Here's an x-pipe set up on my 50AD pick-up. http://www.flickr.com/photos/26014986@N07/2719916874/in/set-72157606265799089/ I will have to rotate the mufflers to clear the propshaft but other than that I can lay the front crossmember on the deck with no clearance issues. The running boards are parallel to the ground at 1/2" at full drop. My only gripe is as Buzznut said, is you loose the lopey idle and it's almost too smooth!
Even though they were around earlier, you probably seen X-pipes when the rest of John Q public did.....back in the early-mid 1980's when the 'weird' sounding NASCARS started heading way north of 200MPH and, subsequently, started becoming airborn with alarming regularity. You can be rest ***urred that the X-pipe is not a gimmic. Its the real deal and if the NASCAR boys are using it you can bet your *** its worth something. There's nothing stuck on any serious race car (except the paint and decals) that is there simply because its cool looking.....everything has a purpose. They aren't magic bullets but X-pipes are proven to provide gains worthwhile of the time/money needed for the install. They are, however, not traditional and would not sound or look right on a "period" correct build. -Bigchief.
For a really low car, would the X pipe have the same positive power effect with oval lead pipes? Where is a good site to learn the theory behind the aplication?
I am going to get one of those plastic "turbo things" that fit on the top of the carburetor, a scientific study says that they are good for 25 hp and 6 mpg, and as a bonus they actually IMPROVE global warming.... Sorry, I tend to agree that Hs and Xs help with power/torque, but certainly not enough to be considered "necessary" on a hot rod or custom.... Even though I agree with this particular ***ertion about the benifits of crossover pipes, you might gather from the tenor of my statement that I tend to look at "studies" with a certain skepticism, and you would be right in that ***umption.. None the less, if making power is the top consideration then for sure an X is in order. It is all about making choices...
Necessary? Sheeesh...I didn't realize we were talking necessity here. Damn...better scratch the stainless bed bolts off the list and forget the flames...no need. LOL..all kidding aside, I have two reasons: 1) the tone that I get at around 60 mph KILLS my eardrums 2) I LIKE going fast and having that extra oomph is always a plus. Also, not mentioned, since the engine is now running more efficiently, you get slightly better mileage as well. cornfield: read through the past posts here...there's plenty of theory mentioned...
X pipe= awesome. h-pipe- awesome, but not as much so. drue duals=awesome, minus power, mo bettah sound.
I had an exhaust system on my '36 (blown flatty) that sounded ratty, way too much rap for my taste. Added an H-pipe to smooth out the sound, and it was a huuuge improvement.