I will stick to the true duals they look and perform good, I have a friend that is rather wealthy, and can play with different parts to see what works best, he has tried them all 2-1, stock with slip-ons and so forth. What is he running, on all three of his HD's? Rineharts after dyno runs and different exhausts the Rineharts did the best on all around performance, did I mention they look good too. There is a former post from TN Heritage about Gerald Rinehart and his exhaust performance if you want to do a search.

 

My Rineharts are on order...they look great, and really clean up the aft right side of the motor IMHO.

Mac

 

I most likely will get the dual headers when I graduate to a bigger engine in a few months or so.

 

Gotta go with TC on this one. I have several friends that have switched over and they are not happy with the loss of power. Yes, they will allow the engine to breath a little better, but your sacrificing power. The dyno results don't lie and both of these guys had a significant drop. For the record one of the motors is really built and the other minor mods (cams, breather, etc... nothing major). I do like the looks of the Rineharts, but spend a little time in the twisty mountain stuff and prefer every bit of grunt, I really hate shifting, lol...

 

Don't compare the various "true duals" to the stock system, but compare them to another high performance system. And forget about the HP stuff; look at the torque figures, especially in the 2000 - 3500 or 4000 rpm range where you spend most of your time.

A well designed 2 into 1 collector system will outperform an equally well designed true dual system. Period. The 2 into 1 has an inherent advantage over the true dual system because it can scavenge exhaust gases from the pipe with the closing/closed exhaust valve. If your cams have overlap (exhaust & intake open at the same time) this scavenging almost completely prevents reversion (spent exhaust gases getting back into the cylinder & mixing with the incoming fuel-air charge).

The true dual is essentially a drag pipe system, and must have some way of preventing exhaust reversion. The Rineharts, and other brands, do this by stepping the pipe from a small diameter, to a larger diameter, and to an even larger diameter. At each step up in pipe diameter the exhaust gases slow in velocity and decrease in pressure. As reversion attempts to happen the lower pressure exhaust gases try to flow back up the pipe toward the cylinder. When they hit the step in the reverse direction they meet a column of gas that is at a higher pressure and are basically stopped. However, the true duals are not as efficient in stopping reversion as is a well designed 2 into 1 system.

I've often wondered why someone doesn't make a 2 into 1 system with a "fake" left side pipe. You bagger-boys would get the looks you want, and also the increased performance of a 2 into 1 system. Or maybe someone has come up with this, but since I ain't a hard core barge pilot I haven't noticed!

 

skippy, you got a way with words, thats why i hang out here!!

 

Skip,

You just answered every question I had about true duals, two into one, and crossover.

Thanks.

Mac

 

Excelant post Skip Keep it up. Thank you for the True Duals tech tips.

 

Tryiny Something?

[IMG]local://upfiles/3705/B49FA3F8BB7A481CA4A6BA0827ADDF96.jpg[/IMG]

 

Over the past few weeks, I have seen some baggers in town with two into one systems. Today, while waiting to pickup my RG, I saw at least 3 EGs with 2-1 systems parked in the bike shop/cafe lot. They don't really look that bad to me.