'H' crossover

[americanhorses]

I'm putting on a new exhaust this weekend. Is there a 'sweet spot' for the crossover.

 

[rjlougee]

I haven't done this myself, but it was explained to me as such:
1. Get the exhaust in and ready to go.
2. Spray some cheap paint on the exhaust pipes and run it for a while.
3. After a bit, the paint will bubble up/peel off at some point.
4. That point is where the H pipe should go.

Something about how the gas pulses join together, which I really didn't get at the time. Hopefully, one of the smart guys will get on here and explain the "why" to it.
Joe

 

[77BroncoWag]

all the mustang guys say a X crossover is way better than a H type!

 

[Explore74]

crossover, no matter how it is done does only one thing, it helps the engine to scavenge the exhaust gasses from the combustion chamber. I have an H on my bronc. Honestly, I can't even tell it is there, but I'm sure a dyno could. There is not enough room to do an X. Unless you are going to be doing Q-mile pulls, the only benefit I have figured, is that it does sound cool with FM's on it(40's). Oh, by the way, I also wrapped my headers to assist in this scavenging effect. I was actually hoping that it would improve fuel milage, but after about 10k miles(30k on engine) I havn't noticed a darn thing. I suppose efi or an egg under the accelerator pedal are the only two ways to achieve that.

 

[67ster]

Having done many dual exhaust systems in my early days , I can tell you one thing about crossovers . They do make a sweet sound on a dual system . Many early V/8 systems used a crossover on the headpipes , we used to eliminate them if the guy wanted more noise but for a great sounding system , we left them in . On an EB there is not much room to put a H or X in , I'm sure it can be done but I don't think there is that much benefit .

 

[lars]

Way back when I had a stock 302 with cast iron exhaust manifolds, I installed a James Duff dual exhaust. It had a nasty resonance at about 2200 rpm that was almost unbearable (uninsulated EB with hard top). I did what Joe described- sprayed some paint on the pipe downstream of the manifolds, then drove around. I can't justify the procedure, but it turned out that the place to be was just upstream of the transfer case crossmember. No room there, so the exhaust guy installed the h-pipe behind the t-case. BIG difference. The 2200 rpm drone disappeared and (in my opinion) it sounded much better.

Just my experience...

 

[TexasBronco]

While on the topic of sound. Are Flowmaster 50's a mellower tone then 40's? I have a 351C and most mustangs run 50's....right?

 

[77BroncoWag]

I think the higher the # the quieter

 

[Hnrys69]

[quote author=TexasBronco link=board=5;threadid=14744;start=0#111378 date=1046490851]
While on the topic of sound. Are Flowmaster 50's a mellower tone then 40's? I have a 351C and most mustangs run 50's....right?

[/quote]

Think so. I do know higher the num the quieter it will be...

 

[funkypunkmonkey]

You are kinda right about the pulses, basicly you can tune your exhaust so that the pulses are set up so that they help draw exhaust out of the engine, or ad resistance or what ever you want to do. If I remember right the basic idea is that one side is going through at a time and you can use this so that the wave from one side of the engine will effect the other and visa versa. This type of tunning is pretty difficult and you usually will not see a difference on something like a four wheeler, but if you were racing and every little tiny bit helps then it is worth the time and energy. I recommended that you run some kind of cross over, it will help with harmonics (sound and vibration). There is enough room to run an X on a bronco I measured, but it would be way back and probably really wouldnt do much, I would go with an H. So pretty much I am just saying what everyone else had to say.

 

[CheepJeep]

[quote author=HNRYS69 link=board=5;threadid=14744;start=0#111405 date=1046497990]
[quote author=TexasBronco link=board=5;threadid=14744;start=0#111378 date=1046490851]
While on the topic of sound. Are Flowmaster 50's a mellower tone then 40's? I have a 351C and most mustangs run 50's....right?

[/quote]

Think so. I do know higher the num the quieter it will be...
[/quote]

Well, actually most mustangs run the 40 series flows. The 50 series is an alternative to the 40. It is a little deeper, but a whole lot quieter. If you love the sound of flows on a mustang, you are thinking of the 40 series. It is important to remember that there are also two types of 40 series: "the original flow" and the "delta flows." The originals are much louder inside and out, however they create much more resonance inside. The Deltas have the same tone but are a whole lot quieter. Personally I think nothing sounds better than the Original 40 series, but would not do them unless you like LOUD

 

[broncoswede61]

My H pipe is about 10" behind the T-case...definitly helped to mellow the ressonance on the Flows and the performance resonse was a bit better.

 

[americanhorses]

I got em' on and WOW!!! what a difference. Noticable increase in HP. I've been running a single system that has been trail fixed and leaked. I had gotten used to it.
On the way to work this morn. I burnt the wires to my tailights. I didn't check my clearance well.

 

[jeev]

[quote author=77BroncoWag link=board=5;threadid=14744;start=0#111310 date=1046474793]
all the mustang guys say a X crossover is way better than a H type!
[/quote]

I'm a mustnag guy (02 GT totally tricked out) and this is what I found before I did my exhaust on the stang. H will give better low end torq due to more back pressure - X will give high end HP but you will loose low end torq (sp?). So on an EB I would think you would much rather have low end since unlike a stang you are not going to be hitting above 3-4k RPM or over about 65mph.

 

[brian72]

[quote author=americanhorses link=board=5;threadid=14744;start=0#111841 date=1046705068]
I got em' on and WOW!!! what a difference. Noticable increase in HP. [/quote]

What did you get? What about the sound, a difference there?

 

[americanhorses]

[quote author=brian72 link=board=5;threadid=14744;start=0#111876 date=1046720405]
[quote author=americanhorses link=board=5;threadid=14744;start=0#111841 date=1046705068]
I got em' on and WOW!!! what a difference. Noticable increase in HP. [/quote]

What did you get? What about the sound, a difference there?

[/quote]

2-1/4" to behind the rear tires w/IMCO-t904 mufflers. Defently better sound. Could'nt beat the price 'Ipsolo' gave the setup to me. Hardly used, wern't even dirty

 

[NicksTrix]

if you are interested in a true x pipe set up, go check out this site:
http://www.drgas.com/
this is where all the teams get their pieces from.
imop for a 4wd, if you want a cross over, get an h set up.

 

[JaxLax]

Gonna use an H on my new exhaust (going in over Spring Break). Gonna put on my Shorty Headers, high-flow cats, gonna be 2.5" true duals with Delta Flow Flowmaster 40 Series, 3" tips. Gonna go out 45 degrees behind the wheels.... ;D Can't wait to spray my exhaust in the ricers faces :

 

[BwoncoHowie]

[quote author=Lars link=board=5;threadid=14744;start=0#msg111364 date=1046489009]
Way back when I had a stock 302 with cast iron exhaust manifolds, I installed a James Duff dual exhaust. It had a nasty resonance at about 2200 rpm that was almost unbearable (uninsulated EB with hard top). I did what Joe described- sprayed some paint on the pipe downstream of the manifolds, then drove around. I can't justify the procedure, but it turned out that the place to be was just upstream of the transfer case crossmember. No room there, so the exhaust guy installed the h-pipe behind the t-case. BIG difference. The 2200 rpm drone disappeared and (in my opinion) it sounded much better.

Just my experience...
[/quote]

That is where mine is, just in front of the x-fer case before the pipes go through the skid plate.

BH

 

[americanhorses]

Just for anyone surfi'n these posts I noticed a drop of 10-15drg. in temp. and at least another mpg. and this is a stock manifold, just new pipes(split) and mufflers.