airspeed247

I recently removed the mufflers of my C6 to get an idea of the sound and really like it. I plan on leaving it off with the turndowns I attached after the H- Pipe but am about to start doing AutoX and my first HPDE.

Before I dirve all the way over to the events does anyone know if I will get busted for no mufflers or will i be good to go for both events?

Thanks,
- David


Sound vid of car now: http://www.youtube.com/watch?v=uuyjL7hre-M

shakedown067

It all depends on the venue. One of our locations would be fine, the other we'd let you take a run at your risk of us ending your day if anyone complains. HPDE's are all up to the track as well. A lot are having DB level requirements these days, as people are stupid and move next door to a racetrack then complain about the noise. I'd contact the track you plan on running about DB level requirements.

airspeed247

I'm tracking, they are doing similar thigns with Motocross DB's. I'm actually living near Pensacola right now. What locations are you familiar with and how do they measure the DB readings? At idle, while driving..?

sperkins

I have done something very similar to this. Noise will not be an issue at most RR tracks since most of the sound gets trapped underneath the car. What will be an issue for HPDE use is under car temps.
You will heat the tranny and the rear spring after 20 minutes of on again and off again WOT.

grantar2

All SCCA National, and divisional events require sound monitoring and have a limit. believe it is 108db for disqualification, but you will have to check the rule book. At the pro solo in El Toro we had two cars that had to go put mufflers on to compete. 1 was a street car that had removed his at the track and just put it back on. The other was a trailered track car and had to do some parking lot fabrication to continue.

waktasz

I was thinking of having a cheap, light exhaust built up using bullet muflers and dump pipes but was also worrying about this. Does anyone else (I know Ted D Bere does) have this setup that actually drives there car on the street?

airspeed247

I'm driving mine on the street pretty regularly with the dumped setup now.

waktasz

I worry about long drives, and sitting in traffic with the hot exhaust dumping under the car. We drive it to national solo events, so in a month that will mean an 8 hour drive across PA and OH to Toledo, and next year hopefully to Nebraska. Should I worry? gf wants to get me an anniversary present and I told her the race car needs new pipes

airspeed247

With dumps be prepared for a pretty decent drone. It subsides pretty well at an even rpm in 5th and isnt too bad in 6th though. As far as heat goes I haven't noticed a difference in the cabin. On a highway I dont think you would have too much of an under car heat issue due to the fact that your maintaining a pretty constant air flow under the car. If you email me I can email you a picture of my setup. Or check my garage under my 05. I will try and post a picture of under the car.

NTMD8R

In the Vancouver area we only have one place to Autox
(near an airport... but with lots of "residents" living all around the area).
We also have a local track (50 miles east of Vancouver) for HPDE.

There is a 92 db maximum limit at both places.

With my stock C6 with Corsa Extreme mufflers,
on the Autox track, I have to short-shift to 2nd, to keep the loudness
at or below the limit.
They measure from 50 feet away as you pass by.

On the track, I barely make it under the limit on the straight-away.
They measure from 50 feet away as you pass by.

waktasz

I'm mostly just worrying about heat. Heating up the spring or transmission I guess. Maybe my concerns are unfounded.

airspeed247

SPERKINS is probably the guy who can give you the most facts on that part.

waktasz

btw, how about some in-car video/audio on the road in your car?

2000BSME

if someone hasn't told you yet, you will destroy a factory fiberglass spring with dumps.

waktasz

I guess that's my answer then. I was hoping to get a new exhaust that was louder and at least as light as the stock Ti. (oh, and didn't cost $800!) Oh well

airspeed247

Not sure what your into but I am presently in the process of testing another mod also. I cut a slot on the inside of both mufflers and removed what was almost a small to medium sized pillow of fiberglass/carbon/ sound deadoning and had the cutouts rewelded back on. (cost $40). Should have them reinstalled tonight or tomorrow with a sound check to see if it sounds decent. It should really open it up alot and its a really inexpensive mod. The same shop I went to also said for another $45 they will delete the mufflers altogher for me putting a pipe in place of them and leaving the ability to still have rear exit pipes with a bullet like appearance and sound.

Either should produce a good sound and both are very inexpensive.

waktasz

I would go for that but nobody around here that I know of works with titanium. I'm sure I could find a place if I really tried.

As for what I'm into...the car is too quiet for the engine sound to get picked up over the wind noise when we record our autocross runs, so it needs to be louder, . No point in spending $$$ for a catback that is going to be heavier than stock though.

airspeed247

Titanium? What year/model is your car for it to be titanium stock?



Also, anyone know if all of the models leaf springs fiberglass?

waktasz

The c5 z06 has titanium exhaust.

The springs are some sort of super composite space age thermoplastic (ok I made that up)...definitely not metal, although not fiberglass either.

edit: I guess I lied...the internets says it is fiberglass.

airspeed247

I'm tracking. Didnt realize you had ZO6. In that case you could pick up a non Zo6 exhasut for cheap and play with that while still maintaining your stock exhaust as a backup. Just a thought




So if I am correct, my non ZO6 has a fiberglass like leaf spring that could heat up from running dumps?