I was wondering if anyone runs and exhaust turn down before the rear axle? I know a lot of the Vette guys do this to save weight on the axle back section of exhaust. I was thinking of doing something like this after the Y-pipe to save weight. There is a guy I race with that has a 240 that has a setup like this. Does anyone see a downside to doing this other than the car would be extremely loud? Back pressure issues maybe? I am not entirely sure, that is why I am asking.

 

You will have a slight loss of low end torque, but the top end will feel slightly stronger as well. Just a warning, this will be crazy loud.

I ran open Y pipe for about a week just to see how bad it was. I could see people turn to look at what was coming at least a quarter mile to half mile away. Drone on the highway is so bad it distorts the sound of your voice if you try talking.

 

Back pressure, lol. Please read this (http://www.nsxprime.com/FAQ/Miscella...austtheory.htm) helped me when I had similar questions years ago.

Why not just go straight-pipe from the Y-pipe back? A tube of aluminized steel weighs much less than the stock exhaust system and it won't dump out right beneath the cab.

 

I would want the heat of the exhaust to at least me behind the gas tank and diff.

 

My car is track only. I already am straight pipe for the most part from the Y-pipe back. I am just trying to save a few more pounds here and there. Every bit adds up.

 

Thanks for the link. I'm a newb when it comes to exhaust theory and all that.

 

I wouldnt do a dump. Maybe find you some Titanium pipe and straight pipe it. Iv seen a few custom ones hit the marketplace years ago

 

^^^ Custom titanium straight-pipe. & you're welcome for the link.

 

I had turn downs before the rear axles on my 99 SVT Cobra track car. It makes it loud as hell inside the car, but cars with exhaust that exited outside the confines of the car were actually louder. Dumping it under the car actually makes the car seem "quieter" to people on the outside.

 

For a high speed track car wouldn't there be an advantage to having the exhaust exit at the lowest pressure zone on the car? I would guess that the over all exhaust function would a lot less restrictive if flowed out into low air pressure instead of bashing into a wall of high pressure.

From years of motor-pacing training behind cars, I know there is an area of low pressure following behind the rear bumper, are there any other places like this on a moving car?

 

Interesting...never thought about that.

Some guys did do the side exit exhaust, but I believe the NASA rules changed and they aren't allowed to do that anymore. Maybe that was for a certain class? I can't remember.