If the idea behind an X or H pipe is to balance the pulses between the left and right bank, how about something different? David Vizard preaches the idea of building a resonator box (expansion chamber) to make the header collectors think they've achieved atmospheric conditions, then you continue the pipes back to mufflers. Mac makes an expansion chamber they call the Pro Chamber. Although the box is not as large as what Vizard recommends, I'm wondering if an approach like this would be better than an X or H pipe for true duals? Please chime in, especially Mustang guys.

 

I agree, and having read a far amount on it by far more intelligent people than myself I see on reason to dispute it.

 

Where can you get one and how much?

 

I think it would be better than an H pipe, but I would think an X pipe pulls the exhaust from each bank with every pulse. This system doesn't look like it could do that. It would just equalize pressure.

 

Maybe a combo of an X leading into a chammber/resonator would work??

That way you could still benefit scavenging and be able to run mufflers without affecting the exhaust pressure wave.

 

Some of the old racers used something similar to that and the old school guys still swear by it. Maybe old tech that still works?

 

In simple terms,it makes the exhaust think is that wherever that box is located is the end of the exhaust, so if you put a box, larger then the one that is pictured above in the exhaust after say 2 feet of pipe, the motor will think that you have headers and 24 inches of pipe extending past the collectors. It's hard to explain in simple terms, but pretty much what it's doing is eliminating any back pressure from the point of the box back to the rest of the exhaust, so the remaining part of the exhaust after the box's restriction is negated.... there's alot of techie terms that explain it alot better, but that sum's it up in a way most people can understand. I think that the reason alot of people aren't doing it anymore is it adds alot of weight, and takes up alot of space, the latter of the 2 being the reason most guys with newer cars don't even try it, there's not alot of room for a box big enough to really work right I think.

 

Very well said.

 

How about this box. vs. a 180 degree header?

 

Not sure about that one.. I only know about the box beacuse of some old school drag racers that I know, and what it did for them back in the day... that and I've read alot of books LOL. I probably have that info in a book somewhere at home.. but it might take me a while to find it, alot of that stuff is still packed up from when I moved about a year ago now.

 

I know that on a Mustang it is quite good as for as flow, I have seen a 99 Gt with bolt on's go 13.1 at 107 w/Prochamber and dumped duals. It is also quieter w/Prochamber over an X or H setup.

 

it also deepens the exaust note and removes tinny and raspy noises. flowmaster did that on there V6 98+ fbody cat back for that very reason.

 

I had a Pro Chamber on my '00 GT and it made excellent power, and sounded very good.

I saw where it was tested with various X's and H's on the market and it out performed them all - on a Mustang..

I think it would make great power, but there's not much room on an F-body for that box - depending on how big it actually needs to be.

 

Lane, I can buy Mac Pro Chambers in various tubing sizes and configurations. After doing countless dual exhausts on F-bodies, do you think you could adapt one to fit? I'd prefer to use a dual 3" in/out. Do you think the box would need to be larger than the Mustang version?

 

Most, if no all Mustang PC's are 2.5", so yes - it's gonna be bigger - maybe/probably too big... It would be interesting to experiment with though.

 

Box would probably have to be 4 by 10 by 12 to really work. That'a not a calculation.. just a size that my old timer drag racers used to use on small blocks.

 

I am guessing that this is almost the same idea as what dirt bikes use for racing with the expansion chamber portion. Looks pretty interesting.

 

Sort of.. but not exactly.... a 2 cycle engine is a differnent deal, as the expansion chamber acts like a vacum to suck gases out when the port is opened by piston movement. Port size and shape with those is ultra critical, along with the size ans shape of the expansion chamber to how and where it makes power... I used to race atv's, and depending on the track, we usually had several pipes that were all differnet that we would try, and usually 2 different motors, one for top end, and one for short tracks with better bottom end... only thign diffenrent was the ports, and the bottom end motor would usually have no flywheel weights, whereas the top end motor would to keep it spun up all the time.

 

the pro-chamber is definitely a proven performer but if it takes us a 4" case for dual 3" won't that have clearance issues?

 

probably no more so than running dual 4" case bullets.

Pro-Chamber is THE exhaust mid pipe to get for a Mustang, but its also $$$ compared to other setups