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Exhaust re-packing
David Jenkins - 10/11/05 at 12:42 PM

I suspect that my exhaust needs re-packing, as the car's getting really loud...

I've never done this before, so what materials would I need for a proper job, and how's it laid out?

rgds,
David


NS Dev - 10/11/05 at 12:47 PM

depends on how good (i.e. expensive!) a job you want to do.

On the rally cars which need repackng every event anyway we just pull the old stuff out and literally just stuff the can with "rockwool" fibreglass again. pushed in with a stick.

You can get proper exhaust fibreglass but it still blows out, it just takes a bit longer to do so.


David Jenkins - 10/11/05 at 01:11 PM

Well, it would be good if it lasted until next Winter's service! (2000+ miles).
The current one's lasted about 1500 miles...

David


NS Dev - 10/11/05 at 01:22 PM

I'd guess you'd get about 1000 to 1500 miles out of std rockwool (slightly informed guesswork!)

All depends on how hard the driving is, revs used, exhaust temps etc but between 1000 and 1500 miles is prob typical. just live with the noise for the last 500 miles


craig1410 - 10/11/05 at 01:26 PM

I understand that it makes a big difference if you use stainless steel mesh wrapped around the perforated tube and then wrap the insulation around that. I think the SS mesh helps to take some of the heat and force out of the exhaust gases which stops the insulation taking so much of a battering. I also believe that you need to pack the cans right up to the point where you can't get any more material in.....and then pack in some more!

I hope this helps,
Craig.


jimgiblett - 10/11/05 at 04:16 PM

I think a number of suppliers supply packing on a cardboard tube wrapped in clear plastic (Got mine from fisher sportscars). With this you take the end off the can and slide it in compete with plastic wrap. The perforated core of the silencer pushes out the cardboard tube.

Use some clear silicone sealant when reassembling the end of the can and if possible let cure overnight. When you start the car it will sound noisey but the silencer will reach operating temperature and burn the bag away and noise will drop.

HTH

Jim


NS Dev - 10/11/05 at 04:28 PM

in the days when I was VERY poor (rather than just completely skint!!!) we used to go round scrapyards stihlsawing the ends of knackered tailboxes (many of which are glasspack) and pulling the glassfibre out to use for repacking, as it's a bit heavier duty than rockwool. usually the scrappy owner let us have a bin bagfull of it for free.

Them were the student days!!!


paulf - 10/11/05 at 05:55 PM

I have repacked mine a couple of times with loft insulation, i also wrapped some very fine stainless gauze around the perf tube and it does help it last a bit longer.I still only got about 600 miles before it started to get noisy again though, but at least it is only about £6 for enough to repack at least 4 times.
Paul.


David Jenkins - 11/11/05 at 08:07 AM

Thanks to all,

A few ideas there...

cheers,
David