Track decibel noise levels

[BenjaminBraddock]

Has anybody had a decibel check done on their 4200/GS prior to putting their car on a track when the car has a modified exhaust?

I've got a Larini H-pipe and Larini rears on the car - I'm hoping that by sticking the factory rears back on (and leaving the H-pipe on) the noise will be significantly reduced despite having the H-pipe, hopefully the baffling in the rears will suppress the sound enough to pass.

The max track noise levels are: static 105dB, drive-by 92dB.

Has anybody else done something similar to get by the scrutineers?

Has anybody fitted/heard a 4200/GS that has an H/X-pipe with the factory rears on?

Thanks in advance, Simon

 

[Andyk]

Simon, get yourself on the Llandow track day on here as they don't check your noise...

 

[Zep]

You can get an iPhone app which measures sound levels, I have used one against a calibrated meter and it was pretty close...

 

[BennyD]

They seem to be, but only up to the level of the mic. In my experience, readings at the top of the scale tend to stop at around the 100-105db level.

 

[BenjaminBraddock]

I've just used the iPhone App to check, standing a metre from the back of the car, and the results are:

> Static: 98-99dB

> Drive-by, which 4500revs: 100dB


I realise the App is an indication only, but I'm screwed in current set-up. Hope by switching to the factory rears brings it down to 92dB. Maybe a bridge too far though with the H-pipe still on...

 

[spkennyuk]

Has anybody had a decibel check done on their 4200/GS prior to putting their car on a track when the car has a modified exhaust?

I've got a Larini H-pipe and Larini rears on the car - I'm hoping that by sticking the factory rears back on (and leaving the H-pipe on) the noise will be significantly reduced despite having the H-pipe, hopefully the baffling in the rears will suppress the sound enough to pass.

The max track noise levels are: static 105dB, drive-by 92dB.

Has anybody else done something similar to get by the scrutineers?

Has anybody fitted/heard a 4200/GS that has an H/X-pipe with the factory rears on?

Thanks in advance, Simon

Hi simon

Ive got a H pipe on mine with standard rear 4200 mufflers. I dont think you would have a problem passing scrutineers with that set up.

Below 3000 rpm there is very little difference. Slightly deeper tone but thats about it. Above 3000 rpm the noise level increases but not over the top. More pops and crackle on over run and a deeper tone.

Ive got a db app on my phone so i can give you an idea of the static level. I will try and get a recording for you in the next few days if that helps.

 

[BenjaminBraddock]

Kenny that would be great thank you - any chance you getting out there this afternoon as I'll be taking car along this week

And encouraging to hear that you say this set up isn't too loud. The order of the mods I made was to put on the rears firstly, and then add the H-pipe later. By changing the rears it up'ed the noise significantly, and the H-pipe brought out much more bass. I guess the factory rears are heavily baffled so I'm taking your feedback positively.

Cheers, Simon

 

[spkennyuk]

Leave it with me Simon. Im working at the moment. Will see if i can sort something out this evening.

 

[BenjaminBraddock]

Ah no problem Kenny - please don't worry I'd rather you put your feet up when you get home after a day's work.

I'm taking to in this week anyway, will be interesting to see how it ends.

 

[spkennyuk]

Hi Simon

Ive just checked mine with a db meter app and static from 1 meter away its showing 85db at 3000 rpm. At 4500 to 5500 rpm it is peaking at 89db. Not ideal test conditions as it is persisting it down here.

I have taken a couple of video clips as well. If you have wattsapp i can send them over to you.

 

[BenjaminBraddock]

Hi Stuart

Thank you for doing this it's very much appreciated, and those readings are excellent news as mine were showing 10db or more with the Larini rears.

Hopefully I can pass the noise test and enjoy the track day!

Cheers, Simon

 

[BenjaminBraddock]

Update:

The factory rears have now gone back onto the car today fitted to the Larini H-pipe which is still on the car which will get me past the scrutineering dB test.

The impact is huge - and in a strange way I like it. Instead of hearing the massive sound coming out of the back of the car, I can now hear the beautiful sound of the V8 engine instead and a lovely purring exhaust note.

I'm sure I'll put the Larini rears back on at some point, but I'm looking forward to the 'new sound' over the next few weeks/who-knows-maybe-months.....

Thanks Stuart for the sound clips - you are right that while the sound is significantly quieter, it is still a very noticeable sound, and I still got heads turning on my drive home this evening.

 

[spkennyuk]

You are very welcome Simon.