I am announcing this project because I'm inviting forum help.

Starting last month, I have been testing ignition curves. Making Dyno runs. Accumulating Dynobutt data. Reading and researching theory and practical application of performance ignition curves, etc..

I am knowledgeable enough on the subject, at this point, to know that I should ask for any available forum wisdom. If you've got it, please chime in..

All I'm ready to say, at this point, is that it's looking like you all should be saving up to buy the PayRay KLX CDI and its' programming cable - http://www.parayelectro.com/products/CDI/


For those interested, the previous, older thread, testing of the 25° and 35° curves indicated no additional power. This always bothered me as a 10° bump in advance WILL make some kind of difference.

I now know why the old testing was "inconclusive". The bike used for that testing was not able to run 35° effectively, neither is mine (below 8800 RPM, as per Dyno testing). And 40° is/was even worse, with power loss everywhere. Both bikes are fully modded with performance fuel curves of 12.5-12.8:1 AFR - Any engine running such quick burning AFR in the KLX's fast burn combustion chamber will not require as much total advance as the same engine running a leaner AFR.

So, point is - if you are running stock exhaust OR a lean AFR (DJ jets around the 128 or K jets around 138 - near sea level) you would stand to gain from the standard 35° "Aussie" curve. If you are running "best performance" setups, the 35° curve generally over advances and the stock 25° curve under advances the engine.

 

Oh, BTW, I have a problem that needs to be solved, outside of curve theory/application.

Before I dyno a curve, I need a way to assess it. I have been doing 3rd gear WOT runs from 4k to 10k - switching between the base 25° curve and a test curve.

I need a way to determine improvements in power before dyno charting. I am thinking of various ways of "timing" the runs. I am looking into accelerometer apps, etc..

 

Are you using a PaRay module ?

Ride on
Brewster

 

Sounds like a great project for the furthering of info of ignition timing for the community. We KNOW that 25 deg is too little advance. We just dont know how much power and torque is lost.

The simplest and most accurate way would be to:

1.) Find a good place to run with a slight uphill grade. Mark a set distance with two distinct land marks.

2.)Use a Go-pro type camera looking at your instrument cluster and a stopwatch of some sort.

3.)Using a rolling start, in 3rd or 4th, roll to the starting marker at a set RPM/speed, and wick the throttle upon crossing the marker. The camera can capture RPM, speed, and time it takes to cross the finish marker. You can download the video and examine the finish lines frame by frame.

You can then easily compile the data from multiple runs, gears, and timings into a spreadsheet. Additionally, should you aquire such a setup, you could also use it to test MCM vs. non-MCM vs. half MCM-- should you really want to go nuts.

Personally, I wouldnt trust accelerometer apps from a phone, etc. as a standalone-- you need to at least be able to see speed, time, distance, and RPM first, then perhaps you could add accelerometer data to that if you wanted.

 

Outstanding idea Josh.. I have 3 or 4 of those things and I never thought about using them for this.. I tried a timer- without success ..

 

Yes, with the handlebar switch and programming cable as well..

 

Adding more advance early (35°), and then ramping it to 40° does not work (on my bike). Power levels down everywhere compared to stock. I am currently experimenting with the curving in the 4k-10.5k range with 35° by 9k..

 

How about making it equal what Kawie lists for the KLX250R/Australian model-- 10 deg @1300 then 35@ 5000 and just leave it there for the rest of the range. According to their website you shouldnt even have to program it to get this timing, its one of two selectable presets.

You could also try the Mojave timing which puts it at 35deg @3000 instead of 5000. Also, keep in mind the 250r/300r used this ignition timing with stock cam timings-- the MCM may not allow for increased power in the upper range with the 250R ignition timing-- we really cant know for sure until someone presents data in a non-MCM bike.

How many points in the range can you have when you program it?

 

I can program a value at 500 RPM intervals. I assume it interpolates everywhere else.

 

On my bike, the Aussie curve adds as much as 1hp in the upper range.

I'm sorry, gotta keep this easy to understand - Aussie curve is 10° at idle that then straight angles to 35° at 5k and stays there for the remainder of the RPM range.

Both it and the stock curve are very simple and crude mappings.