Exhaust packing

Simon · 07-15-04, 03:54 AM

I've decided I can live without the deafaning noise from my exhaust (fantastic though it is) and would like to tone it down a bit. I'm going to cut a hole in my exhaust box to fit "doors" but what should I re-pack the insides with to reduce the noise a bit? is there a special exhaust repacking material?
Thanks
Simon

daveg · 07-15-04, 04:08 AM

Simon,
Try Demon Tweeks part no:wadd 1. phone 01978 664471, or Merlin Motorsport on 01249 782101

Lynn · 07-15-04, 06:02 AM

I am not sure if this is what Dave is talking about or not, but they make a continuous strand fiberglass now that will not blow out (or not as easy anyway- never say never.) The problem with the older glass packs was that, even though they did a wonderful job of taking the edge off the exhaust note and leaving a nice smooth low rumble, the packing didn't last long and blew out, so they didn't do it very long. This was because the individual glass fibers weren't that long and would blow out one by one. With the new stuff the strands are extremely long and don't blow out nearly as easily.

Lynn

Simon · 07-15-04, 07:23 AM

Thanks guys,

I guess this'd be why then...... (see pic)

Simon

Incidentally, it's built out of steel thick enough to build a battleship from (well...almost) [img]/ubbthreads/images/graemlins/smile.gif[/img]

Gary Gibbs · 07-15-04, 07:51 AM

I understand that many high end mufflers use steel (stainless?) wool.

Bill Bayard · 07-15-04, 08:08 AM

Gary,

I use stainless steel "pot scrubber" packing plus Car Chemistry inserts as a temporary baffles,
for inspection purposes. They work quite well(barely pass).
That's just in the exhaust "tip". My stainless packing has broken down to the point of needing replacement for my next inspection, and it only has a total of about 10 hours of running time on it. Packing a pair of mufflers enough S.S. wool to make a big difference, would be kind of expensive.
I'm sure that there is a better grade of S.S. wool available, but anything you put in there would need to be replaced eventually.
Borla makes small, S.S., low backpressure mufflers that
would do the job better. Not cheap, but they would be a one time expense.
Dynatech also has similar small mufflers, as well
as very small cats, for those who might need them.

Bill

Neal · 07-15-04, 09:57 AM

I wondered where the neighbors cat was... [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

daveg · 07-15-04, 11:59 AM

Don't think it looks like long fibre wadding Lynn, but it's cheap enough to replace once or twice a year, I suppose.
http://www.demon-tweeks.co.uk/catalogue/...ORT&from=search Don't know if this link will work, may have to cut and paste.

Simon · 07-15-04, 12:51 PM

I've taken the plunge and ordered two rolls of exhaust "wrap" that goes around the baffle and a bag of loose wadding to fill up the void. Will let you know how it goes.

Simon

Simon · 07-19-04, 08:23 AM

Update:
Finished re-packing the exhaust and fitting my removable "door" (please don't laugh at my welding)
Hell of a difference! Still loud (big lumpy cam) but MUCH better than before, it's taken the hard "edge" off the exhaust note and turned into a loud rumble. Hopefully it will stop me getting a headache every time I drive the car.
Simon

Malcolm · 07-19-04, 01:48 PM

I have always used the Merlin Motorsport exhaust packing. It is about 10 GBP per square meter. I think it is called E Glass. A repack lasts about a season for me and I get a couple of sq metres at a time. I pack it in very tightly.

The higher the rpm you go the quicker the wadding blows out. Over 5000 rpm seems to be a break point for accelerated exhaust wear!

The wire wool I have used in the past just melts. Once I blew one of my covers off and the wool was just glowing bright cherry red. HOT!

On making the covers for access to repack, I cut my hole with a grinder but chucked away the off cut. I had my local supplier cut me new covers that made a 1 inch overlap all round so there was no need to make a raised bolting down platform. I then used large 5mm self tapping screws with bolt style heads and cut them in using some oil on each initial use. Some exhaust sealant could be used but I found that the 1 inch overlap sufficient to get me through RAC scrutineering.

Just another way of doing the same thing I guess!