Exhaust/Crossover Question...
#11
Join Date: Dec 2008
Location: Summit, Mississippi
Posts: 1,458
Likes: 0
Received 19 Likes
on
16 Posts
Heaven forbid that I wake-up some rocket scientist that jumps in here with a three page technical post, but the cross-over is suppose to offer better performance through the delivery of a pulse back-n-forth between the cylinders at just the proper moment. Now...that's as far as I will take that and I currently run true duals.
I do know that the length of the pipes and drag-pipes can make a huge difference in power. The worst running pipes I ever had were open drag-pipes with no restriction whatsoever. I also had an early 2-into-1 pipe on a softail that I shortened and had it re-chromed because I thought it was ugly. It absolutely ruined the power curve on the bike.
Pipe design is a science and it's not all just looks. I have killed motors with the wrong pipes. I am going back to the stock cross-over design because my Vance & Hines true duals have a hole burned in the rear header just as it makes the sharp bend and I have the brand new stock cross-over headers out in the shop. I am not ready to pay upwards of $400-$500 for a new set of true duals.
I do know that the length of the pipes and drag-pipes can make a huge difference in power. The worst running pipes I ever had were open drag-pipes with no restriction whatsoever. I also had an early 2-into-1 pipe on a softail that I shortened and had it re-chromed because I thought it was ugly. It absolutely ruined the power curve on the bike.
Pipe design is a science and it's not all just looks. I have killed motors with the wrong pipes. I am going back to the stock cross-over design because my Vance & Hines true duals have a hole burned in the rear header just as it makes the sharp bend and I have the brand new stock cross-over headers out in the shop. I am not ready to pay upwards of $400-$500 for a new set of true duals.
#12
Pipes are what makes a Buell so much more powerful than a Sportster, using essentially the same engine. Erik Buell was able to use far more radical cams and compression ratio and get superior power and torque, using a tuned-length 2-into-1. I reckon my XB12R engine would be great in a Glide! That thing oozes so much torque. We can only speculate what a Buell-tuned big twin would perform like!
Last edited by grbrown; 09-03-2010 at 03:58 AM.
#13
#15
#16
Thanks again all!!!
Wow, what a valueable tool this Forum can be. I'm imagining myself putting out $1000 plus for "true duals" thinking they "look cool" and will be "faster" and being disappointed by worse performance and the wasted money. Funny that my mechanic was evasive when I asked him but he primarily builds "choppers" with short drag pipes so either didn't really know or didn't want to give me bad advise. Now I'll make the decision for him and for me and Blue Belle.
#17
That's a leap of logic too far! True duals will not necessarily give worse performance and be a waste of money, otherwise I wouldn't be using them on my Glide! I have an S&S 107 in my bike and contacted S&S before fitting my TDs. They recommend them as a suitable system and I get slightly better figures on the dyno than they advertise, so they work well for me, just as your system obviously works well on your bike.
Thread
Thread Starter
Forum
Replies
Last Post