SR8 db's

Author
Discussion

dptdpt

Original Poster:

100 posts

171 months

Wednesday 25th May 2016
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Anyone know if it's difficult to get an SR8 onto Trackdays requiring sub 100db?
I assume it would be tested as a car engine and not a bike engine?

BertBert

19,706 posts

218 months

Friday 27th May 2016
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would it not be tested according to the max revs?

dptdpt

Original Poster:

100 posts

171 months

Saturday 28th May 2016
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Castle Combe measure car engines at 4500 (I think) and bike engines at 75% of max rpm. Goodwood everything at 75% but their meter reads 2db higher than CC .

splitpin

2,740 posts

205 months

Saturday 28th May 2016
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It'll be tested as a car - the fact that certain major components of the RPE V8 are based on a Suzy Busa (x2) is of absolutely no relevance - an SR8 has four wheels and is therefore a car which will only be allowed on track on Car Trackdays / Car Trackday Sessions. So the noise tester will be looking for 75% of max revs as per the MSA requirements, not the ACU requirements which involve set (and generally quite kindly) rpms which vary according to how many cylinders (1/2/3/4) and whether four or two stroke.

You will struggle at virtually every trackday with an SR8 especially those owned by MSV (which unfortunately means most!) which have some decent statics but unrealistic drive-bys associated with them eg 102 or even 105 static with a drive-by of just 92! 92 can trouble many a Busa engined Radical, so heaven help an SR8er! So all the MSV tracks can trouble a Radical, Brands, Snett, Oulton, Cadwell and most especially Bedford to the point of forget it most days.

The best bets would probably be Silv and/or Dony, as neither static test except if the drive-bys trip.

Short of doing what most of the others have done and buying yourself a knighthood, whereupon that dodgy noise meter apparently suddenly shows 4dB less, I should forget Goodwood laugh

BertBert

19,706 posts

218 months

Saturday 28th May 2016
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splitpin said:
So the noise tester will be looking for 75% of max revs as per the MSA requirements
As per the OP, it's a track day so they can run whatever noise regs they want without reference to the MSA.
Bert

splitpin

2,740 posts

205 months

Sunday 29th May 2016
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Fair enough, do carry on if you want to kid yourself with the theory rather the reality.

For MSV's trackday 'rule' (so this covers Brands, Snett, Oulton, Cadwell and Bedford) have a look here >

http://www.msvtrackdays.com/car/faq.aspx

Here's a snip for those that can't be arsed >



So the noise testing method for trackdays is exactly the same as testing/racing there under MSA Rules, only the static varies plus trackdays have the addition of a drive-by.

BertBert

19,706 posts

218 months

Sunday 29th May 2016
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Thanks trev for agreeing and proving my point. Exactly the same as msa rules but different!!

Racingroj

488 posts

170 months

Sunday 29th May 2016
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Radical have track day silencers.

splitpin

2,740 posts

205 months

Sunday 29th May 2016
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So the noise tester will be looking for 75% of max revs as per the MSA requirements, not the ACU requirements which involve set (and generally quite kindly) rpms which vary according to how many cylinders (1/2/3/4) and whether four or two stroke.

Sigmamark7

368 posts

168 months

Sunday 29th May 2016
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Racingroj said:
Radical have track day silencers.
Which are far too noisy for track days, so don't bother! I had a nice twin silencer system made for my SR3RS by Neil Handbury Racing in Taunton. It was too noisy so it went back for some rework, then he went bust, so I have no exhaust and he has my £450.00!! In the end, I gave up track days and went racing instead.
I'm sure someone reputable like Infinity Exhausts or Simson could sort you out.

