so is it possible that the engine mounts are too stiff and all the stress is transferred down the pipe to a rather rubbish looking spot weld on the decat pipe?

 

Gonna try and take it to a powerflow dealer tomorrow and weld up the existing hole and strenghten it by seam welding the plate to the edge of the can - but I'm guessing it could well happen again in the near future?

 

Any help much appreciated - has this happened to anyone else?

 

Tom :)

 

Its a G60 by the way! :)

[Rustynuts 0]

You don't have a flex joint in there? If you have not that will be the only answer to your problem. Even with stiff rear mounts the engine will move, potentially still enough to find the point of weakness and cause it fail.

 

Get your power flow specialist to put in a flex joint before the decat if you can.

[TomD 0]

The G-werks 4 branch doesn't have one I don't think - it does have a joint just before the flange to the decat pipe but I don't think its a flex one as it doesn't seem to do much moving, more for alignment when fitting I think. Maybe it is though....

 

http://www.g-werks.com/Site/Default.asp ... s_Exhausts

 

its the 7th pic down - quite hard to see but its where the bolts and springs are.

 

I took it to powerflow and the decat pipe is now welded up and sounds much better, he said that the welding was rubbish and that the tack weld holding it the plate onto the edge of the muffler would have dropped off without too much stress. Any thing tack welded is now seam welded so fingers crossed...

 

:)