Exhaust packing. E-glass or basalt

[Drumster]

I need to repack my Techcraft silencer and having searched the archives some people talk about E-glass and others talk about basalt packing. Are there any distinct pros or cons with either i.e cost, length of life, ease of handling etc... bearing in mind I have a popping, banging and flaming x/flow 😬

 

Chris Alston

1800 Supersprint here

Drive it like you stole it! but don't tell my pupils that 😳

 

[Paul Deslandes]

Chris

 

I'm a great fan of e-glass and have used it for several years. On my, admittedly not popping and banging Vx, a repack lasts nearly a season, but its getting marginal by the end. With either material, packed carefully, the performance is about the same to start with but I've found that the basalt drops off much more quickly than e-glass. I usually manage to get down to about 96dB initially.

 

Basalt and rockwool seem to compact tightly after a while and form donuts with gaps in between. The silencing efficiency drops dramatically and you start to see staw coloured rings on the stainless silencer sleeve casued by the heat. It rings when you tap it. They also absorb moisture and the silencer needs to heat up before it works properly. This can be a problem for noise testing at the beginning of a track day or event.

 

In terms of handling, rockwool and basalt goes in in chunks and you tamp it down. The packing density can be quite variable. With e-glass, which comes in hugely long strands. I sort of wind it round the pipe (I can only get the end cap off my box so I have to pack the material between the inner pipe and outer sleeve), tamping it down as I go. The packed material has a natural springiness of its own so its easy to get the density reasonably uniform and consistant.

 

You can buy e-glass loose in bags or preformed into sheets. Some also recommend wrapping the inner pipe with stainless steel wire wool but I've never been able to do this due to the design of my silencer, so I don't know whether it makes any difference to the life of the packing. Bagged material is a lot cheaper (£3.00 + vat for 600gm) and is easy to use.

 

As I mentioned on a previous thread, I tried washing out the old e-glass taken out of the silencer after 12 months. It was filthy job and I wouldn't bother again!

 

Paul

 

 

[Drumster]

Thanks for your thoughts Paul

 

Any other opinions out there?

 

Chris Alston

1800 Supersprint here

Drive it like you stole it! but don't tell my pupils that 😳

 

[Crudders]

Have you checked out this thread Chris?

 

Crudders

[Drumster]

Thanks Crudders , missed that one 😳

 

Chris Alston

1800 Supersprint here

Drive it like you stole it! but don't tell my pupils that 😳