Exhaust selection is critical for optimal performance. Open drag pipes work reasonably well for peak horsepower numbers on some engines but limit low speed performance on the street and can be nearly impossible to carburet. S&S Cycle has not had good results with baffled drag pipes due to the increase of exhaust gas restriction (back pressure).
Special low restriction Cycle Shack XP baffle is available through most retail suppliers, and will help with tuning in some cases.
Overall, drag pipes are a poor choice for street use. Drag pipes offer nothing to break up the reversion wave pulse. This wave goes down the pipe and then the wave returns back up the pipes. When this wave is in proper time sync to hit the exhaust valve when it is open (pipe length affects the rpm that this happens) it allows the wave to enter the cylinder and when the intake is open during cam overlap it travels across the top of the piston (it is near top of the cylinder at this time) and out the intake valve.
This wave continues out the intake through the carb where the next intake stroke draws it all in again. Each time this wave passes through the carburetor the venturi adds gas and makes the next incoming charge richer creating a flat spot or stumble or worse a blubber at this rpm. The longer the duration cam the worse this situation is. Also larger diameter drag pipes and fishtails seem to make this situation worse.
If you have an existing 2-into-2 system that uses slip-on style mufflers, whether it is an OEM or an aftermarket system, we recommend the new S&S slip-on mufflers. If you don’t already have an exhaust system that accepts the S&S Slip-On mufflers, and you need to buy a complete exhaust system, the RevTech staggered dual, or Python 3 systems work well. S&S Cycle.
S&S knows better.
If you have S&S motor, buy S&S Exhaust & Intake = More Power! since 1958.
Thunderheaders. using them for years
I’ve always like Cycle Shack pipes. Great sound and low end torque. Drag pipes are for guys(and gals) that like to make a lot of noise.
Why would you buy a high performance engine & then pretty much waste a lot of the power you paid for by giving away almost all the low end torgue with wide open drag pipes ? Unless youre going strictly to the drag strip you’d be wasting a ton of money to ride with those pipes on the street…just sayin…
A noisy bike is just a way of screaming “Look at me!”
You’re bang on Sharkey; very uncool too and, as you say over there “better dead than uncool” 😉 !
Cycle Shack slipons hooked to a nice running twin cam….sweet! Especially on a Dyna.
Brocks Performance new 2 into 1 for baggers is VERY functional and sounds great..makes roughly an extra 5 ponies over other 2 into 1s that are currently out there…all the low end torque and all the high end horsepower..pretty unheard of up til now…
Open pipes kill performance,just makes noise.
Lots of options from a lot of great companies
S & S knows best !!!!
Zippers makes a great set of baffles for drag pipes. you get the classic look combined with performance that is very close to a 2 into 1 type set up. Look ’em up, they are 4 perforated spheres attached to a mounting band. If they provide to much back pressure for your tune, you just cut one of the spheres off. They also give a deeper throatier sound, especially on my stroker.