Ponderings about exhausts

[madhat]

I know that the farther along in the exhaust the gases get, the cooler they get, and the more compact they get. Well, what I am questioning is how going from a 3" dp to say dual 2.5" pipes will help. It seems to me that if you just kept the 3" all the way back(one pipe) that you would not only save weight, but not lose any power compared to the dual set up.
Also, at what point is the exhaust too open and it actually hurts spool up? When is it too restrictive that it hurts spool up, or will it just hurt top end more?

 

[Pablo]

Yeah, the 3 inch is alot lighter and probably flows the same if not more. The only problem is that its substantially louder. With the dual 2.5s, you have two mufflers to quiet things down. If you dont care about noise I would definately go with the single 3"

I was surprised at how loud that can be on these cars though even with the turbo. On my old F body I had a single 3 inch system that was pretty loud and I wouldnt have expected the v6 with a turbo to be anywhere near that loud but it was (I used to have a single 3" then went to hooker duals because of price after the 3" rotted out)

 

[madhat]

seems like if you had two mufflers you could get it down to a resonable volume though...

 

[cool 84]

I sort of doubt a 3" pipe will flow the same if not more than a dual 2.5". In fact a dual 2.5" flows 66% more than a single 3"

I doubt it's possible to have too little exhaust restriction on a turbo car. It will only help spool.

While the 3" DP might be the biggest restriction post turbo, backpressure is a sum of all restrictions.

 

[Pablo]

I sort of doubt a 3" pipe will flow the same if not more than a dual 2.5". In fact a dual 2.5" flows 66% more than a single 3"

I doubt it's possible to have too little exhaust restriction on a turbo car. It will only help spool.

While the 3" DP might be the biggest restriction post turbo, backpressure is a sum of all restrictions.

Well you are right, I was just going off the top of my head. I should have made the point that I would guess that one single system straight out is going to have less frictional losses than a dual system with two mufflers in parralel and he has a point about the ex. gas temp cooling and condensing the gasses. So the difference between them is probably marginal. Ray Bunch just belted out 579 RWHP through his single shot 3" exhaust down here so it cant be too terrible.

 

[Pablo]

btw I did the math and if im not mistaken, its actually 37% more flow area than a single 3"