free website stats program Pro pipe 11hp loss | Harley Davidson Forums

Pro pipe 11hp loss

Brutal FXDX

Active Member
Has anyone lost power from inst a 2-1 V&H propipe?? Ive got a 2009 FLHX here at the shop that i inst a SE 103 stage 4 kit back 9 months ago. Bike made 113hp and 107 ft/lbs with V&H power duals with rinehart slipons tuned with SE super tuner. Today cust brought me a propipe 2-1 to inst in place. After tuning it made 102hp and 93 ft/lbs. I just dont understand why. Anyone??
 
I would have thought better scavenging for more power with the new pipe?
 
My thoughts the same Jack. Ive inst. a number of different 2-1 pipes on everything from stage 1 up with gains in hp and tq. this is the biggest build ive installed a propipe though. Just dont understand the 11 hp loss. Anyone tried the RB racing LSR 2-1. Heard they are very good 2-1.
 
Did you do a baseline run before you changed to the exhaust, or did you assume the engine still had the same HP?
 
There are a lot of factors that can change dyno runs. I've seen the same bike produce different #s with a change in the temp or moisture in the air. While your looking at a large drop from an initial run some time ago, some of the parameters of the dyno may not be the same. I would think that with the 2 onto 1 you should see increased torque and HP.
 
To add along with what HDDon said,, software used on inertia dyno's is not perfect. Be sure that the numbers are "corrected" for the settings of the day during which the pulls are taking place. If they are Not measuring intake temperature, baro pressure & humidity, it could easily explain the differences in numbers. Those numbers should be "corrected"

Most of the Dyno's that are used are not pony brake or true torque arm dyno's which will produce accurate numbers. They are software calculations of the inertia of the spinning drum. Therefore the correction factors really come into play.

Good Luck with your numbers!:)
 
Back
Top