How long can an H pipe be?

[lyrikz]

Im doing my exhaust, and adding an h pipe. Where is the ideal place to put it, and how long is to long. running one from frame rail to frame rail is that to long??

Any advice or tips would be appreciated...

[71 super]

Take a piece of crayon or some type of cheap paint and make a line from header to roughly 3 feet down pipe (just a thin line) the H ideally will go in the location where the crayon/ paint stops burning off. This is the optimum location but you might be limited by cross members etc. This from flowmaster and the set up of the 4-2-1 collectors they used to sell.

[lyrikz]

Originally Posted by 71 super

Take a piece of crayon or some type of cheap paint and make a line from header to roughly 3 feet down pipe (just a thin line) the H ideally will go in the location where the crayon/ paint stops burning off. This is the optimum location but you might be limited by cross members etc. This from flowmaster and the set up of the 4-2-1 collectors they used to sell.

Cool, do you know how long the h pipe can be??? Is there a distance you shouldnt go over. Is from one frame rail to the other to long?

[OrangeCrush1970]

the length of the 'h pipe' should not matter...this is just a pressure equalizer b/w the two cylindar banks. You'll notice a little more low end torque and a smoother idle... just looses the cam chop if you have any to begin with.

Good luck! Show is some pics when you get done.

I forgot to add that if you're buying an H Pipe kit, then it'll come in a standard length that you can cut to fit on your application. I think the one that I got was long enough to go from frame rail to frame rail...i had to trim off a bit

[dznucks]

mine was from frame rail to frame rail, basically.
it kind of tucked up in the bottom channel underneath the bell housing crossmember.

i am not a big fan of the h pipe. i am about to redo my exhaust and do an x-pipe.

[lyrikz]

Originally Posted by dznucks

mine was from frame rail to frame rail, basically.
it kind of tucked up in the bottom channel underneath the bell housing crossmember.

i am not a big fan of the h pipe. i am about to redo my exhaust and do an x-pipe.

I want to do an X pipe, but i dont know if i will have the room. ahha... The truck is a stepside and i want the exhaust to exit under the step. I need to fit 2 mufflers and an X pipe in between the headers and the trailing arm crossmember is going to be a TIIITE fit.

[lyrikz]

Originally Posted by OrangeCrush1970

the length of the 'h pipe' should not matter...this is just a pressure equalizer b/w the two cylindar banks. You'll notice a little more low end torque and a smoother idle... just looses the cam chop if you have any to begin with.

Good luck! Show is some pics when you get done.

I forgot to add that if you're buying an H Pipe kit, then it'll come in a standard length that you can cut to fit on your application. I think the one that I got was long enough to go from frame rail to frame rail...i had to trim off a bit

I kinda of like that lopey idle. thats why i went with the cam i went with. ahaha... hmmm...

[VanceH]

Would love to see some pics of the h pipe set up!!

vance

[gcburdic]

Hey lyrikz....

I just installed mine this weekend....here's a pic....

Hope this helps....

[lyrikz]

Originally Posted by gcburdic

Hey lyrikz....

I just installed mine this weekend....here's a pic....

Hope this helps....

Cool, gives me a good idea that i ran mine wrong.. I put holes in my trailing arm cross memeber and was running the exhaust through there.. But as i see yours theres also the auto trans crossmember i need to run around also. ahaha.....

[VanceH]

Ok so here is a dumb questions whats the purpose of the h-pipe??

[lyrikz]

Originally Posted by VanceH

Ok so here is a dumb questions whats the purpose of the h-pipe??

H pipe equalizes pressures from the exhaust. It does a buncha other things... It increases HP and torque a bit. Smooths out idle and allows for a better exhaust note.... blah blah blah.

[gcburdic]

Originally Posted by lyrikz

Cool, gives me a good idea that i ran mine wrong.. I put holes in my trailing arm cross memeber and was running the exhaust through there.. But as i see yours theres also the auto trans crossmember i need to run around also. ahaha.....

I can't remember where I saw this, but if you have a lowered truck, some folks usually run them throught the trans x-member....not sure about the trailing arm x-member (I think you go up over that)....I hope someone else can help with that....My truck is lowered 2.5" (spindle) in front and 4" coil springs in the back....From the looks of it on the ground I THINK I'll be okay....guess I'll have to see!!!!

