Just FYI, I may not be in California, but my exhaust surely isnt legal. Keep in mind also that measuring DB is not linear.

 

pssh, hey, mine's not legal either. i see now that below the avatar it says NY. lol.

what's a good way to measure db?

 

If you kept the stock WG cat connected and then put a fairly quiet muffler in back of that, wouldn't the exhaust technically be legal in CA, since you're not removing any emissions control device and you'd be meeting the noise limits?

Then you could remove the muffler for the track, assuming you met the noise limits?

 

IIRC there is a tiny cat on the WG tie-in.

 

yeah, i call it a "kitten"



i'm clever. someone laugh at the joke....laugh damn you!

 

I have no kitten on my car, and no tiger. Not a cat of any kind, and if I had one it would be a race cat.

 

that was pretty funny

 

Yes with less backpressure the boost will go up with a manual type boost controller.

When backpressure and the rear exhaust are discussed there are always theories but not so much hard facts.

We've tested without anything behind the cat and then with the OEM rear exhaust but with a straight pipe instead of the muffler.
HUGE difference in boost level using a MBC.
Had to turn the boost up A LOT to overcome the added backpressure from just the 2 angled and 1 kinked pipe.

You also have to keep in mind that the flow ratings for different pipe sizes are for straight pipes. When you add several angels and welds things change.

So....if you can... always GO BIG when it comes to exhaust

 

So even the bends affect the overall boost that much???

 

OK i found a host for some of my video's.

Here is one from 2004 with WG dumping to atmosphere.
http://videos.streetfire.net/player....A-42EF3B713CFC

Same day but not opening the WG until the end.
part throttle driving
http://videos.streetfire.net/player....E-0243403BB57F

Heres one from this year with resonator installed to reduse sound.
http://videos.streetfire.net/player....4-291B7B35E28A

Heres one of me doig some donuts. with resonator.
http://videos.streetfire.net/player....6-8D11EE34BFFE

Enjoy

 

honestly for some reason i just don't hear any difference running the wastegate to the atmosphere through the video's. i guess i am just used to loud exhausts and maybe that is where it is making the sound.

 

Daniel,
In the first video, after i shift into 3rd, you can't hear the change in sound when i hit over 15psi.

And in the second video, you can ear the WG open barely in 3rd gear at the end.

I will get my other video tomorrow.

 

Daniel, the second video where he is just part throttle is a good representation of what it sounds like closed dump, whereas the extra noise in the first video is a good way to think about open dump.

 

IC now sorry for being the retard sometimes the simplest things are the hardest LOL. Thanks again guys

 

Maybe thats because you are now deaf!

As well as being non linear scale, distance has a big effect.

Noise is a big issue on UK race tracks and Ricks car would be thrown off on a 98dB day before dumping to atm.

Whilst 110db might be OTT I doubt it is below 100db even with trackside drive thru.

Quickest way to see if you like it is unbolt the wastegate exit, it will be loud until you get on boost (exhaust will leak) but it will be louder still once the wastegate opens.

Tony