Premise: I installed a triton 5.4 V8 in my Crown Victoria. The stock exhaust fit, but who wants to leave well enough alone....
I had an exhaust shop run 2.5" pipe from the manifolds back to the stock muffler location, then welded on a pair of flowmaster 50 series mufflers. I skipped the tailpipe and just dumped them at the rear axle.
MY QUESTION:
I'm going to add an "H" to the design. I can do it one of two ways.
One, I can put it fairly close to the motor, but the crossover itself will be comparitively long.
Or two, I can put it slightly further downstream, in which case the crossover would only need to be a few inches long because the two pipes are closer together.
Which is better and why?
vazbmw
Reader
7/17/10 6:40 p.m.
I would think the closer to the motor the better for a strong exhaust pulse signal for the engine. My understanding of the concept is that the pressure pulses share both exhausts. This allow two things to happen that are the most beneficial: 1. Pressure pulses migrate to the opposite exhaust and create low pressure areas behind themselves, that pulls the pressure wave behind it out of the exhaust increasing the ability of the engine to exhaust spent combustion gases. 2. Spent combustion gases have two routes they could take which increases the volume capacity of the exhaust (but in an h-pipe this is less pronounced
so, with a shorter crossover would it be more pronounced?
vazbmw
Reader
7/17/10 7:01 p.m.
That would be my thought, When I made mine - which is also and H-pipe because and X was too much work at the time - I keep the length of the H as short as possible. I was basing this all on theory, but the sound changed and engine rev'd better in the med range. I also notice that instead of having individual exhaust pulses (when you can see the exhaust on cool mornings) as it had before, both exhaust were blowing out spent gases out of both exhaust tips. Almost as if the engine was exhaling out of both.
I am thinking that my high reving BMW m60 would benefit more from an x pipe, but the added work and difficult fitment kept me from doing it. I will probably make one in the next few months though.
You could also benefit from creating a tuned intake. I did this also along with the H-pipe: http://www.howstuffworks.com/question517.htm
