I am in the final stages of my twin turbo build , I have decided to go with separate 2.5" exhausts pipes from each turbo along with separate barrels . Ive seen a lot of V8 exhaust systems incorporating a connecting H or X pipe beteen the exhaust headers , can anyone explain the purpose of these "pipes" ?, should I put one in ?.

 

"H" pipe and "X" pipes for V8's..........

The "H" pipes are simply for equaling out pressures in the exhaust from the left bank to the right bank of the v8 engines.

The "X" pipes do the same, except it's suppossed to have some scavenging effect since there is a collector between the left and right banks.

I'd go for the "H" type system to balance out the exhaust pressures for both turbos. Since the "X" type pipe wouldn't have any gains if any maybe even a loss because the chopping up effect the turbo has on the exhaust pulse, there'd be no scavaging.

~Mike................

 

The idea behind the x pipe has something to do with pressure waves from the exhaust pulses, and optimal flow can be gained by collecting the pipes at a certain point. I have looked for more information on pressure wave tuning, due to the fact that it is a crucial factor in the vdi system of the n/a's, but to no avail.

 

yea the x pipe is all about exposing the engine pulses, the flow pulse helps the exhaust flow.

 

The X is supposed to be placed 15 to 18 downstream of collectors. I had this built into my A Sedan road race Camaro. This was from the guy who built Chevy race engines for years.
His name was "Smokey" something . He's had several books published and was involved in NASCAR and drag.The cross pulse timing help scavenge and reduce reverse pulse.

 

Smokey Yunnick?

Tim

 

So , should I put in something like (H or X ) this or should I keep each exhaust pipe TOTALLY separate from the other ????????

 

Run two totally seperate systems with a connector between the two. An "H" pipe in other words. Don't use an "X". There will be NO scavenging, you have turbos to effectily delet this option. Run an H pipe simply to keep your back pressures consistant from one rotor to the next. With an "X" pipe, you'd effectively be cramming both turbo's exhaust through one hole.... not good.

~Mike.................

 

I have always been under the impression that the H pipe and the X pipe do the exact same thing, but the X pipe is more efficient at higher exhaust velocity because it brings the exhausts together where the H pipe basically gets bypassed with high exhaust gas velocity.





Its like having a hole in the side of a water hose. If the water is moving quickly and is able to flow out of the end of the pipe freely, not much will come out of the hole.