04-21-2009, 03:56 PM #1
Need Someone to take me to PROP School....
I did a search and reviewed all the threads that I can find on props. When I read the threads - its just as important for me to know HOW and WHY something works as opposed to just knowing WHAT works.
So here are my questions:
1. When someone refers to a 14/19R or 15/20 prop - what do the 14 or 15, 19 or 20, and the R refer to??
2. By increasing or decreasing either number, what actually happens - specifically, "take the 14 to 15 and this will increase/decrease pitch, resulting in faster/slower out of the hole but higher/lower top end speed...etc".....
3. Hitting the rev limiter means the prop is spinning too fast and the motor still has power left - right?? So you would want to increase/decrease which number to drop the RPM's back down to below 8200 ('04 RXP).
Thanks. If there is a thread already that addresses this and you have seen it, you can direct me there. I have been trying to find it but can't see to get my hands on it.
04-21-2009, 06:33 PM #2
On a 14/19R, The 14 denotes the pitch of the leading edge in degrees and the same for the 19 for the trailing edge. The "R" just means that the prop was double checked in a pitch block before leaving the factory. That's it. Adjusting the leading edge will effect holeshot and trailing edge for top speed but the 2 effect each other and both will change rpm's. That's why racers guard their secrets to prop pitching. It's a little science and a little black magic. At least, that's the description I was given for carb. jetting on sportbikes and it seems to apply here to. Generally, you want to add or increase the pitch on the last 1" of prop (trailing edge) to lower rpm's and increase speed. The idea is to put the rpm's dead in the power band at peak horsepower.
04-21-2009, 10:57 PM #3
04-24-2009, 08:54 AM #4
I had read that thread before I posted....was hoping for some more detail if at all possible...."change this and this will happen..." etc.
Might be too much to ask as these are "trade secrets"..just looking for the general idea. I am upgrading my SC and may be bumping my revlimiter when I am done, so I am most likely going to have to do some prop work. Just want to have an idea BEFORE I start messing with it.
04-24-2009, 11:10 AM #5
04-24-2009, 12:49 PM #6
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