Hey,
I'm going to use my car on the track up in Louden, NH this weekend and I need some help with a temporary modification to my B&B PRT's.

Essentially they are too loud (115 db) for the track limit (98 db) and I need a creative way to quiet them for the duration of my track time.

What I have come up with so far is an insert that goes into each flage at the beginning of the over-axle pipe. It would have a smaller hole than the pipe so it should restrict flow enough to quiet it down. It might actually give me a boost in RWTQ as well due to the backpressure increase.

My second idea is to use some screening material and put it in the back part of the exhaust tip. Then I would fill each tip (quad oval cans) with stainless steel wool (rough grade). Then I would affix another screen on the inside of the outer rim of the tip to keep everything in.
This should give me some lowered volume (and of course lowered performance).

Does anyone have any better ideas? Will the things I'm proposing work?
Thanks :D

 

Chris,

WHat kind of wackiness is that? A DB limit at a track?:D Must be for the neighbors, huh? I see CA has imposed a limit on the street too. :(

Anyway, try calling Mike at BB before you do anything. He may have experience with that issue...don't know for sure. He's at toll free 888 228 7435. He's been a great guy to deal with for us.

Good luck, man.

RG

 

Thanks RG,
I had called B&B about it but couldn't get through to Mike. I talked to one of his tech's who suggested the gasket style insert.
He was however, not easy to deal with and didn't want to offer any suggestion that was outside of the original design. In fact he told me at one point, why don't you just put the stock exhaust back on for the event :rolleyes:

I still don't have a good answer for this problem, although I think that a combination of both ideas would work fine.

I also thought of possible supertrapp inserts that would go in the holes of each exhaust tip. Wish me luck on finding something like that.

Anyway, thanks for responding RG, you're a class act. :D

:cheers:


[Modified by chrislee2, 4:39 PM 10/30/2001]

 

How the hell did you get such a big increase in power with the headers?? Your gains are definitely outside of the normal range........

 

Chris Lee,

If you want, I have an extra set of the B&B Sport exhaust that you can use for the track. If you really don't want to use the PRT's.

 

Chris,

Many tracks have DB limits but they are not strictly enforced with a db-meter at every event. I think the rule is just put in place so that people do not show up with open exhaust expecting to race.

I think you would be fine to head out onto the track with the exhaust you have. I highly doubt anyone will say a word to you.

I know the track I race on has noise limits as well but I have never had anything said to me and there has always been way louder cars out on the track than me.

 

Yeh that is usually the case, but in this instance, I was pulled off of the track and told that I have to quiet down my car or forefit the day.

I ended up shifting into tall gears and not accellerating like I would normally just so I could keep racing. It wasn't as much fun.


C5-YA thanks for the offer. I may take you up on that, although I don't know if I want to swap exhausts every time I want to go race.
I wish I had an easy way to hit a switch and quiet it down....


[Modified by chrislee2, 4:39 PM 10/30/2001]

 

I chose the TTS headers.. go figure... :D

 

TTT
Anybody else have any bright ideas?
Thanks,
Chris

 

What kind of track has a ********* noise limitation ?? :eek:

 

Ones that have neighbors and want to remain open. Most states (and many cities) have noise regulations (mostly implemented for outdoor concerts), but they do come into play for other activities that produce noise.

 

a X pipe should quiet it down.

 

When PIR black flagged the #4 C5-R for being too loud, they added little tips to bend the noise down. Apparently bouncing the soundoff of the track quieted it enough to stay within the limits.

 

You mean add another one?
I don't want it quiet all the time, just when I race.

 

Now that is a good idea! I wonder if I could put some deflectors inside the PRT tips that would do what you say.

Cool thanks :cheers:

 

Oh. The #4 was only off by a couple of db's and I don't know how far they dropped.

 

Hi Chrislee2,

I would like to offer my thoughts to our "think tank" and I truely hope you figure something that works easy for you.

1) Another set of mufflers...OK good idea. Borrow the set that is offered...find your stock system to install. Pain to switch back and forth.

2) Restrictive Gasket...I kind of like this on. Slip a gasket with a smaller hole in it iunto one of the joint connections. Maybe will burn out toward the end of the day.

3) Sheet metal flap on the tips....push the sound toward the ground to fool the DB measurment tool (Like the CR5 trick). May or may not work plus having to dril holes into the tips to secure the metal.

4) Set of Glass Pack mufflers installed in the straight part of the pipes. Well, am I dating myself with glass packs.

5) For motorcycles years ago we made spark arrestors which also quited down the bikes with steel wool in a cola/ beer can. Very cobby but will work.

6) Again motorbikes a muffler insert (cylinder pipe with many holes in it) surrounded by fiberglass muffler packing.

7) A butterfly valve. Could be a permanent mod..welded in. Straight to retain original volume, somewhat closed to muffle.

8) Substancial donation to the track.

Well that my .02 in this think tank. Good luck and remember in racing second place is the first looser, so please finish first.

Sincerely,
Kenny

 

I would try to run as is. They probably won't ask/you don't tell. Smokey Yunick once said after admitting to a degree of cheating---"cheating? I was just protecting myself "