Track Day - Drive By Limits -

[2barGee]

I've not done Snetterton yet in the MR2 so it's one i'm wanting to do, it's a decent drive for me and i don't want to get kicked off the track for been over on the drive by limit which for this track is 92db.

I've never had a problem on any track i've done so far in the MR2 but then looking at most don't have drive by limits - like Cadwell and Anglesey.

Also i'm now running a berk from the cat back which seems a bit louder than my old mongoose........

Has anybody done a track day with drive by limits as low as 92db and did you have a problem?

Mods are ct20b 1.2 bar of boost
Decat and berk from cat back.

Cheers Dan

[ashley]

Maybe sommit like this...

https://www.castleshop.co.uk/atp-mini-d ... 0wod1fIHBw

?

[SonicSW20]

It's 92dB at 20 metres, and sound levels drop off according to the inverse square law in perfect free-field conditions. This means a sound that measures 105dB at a 1 metre distance will ~78dB at 20 metre distance. This is assuming perfect conditions, no reflections etc which of course is not the case in a real application so you would be reading higher when that's taken into account, wind noise, and the exhaust being louder under high load conditions.

In practice because it's measured at 20 metres if you pass the static at Snetterton the driveby shouldn't be an issue.

[auzzam]

I'm sure brands hatch has a 92db limit, I was fine ... didnt trip it once.

Mods - apexi air filter, decat, ebay japspeed style exhaust.

I did however keep baffles in the boot just in case I was stopped - cost me about £40, but good to use for early starts in the morning too

[GTMatt]

I did a track day at snetterton in February, drive by limit was 96db I think. Either way I have a screamer pipe which is pretty loud on drive by and had no issues mainly due to (like others have said) the sensors are quite far off the track. In comparison I did goodwood in December with driveby of 98db drive by and I eventually got black flagged for being too loud.

[Race Idiot]

Sounds like Donnington where they don't do a static test and just flag people for the driveby limit.

Usually if you have to do a static test they also have a driveby limit which is lower db than the static.

The only cars I saw getting flagged at donnington were stupid loud, one was an rx7 and the other was an aston martin track special.

[SonicSW20]

Snetterton have static tests too, 105dB @ 0.5m is typical but the limit is sometimes lower.

Every track publishes their noise testing regs.

http://www.snetterton.co.uk/media/97529 ... 010_rm.pdf

Snetterton driveby is always 92dB @ 20 metres for track days.

[MartinF]

I was close to the 105dB limit when I did the static test at Snetterton in November.

I have a Rev1 turbo engine with no CATs and Japspeed exhaust. I had bungs in the boot just in case but no issue.

[pnelson]

I've seen a load of super loud cars go round Snetterton on track days I've attended with no issues on the drive by limit.

As others have said, if you pass static you'll almost certainly be fine! Do they test it at the pit wall? Maybe keep to the far side of the track if you're worried

[SonicSW20]

Driveby meters are 20 metres from the track - see the link I provided above.

[2barGee]

Well i ended up doing Cadwell Park as i couldn't be bothered with the drive to snetterton

Static i was 98db........... looks like i wont be doing Donnington ever

[SonicSW20]

Donington has noisy days, I think they charge a bit more for them though.

[2barGee]

Donington has noisy days, I think they charge a bit more for them though.

I find donington to be expensive compared to other tracks and then going on the noisy days just makes it silly money just for a trackday

[SonicSW20]

Snetterton is great value for money in the off season, still not too bad during the warmer months either. Snetterton 300 is great fun, loads of run off too

Bit of a way for you though!

[Race Idiot]

Donnington don't do a static test, they just have a single drive-by of like 90 something db. If it's 98 static then it will probably be ok for the drive-by one.