97C5driver

Has anyone figured this out yet?

Turndown pipes?
sideways pipes?
gps device to close flaps?


Running Mazda Raceway Laguna Seca next month & trying to prepare.

In my stingray I was able to pass (even with borla catless x-pipe) by putting stealth mode on manually.

However, in the Z06, the flaps open almost immediately when the gas is applied even with stealth mode turned on manually.

I know i can lift at the sound station, or shift into a higher gear, which I will do obviously if I have to, but would love to shoot for a PR on lap time. Especially in a more powerful car and with sport cup 2's.

thanks

dmaxx3500

how about putting mufflers on the car

Bill Dearborn

As I do more track days I have noticed the exhaust getting louder over time. At a recent VIR event I was giving a ride to somebody who had ridden in another car during a previous session. He said when I had passed them during that session the car was very loud.

Any aftermarket muffler system you purchase will be louder so that is probably the wrong way to go. The muffler valves are electrically controlled by a PWM signal from the body control module and it would take some analysis to add some circuitry that permits the driver to modify the signal coming out of the module so the proper pulse width is sent to the mufflers to close the valves at the correct time. Of course that brings up the issue of how much back pressure can the engine take when you do that.

I don't know if it is possible but having some sort of removable turn down that can be clamped to the two outside muffler outlets might be a way to reduce the amount of noise sent toward the sound meter. Or maybe some sort of removable straight through muffler that would provide some added dampening. The biggest problem with doing something like that would be keeping the clamps tight because the extreme temperature excursions of the exhaust tips will create a fair amount of expansion and contraction.

Bill

spearfish25

I definitely notice the car is much louder and deeper when the exhaust is really hot during a track day. Just the drive to the gas station between sessions has me thinking about it even at 2k RPM. I started wearing ear plugs since my ears would ring at the end of each session.

AzDave47

On my C6Z I ran one track with a very restrictive sound limit. I safety wired the OEM vacuum operated flapper valves closed.

I don't know if the (electronic) control on the C7Z would allow that or whether doing so would create a backpressure issue with the LT4 engine.

KnightDriveTV

Clinch your buttcheeks right as you feel it comin and sneeze toward the mic

four0nefive

I know a guy that tracks his P1 and GT3 RS at Laguna Seca and he was just there recently. Interestingly enough, he joked around telling a friend to sit by the sound booth and rev the golf cart thing he was driving around the pits when he drove by the sound booth. Believe it or not it actually worked in throwing off to "sound gun"

Taz Golf

I had the same problem last weekend at M1 Concourse. They have a 90DBA sound limit and they said my car registered 105DBA at WOT on the straight away !
Would be interested in a fix or ability to close some of the valves without creating too much backpressure !

97C5driver

yeah nady, he has a gps enabled setup on his gt3 and the P1 he lifts at the sound booth.

Im interested in going wot the entire track without breaking sound.

97C5driver

wow 105? That's stock right?

stay tuned I'm working on something. Hope to test it next month at Laguna Seca.

Taz Golf

No not stock. Full Mods... Cam, Heads, Lifters, TB, SC Pulleys, ARH Headers, Akrapovic Evolution exhaust.

Let me know if you find sometime that works!

BEZ06

Other cars have come up with easy fixes - you should be able to rig up something like these guys have:

Kaged

After getting black flagged at Laguna Seca in April (completely stock C7 Z06) for noise, I talked to a few shops in California that make the turnouts for a lot of track cars. None of them were will to go through the hassle of coming up with something that bolts up to the elliptical tips on the Z06 exhaust.
I will say that staying in 4th gear and lifting off the throttle by the sound station worked the first 3 sessions. Was running in "stealth" mode for that day. In the 4th session, I forgot while chasing a GT3 RS and got meat balled. Only registered 94.8 db - but that was enough.

97C5driver

I'm working on something right now that I am hoping will work, and it will be removable without messing with the stock tips. Also hoping to not have to use an external muffler. I would prefer just the sideways pipes.

94.8 db is not bad at all. was that WOT?

my stingray with a borla x pipe was registered at 94db at laguna seca, WOT

97C5driver

lol this one actually is at laguna seca.

I def. don't think I need to get as wacky as the other ones. this porsche setup is not too extreme honestly. I mean it is, but at the same time it isn't.

97C5driver

Lol well what did you expect with all that? I died laughing while reading this.

I wonder what stock DB is at WOT on these cars

billw4559

I was there last Tues on a 90db day. TFB Performance fabbed up some SuperTrapp mufflers to stick in the stock valved muffler tips. Looked clean (relatively) and was able to run WOT up the hill in third gear while tracking full right, no issues. Was my first time there, did not know about requesting a sound check until after the last session so not sure how much buffer was there.

At Sonoma Raceway, was measuring 95db with stock exhaust on a 96db weekend. Got black flagged twice for 97db.

AzDave47

97C5Driver, dB readings need to include a distance and direction of measurement to be meaningful. dB reading at 50' directly in line with the exhaust outlet will be different from 50" but 90* off to the side and 25' away will be different from 50, 100, etc. SCCA has a specific protocol for how sound measurement needs to be done. Tracks may do it differently.

With my NASCAR car on the road course at NHMS I was able to pass with 96-97 dB, but at the same track for open test days, the track measured it at the concrete pit wall exit with sound bouncing off the outside wall and I was thrown out for 104 dB

97C5driver

really? I just sent them an email. you didn't get any pics by chance did you?

yeah they offer test runs before the session starts but i was advised multiple times that this only brings unwanted attention to your car for the rest of the day. this coming from the event organizers.

w00tw00t

rotfl!! :d