Standard Exhaust Noise Level - Zolder ??

[johno]

All,

Have had confirmation for attendance at Zolder this morning from Russ.

Noise level = 95 dba !!!!!!!!!!!!!!!!!!!!!

My exhaust currently is putting out over 113 dba at 4500 (.75m @ 45 degrees)

I was changing for a standard system for the event anyway but am now concerned whether that would even meet the 95dba.

They have not specified a Rev level for the reading and I know that Zolder is a little more relaxed than most other meetings but.....

I also knew of 2 people who were black flagged last year and it spoilt their enjoyment of the event.

Anyone know what a standard system puts out. The other problem is that you can't get supertraps/mufflers etc to fit if the pipes ar too close together !!! ARGH ARGH

HELP !!!

[GreenV8s]

Didn't think the tail pipes were close enough together to prevent you fitting an external muffler. Do you happen to know the internal/external diameter and distance between the centerlines? I'm sure something can be worked out.

[johno]

My previous standard system did not allow supertraps to be fitted as the pipes were too close together.

I was at a track day the other day with another S which did allow a couple of Merlins (monstrous) supertraps to fit. I think it largely depends on manufacturer of the exhaust.

I am trying to spec an exhaust that will allow the addition of supertraps if needed.

The annoying thing is I think they look better closer together and with the ends cut vertical to the back of the car. Both of which cause problems fitting traps.

[shpub]

Merlins are bolt on silencers and not Supertraps which are made by Supertrap and use a patented perferated disc technology.

If the exhaust is already at the levels you are quoting then I don't think supertraps/merlins are going to get the car anywhere near 95db. The only way is to get a standard exhaust system and go from there or pay a lot of money for a complete custom one.

Steve

[johno]

quote:
Merlins are bolt on silencers and not Supertraps which are made by Supertrap and use a patented perferated disc technology.

If the exhaust is already at the levels you are quoting then I don't think supertraps/merlins are going to get the car anywhere near 95db. The only way is to get a standard exhaust system and go from there or pay a lot of money for a complete custom one.

Steve

As I said, I am changing for a standard system anyway as the variety of (supertraps/mufflers used purely descriptively and not specifically) sound reducing devices only knock off around 3-5 decibels at best and therefor would not get my current system anywhere near quiet enough.

What I need to know is what levels have people had standard systems recorded at, to gauge whether I will need additional noise reducing devices.

Anyone ??

Cheers

Mark

[shpub]

1. It is in the bible. Section on exhaust systems.
2. It is on my web site in the noise FAQ.
3. V6 S series are around 100-105 db at 0.5 m static test.

Still think you will find it hard to hit 95 without some serious rethinking!

Steve

[johno]

quote:
1. It is in the bible. Section on exhaust systems.
2. It is on my web site in the noise FAQ.
3. V6 S series are around 100-105 db at 0.5 m static test.

Still think you will find it hard to hit 95 without some serious rethinking!

Steve

Further consultations have lead me to believe that the tests have been conducted historically on a 'drive by' basis rather than a static test.

I wholely agree that a static 95dba would be a mountain to climb for most Euro boxes let alone a TVR !!

Thanks for the info Steve.

Cheers

Mark

[davidy]

Check with Russ, but Zolder always used to be a drive by, the guy would hide at various points round the circuit with his dreaded machine and effectively undertake random tests. Often he was some way from the trackside.

Everyone used to talk about where he was and people with particularly noisy cars used to lift whilst going past him so as not to get taken off the circuit.

Driving hard on the circuit in the untimed sessions is only part of a great weekend, this used to only occupy about 50% of the track time with the rest of day being taken up with the slalom, hillclimb??, acceleration tests, the fastest laps and the relay race. (Assuming the old format has not changed)

A lot of fun and probably the best TVR weekend of the year

David

[tvrinbfg]

I thought the Zolder measuring device was on the straight going pass the pits under the gantry, rather than a little man. I've had no problems at Zolder with either my Cerbera or my Tuscan, both with standard exhausts. And there is always the Nurburgring an hour away with no such problems.

[johno]

I know 2 cerberras and a tuscan who were black flagged last year. All 3 had sports exhaust though

I am really looking forward to it as it is my birthday on the track day aswell.

We have 7 cars going from my club and a couple of them have been loads of times to Zolder and rave about it. I missed last year so intend to make up for it this year. Friday night will be a good one

Are you pair going this year ??

Cheers

Mark

[tvrmark]

A cat'ed S is about 90-95dB mine was 93db (tested Goodwood)

A non-cat S 100-105dB after de-cating mine was about 102dB it has now gone up to 105db, I think I'm blowing the wodding out of the silencer.

Spacing of tail pipes is 90mm centres. Basic disc series super-traps are 3" dia so will fit. This will bring it down by 2-3dB (more if you take all the disc out not recomended)

When I went to Castle Combe last year I fitted two small oval silencers to the tail pipes and was measured at 92dB. Although it did not happen at the time the welds on the rear exhaust bracket have broken (the thin bit of plate welded between the two tall pipes with a hole through it 10 times larger then the mounting bolt). So I will have to beef up its mounting.

(another) Mark