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Bigger silencer
smart51 - 17/3/06 at 05:44 PM

I am going to buy a bigger silencer to try and quieten my exhaust a bit. How much bigger do I need it to be?

I currently have a 24" x 5" straight through stainless steel can. I need to lose 3 or 4 dB to get into a track day.

Before I shell out a load of cash for a new can, only to find it is still too loud, What size do I need to make a noticable difference?


smart51 - 17/3/06 at 05:56 PM

I'm not sure that a 7" can will clear the body work. How much difference would a 6" can make?

I could fit a 30" can in the tail pipe was short, i.e. straight. A curved tail pipe would take up more room. Which is best, a longer can with a stubby pipe or a shorter can with a curved pipe?


marc n - 17/3/06 at 06:01 PM

colin if you are going to fit bigger give me a bell tomorrow and i can bend you up a offset link pipe to give you more clearance, as i have the 2 inch tooling still in the machine

best regards

marc


smart51 - 17/3/06 at 06:07 PM

Cheers Marc. Can you supply bigger silencers as well?


marc n - 17/3/06 at 06:09 PM

hi colin not in diameter but can in length

best regards

marc


marc n - 17/3/06 at 06:10 PM

quote:

then length can make a big difference on it's own



follow with smutty comment of choice

know what youre getting at though

[Edited on 17/3/06 by marc n]


smart51 - 17/3/06 at 06:15 PM

Marc, How much longer is the longer can, how much does it cost and how much might it reduce the noise?

I'm thinking of going to total kit car live and so may be able to collect.


smart51 - 17/3/06 at 06:17 PM

I've looked at cans on a few places and they quote figures of 1dB less for aly than stainless. Aly might be an option.


smart51 - 17/3/06 at 06:23 PM

I'd thought of that. If I could get a 6" long can with 2" outer diameter tubes on the end then I could put it in place of my link pipe. I don't know whether it would be as effective as a 6" longer can or whether it would be much cheaper than a longer can.


smart51 - 17/3/06 at 07:31 PM

The reason I suspect it wouldn't be much cheaper is that there are the same number of parts, requiring the same amount of time to make, just the perforated tube, outer cylinder and wadding would be shorter. the saving would be in material only. Still, it would probably be cheaper and if it would work as well it would be a nice option.


Lightning - 17/3/06 at 07:45 PM

Why not just shove a Merlin Motorsport muffler on for track days. Mine made 4db difference. costs about £50.
It effectivly gives you 4" extra length.

[Edited on 17/3/06 by Lightning]


smart51 - 17/3/06 at 09:39 PM

Merlin say that on some cars their small muffler does nothing and on some cars it does a lot. it's a bit of a risk. I've tried allsorts with little success so I wouldn't hod out much hope.


mnr laptop - 17/3/06 at 09:58 PM

not sure what to suggest colin, my car has passed sva and brands noise tests, but failed donnington by 2db added a db killer and reduced it by 5db, had various customers who have had similar sucess. including ians v8. guess i will se again at oulton ?????
is the packing ok, i ask as i managed to solidify the packing in mine hence the fail at donnington, running lean on emmisions at sva with cat caused it. are any of the breathers left to vent to air as some of it could be engine noise especially from the crankcase breather

best regards

marc


ned - 17/3/06 at 10:17 PM

we used the merlin muffler at goodwood and managed ot get our 235bhp xe within the limits there which is pretty tough - i've heard they have less effect on bike engines though.

Picking up my new exhaust tomorrow, depending on space its going to be 27-29" x 7" with 2 3/4" exit.

Ned.