rodgling
|
| posted on 13/11/15 at 10:23 AM |
|
|
trackday noise
Need to find a solution for trackday noise. My exhaust is massive (with a cat to help noise) and there's no room to fit a bigger one, so looking
at additional bolt-on bits.
I've tried a bung with wire-wool, which is a bit of a crappy solution but does get me just-about OK for most tracks.
Looking at this now (to bolt in the end of my existing exhaust):
http://www.demon-tweeks.co.uk/motorsport/universal-exhaust-silencers/jetex-universal-exhaust-silencer
anyone got any experience with these? Or suggest similar bolt-on alternatives?
|
|
|
|
|
loggyboy
|
| posted on 13/11/15 at 10:24 AM |
|
|
Is it defo exhaust noise that is your concern not intake?
Mistral Motorsport
|
|
|
sprintB+
|
| posted on 13/11/15 at 10:31 AM |
|
|
I have a "motor cycle insert baffle" Will try to get the details, find the receipt etc. Brought it down to the legal bit for Castle Coombe
but does knock the performance some what.
|
|
|
rodgling
|
| posted on 13/11/15 at 10:33 AM |
|
|
quote:
Originally posted by loggyboy
Is it defo exhaust noise that is your concern not intake?
Hard to say. Probably exhaust, as it's border line on static testing when they shove the probe up your exit pipe, which presumably mainly
measures exhaust noise. I've got a fully enclosed filter which should help on the intake side.
|
|
|
DW100
|
| posted on 13/11/15 at 10:57 AM |
|
|
Fit a turbo!!
|
|
|
INDY BIRD
|
| posted on 13/11/15 at 10:59 AM |
|
|
Had the same problems before my self,
So put on the extra silencer on the rear more permanent solution
 
rear exit exhaust
|
|
|
livelee
|
| posted on 13/11/15 at 11:09 AM |
|
|
I've got one of these on my car:
http://www.carbuildersolutions.com/uk/6-stainless-steel-silencer
Trackday at Snetterton, 97static and drove round all day without issue.
Next trackday was a wet one at brands hatch, I missed the morning noise test as I was late but then drove round slowly all morning without issue. In
the afternoon a dry line appeared and I was blackflagged for noise after 1 "hot" lap out of the pits.
£80 later i'd bought an exhaust bung from the trackside shop. One of these:
http://www.demon-tweeks.co.uk/Product.do?method=view&n=1884&p=446389&d=124&c=4&l=2&utm_source=Google&utm_medium=Base&u
tm_campaign=Universal%20Exhaust%20Silencers&gclid=Cj0KEQiAsZayBRCrioKRkYetvc0BEiQAI70-A3NfhxYafuGYeiLHVsY2rDms4LnSmWiRgsGNfASHYEEaAqoV8P8HAQ
Static noise was recorded at 100! I was able to continue the day though, I drove round as I normally would and didn't trip any meters. 1st
time I've googled to see if I could find the bung and it mentions no reduction in power. I'm dubious.
Conclusion, there's no logic to noise. If you're close to being "loud" somedays you'll be fine and other day's
you'll be noisy. Do the best you can and also carry a bung.
|
|
|
Irony
|
| posted on 13/11/15 at 11:27 AM |
|
|
I bought some DB killers from Furore for my IVA and my Rover V8 with no cats and 5 inch mufflers sailed through at a tiny 92Db. I am not sure what
the do to BHP though. They came straight from Furore but I have curved them to fit up the curved exhaust. I don't need them now so they are
available for small amounts of cash. U2U if interested.
|
|
|
rodgling
|
| posted on 13/11/15 at 04:12 PM |
|
|
quote:
Originally posted by INDY BIRD
Had the same problems before my self,
So put on the extra silencer on the rear more permanent solution
Thinking about going this route, I'd rather not though if it can be avoided. Would be interested to see more pictures of how that's routed
past the rear wishbones, that must be a bit of a squeeze?
|
|
|
mark chandler
|
| posted on 13/11/15 at 05:32 PM |
|
|
You need to take it out the back really, mine failed however if I stood between the outlet and engine the noise dropped by 3db
Cut 3 1/2" hole in front of the wheel, under the arch
 
