996 GT3 exhaust advice please
Discussion
Hello chaps.
After three months of waiting to register my car (imported from overseas), it failed its IVA (AGAIN!
) The final sticking point is the exhaust is too loud. A fellow PHer very kindly loaned me his standard system but the silencers are shot and a new set costs £600 plus fitting.
Does anyone know if the vacuum pipe trick on the 997 exhaust also works for the 996? Failing that what's the cheapest bolt on kit to get me through the test?
For reference, the car is currently registering 103dB on my own exhaust, 102dB on the standard exhaust (with old silencers), and needs to be down to 99db to pass.
Thanks,
Harris
After three months of waiting to register my car (imported from overseas), it failed its IVA (AGAIN!
) The final sticking point is the exhaust is too loud. A fellow PHer very kindly loaned me his standard system but the silencers are shot and a new set costs £600 plus fitting.Does anyone know if the vacuum pipe trick on the 997 exhaust also works for the 996? Failing that what's the cheapest bolt on kit to get me through the test?
For reference, the car is currently registering 103dB on my own exhaust, 102dB on the standard exhaust (with old silencers), and needs to be down to 99db to pass.
Thanks,
Harris
hi irf,
99db is a task and a half for any gt3 in my experience.. i'm dropping my engine in a few week, you can use my full standard system (low mileage) no problem at all.. but it blows right on the static 105db limit @ Oulton every time.. no idea how you would fit the 997 valve set-up on a 996..? also in my experience 997's have always been louder than 996's in standard trim....
ade
99db is a task and a half for any gt3 in my experience.. i'm dropping my engine in a few week, you can use my full standard system (low mileage) no problem at all.. but it blows right on the static 105db limit @ Oulton every time.. no idea how you would fit the 997 valve set-up on a 996..? also in my experience 997's have always been louder than 996's in standard trim....
ade
Ade, that's a really kind offer. I fear 105dB won't get me far, lol! There's a trick on the 997 to pull the vacuum pipe from the solenoid that controls the exhaust valves, thus drastically reducing the noise at revs. Having never fiddled with the 996 exhaust (and with the car being an hour and a half away), I've no idea if it has similar hardware.
If it doesn't, would I be mad to consider something like this instead:
http://www.demon-tweeks.co.uk/motorsport/universal...
If it doesn't, would I be mad to consider something like this instead:
http://www.demon-tweeks.co.uk/motorsport/universal...
There's no vacuum valve stuff on the 996. It's just a regular passive exhaust system so no chance there.
You should be able to clear 99db with a good condition stock system though.
A standard C2/C4 system is the same as a GT3 system on the 996 save for the headers. You might have more luck tracking one of those down from someone to use for a day for your test?
Those super traps work well but you need quite a length of them. Will you past IVA with two big removable rocket launchers poking out of your bumper?
Static noise tests are always a killer for 911s. The engine noise reflects off the ground and into the mic.
I'd loan you something if I had anything that would work. My 996 cup setup is 110db dynamic though. I've a 2008 cup setup too but it's not much better.
You should be able to clear 99db with a good condition stock system though.
A standard C2/C4 system is the same as a GT3 system on the 996 save for the headers. You might have more luck tracking one of those down from someone to use for a day for your test?
Those super traps work well but you need quite a length of them. Will you past IVA with two big removable rocket launchers poking out of your bumper?
Static noise tests are always a killer for 911s. The engine noise reflects off the ground and into the mic.
I'd loan you something if I had anything that would work. My 996 cup setup is 110db dynamic though. I've a 2008 cup setup too but it's not much better.
Edited by fioran0 on Tuesday 6th November 22:49
Have you tried getting the exhaust really hot before the test? My 996GT3 failed at Goodwood a couple of years ago, the tester recommended geeting ti really hot, by driving 2-3 miles in second gear at 5000rpm, came back, went straight through the test, theroy is the extra heat expands everything in the exhaust and reduces the db reading.
Might be worth a try
Might be worth a try
keep it lit said:
irf, me or mike will find you a c2/4 system no probs.. i know that kev or cath will have some also.. i'll have a word in the morning & let you know mate.
You're a star. I will keep this option in reserve as I don't want to go through the hassle of sending it over, fitting, then removing and sending back. Already been through that once and it's lost me a month in time.fioran0 said:
Are you running an aftermarket intake? This will hurt you on a static sound test too. You will need to pack it with foam to get through.
You could try this with the stock box anyways to get noise down an extra bit.
Nope, standard intake. I asked the workshop to pack the exhaust to be safe but now I'm not sure if they did.You could try this with the stock box anyways to get noise down an extra bit.
andrew symms said:
Have you tried getting the exhaust really hot before the test? My 996GT3 failed at Goodwood a couple of years ago, the tester recommended geeting ti really hot, by driving 2-3 miles in second gear at 5000rpm, came back, went straight through the test, theroy is the extra heat expands everything in the exhaust and reduces the db reading.
Might be worth a try
Yep, I asked them to make sure it was hot. Again, I will have to check with them to make sure they did that.Might be worth a try
I checked the IVA manual and the mic is placed 500mm away at the height of the exhaust at a 45 degree angle, with the engine at 3/4 revs. Ludicrous.
Just heard from the workshop that they are asking Porsche GB to produce a letter that 99dB is just not going to happen.
Thanks for everyone's very helpful suggestions - I will let you know if Porsche oblige.
Just heard from the workshop that they are asking Porsche GB to produce a letter that 99dB is just not going to happen.
Thanks for everyone's very helpful suggestions - I will let you know if Porsche oblige.
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