Static Noise Test - Standard Exhaust

[GlowRed]

I've recently booked a track day at Anglesey with a static noise test at 105db.

The organiser has just emailed to advise that there was some miscommunication with the circuit and that they have actually booked 95db static.

Question is, will my Lotus Exige LF1 pass this new 95db static test? I have the standard exhaust and the car has covered 2,500 miles.

[LotusPilot]

Good question.  The stanard exhaust does get noticeably loader with greater mileage.  As you have relatively low mileage, any packing might still be where it is needed to reduce noise.

As you have the Race Pack fitted, you can override the exhaust valving in all modes with exception of DPM-off.  If unconditionally set to EX-SHUT, the exhaust valving will remain closed below 5500rpm. That should help get you past the static test.

Edited April 22, 2016 by LotusPilot

[Arun_D]

Last one for mine was 93dB with around 2700 miles on the odometer.

[GlowRed]

1 hour ago, LotusPilot said:

As you have the Race Pack fitted, you can override the exhaust valving in all modes with exception of DPM-off.  If unconditionally set to EX-SHUT, the exhaust valving will remain closed below 5500rpm. That should help get you past the static test.

Thank you for your answers. I was going to keep it in TOUR mode for the test as I think it keep the exhaust valves stay closed until higher RPM.

Static noise tests are 3/4 of full RPM so 3/4 of 6800rpm (Max TOUR RPM) is 5100rpm. This is below your 5500rpm for the exhaust valve opening.

I have read about circuits asking 3/4 of the 9,000rpm shown on the rev counter and this could be a problem.

Anyone with some real life test results?

30 minutes ago, Arun_D said:

Last one for mine was 93dB with around 2700 miles on the odometer.

Thanks for the answer.

Was that in TOUR mode?

[Arun_D]

I can't recall whether I open the valve for worst case so I'm not kidding myself or whether I left it in tour, but I was test in this instance at 4800rpm.

More often than not, I'm asked by the tester where redline begins, rather than max speed. With no actual redline on our dials, I use the rpm of first shift light, which is around 6500rpm, IIRC.

[D.no]

I think it's luck of the draw regarding how many rev's you're asked for.

The last test I had, I was asked for "Four and half please". So I gave them 4, which in hindsight and looking at the graph below, was not so clever

I still failed by a HUGE margin (105db versus a limit of 100db). I suspect my Quicksilver muffler which has been on the car for an indeterminate length of time (it was on when I purchased the car) may be suffering from a certain amount of packing deterioration! I had checked the Quicksilver website before booking the trackday, and my muffler is stated as emitting a maximum of 98db up to about 6k rpm, whereas standard is supposed to be ~93db...

[LotusPilot]

2 hours ago, Arun_D said:

I can't recall whether I open the valve for worst case so I'm not kidding myself or whether I left it in tour, but I was test in this instance at 4800rpm.

More often than not, I'm asked by the tester where redline begins, rather than max speed. With no actual redline on our dials, I use the rpm of first shift light, which is around 6500rpm, IIRC.

 

[alias23]

I've had 97db at 4.5k revs static with the valve closed... My v6 has done 7.5k miles so well bedded in...

[2bular Exhausts]

On ‎22‎/‎04‎/‎2016 at 13:26, LotusPilot said:

Good question.  The stanard exhaust does get noticeably loader with greater mileage.  As you have relatively low mileage, any packing might still be where it is needed to reduce noise.

As you have the Race Pack fitted, you can override the exhaust valving in all modes with exception of DPM-off.  If unconditionally set to EX-SHUT, the exhaust valving will remain closed below 5500rpm. That should help get you past the static test.

What packing? -

 

[Stubox]

Back to the welder you ????

Stu

[Daddy]

98db static at Snetterton last month with 1000 miles !

[2bular Exhausts]

9 hours ago, Stubox said:

Back to the welder you ????

Stu

He He - one week to clear the order back-log, then I'm outta here!

[GlowRed]

On 22 April 2016 at 13:57, Arun_D said:

Last one for mine was 93dB with around 2700 miles on the odometer.

 

12 hours ago, alias23 said:

I've had 97db at 4.5k revs static with the valve closed... My v6 has done 7.5k miles so well bedded in...

 

11 hours ago, Daddy said:

98db static at Snetterton last month with 1000 miles !

So 95db is looking like hit and miss.

For the minimum noise, I will need to be in Tour mode with the EV closed (which is set as standard in this mode) and use as little revs as possible, around 4,800rpm.

I've had a quick look online but could not see any bolt-on additional silencers that could help.

[2bular Exhausts]

It's the drive-by which gets you - and the valve will open below 5000rpm anyway.

Bolt-ons? - ridiculous - but we'll see how they get on shortly.

 

[quantum2000]

Hi Jim, Do you want me to test them for you 

[2bular Exhausts]

1 hour ago, quantum2000 said:

Hi Jim, Do you want me to test them for you 

ummm, that's why I threw £400 of Titanium add-ons at you Jeff - get on with it man!

[quantum2000]

1 minute ago, 2bular Exhausts said:

ummm, that's why I threw £400 of Titanium add-ons at you Jeff - get on with it man!

Lol, I've got a new SD card and reader and the sound meters ready to go.....just need it to stop raining now

[2bular Exhausts]

Just now, quantum2000 said:

Lol, I've got a new SD card and reader and the sound meters ready to go.....just need it to stop raining now

pffft - snowing/blizzards here today

[Stubox]

Jeff stop distracting the man 

[GlowRed]

The 'official' word from Lotus is that a standard car in good condition should pass the 95dB static test as long as the engine revs are held at a point that prevents the exhaust valve (EPV) opening.

This may require a degree of controlled application with regard to the maximum engine speed as 3/4 maximum throttle is on the opening point.

Alternatively you can use the EPV override button to keep the valve closed during the test.

[Bibs]

It opens at the pre-determined RPM no matter what you do with the button. It's called an Engine Protection Valve after all! The button only opens it under that RPM if you select 'open', closed means it's closed up to that RPM only then after it will still open.

[GlowRed]

On 26 April 2016 at 09:33, Bibs said:

It opens at the pre-determined RPM no matter what you do with the button. It's called an Engine Protection Valve after all! The button only opens it under that RPM if you select 'open', closed means it's closed up to that RPM only then after it will still open.

Thanks for clarifying that.

What is the RPM for the EPV to open in TOUR Mode?

[Bibs]

It's based on throttle position as well as RPM. Less than 50% throttle it opens 5,500 - more throttle at any RPM and it'll open anyway. Just go easy on the throttle at the noise test, keep it below 50% and the valve will stay closed up to 5.5k.

http://www.thelotusforums.com/latest-news/lotus-cars-news/driven-exige-s-roadster/

[DJW]

97db static at 4K revs, 7k miles , exhaust shut 

Edited May 12, 2016 by DJW

[mbes2]

What / what brand make is the standard exhaust?