Under arch
Then another facing the rear wish bones close to the diff as less movement
Use very tight mandal bends, then a kink so it fits nicely between the bone and half shaft
 
under halfshaft
 
through bulkhead
Box in behind the seat
 
bulkhead box
Then out the back
 
Exhaust rear
, made life hard for myself with 3" exhaust all through.
Some people follow the curve under the wheel arch.
HTH
[Edited on 13/11/15 by mark chandler]
|
|
|
motorcycle_mayhem
|
| posted on 13/11/15 at 08:54 PM |
|
|
I solved my noise issues by (now) using a tired MX5 as a track hack. No more black flags, worries or NIMBY crap.
However, I did have some limited success on competition days (with the BEC) using a Merlin Motorsport bolt-on. Wasn't a great deal quieter with
the thing on the tailpipe, but sank the static noise to just over 106 dB to just under 105 dB - so I could go and play at Combe - just.
|
|
|
The Black Flash
|
| posted on 14/11/15 at 08:59 PM |
|
|
I'm in a similar boat - black flagged at Oulton and used a bung and short-shifting to carry on. I've tried a variety of the cheap
perforated bungs and they all only seem to take off a db or two. I've got large wunoff silencers on but it's still much louder than
I'd expected, given only 1.5L per exhaust.
Wondering about the decibel devil next - bit more of an investment but if it makes the problem go away I won't mind.
Decibel Devil Race & Trackday Car Exhaust Noise Reducer Fits 3" O/D Tailpipes
|
|
|
rodgling
|
| posted on 14/11/15 at 10:15 PM |
|
|
quote:
Originally posted by The Black Flash
I'm in a similar boat - black flagged at Oulton and used a bung and short-shifting to carry on. I've tried a variety of the cheap
perforated bungs and they all only seem to take off a db or two. I've got large wunoff silencers on but it's still much louder than
I'd expected, given only 1.5L per exhaust.
Wondering about the decibel devil next - bit more of an investment but if it makes the problem go away I won't mind.
Decibel Devil Race & Trackday Car Exhaust Noise Reducer Fits 3" O/D Tailpipes
Yeah, my thoughts exactly. I've also tried various bungs, none hugely successful. Looked at some reviews of the Decibel Devil: "Failed
with 108db. Fitted decibel devil and passed with 103db" and elsewhere, "Supercharged XJS. Drive by noise was reduced from 106DB to
96DB", also "exhaust system is 108dbs at 6000rpm he did get black flagged once when he got caught up in traffic, but apart from that
managed to run all day [98 driveby]"
Sounds worth a punt, could you buy one and let me know how you get on :-)?
|
|
|
Matt21
|
| posted on 15/11/15 at 07:29 AM |
|
|
Have you tried re-packing your exhaust?
You may need to cut it open and re-weld if it's not a re-packable one.
Before I did mine the in-laws could here me coming over the moors 5 miles away!! now they don't hear me turn up!
I used acousta-fil (the figures on how much you need are miles out, you need much less!)
|
|
|
The Black Flash
|
| posted on 16/11/15 at 06:11 PM |
|
|
quote:
Originally posted by rodgling
quote:
Originally posted by The Black Flash
I'm in a similar boat - black flagged at Oulton and used a bung and short-shifting to carry on. I've tried a variety of the cheap
perforated bungs and they all only seem to take off a db or two. I've got large wunoff silencers on but it's still much louder than
I'd expected, given only 1.5L per exhaust.
Wondering about the decibel devil next - bit more of an investment but if it makes the problem go away I won't mind.
Decibel Devil Race & Trackday Car Exhaust Noise Reducer Fits 3" O/D Tailpipes
Yeah, my thoughts exactly. I've also tried various bungs, none hugely successful. Looked at some reviews of the Decibel Devil: "Failed
with 108db. Fitted decibel devil and passed with 103db" and elsewhere, "Supercharged XJS. Drive by noise was reduced from 106DB to
96DB", also "exhaust system is 108dbs at 6000rpm he did get black flagged once when he got caught up in traffic, but apart from that
managed to run all day [98 driveby]"
Sounds worth a punt, could you buy one and let me know how you get on :-)?
I would, trouble is, I need 2 :-/
I'll have to do something come the new year though.
|
|
|
rodgling
|
| posted on 9/1/16 at 01:44 PM |
|
|
quote:
Originally posted by The Black Flash
I would, trouble is, I need 2 :-/
I'll have to do something come the new year though.
I'm going to do Snetterton in a few weeks, will do noise test with and without one of these fitted and let you know how much improvement I get.
|
|
|
The Black Flash
|
| posted on 12/1/16 at 04:50 PM |
|
|
That'd be really good to know, I'm sure it'll save several of us either time or money, or perhaps both!
|
|
|
owelly
|
| posted on 12/1/16 at 05:05 PM |
|
|
I fitted a homemade Supertrapp type thingy to clamp to my tailpipe 
I had a local fab shop punch out a pile of thin washers out of sheet metal, and one with no centre hole. I then punched two holes in the edge of each
washer at opposite sides and poked a 3mm rod through each one I then tack-welded each washer to the rods leaving a 1mm gap between each one. Then I
made an outer tube to enclose it all and clamped it to the tailpipe.
It reduced my car from 104bd to 95db. Eventually, it fell off and I drove over it.
http://www.ppcmag.co.uk
|
|
|
Jon Ison
|
| posted on 12/1/16 at 06:31 PM |
|
|
Static noise testing does my head in!
My car is pretty quiet on track, never triggered a drive by.
My car is pretty noisey on a static test, without tinkering almost guaranteed to fail a static test.
I put it down to at around 3/4 revs it must be the worst possible engine speed for vibrations to rattle the wafer thin bodywork, metal floor, dunno
but whatever it is the meter don't like it.
I did ask at Cadwell last year if they could move the probe towards the front of the car just to see what happened, the reading increased as they
moved forward then decreased again from about 3/4 way forward until they got to the very front where it increased again, the intake for the enclosed
air box is behind the nose cone grill in front of the radiator.
The annoying thing is like I have mentioned once on track it's like a mouse compared to most trouble is Oulton for example won't let you
out without passing a static test, Cadwell on the other hand (same 105) is a doddle.
Is your exhaust re packabke? Acustafil seems to work best for me and my Oulton static test washer, I have a butterfly like a throttle in the pipe,
turn it to all but block the exhaust for test, open it back up once passed.
|
|
|
smart51
|
| posted on 14/1/16 at 05:39 PM |
|
|
I replaced the link pipe between the collector and silencer with another small silencer. I had it made with 2" OD end pipes so it would slip
inside the collector and the main silencer. It was 5" long and took exhaust noise down by 5dB from 103 to a more bearable 97dB. Performance
wasn't affected at all so it became a permanent fixture.
 
