exhaust too noisy!!
Discussion
Attended a track day at Donnington on Friday and after 6 laps was blacked flagged for being too noisy.
The limit is 98db but i was putting out 101db (this is actually nearly twice the limit).
Apart from buying new exhausts (I have mild steel ones), will repacking reduce the noise output enough or does anyone know where i can buy a second stage silencer that can temporarily bolt onto the existing silencers for track days where the limit is below 101db?
The limit is 98db but i was putting out 101db (this is actually nearly twice the limit).
Apart from buying new exhausts (I have mild steel ones), will repacking reduce the noise output enough or does anyone know where i can buy a second stage silencer that can temporarily bolt onto the existing silencers for track days where the limit is below 101db?
The last owner who used bolt on extra silencing ended up with a yellow rear clip that changed to orange due to the heat built up in the existing silencers.
There are some (who will no doubt report later) who have fitted re-packable silencers that they re-pack just prior to going on track. I suspect this will still be marginal.
Steve
There are some (who will no doubt report later) who have fitted re-packable silencers that they re-pack just prior to going on track. I suspect this will still be marginal.
Steve
I repacked my exhaust after doing a noise test on Friday. This was in preparation for a trackday at Elvington; typical an airfield that has a 105dB noise limit, locals who needs them!?
Well I was some what shocked to find after the 3 sighting laps we all formed a queue back into the pit lane only for every car to be tested. My heart sank but I got through, just, at 104.5dB. That is with a threshly packed exhaust and a cross-over pipe. This was a static test at 4500rpm and most people seem to think my car runs quiter under load out on track, and is quiter than some other cars that where out there for sure. You did well to survive 6 laps, was 101dB a static value, if so you have got a good exhaust system!
What I have found is that on a static test the general engine noise is what seems to effect the reading, I have solid lifters which give a lot of additional noise that gets picked up, you can move the meter around the rear clip and not see any significant reduction in the dB reading.
Well I was some what shocked to find after the 3 sighting laps we all formed a queue back into the pit lane only for every car to be tested. My heart sank but I got through, just, at 104.5dB. That is with a threshly packed exhaust and a cross-over pipe. This was a static test at 4500rpm and most people seem to think my car runs quiter under load out on track, and is quiter than some other cars that where out there for sure. You did well to survive 6 laps, was 101dB a static value, if so you have got a good exhaust system!
What I have found is that on a static test the general engine noise is what seems to effect the reading, I have solid lifters which give a lot of additional noise that gets picked up, you can move the meter around the rear clip and not see any significant reduction in the dB reading.
You can get a device you stick in the end of your exhaust (I think it’s called a sound trap) it does reduce your power output, but it does mean you can go back out on track.
“I have solid lifters which give a lot of additional noise that gets picked up”
The R500 made more induction noise than the exhaust, you can lift when going past the sound traps, it normaly works, aslong as your static tests are ok.
“I have solid lifters which give a lot of additional noise that gets picked up”
The R500 made more induction noise than the exhaust, you can lift when going past the sound traps, it normaly works, aslong as your static tests are ok.
My static reading is 103 -104, which gets me into Oulton Ok, i've never been pulled at Donnngton on the drive-by. I'm running the standard factory GTR silencers which IMHO do the job but can't be very efficient.
A friend of mine runs a Sport with repackable straight through silencers, always gets through the static and the drive-by
A friend of mine runs a Sport with repackable straight through silencers, always gets through the static and the drive-by
Dr Peter said:
You can get a device you stick in the end of your exhaust (I think it’s called a sound trap) it does reduce your power output, but it does mean you can go back out on track.
“I have solid lifters which give a lot of additional noise that gets picked up”
The R500 made more induction noise than the exhaust, you can lift when going past the sound traps, it normaly works, aslong as your static tests are ok.
Don't do this. It will reflect the heat back into the engine bay. A guy did this at Goodwood a couple of years back, to an incredibly quick CanAm, and just about everything under the rear canopy that could melt, did. It was one hell of a mess under there!! (it was probably the same car steve d is referring to)
Try these they worked on Piers car... 98db..... Put them in the collector, and another one in the back of the Box......
http://store.summitracing.com/partdet
http://store.summitracing.com/partdet
gtrclive said:
Try these they worked on Piers car... 98db..... Put them in the collector, and another one in the back of the Box......
http://store.summitracing.com/partdet
Will they ship to the UK?
I'm planning on doing Brands soon, and I don't want to spend all that money just to get black flagged...
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