Hi i have bought a pre-built Stuart Taylor 'Locoblade' sorry for cheating !!
I want to use the car for track days but will the car be too loud the guy i bought it off said 'well it passed it's SVA so should be ok for a track day' i have had it roughly measured at about 100dB at about 5000 rpm what is the concensus?

noise must be under 101 dbs for SVA pass

Alot of trackdays have different noise levels. Some are below 100 i believe.

Likr Danozman says, noise levels are track dependant. I'd find out the max level at the track you're going to use most/first and work from there

Welcome to the forum, and put your location in your profile, people here like to know these things

John

If you can get it down to 98 you should be pretty much ok everywhere, although I'm sure I've heard of one as low as 95 - what are they expecting....pedal power!!

SVA isn't your problem, as regards noise, neither is an MoT, and the least of your worries is noise on the road.
Noise on track day is something else though. Some will require a measurement at a few thousand revs (they'll make no distinction for hairdrier motors). Hairdriers are very quiet at 5K rpm, this is the Japanese 'drive-by' test for the bike. I digress, some trackdays 98dB, race test days are usually higher. Some tracks don't care, some have to, Combe, Goodwood, others, are surrounded by NIMBYs,
What is your main worry is the on-track drive-by. Your hairdrier at 11-13K revs is not quiet, it will fail this at most NIMBY-affected circuits. You'll be aching for that Zetec.

Thanks guys i will try a db killer first as that is the cheapest and see what effect that has on the power, if that fails then i'll have to get out my wallet, hmmm zetecs aren't always that quite!