When I went from mufflers to open pipes I felt the mid range power loss. But they sounded so much better I've just dealt with it. I've been modding and racing Vettes and other cars for years, chasing tenths at the drag strip, so my butt dyno is pretty well tuned. I bought a PCIII tuner from Fuel Moto with a custom tune for my mods but it didn't do much, cut back on decel popping but fuel mileage went way down and power was the same so I took it off to get my mleage back.
This dyno result in the video opened my eyes. I feel that dip from 2500-4000, which is 60-85 mph or so. The lower dyno is the open pipes, then the thumb screw at 45 degrees, then 90 degrees, all compared to S&S mufflers. As you can see, the 90 degree thumbscrew gives back about 15 of the 20 foot lbs lost from open pipes. The video explains reversion in a fashion anyone can understand using the slinky.
Well, for $1.18 at home depot and a few minutes to install the thumb screws where baffles would go, I had little to lose.
I am amazed at the difference, for sure you can feel the 15 rwtq being given back by two silly thumb screws. This is right at highway mph on my bike, and the bike is noticeably snappier and pulls harder when passing at part throttle.
For those with open pipes, I highly recommend this mod. Best $1.18 I've ever spent on mods.
I'm not clear if the custom lollipops do better than the $1 thumb screws, I think you need a dyno to tell the difference. I can tell you that the thumb screws make a very noticeable difference, most notably when on the highway - I used to have to drop a gear to pass folks, but now I've got plenty of roll on power to pass. From 65-80 mph it's a very noticeable difference. Sounds nuts but it feels like a put a high performance cam in (I've done that plenty of times so I know what it feels like). Pretty good result for $1.
06-23-2015 | 09:53 AM
Lollipop for drag pipes myth - Confirmed
