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Track day noise test
Jambohargs - 14/1/17 at 08:34 PM

Hi, I have a Hayabusa MK Indy RR and I'm right on the track day static noise limit (105db). Has anyone used a decibel killer or similar and had good results...or any other ideas? Not been pulled in on drive by's so was thinking of getting the bolt on for the static test then remove when out on track.


daniel mason - 14/1/17 at 08:54 PM

Less revs on static! I've been doing it years


Jambohargs - 14/1/17 at 09:01 PM

Haha good shout!


Toprivetguns - 14/1/17 at 09:05 PM

A wise man once told me putting it into 1st gear helps reduce the noise for static testing.
Apparently kawasaki engines have different fuelling maps for neutral and gears 1-6, hence different detonation points.
Not sure about Suzuki, but worth a try....

[Edited on 14/1/17 by Toprivetguns]


skydivepaul - 14/1/17 at 09:06 PM

quote:
Originally posted by daniel mason
Less revs on static! I've been doing it years


+1 on the lower revs, works a treat


bi22le - 14/1/17 at 09:49 PM

Im surprised you get away with fewer revs. Maybe its a BEC thing. I always get checked, he looks at my tacho. One thing I do is lie about the limit. I state 7k limit when actually its 8.5k!

The experiences I have had with track day noise limits are that the drive bys are tight. I got kicked off of brands yet I was 3db below the static limit.

Dont remove any db killers you fit.

If I ever had an oportunity to make my own money, making track day specific db killers would be one of the things I would do. The "professional" one I bought is crap and did nothing yet apparently drops 5db.


daniel mason - 14/1/17 at 10:03 PM

For anyone to see my tacho.their head would need to be buried in my crotch! Single seaters do have some advantages


bi22le - 15/1/17 at 01:05 PM

quote:
Originally posted by daniel mason
For anyone to see my tacho.their head would need to be buried in my crotch! Single seaters do have some advantages


Yup, bearded men in ovalals tickling your tackle to get you focused before an event!


daniel mason - 15/1/17 at 02:17 PM

Was more meaning they can't see the tacho.
Not that I wanted a marshals head by my crotch


rodgling - 15/1/17 at 03:12 PM

My car was about this level. I experimented with bungs, if you stuff them with enough wire wool you can get up to around 3 dB off static, but it's still very marginal in my opinion. Eventually I had a second silencer made which sits under the fuel tank, 620S style - the car is now 93 dB static with no bung.


Jambohargs - 15/1/17 at 04:24 PM

That's a massive difference! Have you got any pics of it and what did it cost you to do? Any perforamance change? I could be tempted to do this for the peace of mind it will give, driving 4 hours to get turned away at a track day doesn't bear thinking about!


rodgling - 15/1/17 at 05:20 PM

It cost about £300 from Demand Engineering in Ipswich who did a great job. It can be removed for road use in minutes.

There is a slight performance benefit compared to having a bung as its obviously a lot less restrictive, and quite a big benefit from being able to go 110% flat out without worrying about noise. Compared to having no bung its hard to say as I'd never be able to go on track without one. On the road it certainly doesn't feel any different.



[Edited on 15/1/17 by rodgling]


Jambohargs - 15/1/17 at 05:39 PM

I think this is the way to go. Was the silencer made from scratch or bought and adapted? I wonder if getting a standard hayabusa silencer on ebay would do the trick or if there is a bit more calculation involved than that??


daniel mason - 15/1/17 at 05:59 PM

Standard bike cans are very quiet


raptor700 - 15/1/17 at 07:30 PM

my first port of call would be to repack the exhaust can, which if you have been doing a few track days it may have burnt out.

I would do this before any messing about


rodgling - 15/1/17 at 08:24 PM

quote:
Originally posted by Jambohargs
I think this is the way to go. Was the silencer made from scratch or bought and adapted? I wonder if getting a standard hayabusa silencer on ebay would do the trick or if there is a bit more calculation involved than that??


Demand Engineering had a load of various sizes in stock, they selected one and built the link pipe to suit the car. They also modified the end of my old can so that it could attach.


Jeano - 20/1/17 at 11:54 AM

quote:
Originally posted by rodgling
It cost about £300 from Demand Engineering in Ipswich who did a great job. It can be removed for road use in minutes.

There is a slight performance benefit compared to having a bung as its obviously a lot less restrictive, and quite a big benefit from being able to go 110% flat out without worrying about noise. Compared to having no bung its hard to say as I'd never be able to go on track without one. On the road it certainly doesn't feel any different.



[Edited on 15/1/17 by rodgling]


100% i want this done to my Dax. Needs to be custom due to the bore. DO you have any contact information?


rodgling - 20/1/17 at 01:35 PM

quote:
Originally posted by Jeano
quote:
Originally posted by rodgling
It cost about £300 from Demand Engineering in Ipswich who did a great job. It can be removed for road use in minutes.

There is a slight performance benefit compared to having a bung as its obviously a lot less restrictive, and quite a big benefit from being able to go 110% flat out without worrying about noise. Compared to having no bung its hard to say as I'd never be able to go on track without one. On the road it certainly doesn't feel any different.



[Edited on 15/1/17 by rodgling]


100% i want this done to my Dax. Needs to be custom due to the bore. DO you have any contact information?


If only Google had a website where you could type in "Demand Engineering in Ipswich" and the very first link it came up with would be http://demandengineering.co.uk/...


Phil_1471 - 20/1/17 at 07:58 PM



I have a selection but standard can is easily good enough! The little one is a no no 🤣


Jeano - 21/1/17 at 04:21 PM

Thank you for the website thats brilliant.

With a second can what do people fit then? The original from the bike or just another exhaust silencer i assume.


Phil_1471 - 21/1/17 at 06:08 PM

GSXR can, perfect as it breaks up the sound waves.

https://goo.gl/images/Vmn7jD