Quote:
Originally Posted by 2LZ
Here ya go...
"Manual transmissions lose 15%. To determine rear whp, multiply the base horsepower by 0.80 if you have an automatic transmission and 0.85 for a manual transmission. Example: 250 hp x 0.80 = 200 rear whp."
So a rear wheel HP on rtkings bike at 22.5 would come in at about 25.8....which is better than spec just by changing a pipe at the time. I'm curious to see how he thinks the breather helped.
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You nailed it, 2LZ. I did a write-up in another link here:
http://chinariders.net/showthread.ph...highlight=dyno
I was using a conservative 10% drivetrain loss instead of 15%. But the fact is that the dyno is rear wheel, and the engine is delivering the advertised horsepower.
About performance... the muffler probably frees up a little (maybe 1 hp?) which is tough to feel. But the throttle response is good with the aftermarket muffler.
With the K&N filter (and this is based on riding around the parking lot near my house), the bike feels like it's breathing better and is more responsive. I don't know how much of that is wishful thinking vs. actual performance. My "test" will be next weekend when I can get in a ride and see if there's any top speed and drivability improvements.
In terms of the part - I want to re-measure the throttle body as this filter (K&N part number RC-1290, 48mm inside diamter) is a little big for the throttle body. I think the cone filter the Grom riders are using (K&N part number R-1100) might work better with its 43mm inside diameter. And whatever filter is being used, having a 10 degree (or so) bend is necessary to clear the airbox (which I sealed off with foil tape for this experiment.)
Bear in mind that in this location, the filter will be exposed to a lot of dirt and moisture. I plan to purchase a Filterwear Pre-Filter for the cone filter to help filter dirt/dust and water. I'm also planning to use some aluminum tubing to extend the filter into the stock airbox (and make some more breathing holes) to see if that makes a difference.
Like I wrote... I love to tinker.
