quick track day noise limit question

[LaserTam]

How do they generally measure it? Guessing a couple of meters behind the car, but what revs? Thinking of venturing onto the track, but thought I best check if I am quiet enought first.

[RedSpike66]

Apparently it's 0.5m from the exhaust, at 45 degree angle, and 2/3rds RPM, so typically about 4,500 RPM for a Speed Six. Secret is to raise revs slowly apparently.

HAve you got a DB meter then? What kind/Where from ?

[spercy]

RedSpike66 said:

Apparently it's 0.5m from the exhaust, at 45 degree angle, and 2/3rds RPM, so typically about 4,500 RPM for a Speed Six. Secret is to raise revs slowly apparently.

HAve you got a DB meter then? What kind/Where from ?

I have heard the above from several people, but where does the 45 degress taken from with twin exhausts. In theory it should be central to the two pipes to give an acuurate measurement.

[LaserTam]

RedSpike66 said:

Apparently it's 0.5m from the exhaust, at 45 degree angle, and 2/3rds RPM, so typically about 4,500 RPM for a Speed Six. Secret is to raise revs slowly apparently.

HAve you got a DB meter then? What kind/Where from ?

Only an iPhone app.. probably not the most accurate, but will give me an idea.

Thanks for the replies.

[Templedog]

My Tam with standard exhaust was measured at 102db at Castle Combe earlier this year, static test at 4,500 rpm

[Car Mat]

My Tuscan II S had a static at Goodwood a month or two ago at 101 db. Standard exhaust. Must confess was a little light on the revs......

[LaserTam]

Templedog said:

My Tam with standard exhaust was measured at 102db at Castle Combe earlier this year, static test at 4,500 rpm

Thats interesting to know. I have Blueflame pipes, which are not as loud as some, but could be struggling to be under the 105 limit. Two options if it's over - the mufflers that came with the pipes, or temp re-fit the standard box, thats still in the shed!

[Far Eastender]

If you own an iPhone you can download an DB app (for free!)

[Jasper Gilder]

Trackdays at Guadix have no noise restrictions....Next one April '12

[spercy]

Jasper Gilder said:

Trackdays at Guadix have no noise restrictions....Next one April '12

I was at the skid day at Rockingham, and according to some bikers i was talking to over a bacon roll, they don't have noise resrictions there either

[Jasper Gilder]

When I did a track day there no one checked my Dbs

[grahamw48]

Here's how static test is done:

http://www.youtube.com/watch?v=YmWhsdLrrL8

[KelWedge]

grahamw48 said:

Here's how static test is done:

http://www.youtube.com/watch?v=YmWhsdLrrL8

Was that loud then?

[grahamw48]

YES !!! Sorry for shouting.

Certainly 120db +.

Blackpool Wedgefest.

My 400SE was 108db at two thirds revs.

[KelWedge]

grahamw48 said:

YES !!! Sorry for shouting.

Certainly 120db +.

Blackpool Wedgefest.

My 400SE was 108db at two thirds revs.

Cant remember but think mine was 106.5db at 4500rpm, the other reading was 122.8db BBWF 2011

[dickieandjulie]

Funny seeing the posts about db's at Castle Coombe and Goodwood. I was tested at Goodwood (between buildings) at 105db and sent home, popped into Brands on the way, 98db!!

Same car, tested at Castle Coombe (in the big garage building!), 102db.

Current car, Tamora with JP exhaust tested 102db at Brands, three weeks later, 98db at Snetterton! so probably 110db at Goodwood or Castle Coombe!

[Keithyboy]

dickieandjulie said:

Funny seeing the posts about db's at Castle Coombe and Goodwood. I was tested at Goodwood (between buildings) at 105db and sent home, popped into Brands on the way, 98db!!

Same car, tested at Castle Coombe (in the big garage building!), 102db.

Current car, Tamora with JP exhaust tested 102db at Brands, three weeks later, 98db at Snetterton! so probably 110db at Goodwood or Castle Coombe!

Rich, they should not noise test inside any building as it will give a false reading! I'd be seriously hacked off if I was refused a run in such circumstances and would take appropriate action for recovery of any fee paid plus travelling expenses. When I've raced and on track days they've tested outside the scrutineering bay!