I have a question concerning the pipe design on touring bikes. Just what exactly is the purpose for the crossover tube on my electraglide exhaust?. It seems to make no sense. Why not just have one pipe dedicated to each cylinder?. Most of the exhaust comes out of the right pipe, at least 80% of it seems to anyway.

I did a little experiment and found suprising results. First of all I have V&H 4" hollow slip-ons (bad azz sound) and when at an idle I held a paper towel at the end of the left pipe and it wanted to suck the paper towel in the tube. Tells me the right pipe is creating a vacuume or a venturi effect of some sort on the left pipe. I hear alot of talk about getting rid of air leaks in the exhaust system but it would seem to me that the crossover tube is nothing more than one big airleak.

I am new to Harleys so please excuse me for the dumb question but it is bugging the chit outta me as to why this design.

Also is the true duals a good pipe?

 

Just a guess on my part but I think it is to create a certain amount of back pressure, maybe for torque, because tthat's what is affected when you change to true duals.

 

What he said. Do most people really notice a drop in torque from going to a true dual setup? Some say yes, some say no.

Kind of like the question: "What's the best seat for xxxx bike?" Everyone will have different opinions.

And I know someone more technically/mechanically inclined will come aboard and provide facts regarding true duals vs. stock setup vs. aftermarket slip-ons vs. whatever. That's okay.

 

Two into one has advantages over true duals, the cross over probably has similar effect.
There are some makers that sell 2 into 1 exhaust with a fake pipe for the left side that still gives the balanced look of duals.

 

http://www.americanrider.com/output.cfm?id=1021987

Read This

Shawn

 

Good information above. Although I have not done extensive exhaust work on my bike, I have added crossovers (H-pipe) to a V8 and you can both hear and feel the difference over true duals.

 

The new design on the 09's where the cross over goes under the bike and in front of the rear tire (the so called 2 into 1 into 2) is showing dyno numbers with just slip ons that is an improvement over the design it replaced. This is according to several tuners I have talked to. It would be interesting to know if MOCO planned it that way as the way I understand it is, it was changed to help address heat issues.

 

From my understanding, the main purpose of the HD pipe (stock) setup is for scavanging. I couldn't tell you the engineering of it, but I believe it's supposed to help primarily to get the bikes to pass EPA specs. The other bikes have a similar process btw, there is typically a hidden crossover type pipe connecting the main exhaust pipes.

Are true duals good? It all depends on who you ask. If you are looking for the best increase for horsepower, then most likely not. 2-1 pipes typically generate the best power increases. True duals can give you more torque sometimes though. Not to mention the look and sound!

 

Yep the crossover pipe is for bottom end torque, go with true duals and you will loose bottom end torque. Got two buddy that I is experiencing that after he went with reinheart true duals. One has gone with a two and one and found out how much power difference there is. The other is stuck on what direction he will go. Mabe trade the bike.

 

Enjoyed the link above very help full