BertBert

19,706 posts

218 months

Sunday 29th May 2016
quotequote all
splitpin said:
So the noise tester will be looking for 75% of max revs as per the MSA requirements, not the ACU requirements which involve set (and generally quite kindly) rpms which vary according to how many cylinders (1/2/3/4) and whether four or two stroke.
Apart from Castle Combe who, and I quote, say...
CC website said:
Noise limit: STRICT100db(A), which is measured at ½ metre from the exhaust outlet at 4500rpm
[endquote]

splitpin

2,740 posts

205 months

Sunday 29th May 2016
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Blessed be CC for providing the exception that proves the rule!

That's true, except, and only except, in the case of motorcycle engine cars on car trackdays @ CC, which are measured at 3/4 of maximum rpm. It'd be nice to think the SR8 would be considered to have a 'proper' engine i.e. not a motorcycle engine, but somehow I kind of doubt it!

On a positive note, as we all know, Radicals have never been known to have noise issues at CC rolleyes

dptdpt

Original Poster:

100 posts

171 months

Monday 30th May 2016
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I hadn't considered a knighthood was required at Goodwood, but it's probably a good idea. I always thought i'd be more welcome if i had turned up with a moustache and a real C Type. I think the staff there have begun to believe their own proposition, ie regard yourself as privileged to be here. However, that's another story, and in any event they run 105db days as well as 98db days so drive by permitting, (the one just after Fordwater seems particularly sensitive) I hope it would be possible to get an SR8 on, sub 105 at 7000 rpm. This would work at the MSV circuits too, just leaving CC to try and get to sub 100 db at 4500. I guess they could be convinced there were no motorbikes with 2700cc V8 engines. The question I am asking then is, is it possible to get an SR8 to 100 at 4500 and 105 at 7000?
The Radical TD silencer bought for my SR3 was not good enough, and I eventually had a system made by Neil Handley after some attempts of my own (sorry to hear he's gone bust and sorry to hear about your loss Sigmamark7)that got it down to 98, so is it reasonable to assume the Radical TD silencers (I think it uses two) will not work either?

BertBert

19,706 posts

218 months

Monday 30th May 2016
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One of the problems at Goodwood is that the drive by test actually 'adds up' the drive by noise over time (and reports it to the council). I've been there when they have had to have a break to get the accumulated levels down again.

Of course, to please Trev this is all defined by the MSA so supports his claim. Oh, hang an a minute. And Trev you presumably do know what that phrase actually means about the exception proving the rule?

Hehe, I love a bit of PH jousting! Hope all is good Trev, not run into you for ages, not since I became too poor to run a Radical. Mind you, it wasn't the running that was the problem, more the crashing biggrin

Bert

Willbee

340 posts

205 months

Monday 30th May 2016
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BertBert said:
One of the problems at Goodwood is that the drive by test actually 'adds up' the drive by noise over time (and reports it to the council). I've been there when they have had to have a break to get the accumulated levels down again.

Of course, to please Trev this is all defined by the MSA so supports his claim. Oh, hang an a minute. And Trev you presumably do know what that phrase actually means about the exception proving the rule?

Hehe, I love a bit of PH jousting! Hope all is good Trev, not run into you for ages, not since I became too poor to run a Radical. Mind you, it wasn't the running that was the problem, more the crashing biggrin

Bert
I have had first hand experience of the strict Goodwood noise rules. Some years ago David Watson kindly lent me a drive in his 1500 SR4 for a 2 lapper sprint meeting. I went out with 3X V8 Tuscan race cars. Having never driven Goodwood before I did two very cautious laps, short-shifting etc. I was then told I had exceeded the noise limit and i would not be allowed out on circuit for the remainder of the event! We were not even allowed to change the silencer and have another crack. To this day I'm convinced it was actually one of the Tuscan V8s (LOUD!) that was actually responsible for tripping the noise meter!


Edited by Willbee on Monday 30th May 23:13

Juno

4,485 posts

256 months

Friday 24th June 2016
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Simple solution get a Juno 2.0 Honda 83db drive buy at Bedford biggrin

sweetmate

55 posts

128 months

Sunday 26th June 2016
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Its not just the exhaust DB that causes the problem with noise its also Induction noise on Radicals