swift 016 sound limit

[Dee]

can the swift 016 meet the 103 sound limit if not what can be done ,it should be noted this car has a geartronic paddle shift system.
please advise thanks,
RT41

[Lotus7]

by no means a definitive 'all cases' reply, but all we ever did was use a 90 degree outlet pipe to point the exhaust appropriately.....

that said, most racers have very little idea of what affects sound readings, and how measuring techniques affect the results ... its basically a crap shoot from weekend to weekend.

fun fact: at a TAm race at Laguna one year, the ENTIRE field failed sound during practice ..... chaos ensued ....

[Dee]

Thanks Ian, we are thinking of running at Thunderhill next year it's a looong drive we would hate to get their and spend the whole time fighting the sound limit
Dee

[Rick Kirchner]

density altitude and humidity are two huge factors. Laguna - frequently cool, low altitude, and damp - perfect conditions for conducting sound

[DanW]

Thanks Ian, we are thinking of running at Thunderhill next year it's a looong drive we would hate to get their and spend the whole time fighting the sound limit
Dee

Dee,

Your concern is valid. Our supps call out a sound limit of 102.9 dBA at Thunderhill. The region leadership is having some internal discussions on the sound limit number, measurement accuracy and precision (bangs head against wall). We had some challenges with sound hits at the last regional of the season. It led to some interesting discussions at Black Flag and Impound.

My career was heavily involved in sound and vibration and have some concerns.

Regards,
Dan

[Joules5]

As racers we really never know how close we are to the limit until triggering a black flag for sound!

First time out at Thunderhill with the 008 (some years ago) I got black flagged for sound, fortunately in my case a 90 degree tip at a 45 degree angle was sufficient, but it's as tense time knowing if you have done enough or not, as it's a 3rd strike and out policy.

Acoustics are almost impossible to replicate at home to even get an indication. On my mid engine closed wheel car with short headers I ended up throwing glass pack mufflers, inserts and 90 degree tips at it to have some confidence. I didn't get pinged, but equally I have no idea if all that was necessary and how restrictive it is to the engine.

Do any of the tracks you currently race at have sound limits and if so what levels that you have confidence you are under?

[Dee]

no tracks have limits yet !

[Graham Rankin]

Hi Dave,
Track specifics aside, your 016 is likely to be on the hairy edge of 102.9. Not sure what muffler you have but if its a Coastfab / Profab style, you can expect to be fighting it all weekend .Chip Romer spent a lot of time fighting the sound police this year.You may need to go to a Quiet Horsepower style muffler.Its the only one we can make work on the 014. (The Coastfab style hits 107db) !!)Give me a call if you like.

[J Leonard]

I think Pete Weber passed away. I heard Quiet Horsepower was for sale.

[Graham Rankin]

Yes, thats correct. My understanding is that the folks at Reno Rennsport are now making them. Think Jim Mali made a post in the PFM section about this.

[Tony Opheim]

Was visiting with Dee a few minutes ago and he mentioned that several members responded to him they had 2.5" Phase 9's for sale. Specifically, as used on Toyota powered FA's for decades here in the West as the only way to pass sound as Graham and others have mentioned. If they are still available I'm interested in at least one if not two. PM me if you have one for sale or know someone who does.