Droopy Exhaust

[ScottR400D]

An odd problem. The other week I noticed the tailpipe of my silencer pointing down at about 45 degrees instead of horizontally. 

Thought one of my small granddaughters had stood on it climbing in (they love to sit in the Caterham!) so slackened the clamp, swung it back up and retightened. 

A few days later it's drooping again. Again repositioned but it's quite easy to rotate down when clamped up and drops on the first few bumps. 

I've changed the clamp for a new one, but it just doesn't clamp the pipe solidly even when fully tightened. I've put exhaust paste on which makes it better but still possible to just push the pipe downwards. 

Any thoughts? I'm using a Mikalor clamp, very similar to the original Norma clamp. 20mm wide band seems a bit wide to exert a good pressure on the pipe, but it was OK for nearly two years till this happened. 

Thanks

Peter

 

[John Vine]

My Norma clamp works just fine. Are you clamping right at the open end of the slots in the silencer inlet? Are the slots clear of debris? Is the bolt in the clamp binding on anything?

JV

[SM25T]

Have you got the clamp as far forward on the female part as you can get it ... So it clamps the tongues on to the pipe ? This makes a lot of difference. If so ... change it for the u-bolt clamp type which will exert a greater clamping force.

[ScottR400D]

Yes, right at the end, the slots are clear and all's clean.

The OE clamp threaded 'nut' was collapsing, as was the support under the head of the bolt but that was just through over tightening trying to get it to hold the silencer. 

The replacement clamp has better 'nuts' and was tightened carefully and fully but the silencer still turned. 

I was thinking of trying a regular U pipe clamp, that would clamp harder but they don't look as neat. 

[Jonathan Kay]

Can you add a photo of the whole exhaust system and a close-up of where it's rotating?

Jonathan

[ScottR400D]

Not with car at moment JK. Can do on Monday. 

[MADMALC]

Check the 'bobbin' is in good condition so it takes some of the weight without flexing. I always had to be brutal with the torque to stop mine drooping.

[SM25T]

Are you using the centre mount from the chassis too ... to support system at front of silencer ? This helps a lot.

[ScottR400D]

The bobbin looks fine. The clamps just aren't gripping. Tighten up and you can fairly easily rotate silencer by leaning on pipe. 

System was polished but it's been fine since built in May 15 and I've roughened up end of pipe. 

 

[elie boone]

Mikalor is to flimsy, i wouldn't even use it on a water hose. you need something like this http://www.amazon.com/Torca-AccuSeal-Exhaust-Clamp-Stainless/dp/B004G8XZJ0

[SM25T]

I was thinking of something like this https://www.google.co.uk/search?q=bulldog+exhaust+clamp&oq=bulldog+exhaust+clamp&aqs=chrome..69i57j33.10715j0j4&client=ms-android-h3g-gb&sourceid=chrome-mobile&ie=UTF-8#imgrc=cP6OsRkPUeG3oM: .... In the right size of course.

[ScottR400D]

The Mikalor is actually much better than the OE Norma but I agree what you recommend would be better but I can't find in the UK in 2 5/8" or 67mm. 

The bulldog link doesn't work for me, SM25

[ChrisC]

Found mine needs a nip when hot to make it clamp tight enough to hold the exhaust level.    Until that point it droops. 

[slap_ed]

I've removed my R400 box a couple of times recently and it's gone back nice and tight without me swinging on the spanner. One of those times was to polish it and that included these connection surfaces. If I flex the tail pipe you can see the whole exhaust flex right into the engine. I know this doesn't help you really but it's just for information.

/sites/default/files/images/users/3729/medium_IMG_4428.JPG

[Wrightpayne]

Could you slip a strip of beer can inbetween whilst you procure a better clamp, to take up the slack. Only downside is you have to drink the beer first!

Ian

[Jonathan Kay]

Could you slip a strip of beer can inbetween whilst you procure a better clamp, to take up the slack.

As In "Zen...

:-)

Jonathan

[ScottR400D]

Tried that Chris, doesn't work now!

[ScottR400D]

That's how mine has been until just recently. Just won't grip now!

[SM25T]

Try another http://www.eurocarparts.com/search/712772100?gclid=CjwKEAjwutXIBRDV7-SDvdiNsUoSJACIlTqlUwVsNVpWOh693nYRGAKx4DGKKe1-A0e-l3QV1MWwxBoC91Hw_wcB

[SM25T]

If that doesn't work ... Just Google 'exhaust clamp' .... you'll soon see the u-bolt type. Buy them in any car parts shop or exhaust centre

[ScottR400D]

Thanks SM. Yes I'm aware of that type of clamp,im sure one would work but they're a bit ugly! 

 

[BlackSeven]

I had exactly this problem. The type recommended by Ellie earlier in this thread worked perfectly for me - replacing a Mikalor and giving a huge amount more clamping force. The cheap and nasty u bolt type from your local car spares shop might work but will look scruffy and will be a rusty mess in no time.

Rob

[ScottR400D]

Where did you get it from? I can't find one of 67mm or in the UK. 

[elie boone]

Here you go http://www.ebay.co.uk/itm/Jetex-Universal-Heavy-Duty-Exhaust-Single-Bolt-Clamp-2-5-034-67mm-Stainless-Steel-/291915194322 otherwise BMW has some 3 & 5 series with 67mm exhausts

[micksmetafors]

I had a similar problem with the 7 inch can Simpsons made for me. Nothing wrong with the silencer, just the mounting. Copper RTV in the female part and clamp up tight with the Mikalor. Left it to set for a day and it does not move at all.

Cheers, Steve