• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Exhaust Systems- what are you running?

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,761
Loc.
Conway, AR
This is ture. It is Bernoulli's Law. A given volume of gas travelling through a smaller diameter tube will flow faster than the same volume of gas through a larger tube. Boyle's Law states that a given volume of gas at a given temperature has a given pressure and as the temperature decreases, the volume decreases if the pressure stays constant. So lower volume (because it is cooler) in the same size tubing = slower flow. Reducing the diameter of the pipe increases the gas veolcity and actually deacreases the pressure slightly (Bernoulli again).

I love science.

Tim
 

tatersalad

Bronco Guru
Joined
Jan 17, 2009
Messages
1,067
I have been running Duffs long tube coated headers into a Duffs dual system for 13 years now, they were originally on a 302 but I went EFI 351 last year . They came with cherry bombs (If I remember right) which blew out around the 4th or 5th year and then I put a set of flow masters on in their place. The flow masters sound real nice on both setups but I am a little older now and when they need to be replaced I want to quite it down. Thinking about a 2 into 1 out the passenger side next. The passenger side long tube header is real close to the passenger side floor board so I am in the process of putting on a 1 inch body lift to compensate so mommas feet are a little more comfortable : ) I've been told that the body lift may help me acheive a little better air flow under the hood too, potentially helping out the cooling system a bit...
 

jim3326

Bronco Guru
Joined
Jul 12, 2010
Messages
1,781
Loc.
Appleturkey
Thinking about a 2 into 1 out the passenger side next. The passenger side long tube header is real close to the passenger side floor board so I am in the process of putting on a 1 inch body lift to compensate so mommas feet are a little more comfortable : ) I've been told that the body lift may help me acheive a little better air flow under the hood too, potentially helping out the cooling system a bit...

I had long tube also and the only way I got it to cool down was to wrap the headers. Now I have shorties and 2 into 1 w/ 1" BL and the tubes are a lot further from the floor. When I ran it to running temp and for a while longer, the only part of the floor that even got close to being hot was right over the muffler and it wasn't that hot. Once I get the interior done it won't even be noticable.

Jim W.
 

DuctTape

Bronco Guru
Joined
Jun 20, 2008
Messages
1,148
Loc.
Bozeman, MT
I had long tube also and the only way I got it to cool down was to wrap the headers. Now I have shorties and 2 into 1 w/ 1" BL and the tubes are a lot further from the floor. When I ran it to running temp and for a while longer, the only part of the floor that even got close to being hot was right over the muffler and it wasn't that hot. Once I get the interior done it won't even be noticable.

Jim W.

I have long tubes and duals running out to side behind rear tires. If I redo the exhaust it will be shorties 2-1. I really don't like how close the drivers side exhaust is running next to brake and fuel lines.
 
Top