Do you support your exhaust in the middle?

[slomove]

I have one of these fancy Raceco cans with the titanium shell. Nice light and quiet but after 4 years the inlet cap now cracked the second time around the inlet tube weld due to fatigue. Not a disaster since it can be welded easily (the cap is stainless steel) but quite annoying.

 

I am beginning to wonder if I should do more to reduce vibration. Right now the exhaust is only attached in the front to the engine and in the rear at the side exit tailpipe with a minimally flexible steel bracket.

 

How do you all hang the exhaust? Is there a bracket in the middle and should I better use a rubber vibration damper on the rear end?

 

Thanks.

[MHKflyer52]

Hi Gert,

On my car I have two support brackets on the exhaust. One in front of the muffler and one after the muffler. Both are one inch by eight inch flat bar welded to the muffler and they go under the car to the frame and I then have a quarter inch diameter bolt that goes through the floor pan to hold the brackets to the car. I cut a chunk of rubber from an old car tire tread to sandwich between the floor and the bracket to reduce vibration and to give the exhaust a little movement to reduce the stress that no movement would create. So far in five years of driving my car I have only had to replace / repair the exhaust manifold and pipe twice and one time was due to me grinding the exhaust tip into the ground while auto-x's because of the way I had the tip angled and way to close to the ground and the amount of lean that I had in the setup.

Made a neat spray of sparks when turning hard right and caused a crack in the header.

Hope this helps.

:auto::driving:

[JohnCh]

Gert,

 

My rear collector and secondaries are connected by spring clips, so some flex there, but the rear of the Raceco is rigidly mounted. No center/front support and no cracking issues in ~20k miles.

 

-John

[Croc]

Sorry to hear about the crack. I have not got a raceo can however, in my first 2 years of driving my car I had 4 cracks at the 4 into 1 just before the muffler chamber. At the time I was using the standard Caterham mounts - front support off the collectors, a big unsupported stretch and then a rubber bobbin mount at the rear of the muffler. Apparently the unsupported stretch would flex too much thereby causing the continual splitting (and need for welding) on the crap quality NJ roads. It is a fairly common problem I am told. I ended up putting a middle mount that bolted through the floor and extended out under the body to support the front of the muffler near the 4 into 1 join. It is invisible from the side and can only be seen when looking from the top or bottom. This has made it much more rigid but the rubber mount still allows a minimal amount of flex. No problems since then and it still looks ok after 1 year.

 

I can take a pic if you want when I get back home later this week

Edited August 30, 2010 by Croc

[Hank]

I support mine almost mid muffler. It is a rigid mount. No rubber. No cracks.

 

http://hanksmegabusa.com/images/032710/08.jpg

[MichaelD]

Hank,

 

Nice looking car. Well done.

[slomove]

Thanks guys....looks like everybody is doing this somewhat differently.

 

Another aspect is that my motor mounts may have got a bit soft and led to more engine movement than necessary. I will replace them and try to attach a rubber damper to the muffler inlet pipe so that I don't get too much resonance vibration. I believe it was mostly the idle that did it.

 

Otherwise I will just weld it up every 10,000 miles and replace the can when there is more than 10 pounds of welding wire on it ;-)

[athens7]

Ben at Caterham USA sold me an exhaust mount that connects to the collector flange, because my exhaust cracked in the first few thousand miles. Since then, no problems.

[Hank]

For what it's worth my engine is rigidly mounted and so is my exhaust. It's quite the massage throughout the RPM band.

 

Thanks for the kind words, Michael.

[TheDingo8MyBaby]

For what it's worth my engine is rigidly mounted and so is my exhaust. It's quite the massage throughout the RPM band.

 

Thanks for the kind words, Michael.

 

Is that the way the megabusa kit comes? Hope you used lots of nylocks and safety wire and do lots of nut and bolt checks...

[Hank]

That is the way the Megabusa kit comes. If a bolt isn't equipped with a nylock it has a Binx nut (exhaust manifold only). I perform routine nut & bolt checks.

 

Sometimes I check my passengers too.

Edited September 1, 2010 by Hank

[slomove]

Ben at Caterham USA sold me an exhaust mount that connects to the collector flange, because my exhaust cracked in the first few thousand miles. Since then, no problems.

 

Ah, something like that is maybe what I need.

 

In the meantime I removed the starboard engine mount and found the rubber sandwich to be completely separated. That means the engine was mainly held in place by gravity, except for the metal cup around the mount. No idea how long it has been like that but I will check the other side today.

 

So, that may have to do with it.....

Edited September 1, 2010 by slomove

[KiwiBirkin]

My exhaust is held in the middle of the can by a cradle thats bolted under the car and through the floor pan via 2 big rubber bushes. The exhuats then sits on the cradle and is held in place by two large hose clamps.

 

Slomove I will put a picture up when I get my exhaust apart for painting this week so you can see it.

 

Cheers Stephen

[KiwiBirkin]

Here is a picture of my exhaust mount

 

http://i660.photobucket.com/albums/uu326/Hotdognz/bits%20and%20pieces/P1000231.jpg