Those of you who already have the noise reducing exhaust tips produced by my friend Will may be interested in the latest development in the pipeline, and indeed those who don't have one yet, this might help change your mind..... I should add that I have no financial interest here, just want to find a way to get my RS onto the 100db "quiet" trackdays.
As we know by now the 964 doesn't tend to have a problem with driveby noise tests, it's the static tests that cause the problems. Some circuits will take a pragmatic view about the static test and at least let you out on track to see if you trip the meters on driveby. Other circuits simply won't let you out unless you can comply with the static test (as I discovered !), regardless of whether you will trip the driveby meters or not.
Will and I were at Castle Combe on Tuesday with the Crescent Suzuki British Superbike team giving hot laps on a sponsors' day. We both failed the static test at c.105db (it was a 100db day) despite using the replacement exhaust tip - no great surprise there. Being enterprising chaps, the Suzuki boys took apart one of Will's tips, found an extra perforated baffle pipe that fitted precisely inside the removable core - packed round it will a bit of rag (obviously not a long term solution !), and hey presto we both tested 100db. Having passed the static test we were allowed out on track and simply removed the extra exhaust bung and ran happily all day without tripping the driveby meters.
What Will is now trying to do is to create a new bolt-in core for the exhaust tip that will pass a 100db static test, which can then be taken out by removing one screw before you actually go out on track. Given that it will only be used for static tests the restriction or any small amount of power loss is not too relevant as you will never need to run with it in on track.
This will allow three different exhaust configurations dependent on the noise requirements.
1.) Open (c.108db assuming decat and cup pipe) - for use at Spa and on road etc.
2.) Original removable silencer core (c.105db) - for use on most other circuits.
3.) New removable core (c.100db) - for use for static tests at Combe, Donny, Bedford etc, but to be removed before you actually go out on track.
The silencer cores will be totally interchangeable using a single screw - so literally a 30 second job to change them around.
Personally I think this is a winner - no need ever to fail a noise test again ! Post up any interest on this thread, and when Will has a prototype ready to go I will post up the details then.
Jamie
As we know by now the 964 doesn't tend to have a problem with driveby noise tests, it's the static tests that cause the problems. Some circuits will take a pragmatic view about the static test and at least let you out on track to see if you trip the meters on driveby. Other circuits simply won't let you out unless you can comply with the static test (as I discovered !), regardless of whether you will trip the driveby meters or not.
Will and I were at Castle Combe on Tuesday with the Crescent Suzuki British Superbike team giving hot laps on a sponsors' day. We both failed the static test at c.105db (it was a 100db day) despite using the replacement exhaust tip - no great surprise there. Being enterprising chaps, the Suzuki boys took apart one of Will's tips, found an extra perforated baffle pipe that fitted precisely inside the removable core - packed round it will a bit of rag (obviously not a long term solution !), and hey presto we both tested 100db. Having passed the static test we were allowed out on track and simply removed the extra exhaust bung and ran happily all day without tripping the driveby meters.
What Will is now trying to do is to create a new bolt-in core for the exhaust tip that will pass a 100db static test, which can then be taken out by removing one screw before you actually go out on track. Given that it will only be used for static tests the restriction or any small amount of power loss is not too relevant as you will never need to run with it in on track.
This will allow three different exhaust configurations dependent on the noise requirements.
1.) Open (c.108db assuming decat and cup pipe) - for use at Spa and on road etc.
2.) Original removable silencer core (c.105db) - for use on most other circuits.
3.) New removable core (c.100db) - for use for static tests at Combe, Donny, Bedford etc, but to be removed before you actually go out on track.
The silencer cores will be totally interchangeable using a single screw - so literally a 30 second job to change them around.
Personally I think this is a winner - no need ever to fail a noise test again ! Post up any interest on this thread, and when Will has a prototype ready to go I will post up the details then.
Jamie
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