Well, It's the stock Maggie pulley so right at 6.5 pounds.. When we added the CAI I actually gained a little boost... So, I'm just under 7 now I think.

Also we've been playing with the mufflers. It was dyno'd with a 3' open muffler that was way too loud.

Then Tom put the 3" chambered muffler on (what I have now) and it should perform the same... maybe better with the increase in back pressure.

After talking to ARH, they want me to put a 2.5" on and I should get a bit better performance...

So my RWHP numbers a a bit of an estimate... Everyone that has worked on my car says I should be over 550 in the winter... ;)

But I'm not quite ready to make that claim without a dyno....

FWIW.

:sm0:

The only defence I have to that is you've driven my car??? :help: :iono:


:laugh:

DUDE !!!

Awesome video. It looked like someone kicked the camera at the end.

It's the THR22 "Sonic Boom"

Great video :thumbsup: :thumbsup: :thumbsup:

Thanks man.

Hey when you have a sec. Can you help explain why the mufflers should be necked down to 2.5" and how that helps performance.. Back pressure and scavenging..

Thanks!

:rolleyes: Oh, ya. Right. And I've yet to start your car without smiling at the sound. lol

:laugh:

oh and to you and PQ...

My car may be supercharged... But I really need to catch you two in the looks department..

your cars are gorgeous. ;)

it wasn't the camera.. the Earth moved. :sm0:

I heard there was gonna be a new federal law that no more than 15 Camaros can be driven at any one time because of that problem...

:laugh:

Here:

The exhaust gases leave the cylinders of an automobile engine at a pressure of around 60-80 lb. per sq. in. and with a velocity of up to 150 ft. per sec. This results in a considerable volume of noise, which must be reduced sufficiently to make the vehicle inoffensive to the driver and passengers, and to the public at large. This legal requirement is achieved by allowing the gases to expand into a silencer chamber, where the intermittent and violent discharges of gas are broken up and emerge from the tail pipe as a continuous and relatively uninterrupted stream.

The exhaust note of an internal combustion engine is made up mainly of a low- to medium-frequency band of 50-600 cycles per second, and a high-frequency band of 3000-10,000 cycles per second.

The low-frequency vibrations appear to result from resonance between the varying capacity of the cylinder and the exhaust system as the piston moves through its exhaust stroke, while the high-pitch sound originates in the release of the high-pressure gases through the exhaust ports.


According to experts (I usually check with David Vizard first) you should shoot for around a 0.2 psi backpressure for no HP loss in a system.

In our terms, you are trying to use the exhaust to both control noise and optimize the flow IN THE COLLECTOR AREA. Basically you want the next cylinder in the firing order (on the same bank of a motor like your LS3) to scavenge such that the next cylinder does not have to do the work. For your THR22 items such as cubic inch, stroke, compression, forced induction boost, cam specs, etc. come in to play. Whether you go with 1-7/8 or 2" primaries, use a 2.5 or 3.0" exhaust, necked down or not, a X-pipe, H-pipe or any other combination is best determined by dyno testing or trial and error. I am sure THR researched this prior to putting your beast together.

Sorry, the long winded version. Yes, you guessed it, I am sitting on a boat in an island cove right now. Getting ready to leave and get some dinner. :D

:emoticon17:


Did you decide to stick with the chambered mufflers?

I think what you're planning will get that done...patience...;)

I'd like to try the 2.5" just to see the difference.

Yeah -- it's probably worth a try. But consider that Doug's car about made my ears bleed when he first arrived at the hotel...:bellyroll:

That's a healthy growl you've got there, and I thought maybe you switched them. hehehe...I remember when I made some noise for your kids, Billy got all silent and said, "Now that sounded beautiful." ;)

:D

Yeah I'm pretty happy with it. ;)