As promised, I did some timed runs this morning at 100' and 300' on fairly level asphalt road to measure the difference in performance between the stock cdi with DG holeshot turned off, the stock cdi with the DG holeshot turned on and the new Dyna cdi. As usual, I recorded the time, temp, surface condition, etc...but I won't bore you with those details. Two things to keep in mind as you read on are that my P650 motor is slightly modified and I live/ride at 100' above sea level.

Now lets get to the good stuff. The below times are the avg of 3 timed runs each.

1) Stock CDI with DG Holeshot turned off
100'......3.36 sec.
300'......6.83 sec.
Top Speed at approx. 1/2 mile......56 (not sure why this was so low today???)

2) Stock CDI with DG Holeshot turned on
100'.......3.05 sec.
300'.......6.22 sec.
Top Speed at approx. 1/2 mile...63

3) Dyna CDI
100'.......3.05 sec.
300'.......6.16 sec.
Top Speed at approx. 1/2 mile...64 (But I actually reached 66 MPH last night on a longer stretch of asphalt road).


***Dyna CDI with different DAJ adjustments***
300' with leaner DAJ setting (#2).......6.21
300' with richer DAJ setting (#4)........6.37
NOTE: I did the DAJ setting adjustments at the end of this morning's test runs and the motor started surging a little at 50 or 60 mph...afterwards I reset the DAJ to the middle setting (#3) and it still continued to surge a little. Not sure this is a temporary condition caused by messing with the other DAJ settings (which may have fouled the plugs a little) or if I need to rejet my carbs. You may recall that I had surging problems right after I first installed my DAJs and did other motor mods at the same time...to fix that problem I rejetted DOWN 2 SIZES and it cleared up the surging and it ran faster too...so I'm now considering whether I should try going down 1 more size on the main jets to see if that smooths out the motor and increases the performance.


CONCLUSIONS & OBSERVATIONS:
1) New CDI is about 1/2 quad length faster at 300' as compared to the stock cdi with a DG holeshot module turned on;
2) New CDI is about 7 quad lenths faster at 300' as compared to the stock cdi without DG module;
3) New CDI is 3 mph faster on top-end than stock cdi with the DG module (as measured last night on a longer paved road);
4) The seat of the pants (SOP) feel for new CDI is that it pulls the same as stock cdi with DG holeshot right off the line, but the new cdi pulls a little stronger at midrange and top-end. The times and max top-speed runs above seem to varify this SOP feeling.
5) New CDI pulls harder from 50 mph up to top-speed than stock cdi with DG holeshot, but the above times neither support nor deny this observation because I was usually close to 50 mph or so when I reached the 300' mark.
6) The above improvements are indeed noticeable and well worth the money IMO, but don't expect the new CDI to turn the V-twin into a 2-stroke motor with respect to acceleration.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Thanks Mikey I was hoping The CDI was going to do more. I think I'll go install mine and try it out.

 

Looks to me that the holeshot module is more bang for the buck than the cdi. 1/2 quadlength for an extra 120 bucks . Just not worth it to me. But other benefits would apply. Like running cooler, starting easy. What do you guys think ?

 

Trailride,
To be quite honest, I was hoping for at least 1 or 2 quad lengths improvement at 300' over the DG holeshot. From the results shown above, I obviously didn't see that much improvement at 300', but I still think the new cdi's real advantage over the DG holeshot (and perhaps over the DG3 as well) is the continued acceleration from 50 mph to top-end...and this advantage is not measured in the numbers above.

I should also mention that I am now planning to rejet the carbs to see if I can squeeze a little more acceleration (at 300') out of her...if that doesn't work, then I'll have to settle for the 1/2 quad length improvement at 300' plus 3 mph more top-speed. That may not sound like much improvement, but keep in mind that I finished only 23 seconds behind the overall 1st place finisher at the last local XC race (its a 1 hour race), and this new cdi might have made the difference between 1st place overall or 2nd place overall. I'll post back with my results after I have a chance to rejet the carbs (assuming that rejetting actually improves my performance).

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Did you have to rejet the 650 when you put on the cdi? I got my cdi and was wondering if i have to rejet, dealer told me they didnt make any jets bigger than 148.
thanks

 

Cueball,
I did not rejet when I ran the timed runs posted above. However, I did make adjustments to the DAJs and that only made things worse for me...I think my carbs are a little too rich right now, and I am going to rejet the carbs at least 1 size leaner so that my DAJs will work properly.

I assume that most folks (who don't have the DAJs) that get the new cdi will either not need to rejet or they might need to go up a size on the main jets to richen the mixture.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

It looks like there is some truth to the notion that the cams/heads/cvt is doing alot in the way of restricting top end. I am thinking an offset key and the DG3 might be a cheap way to get cdi results, that is up to whatever MPH that you hit 7000 RPM or so. If the DG3 can pull the old Holeshot by 2 or 3 lengths without the offset key, than adding a 4 or 6 degree key would be the ticket.

Thanks for the info Mikey.

 

633... I agree... with the cams that came in my FST 750 kit, I can easily reach 70 mph in a very short distance... the power really comes on from 30 - 60 mph... I do think that a CDI on my quad would help alot, as the stock CDI retards the timing at the top so much, but I'm still pulling strong to 8000 rpm, & then slowly creep to 8450 rpm... I'm betting that with out the stock timing retard & the FST cams... that will be the most radical combination...