advertpic1
|
|
|
The Black Flash
|
| posted on 21/1/16 at 09:28 PM |
|
|
quote:
Originally posted by owelly
I fitted a homemade Supertrapp type thingy to clamp to my tailpipe
I had a local fab shop punch out a pile of thin washers out of sheet metal, and one with no centre hole. I then punched two holes in the edge of each
washer at opposite sides and poked a 3mm rod through each one I then tack-welded each washer to the rods leaving a 1mm gap between each one. Then I
made an outer tube to enclose it all and clamped it to the tailpipe.
It reduced my car from 104bd to 95db. Eventually, it fell off and I drove over it.
I did wonder about those as they seemed diy-able. Wasn't sure how effective they'd be, but sounds like they're pretty good. Might
be worth a try...
|
|
|
owelly
|
| posted on 21/1/16 at 10:38 PM |
|
|
You can add/remove the discs to suit. Mine worked very well.
http://www.ppcmag.co.uk
|
|
|
Sam_68
|
| posted on 22/1/16 at 08:39 AM |
|
|
quote:
Originally posted by mark chandler
You need to take it out the back really...
Exhaust rear
That's a much neater job than Caterham managed with their new 620S!:
|
|
|
Shaggydoo
|
| posted on 23/1/16 at 11:58 PM |
|
|
Try repacing the silencer using Acustafil material, managed to lower my db level 4decibels
|
|
|
Fcck2000
|
| posted on 28/1/16 at 03:44 PM |
|
|
We fit one of these when we have to on track days, brings static down by about 5dbls. Problem is now the intake..
http://www.custom-chrome.co.uk/Track-Comp-Boxes.html
Tiger SSC
220bhp on standard MZR Duratec engine with throttle bodies and mild camshaft upgrade.
|
|
|
