90 db at laguna seca

[rickmortimer]

Is 90 db even possible with a gen 3 stock motor at Laguna Seca.

 

[bob]

I do not know but I ran stock mufflers no center resonator gutted cats twice last year at LS and no black flags on 2019 GT. I am under powered because I have to run a restrictor for my race class. I do not know if that effects the sound coming out.

 

[Mad Hatter]

I know Its not Laguna Seca but we have a 90 db limit down here and it is possible!! Have a 3" custom exhaust with a pair of dynaflow glass packs right after the headers, then another longer set after the Xpipe. flowed that up with a H pipe just to make sure, and At the end, there is a Dynomax Ultraflow muffler... We ended up a fraction over 90DB (90.4). Adding some turn downs to kill the 0.4 Db. Or might just wrap the muffler.

Its a ported and modified Gen1 with 468rwhp so its a noisy beast. On a gen3 with out headers and a big exhaust, should be much easier.

 

[rickmortimer]

I know Its not Laguna Seca but we have a 90 db limit down here and it is possible!! Have a 3" custom exhaust with a pair of dynaflow glass packs right after the headers, then another longer set after the Xpipe. flowed that up with a H pipe just to make sure, and At the end, there is a Dynomax Ultraflow muffler... We ended up a fraction over 90DB (90.4). Adding some turn downs to kill the 0.4 Db. Or might just wrap the muffler.

Its a ported and modified Gen1 with 468rwhp so its a noisy beast. On a gen3 with out headers and a big exhaust, should be much easier.

View attachment 62899

Great idea

Thank you

 

[blacksheep-1]

have you tried having some custom made tailpipes with 80 degree bends in them made up just for track days? this way they point away from the DB meter. They look goofy but they work and they run them all the time at SCCA events

 

[Fabman]

This worked for me:

 

[flyhalf]

Stock gen3 engine with stock exahust pass 90db without issues.
Laguna pipes reduced 3-4 db extra

 

[vetracer]

Sound booth at Laguna Seca is on outside of turn 5. I had no end of grief trying to make 90db limit with my SCCA racing Corvette. I had Supertrap mufflers bolted to exit of Flowmaster mufflers and still couldn't make limit. Problem at Laguna is weather. Many times sky is overcast and sound bounces off low lying cloud cover. One trick that I've seen work is to have exhaust exit at rear wheel centerline using wheel as sound block. Use this in combination with exhausts turned down to close to ground or to drivers side of car to aim exhaust away from sound meter.

 

[SlowstangGT]

This worked for me:

View attachment 63125

Did you get this manufactured from a shop? I need me one of these
I'm pretty sure my Corsa Sport CatBack will exceed 90db without something like this

 

[Fabman]

Did you get this manufactured from a shop? I need me one of these
I'm pretty sure my Corsa Sport CatBack will exceed 90db without something like this

I am the shop.

 

[vetracer]

Is 90 db even possible with a gen 3 stock motor at Laguna Seca.

When I ran my SCCA Corvette at Laguna Seca making 90 db was very difficult because the often low cloud cover amplified the sound and turn 5 is where you get back into power to get up the hill. . I ran Flow Master mufflers to which I added Supertrap mufflers. I also added plate on the passenger side of each exhaust to aim sound away from booth turn 5. Even with this set up there were time I could not make 90 db.

 

[Bugs]

I previously posted a '19 GT350 sound mitigation method here. I measured 86dB on a sunny day at Laguna Seca. In that thread, a commenter made a good suggestion to ditch the attachment springs and instead use safety wire to retain the extended mufflers.