So I auto-x my Z for the first time in a year, and the first time since adding unresonated test pipes. I registered at 98 decibels when I was floored headed to the finish line (also the closest area from where the mic was set up).

So basically I am wondering what all you BSP guys are running for exhaust and if you have run into any issues at any National Tour events or even local events.

 

98 would deffinately be an issue at some tracks, especially at quiet hour

 

I ran my Z with APS 2.5" Test Pipes and the Stillen TD exhaust w/o any problems. Are you sure they place the mic 50' from the track?

 

Im 115 dB at the car, and I think 94 50' away...

 

I wasn't entirely sure, I'm guessing not quite 50' but regardless I am still "Loud". Are you APS test pipes resonated?

Can a mod change the title to "98 decibels...Auto-x guys help"

 

wow that is loud.....prob get annoying after a few minutes

 

Done

 

No not really, at idle and cruising it's basically like just having the nismo catback, but give it any gas and it opens up like thunder.

Thank you sir!

 

Have you measured it with cats in to see how much difference they made? I know on mine, the HFC's made it quite a bit louder.

 

Anything over 85 can cause hearing loss, just FYI.

 

You mean quieter over test pipes? I had HFC's but they broke down and clogged, took the cheap route.

Really trying to find people with BSP prepped cars and how they get by.

Thanks for the help, but this is only at WOT. Also, inside the car it is actually pretty quiet. (lol and no I'm not deaf).

 

Well, I do run my car in BSP and I do have a 95db limit in my region and I do get by just fine when running stock cats. With HFC's I am right on the limit. And I have never run just test pipes, but I know they are louder than HFC's. My cat-back however is a one-off, so that part is not help to you.

 

A few tricks I do:

1. Add a 90 degree turn down to the end of the exhaust and point it away from the sound meter and pointing down at a 45 degree angle to the ground.

2. Add a resonator upstream of the muffler. It can be something as simple as a striaght through glasspack (not the louvered kind).

3. Using a small piece of perforated metal, bend a tent shape into it that's as tall as 1/2 the OD of the exhaust tubing. Cut it lengthwise at an angle so that it looks like a pyramid and weld it into the exhaust pipe before the muffler.

4. Buy a Supertrapp exhaust tip and use it at events where there are noise limits.

5. Change to a single exhaust (you did that anyway, right)?

All of the above has worked for me when I and my customers have run the San Diego NT. The limit there is 91db.

 

Actually, now that you mention it, our limit here is 91 as well. We only have one site that allows 95.

 

No the APS are not resonated. Still pretty hard to beleive. Could be just the person being really strict watching the db meter.

 

I run in BSP. I have the INJEN SES coupled with a Magnaflow x-pipe muffler. I also have aftermarket headers & resonated test pipes. No issues at all.

 

Thank you everyone for the replies!