How long should they last, getting a bit worried about mine. We were noise tested at Snetterton in June at 97db.
Again at Hethel in August at 101db and again at North Weald yesterday at 103db seems a massive difference as it only covers about 150 miles. We have another sprint at Debden on Sunday week and I'm getting a bit worried we might fail.

It depends what was in there originally.

My can was filled with domestic insulation when I bought it. 1,000 miles later and it was a bit noisy. Opened the can up and it was completely empty, apart from one tiny bit left trapped under the head of a rivet.

I replaced that with some from car builder solutions, which lasted 5,000 miles.

HTH

Mike

May sound like a daft question(s) but
1. How do you open one of these things up, never done it
2. Do you then pack it loosely or ram as much stuff in there as possible.

My can had a number of rivets around the end. Took the can off, drilled out the centres of the rivets, so the heads fall off. Then the end cap just popped off.

The stuff from CBS comes on a cardboard tube, around which is wrapped some stainless steel wire wool, then the stuff is wrapped around that like a Swiss roll. I took the perforated pipe out of the middle of the can, and slid the new packing on, pushing the cardboard tube out at the same time.

Then just slide the whole lot back in. There should be a bit of a gap for it to expand into.

Then rivet the end back on.

HTH

Mike

Thanks Mike, looks like a job for the weekend just to be on the safe side, As a matter of interest we always warm the engine before testing as I've always thought that's when its at it's quietest, have i got that the right way round.

For the past few months I've been using Acousta-fil for packing cans.
They say it's good for 700 deg C.


As a side note the mixture set up will effect how hot the exhaust runs.
The blokes that show old bikes set the mixture extra rich so their newly chromed pipes don't discolour.

Cheers
Paul G