I was recently black flagged at Bedford on drive by db’s. Static was fine at c.96-98 but on the drive by I failed at a rather picky 90-91 on a level of 89db
The MSV guys were very pleasant and I was pissed but sanguine about it given I’d only done 5-10 laps in anger! and they suggested that the noise was likely the induction and S/C wailing on the downshift (sound bloody great btw) as opposed to the exhaust itself.
So couple of things?
a) Does anyone know the drive by limits on other circuits
b) god forbid does anyone have any suggestions as to how to reduce the noise after failing at a circuit.
Clearly i can put the std induction back on (i’m running a daytona carbon kit currently) but i’d rather not and the car feels considerably more responsive on pickup with the freer flow!
Any comments suggestions gratefully recieved!
I haven’t looked at a daytona induction kit, but I presume there’s a pipe leading from the body side intake towards the filter? If so, it’s also carrying the sound straight to the outside. You might find pointing the pipe away from the body opening would reduce drive-by noise though it would mean sucking in warmer air from the engine bay.
Losing a bit of power is better than not being able to drive at all
I thought most circuits were at least 98dB at drive-by
Off topic slightly
Bedford have a history of strictly enforcing AND changing noise limits,
i was there a couple of years ago and they changed the limit on the day due to complaints from the nearby village, they blamed it on low cloud !, they changed the circuit, and reduced the noise limit, 15+ cars failed the revised limit, there was a riot, end result was a load of people banned from Mr Palmers circuits
all good insight gents…though Brendan you’re expecting alot there buddy!
I’m at Oulton Friday week so i’ll see how I go then!
I was surprised by the difference it made when I attached the air intake to the side vent on my S1.
If it doesn’t do the trick, you could always try stuffing some socks down the intake
If the noise meter is on the same side as the intake, re-position the intake pipe to the other side air intake. When you arrive at the circuit look which side the meter is on and choose your induction pipework accordingly…
Sadly the noise problem is only going to get worse because "we " will soon be classed as low life for warming the planet and daring to ENJOY ourselves in CARS…naughty naughty…
Sadly a silent race car does not appeal…BUT we have to obey or be banned…
Castle Combe has a 89db or there abouts drive by.
I have seen the black flag there more times than the checkered flag
One trick is to find out where the meter is and then just short shift.
Worked for me a Combe and Donny
Worked for me a Combe and Donny
Donny now have meters around the circuit, despite the close proximity of low flying commercial aircraft!
Oh that�s a bit crafty. Best to just leave it in 5th or 6th then for the whole lap
Jim Valentine at 2ubular is just builidng me a tip for the exhaust which we think might be good for 1-3dba so when it arrives I’ll give you guys a heads up…I’ll book bedford /donny and see if I can fool the noise police