prochamp:
MiModRacer: Yes your toolbar is getting better all the time. My question is, if I give you Rad Meter info are you going to be able to convert it into a fill in the blank formula or is it going to be only useable as reference paragraph of info ? MMR
I have the rad workbook if you need it.Its Excel formula Have many others also
Well if you have a link-able formula post it. With mine, Nate will have to build a web page. I have the formula but its sort of a story vs a just type in the # and have a page that does the calculations for you.
I'll go ahead & post my stuff now & maybe you can come up with something better.
Here are my notes.
Initially you need the following
A Rad Meter
A Thermometer
A known altitude
All your jetting specs on the carbs
A RAD Meter cannot be used to find the initial jetting. You must field test to find this. The Rad meter is a reference point that you can use to calculate mostly main jet changes as the weather changes. So what you initially have to do is test until you find the magic in your motor on its best pass with just jetting changes. I call this the Perfect Base #. aka ( PB) When you find this write down all the jet info, the temp the Rad # and the altitude. From here you can make some reasonable calculations on jetting changes as the weather changes that day or the next weekend.
Here are some of my gleaned thoughts with my experience playing around with this in the winter at
different altitudes and
temperature. This is regardless of weather the RAD meter itself reads the same as it did on your PB set up
1. A sled loses 1% of its HP for every rise in elevation of 500 ft above (PB). So if this occurs jet down 1%
2. A sled gains 1% of its Hp if temp drops 10 degrees from (PB) So if this occurs jet up 1%
3. This is mostly MJ but if your running into a huge swing in parameters from your (PB) parameters then you might consider other parts of your carb jets like AS or Pilot jet.
BY example.
lets say your PB is found to be a 800 MJ at 106.5 Rad at 20 degrees at 1100 ft above sea level
Base jet is 800
Base Rad is 106.5
Bast temp is 20
Elevation is 1100 ft
Next day out, Rad is reading 102, Temp about same & your at the same location
So here is the formula for new MJ
( Base Jet x New RAD) divided by BASE RAD = new MJ or 766 MJ
This may not be exact but it does give you a decent guess on jetting to find the magic under different air quality conditions.
Note if you find yourself in conditions that are much superior or must inferior to your PB , you may consider more or less weight in the clutch to compensate for more or less available motor HP
Maybe someone has more that they can add to improve or correct anything I've said.
MMR