991.2 GT, how to pass sound at Zolder Zandvoort??
04-02-2019, 02:05 PM
#1
Rennlist Member
Thread Starter
991.2 GT, how to pass sound at Zolder Zandvoort??
Hi Euro guys,
We did Assen today and weren’t able to pass 98dB limit.
Zandvoort is 92 and Zolder is 95dB.
We have seen some gigantic cans hanging off GT3’s.
What do you use? Is it even possible at all?
Or do we need to cancel??
Help!
We did Assen today and weren’t able to pass 98dB limit.
Zandvoort is 92 and Zolder is 95dB.
We have seen some gigantic cans hanging off GT3’s.
What do you use? Is it even possible at all?
Or do we need to cancel??
Help!
04-02-2019, 03:50 PM
#2
Instructor
I think the noise levels you failed on and circuit limits answers your problem.
Porsche Club UK members go to both circuits but are in GT4s and know where to take it easy to avoid tripping the meters.
Following from your favourite browser:
Zolder measure noise at 2 points along the track. One is just after turn 4 (Bianchi) and the second one is between turn 7 and 8. You can recognise them by the blue poles.
Noise at Circuit Park Zandvoort is measured at a point located immediately next to the track (where the cars turn onto the straight).
Porsche Club UK members go to both circuits but are in GT4s and know where to take it easy to avoid tripping the meters.
Following from your favourite browser:
Zolder measure noise at 2 points along the track. One is just after turn 4 (Bianchi) and the second one is between turn 7 and 8. You can recognise them by the blue poles.
Noise at Circuit Park Zandvoort is measured at a point located immediately next to the track (where the cars turn onto the straight).
04-02-2019, 04:29 PM
#3
Rennlist Member
Stop by a hardware store, buy 1 lb (or 0.5 Kg) of steel wool on the most dense form, and a grill material (stainless steel).
Cut the grill material on a round circle that matches the SoulPP turndowns where they connect to resonated pipes. Stuff half the material in one resonated pipe, and the other half in the other, place grill, attach turndowns, hand tight v-clamp, then 11mm wrench to tighten the v-clamp. Done.
This will reduce dB by 5dB. More material reduces more, but on my testing last week, I lost 0.2 secs from 60-100mph stuffing 1 lb per engine bank. At 0.5 lbs per bank, there was no noticeable acceleration difference compared no turndowns at all (but with the resonated pipes). I already tested resonatyed pipes vs. stock tips and no difference in VBox acceleration.
Do not wire the valves closed, it will pass sound easily, but the amount of back-pressure is massive and you could cook the engine. Shutting the valves closed forces the exhaust to flow through a tiny 1.5" exhaust pipe (or 1.75") it is not designed to discharge a 4.0L at full gas and 9k rpm.
Cut the grill material on a round circle that matches the SoulPP turndowns where they connect to resonated pipes. Stuff half the material in one resonated pipe, and the other half in the other, place grill, attach turndowns, hand tight v-clamp, then 11mm wrench to tighten the v-clamp. Done.
This will reduce dB by 5dB. More material reduces more, but on my testing last week, I lost 0.2 secs from 60-100mph stuffing 1 lb per engine bank. At 0.5 lbs per bank, there was no noticeable acceleration difference compared no turndowns at all (but with the resonated pipes). I already tested resonatyed pipes vs. stock tips and no difference in VBox acceleration.
Do not wire the valves closed, it will pass sound easily, but the amount of back-pressure is massive and you could cook the engine. Shutting the valves closed forces the exhaust to flow through a tiny 1.5" exhaust pipe (or 1.75") it is not designed to discharge a 4.0L at full gas and 9k rpm.
04-02-2019, 06:04 PM
#5
Race Director
Don't you have some friends on that Left Lane Prius Facebook page that could loan you a car? ;-)
04-02-2019, 07:30 PM
#6
Sound limits on European tracks? WTF!
04-02-2019, 09:19 PM
#7
Bumping this to the top, tired of seeing the value threads
Trending Topics
04-03-2019, 07:22 AM
#8
Rennlist Member
Thread Starter
I think the noise levels you failed on and circuit limits answers your problem.
Porsche Club UK members go to both circuits but are in GT4s and know where to take it easy to avoid tripping the meters.
Following from your favourite browser:
Zolder measure noise at 2 points along the track. One is just after turn 4 (Bianchi) and the second one is between turn 7 and 8. You can recognise them by the blue poles.
Noise at Circuit Park Zandvoort is measured at a point located immediately next to the track (where the cars turn onto the straight).
Porsche Club UK members go to both circuits but are in GT4s and know where to take it easy to avoid tripping the meters.
Following from your favourite browser:
Zolder measure noise at 2 points along the track. One is just after turn 4 (Bianchi) and the second one is between turn 7 and 8. You can recognise them by the blue poles.
Noise at Circuit Park Zandvoort is measured at a point located immediately next to the track (where the cars turn onto the straight).
Stop by a hardware store, buy 1 lb (or 0.5 Kg) of steel wool on the most dense form, and a grill material (stainless steel).
Cut the grill material on a round circle that matches the SoulPP turndowns where they connect to resonated pipes. Stuff half the material in one resonated pipe, and the other half in the other, place grill, attach turndowns, hand tight v-clamp, then 11mm wrench to tighten the v-clamp. Done.
This will reduce dB by 5dB. More material reduces more, but on my testing last week, I lost 0.2 secs from 60-100mph stuffing 1 lb per engine bank. At 0.5 lbs per bank, there was no noticeable acceleration difference compared no turndowns at all (but with the resonated pipes). I already tested resonatyed pipes vs. stock tips and no difference in VBox acceleration.
Do not wire the valves closed, it will pass sound easily, but the amount of back-pressure is massive and you could cook the engine. Shutting the valves closed forces the exhaust to flow through a tiny 1.5" exhaust pipe (or 1.75") it is not designed to discharge a 4.0L at full gas and 9k rpm.
Cut the grill material on a round circle that matches the SoulPP turndowns where they connect to resonated pipes. Stuff half the material in one resonated pipe, and the other half in the other, place grill, attach turndowns, hand tight v-clamp, then 11mm wrench to tighten the v-clamp. Done.
This will reduce dB by 5dB. More material reduces more, but on my testing last week, I lost 0.2 secs from 60-100mph stuffing 1 lb per engine bank. At 0.5 lbs per bank, there was no noticeable acceleration difference compared no turndowns at all (but with the resonated pipes). I already tested resonatyed pipes vs. stock tips and no difference in VBox acceleration.
Do not wire the valves closed, it will pass sound easily, but the amount of back-pressure is massive and you could cook the engine. Shutting the valves closed forces the exhaust to flow through a tiny 1.5" exhaust pipe (or 1.75") it is not designed to discharge a 4.0L at full gas and 9k rpm.
Its bat**** crazy
04-03-2019, 12:09 PM
#9
Race Director
BUT.......at least you run safer with windows up...so air bags can properly do there thing and your arms can flail and dangle out the window.
04-04-2019, 11:04 AM
#10
Three Wheelin'
I have been to Zolder in my Touring with std exhaust and experienced no problem. on the same day there were another 3 GT3s. All ran without a problem.
@TRAKCAR: I'd say cancel at Zolder because it is no fun to take it easy at the measuring points. But if you can reschedule to a petrolhead day at Zolder, those are always without db limit ! (www.petrolheaddays.com)