[Orange]

gcburdic - what does that sound like in cab (is it too loud - "reverberating" and what not?)

DLB

[PanelDeland]

Orange,G really,really wants to answer your question.He will as soon as he finishes his wiring.I saw the truck and it's very very close.He should have it up and running in a couple of weeks if not sooner.He has a great place to work on it and a lift,he just has it all about 75 or so miles from home,so he only gets the weekends he has a "kitchen pass" to work on it.

[gcburdic]

Originally Posted by Orange

gcburdic - what does that sound like in cab (is it too loud - "reverberating" and what not?)
DLB

Hey orange.....Like panel said....I haven't started it yet, but intend to in a couple weeks....ohhhh it so close....i plan on video-ing it...I'll let you know....I expect it to be loud...

[gcburdic]

Hey lyrikz,

check out how this exhaust is run....no H pipe, but he did run it through the trailing arm x-member....

http://cgi.ebay.com/ebaymotors/Chevr...spagenameZWDVW

[71 super]

With the h pipe you can go through the trailing arm x member but you might have to give up the ideal location for h pipe. I ran 3.5 through trail x member with no issues and h was up and out of site. I would show pics but truck has been gone for nearly 10 years. The idea using the flex couplers at the headers helps out alot. Using wire clothes hangers to map out things will also help, much like carpentry measure twice cut once. The h definitely smooths things out and changes the sound, friend has 341 or something in mustang with x pipe and the thing sounds like a circle track car crisp and throttle is very snappy, this improved with the x pipe and no other changes, if you have the room and you should go x.

[Pyrotechnic]

Originally Posted by OrangeCrush1970

just looses the cam chop if you have any to begin with.

This doesn't really add up. All an H pipe does is connect both sides of an exhaust system so the each side of the motor see's more exhaust capacity. Generally, the tone will mellow out slightly in term of high pitched crackle, because each side of the engine is seeing both muffler rather than one.

A choppy idle is a function of cam design and engine tuning. If a cam has a choppy idle by design, it's going to lope no matter what exhaust you run.

[OrangeCrush1970]

Originally Posted by Pyrotechnic

This doesn't really add up. All an H pipe does is connect both sides of an exhaust system so the each side of the motor see's more exhaust capacity. Generally, the tone will mellow out slightly in term of high pitched crackle, because each side of the engine is seeing both muffler rather than one.

A choppy idle is a function of cam design and engine tuning. If a cam has a choppy idle by design, it's going to lope no matter what exhaust you run.

I run a mild cam. I should have clarified that...no matter, I lost what little chop / loop I had w/ the H-pipe so I ditched it.

[Pyrotechnic]

The best explanation I can come up with is that it's a tuning thing. By adding the H pipe you increased exhaust capacity. With no H pipe, the mixture and airflow may have been perfect to get a little lope, but once you added it, that changed the mixture and airflow.

[jimfulco]

Seems to me the shorter the crossover, the smoother the sound at low rpm. My old Suburban has a crossover as long as its engine is wide, and it sounds almost like plain non-connected dual exhaust at and just off idle. A 5.0 Mustang has a much shorter crossover, and it sounds much smoother, almost like a car with an X-pipe.

[70rs/ss]

An H-pipe is a way to equalize and cancel out exhaust pulses, the X pipe a bit more efficient at this as the rt and lf bank actually cross each other and it will create a scavenging effect that helps pull the exhuast out of the exhaust valves and again equalizes the lf and rt bank of the motor as the odd fire lf to rt can cause one bank to create more pressure than the other, and in theory these both help with that. There may be a bit of muffling of the lope or chop, but I have a crossover on my Camaro and it is still pretty rowdy. I'd say the closer to the collectors you can get it the better, as the exhaust pulses are at their strongest there, but anywhere down from that, that you can find room for would be OK as well. X all the way unless you can fit it, then h is better than two seperate pipes. If you run a 3/4 length header, you can route the exhaust between the floor and trans crossmember and then through the trailing arm X member as well to keep it up tight. It might me possible to run the X or H above the driveshaft (between shaft and floor) then come dowm to go through the trailing are X member?? I believe my H pipe is bent up in the center (think boomerang) to get up over the DS and it allows the pipes to stay level out of the headers and therefore a straight shot to the back. Less bends and curves is better if possible.