View Full Version : Trackday silencers/dB killers
I'm looking to do track days this year and had my mate test my exhaust from half a metre away at 3/4 maximum RPM and it came back as 96-97 dB, but when I let off it seemed to go to about 99dB.
Limit for the track I'm looking at (Donington) is 98dB so it's a bit close?
Any one have a recommendation for a suitable additional track day silencer? I've found a few but struggling to find something suitable in 2.25" fitment (Ashley XE system)
Gareth_C
17-05-11, 10:13 AM
I'm looking to do track days this year and had my mate test my exhaust from half a metre away at 3/4 maximum RPM and it came back as 96-97 dB, but when I let off it seemed to go to about 99dB.
Limit for the track I'm looking at (Donington) is 98dB so it's a bit close?
Any one have a recommendation for a suitable additional track day silencer? I've found a few but struggling to find something suitable in 2.25" fitment (Ashley XE system)
What are the noise regs.
Jetex do a decibel insert I used on last year and i dropped mine by approx 5-6Db. But I was running a 2.5" system. maybe drop them a email. :thumb:
I'm looking to do track days this year and had my mate test my exhaust from half a metre away at 3/4 maximum RPM and it came back as 96-97 dB, but when I let off it seemed to go to about 99dB.
Limit for the track I'm looking at (Donington) is 98dB so it's a bit close?
Any one have a recommendation for a suitable additional track day silencer? I've found a few but struggling to find something suitable in 2.25" fitment (Ashley XE system)
noise limit & donington park circuit..... oh the irony.... all your hard work, you make a car that is legal to go up the road, but they won't allow it on the track... then when you sort it out & are on track, some git lands or takes off a dhl 747 cargo......
True the planes going overhead is kind of ironic lol
Noise limit for Donny is 98dB Gareth. Had a look at Jetex already but they don't do a 2.25" one.
nova ian
17-05-11, 11:36 AM
Your car will be fine for Donnington :)
Don't go restricting your power anymore than that clunky inlet system you insist on running already does!!
Gareth_C
17-05-11, 11:42 AM
True the planes going overhead is kind of ironic lol
Noise limit for Donny is 98dB Gareth. Had a look at Jetex already but they don't do a 2.25" one.
I would double check what at revs etc because everytime i have been noise tested was at 0.5m from exhaust At a 45 degree angle on half the cars max revs. Is the noise tested calibrated aswell, Ihave a ebay special and it said my car was 105db when tested at the track was 96db :thumb:
the noise output will vary depending on the air pressure, temperature, humidity, what surround buildings there are and how close they are etc... plus most meters are crap so you cant compare the readings :(
Ian I'd rather have something in my glovebox that'll allow me to continue the trackday with restricted power rather than go home! I'll make you eat those words lol
I read something on the net it was at 3/4 max RPM and 0.5m away but I guess it depends. Maybe a phonecall to Donington is in order.
MARTIN KELSON
17-05-11, 08:22 PM
You can see the noise level meter on the gantry when you come onto the start finish straight.
I was always advised not to go directly under it, go wide going onto the straight then when passed the meter ease back accross for the first corner.
TeddyThom
18-05-11, 12:15 AM
I thought that the track dB limit was 107 and road legal was 96/97??
Or does it depend on track?
nans_nova
18-05-11, 12:28 AM
it is tested at half max revs mate if u stillwanna buy sumthink to keep in the glovebox just in case lookup suppertraps because as a company we swear buy them as most of our cars end up out on noise controled track and test days
Not sure how it works at donnington, but at Oulton park they use a Hand-Held thing and they do ask what your Max rev limit is.. I presume they half that. If so, lie - I used to say it was 6.4k , when it was actually about 8k...
Half maximum RPM shouldn't be too bad then... I measured just over 5000rpm (3/4 throttle) and it was close so half might be okay.
At Oulton it was 3/4 max RPM about 4.6-8 iirc, 0.5m away at a 45degree angle.
They tested me before i went on track and got a little sticker saying i'd been tested.
chimp007_uk
18-05-11, 12:34 PM
Iain, as said in the email, the jetex one can be made to fit and is effective! Worth having it as a back up, it's not a big job to sleeve it the 0.25" difference. I doubt you'll need it anyway, so no point shelling out loads of money for a supertrapp etc. A cheap back up is what you need.
The trackdays i've done, its 0.5m away at a 45deg angle at three quarters the max RPM.
**edit**
That was MSV's standards.
Off the Fousced Events site:
Will my car pass the noise test? We always advertise the noise limit applicable for the day on our listings for track days available, as this varies from day to day & venues. The process of noise testing is done by the circuit & Focused Events don’t get a say in the outcome, if you fail the test the circuit will not let your car on the track. Most standard exhaust systems would be under 98db which is the lowest enforced noise limit at any track. If you are worried that your car will not pass the test, you can bring it along to one of our other events before your track day at an MSV circuit and get it tested.
Cool cheers for the info. Good point Chimp at £7 it's a good cheap backup. Guess could always use some heatwrap or something to make it fit? lol
When it says 45 degrees, is that to one side or upwards of the exhaust, or directly behind it and angled at 45 degrees?
dicko16v
18-05-11, 07:50 PM
Bin to oulton park today in my nova with a full sportex system and pased ok 92db
Cool cheers for the info. Good point Chimp at £7 it's a good cheap backup. Guess could always use some heatwrap or something to make it fit? lol
When it says 45 degrees, is that to one side or upwards of the exhaust, or directly behind it and angled at 45 degrees?
directly behind it and angled up at 45 degrees iirc
D'oh that's what we did with my mates measury thinggy.
Chimp I've ordered a Jetex 2" insert that I'll bodge in :)
chimp007_uk
20-05-11, 11:01 AM
It'll work fine... I used it on mine. When I took it out towards the end of the session I got red flagged. On mine it dropped it ~10db. Well worth the £7. I'm going to weld a cuff on mine for a more professional fit an look.
chimp007_uk
20-05-11, 11:01 AM
It'll work fine... I used it on mine. When I took it out towards the end of the session I got red flagged. On mine it dropped it ~10db. Well worth the £7. I'm going to weld a cuff on mine for a more professional fit an look.
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