What is the purpose of joining the exhaust pipes on a dual exhaust system?

on fords it serves the purpose of equealing out the back pressure between the left and right bank on the cylinders.it is not necessary on most gm engines cause the exaust is equealised through the intake manifold.if you are running a stock set up with no major mods,it does very little on pontiac engines.

Unless of course you decide to veer away from a completely stock engine. In which case there generally is no heat crossover in the intake manifold (Edelbrock Performer aluminum intake is an example). The crossover would be beneficial for this purpose. It also helps with resonance in the exhaust system. The downside is that if the "X" is welded in and you need to remove the tranny it will generally require you to cut the "X" out.

I have the Pypes (Performance Years) 2 1/2" x-pipe mandrel bent system in my 69 conv with headers. Can you say mechanical music? I don't know the exhaust flow mechanics but it sounds sooooo nice.

According to Jim Hand (Early Pontiac Hero and all-round Firebird smartguy) the X-pipe greatly decreases back pressure and helps exhaust flow like nothing else can.

let me get this straight, so its better for pontiac and gm engines not to have an x-pipe then? or will it still give a little more low-end torque?

Back pressure on 3" exhaust? How can that be? Pypes is making a killing

The Edelbrock Performer manifold does too have a crossover.

Terry is blowin' smoke up your... X and H pipes help balance the exhaust pulses with any twin bank motor.

I had my exhaust 'custom built' ,and added an H pipe ,not an X (since easier and does about the same thing), they charged $50 for that extra piece......= not much extra cost

Any v8 will have better flow, with a x-over.

While it actually also soften the sound, - it will allways make more power. -regardless backpressure or not with 2.5 inch or 3 inch.

X-over is better than H-pipes. -x-over acts like a little 'turbo' -making vacuum, everytime an exhaust pulse passes the X..-thereby sucking the exhaust out of the other bank. -this cycle is endless, -ofcause it won't make 150 horses extra, but it WILL make more horsepower even than with open headers.

I know someone out there made a squashed x pipe that would work without lowering the convert brace. I'd like to put it in, anyone recall who makes it?

Claus is right, there actually have been studies.

Dave, I think Pypes has the new oval exhaust systems.

Opps - that's RARE that has the oval systems.

After my tax refund comes I'll be getting one of the RARE systems for my convertible.

Same here, I am going w/ the RARE system. I am very please with their LBMs so I will go with their dual X w/transverse muffler and stock tail pipe splitters. Should be a good system and should souond good. Right now my system is a bit louder than I thought it would be. I must be getting old as there was a day when it could never be too loud. LOL

It makes the exhaust more like a 360* system.
2 pipes cross over to opposite sides.

Back in the 70's , Herb Adams designed custom 360* hedders for 70's FB's.
His tests proved they out powered any other standard hedders at all rpm's.

who is "RARE"

Ram Air Restorations

RARE

Thanks, I'm gonna get me one of those...

The X pipe will really change the sound of your exhaust. I have one on my car, I liked the sound at first, now Im not sure if I like the sound better with or without it. It is a unique sound, almost like an indy car.

If the x pipe does actually quiet the exhaust down, it's a good thing I put one on. It scares me every once in a while when I'm just minding my own business driving down the street and car alarms start going off. Of course it always brings a smile when I realise why.

Robert

Ya, mine is a tad on the loud side as well, the wife says she can hear me coming for blocks....

Yeah, my wife can usually hear me coming as well...

To really do it right, I recall RARE mentioning a 90 degree bend X over, (at the time, he showed me a 3" pipe for a drag car - 90 degree bend inlet) which allows the pipes to be properly positioned without having to drop the brace on verts. You want this as close to the front of the car as possible. The oval x over is really the best case for clearance without giving up air flow volume. I don't know if he went ahead a made them for a 2.5 system?

pretty personal information...

LOL

Alrighty then. How about them Saints?

Spread the good news: ponchoshops' wife is NOT deaf!

You mean 68Firebird400?

Mine hasnt heard me last couple years

Awe hell, now two wives may want my head on a platter over this thread!

Pypes did the exhaust on my 67 also. They have pics of my car up on their installation gallery site. http://www.pypesexhaust.com/gallery92.html
Everything I read simply said to clear the exhaust as quickly as possible. Letting each side flow to Two 2 1/2 pipes is a good way to do that.
That along with the RacePro Cross Muffler makes for a nice sound.

Hef