Goodwood Noise Test Today

[Rusti Evo]

Nipped into the Bognor Sprint today to scrounge a noise test as a pre-emptive measure prior to track day on Thursday.

Feeling a little pleased with myself for having made up a nice set of Supertrapp add-ons and tested on road they produced a worthwhile sound reduction and no ill effects.

Test: this car only revs to 5500 .... well Stuart, that is bang on 105db! Ooooooh noooo Another rotten day at Goodwood short shifting pass the meters ... obviously if there is lots of cloud and rain about it will fail static as well

Any thoughts on this as I'm stunned that it's so noisy. (may explain the neighbours glum looks.....)

[Steve_D]

Mine tested 107 at Goodwood so you're not alone.

Steve

[Rusti Evo]

LuckyP posted some of his noise figures down around 101 so I was really optimistic that adding the Trapps would see me OK for the 98db days ............. serious redesign needed double quick

[TuxMan]

might be worth re-packing the silencers ,means cutting them open but would probably be a easy fix ,they are alot quiter when they are new .

[Pb3]

I got 101dB at Cadwell, that was after repacking and with a rev limit of 5000 (so tested at about 3700rpm). Move the metre around the back of the car and you may find that it is not all exhaust noise.

[kylemrushall]

I been for an MOT today and the tester said "***k me thats loud" and produced a noise meter that he uses for his track days ... we did a proper test as mine revs to 7500

113db at 30% throttle!!!, so track days look a bit of a struggle at the mo

I think Can am Daves is even louder!!!

[TuxMan]

I think the solid lifter engines are much louder ,when i followed PB3 car you could hear a very mechanical noise over the exhaust !!! 130db ....good going Kyle i,m not following you through France !!! be deaf by the time we got there

[kylemrushall]

TuxMan said:

I think the solid lifter engines are much louder ,when i followed PB3 car you could hear a very mechanical noise over the exhaust !!! 130db ....good going Kyle i,m not following you through France !!! be deaf by the time we got there

Hi mate, it is very loud (maybe a bit too loud) but my god does it go!! I am only using half throttle ( not enough movement on the pedal to fully move the throttle mechanism) and 5000rpm. I think it is going to be difficult to talk at 80mph on the motorway!!

I am really looking forward to France but i will have to take the engine out again before we go as i cant get the bloody sump to seal up. Have you got a time on your tunnel crossing yet?? Can am or BM??

[LuckyP]

Would anyone like me to bring the dB meter to Stoneleigh next weekend?

It won't be the same at the track, but it'll give us all a laugh and compare some of the cars at the same day at the same RPM.

Lucky

[TuxMan]

Hi Kyle,looks like the Can-am at the moment been out today all day and loved it !!!

have you got to remove the sump to fit a new gasket ?? i managed to do it without taking engine out !!!!

[Steve_D]

Good idea on the sound meter P.

Will have a laugh. If we all rev together perhaps we can break it for you.

Steve

[TuxMan]

Yep bring it along Pete ,i need to know as i,m thinking of doing a evening track day at Rockingham . (aslong as you don,t mind useing it on a Can-am )

[kylemrushall]

TuxMan said:

Hi Kyle,looks like the Can-am at the moment been out today all day and loved it !!!

have you got to remove the sump to fit a new gasket ?? i managed to do it without taking engine out !!!!

yep i will need to remove the engine, i have no clearance on the crossmember

[TuxMan]

Kyle . yhm

[gtr-gaz]

Stuart, I'm also surprised it's that high.

If you could get it to Stoneleigh next Sunday, Pete's noise meter will be able to show how it compares to others there

[CanAm Dave]

Yes mine was louder than yours Kyle. My first test after I ran the new engine was 117dB! The backend of the car was just outside the garage so not a true test. I could do with testing it again! I'll bring my sound meter to stoneleigh also so we can get an average.
I hope to do some work on the silencers later in the year! Looks like I may have to give Brunters a miss! Too loud man!

Regards Dave

[Rusti Evo]

gtr-gaz said:

Stuart, I'm also surprised it's that high.

If you could get it to Stoneleigh next Sunday, Pete's noise meter will be able to show how it compares to others there

Howdy Gaz,

The noise reading shocked me a bit as the car doesn't sound too loud, in fact I could handle a good bit more glorious V8 growl
There is always questions with this circuit as 98db Goodwood appears not to be the same as 98db Combe .......

Surprised the Trapps were so ineffective as I had great success with them on the last Evo.

Booked several 98db days at Goodwood so got to something fairly serious!!

Going to attack the silencers Pb3 style tomorrow and stuff some new basalt inside for starters

ATB Stuart

[ezakimak]

Just out of interest, what are the rocker covers like?

Australia has a more restrictive registration requirement for vehicles like the GTR and GT40s. As such I remember reading that some of the GT40 guys have had problems with the fancy after market pressed metal rocker covers. Apparently the heavier walled cast items are better at reducing noise from the valve train assembly.

Also suggest some baffles over some of the vents in the rear clip and a conversion to hydraulic lifters and cam if you don’t already have said items.

[Storer]

For the static test could you not fit some sound proofing over the inside of the mesh grill at the back of the car to cut mechanical noise or do they test you every time you go out on track?

[Rusti Evo]

Thanks for the replies chaps. I forgot to depress the clutch for the test which I am told would cut the sound a bit.

There certainly is a lot of mechanical noise from these SBCs and as suggested making a baffle for the inside rear of the clip is a good idea, however I think the Goodwood noise lady might give me a hard time if she thought I was fiddling her test The previous owner had the foresight to install hydraulic lifters so that helps my cause somewhat.

The drive-by meters appear not to react in the same way as the ear. Cars which to the ear sound very loud like V8s are never a problem, whereas turbocharged cars, Evos, Skylines, can be made very quiet for the static and yet trip the drive-by meters constantly. I had to give up with my last Evo 9 at Goodwood as whilst I got the static down to a remarkable 84db (sounds like a Ford Fiesta!) it continuously failed on drive by at 96db. My guess is that the meters are sensitive to high frequencies and ultra sound whereas we are not.

Ludicrous that we still retain the static test as well as drive-by when drive-by is what matters to nearby residents