Shotgun,
I have found at least for me that going light on the front end works very well as the quad will ramp up very fast from 4000 - 6300 rpm with cdi. This is optimum power range if the quad can stay around 6500 rpm so cdi will keep total timeing with a spring that is weak on 2 sides but stiffer in the middle this allows for the belt to go higher up the sheave. Something else that helps as well is different cam timeing where the cam produces more power on the top end this helps dramatically to push the belt up the machined sheave. As the cdi loses power because of timeing the cam will over take the timeing some what helping to push the belt up higher especially if you have a machined front sheave. I have tried different cuts on the rear helix but found installing a smaller bronze bearing in the rear allows the belt to go lower on the back hence higher on the front. With the same rpm, different cam timeing, motor has the power to push the belt higher up the front sheaves producing more speed. With a different ignition power and rpm is not a problem. The cam is timed to give more bottom end grunt mostly for a 700 lb machine change the timeing this moves the power band a little higher this is common racing knowledge.

All in all the most I have been able to gain with stock cdi in speed is around 15 mph on top end the cdi and cam are the limiting factor. If the cdi where changed then I am very certain the cam will also have to be changed as it makes power to 6500 then drops off just like the cdi. With modified ignition, a little Nos I can cross a 150 foot mud pit with 3 foot deep mud in just over 7 seconds. This motor is designed for bottom end torque the next motor that is close is the Ducati and they thrive on torque. Power band on the Ducati has a wide range from 5000 - 10,200 rpm. I will be in Sweden this September and I hope to talk with Ducati reps I have been in touch with the R& D department there for some time now. I hope to bring an ignition back with me to test if all things work out.

 

OK...ALLTOY's... I'll have to admit it, I was pretty intimidated about meeting / mud racing you... but after posting those ( slow )...LOL... times I'm not quite so nervous... my last 150 foot sticky clay pit times were right at 7 seconds... so bring it on man...LOL... maybe we could find a northern Minnesota, or Wisconsin club thats holding a mud bog, & meet there ???...just giving ya grief.. have a good one ...WAM

 

I agree, let all get together and race somewhere. This would settle a lot of things.

The winner gets the others bikes!

Prairie Wars!![img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img]

 

LOL! I told you he was a Dr Frankenstein just looking to harvest your ATV! [img]i/expressions/face-icon-small-wink.gif[/img]

7 seconds. You can take him.... [img]i/expressions/face-icon-small-confused.gif[/img] LOL.

Shotgun,

Thanks for posting that info regarding the 46G weights. That helps to understand how low we can go.


15mph is a pretty good gain on a stock machine (CDI/Cam). Heck, we are getting excited over 1-2mph gains with subtle changes.

 

DWB; lol

You don't have to worry about my bike, it's not fast, made for pulling not speed.

There isn't a bike on here that couldn't beat me.[img]i/expressions/face-icon-small-wink.gif[/img]

Now back to racing when can we get started.[img]i/expressions/face-icon-small-happy.gif[/img]

Also I was at 46 grams, I lighten my clutch enough that I'm back to the stock weight.

 

ya, well my motors done medium well after all those tests ... "what was there supposed to be fluid in that radiator"...LOL... it's amazining the abuse these machines will take... ye ol 2.8 liter V-6 would have been well done, carved & served in pieces for sure in that heat ... deadbeatle ...LOL ... WAM