Noise Testing

[rogerwills]

Originally Posted by James Murray

Defo Ian and when you think your there early, you find theres a pre collecting area que, usually waiting for a noise test......

Off topic I know, but circuits that test in the collecting area really annoy the hell out of me. Why not do it at scrutineering? At least then if you have an issue you have time to go back and sort it before being re-tested.

Grrrrrrr

[Dave Brand]

Originally Posted by rogerwills

Off topic I know, but circuits that test in the collecting area really annoy the hell out of me. Why not do it at scrutineering? At least then if you have an issue you have time to go back and sort it before being re-tested.

At most circuits it's not permissible for race engines to be started until well after scrutineering commences.

[Tim Falce]

Originally Posted by rogerwills

Off topic I know, but circuits that test in the collecting area really annoy the hell out of me. Why not do it at scrutineering? At least then if you have an issue you have time to go back and sort it before being re-tested.

Grrrrrrr

Two reason maybe, 1, you're supposed to present a car with a cold engine for scrutineering and who would want to rev the nuts off a cold engine? 2, so you can't go back and change anything after the noise test.

[Colin McKay]

But if you changed anything the drive-by check would catch you out anyway (probably). It seems noise testing is quite a lottery regardless of when/where it's done.

[Al Weyman]

103db at Brands, 104.5db at Rockingham and 107db at Mallory on Sunday and warned and quite as a roadcar driving past as it has a big air filter, work it out!

[James Murray]

Why not do it immediately after scrutineering on the way back to the paddock. At least it gives the people who fail a chance to rectify. Plenty of people drive their cars to scrutineering and go through with a hot engine. If people knew they were going to be tested immediately after there car had been checked they would know to warm up before they set off.

Sitting in a que of 20 cars with the temperature guage off the clock watching steam pouring out of your car isnt fun. If it has to be done at the collecting area why not have 2 testers to speed things up?

[James Murray]

Looks like I'm echoing Rogers point........should not be to hasty!

[delta]

Rogers correct they do the noise testing at Castle Combe after Scruitineering.

[James_S]

Originally Posted by rogerwills

Off topic I know, but circuits that test in the collecting area really annoy the hell out of me. Why not do it at scrutineering? At least then if you have an issue you have time to go back and sort it before being re-tested.

Grrrrrrr

For all race meetings its your organising club who determine when and where the environmental scrutineer chooses to do testing.

[Mike Bell]

Originally Posted by delta

Rogers correct they do the noise testing at Castle Combe after Scruitineering.

But if you scrut the day before they do it again in the queue for practice!

[Tim Falce]

Originally Posted by Al Weyman

103db at Brands, 104.5db at Rockingham and 107db at Mallory on Sunday and warned and quite as a roadcar driving past as it has a big air filter, work it out!

They did noise testing a Mallory? I thought they always did track testing from the office by the gate.

[midgetman]

Originally Posted by Mike Bell

But if you scrut the day before they do it again in the queue for practice!

That's no problem if you passed yesterday and made no changes. Worst part about doing it in the collecting area is you get sound bouncing back off other cars/background noise etc. Was once told my everyday road/sprint car was "marginal", normally 85dba, I was parked next to a Locaterfield thingy with a side exhaust warming up right next to my car LOL.

[Tim Falce]

Originally Posted by midgetman

That's no problem if you passed yesterday and made no changes. Worst part about doing it in the collecting area is you get sound bouncing back off other cars/background noise etc. Was once told my everyday road/sprint car was "marginal", normally 85dba, I was parked next to a Locaterfield thingy with a side exhaust warming up right next to my car LOL.

But that's up to the tester to do it properly and do an ambient reading first which would allow for any background noise.

[GORDON STREETER]

We've all been there before and have "harped" on about it on various threads over the years. We all know its a lottery on the day at various tracks and I don't think that there is any short answer.
As an aside I had my car fail at Coombe ( I know its the worst) I took it back an hour later and it was 1db under. What had I done ? Nothing !

[delta]

I can tell you a trick ,don't know why it works maybe there is a boffin out there who can enlighten me. You fail a noise test OK. Back to the Van, truck or what ever find a piece of steel plate 14 gauge or something close,Just cut the plate so that you can fit it in the end of exhaust pipe a couple of inch's deep,so you are now splitting the exhaust into two halves. Back for a noise test and 9 times out of 10 this has worked for me and others Ive helped in the past.

[Al Weyman]

Yes they were testing in the assembly area Tim and right next to a wall which is probably OK for rear exiting exhausts but as mine side exit I would imagine reflected off the wall increasing the noise, also there was a race on at the time with cars streaking past and other cars behind me with their engines running, hardly scientific.

The best was Lydden although the thing passed no problem at 103db. They pull you up after qually and my engine was smoking a tad as some oil had spilt out and I did not want to rev up the hot engine there and then without checking it and he started to get a bit bulshie with me when I said i want to pull over, shut down and let her cool off for five minutes and check out the problem. I did this and he was OK after that.

[GORDON STREETER]

I know one Yank Tank owner (who shall remain nameless) that had a switch in the car that cut out a few cylinders for noise testing !

[midgetman]

Originally Posted by falcemob

But that's up to the tester to do it properly and do an ambient reading first which would allow for any background noise.

I think that's our point. We doubt it's done like that.

[Al Weyman]

Originally Posted by GORDON STREETER

I know one Yank Tank owner (who shall remain nameless) that had a switch in the car that cut out a few cylinders for noise testing !

And they dont notice the difference in engine note?

Actually I am going to redo the system as I am fed up with it grounding out especially at Brands and it was at Mallory at the foot of the elbow so I will try to get it quieter.

[GORDON STREETER]

Originally Posted by Al Weyman

And they dont notice the difference in engine note?

.

The noise tester only tells you what revs he wants. A lot of engines (especially historics ) with carbs and scatter cams misfire and sod about off of load. So he isn't too bothered about that.

[Redneck Rocket]

Originally Posted by Al Weyman

And they dont notice the difference in engine note?

Actually I am going to redo the system as I am fed up with it grounding out especially at Brands and it was at Mallory at the foot of the elbow so I will try to get it quieter.

Talk to Kevin at Zero Exhausts. Unless I'm mistaken he's already done a set of headers and exhaust for Max Rostron's Camaro so he might have an off the shelf stainless system already.