Kissofdeath and I tested the prototype Dyna CDI against the stock one on our 2002 650s. We both have modded exhausts and twin air and dimaond G snorkle. He has a 700 belt. I have a 650 belt. I have a 2003 airfilter. He has 25" ATR's. I have 26" mudrunners (heavier tires). I also have a huge storage box (wind drag). We both have the original Diamond G Holeshot modules. The cdi makes the take off a little stronger. We were able to wheelie a little better. We ran these tests back to back, same rider, same exact road, same starting point.

KOD
Stock CDI = 67mph
Dyna CDI = 69mph, but faster acceleration from 0mph all the way to the top. Less fan running. Faster idle. KOD says he got about 140 RPM higher at the top speed.

Nyroc
Stock CDI = 64mph
Dyna CDI = 66mph also noticed faster acceleration from 0mph all the way to the top. Less fan running. Faster idle.

We didn't do timed tests. We were really just out for a nice ride, but then we decided to switch the CDI's and see how well it worked. I wasn't sure how well it was working until we did this test. We switced back and forth a few times so we really got a good idea of how much better the engine runs.

KOD's 650 is faster than mine. I though that the CDI would make up the difference between the two Prairie. The difference was not that big when I had the CDI. But when he had it he really left me. We didn't really race since we were trying to get an idea of what our own prairie was doing with the CDI. I had bigger tires and the stock drive spring. He had a performance spring so my 650 didn't keep up with his.

KOD's 650 fan runs a lot more than the other two 650's that were there that day. With the CDI, his fan ran less (it seemes more like the amount thatmine ran without the cdi). With the CDI, my fan almost didn't have to come on. The better it cools, the more protection I will have the next time I get in serious mud.

I do not know why some people say they got 5mph faster with the CDI. I don't think 2 more degrees will make 3mph difference, because we have 6 to 8 degrees over stock at this RPM and it only gave us 2mph. This CDI is not the production one. It is 2 degrees less advanced. I will not move my pickup to get 2 more degrees until I hear more about the kickback (read further).

This CDI does not have as much advance (31 degrees) as the real one that people are buying but I think if the real CDI was like this one, it woud definitely be worth the money. This one has the rev limiter set for 10000 rpm. I think the production one will be 9200.

Drawback: Full power reverse. I backed up fast on grnbomb's driveway and had to hit my brakes. Sorry for the skidmarks, Grnbomb. It is not out of control in reverse. I just noticed that I could go very fast backwards.
Drawback #2: Kickback. The increased timing made the engine stop during cranking a couple of times. It did not do it every time, it was about 1 in 5 starts. It wasnt bad. It still started. It won't hurt anything, IMO. I hear that the production CDI does this. But, SgtRock has put many many miles on his prairie with this prototype and has not had any problems resulting from the kickback. I do not suggest using an offset key with the CDI do to this reason.

 

Good write up, I was going to make my own post but will just reply to yours. First of all nyroc and grnbomb are first class guys. I would ride with these guys anytime. Here is what I posted in the other forums.

I met up with Paul Weese aka nyroc, Dustin aka grnbomb from the forums and a couple of other guys for a 23 mile ride today. Great guys to ride with. Paul has the test CDI that sgtrock had in his P650. I borrowed it and ran it in my 02 P650 down a long paved "level, not down hill" country road. I just put the new P700 belt on but changed my primary spring to the Dalton Blue to really get a feel for it on the trail. With stock CDI I could hit 67mph at 7900rpm, with the test CDI I hit 69mph at 8040rpm. I also payed attention to a certain point and reached that point at a higher mph with the test CDI. Im not 100% sure of that gain but I recall it being about 5mph faster at that "check" point.

I was not that thrilled with the dalton blue again. I was really hoping I would get closer to 8500 rpm. I have hit 8430 before and Im pretty sure it was with the Dalton Plain/white but that was going down hill also. The P/W will go back in for sure and when "my" CDI comes in I will have to retest it and the P/W spring on the same road as today.

So, in a nutshell I gained 2 mph on top end, got to topend much quicker, CDI will function with a module hooked up and the dalton Blue primary still sucks to me.

Tim

 

My dang camera didn't take a video and sound clip of your exhaust. Sorry.

I did get Grnbomb's muffler and mine posted on the website. I forgot what kind of muffler grnbomb has, was it an hmf?

 

It was an HMF. I hate that the video didnt come through. Come back tomorrow and redo it ROTFLMAO. [img]i/expressions/face-icon-small-happy.gif[/img]

 

how loud is the hmf compared to you fellas moded cans? i've only heard that they are loud! the rincon i ride with is obnocious loud with and HMF and no q-core.........cant even run his q-core because it'll ruin the pipe........his sparky tones it down some but i think it's still to loud.........being a single it has a funny tone anyway

l8r
cart

 

Could one of you guys comment on what these fella's might be experiencing:
dyna cdi makes motor kickback when startingwondering if this might have something to do with running too low an octane?

 

Cartman, its hard to discribe the exhaust tone without having a base to start with. I guess I could discribe it like this, nyrocs mod "six 3/8" holes drilled" is 100% louder than stock, my pipe mod "eight 1/2" holes is 50% louder than nyrocs, the HMF is another 50% louder than mine is. That probably doesnt help but gives you some idea.

Fireman650, I only had the test CDI on my P650 for two starts, both times it started right up. Only thing I did notice that I havent mentioned before was it idles approx 100rpms higher than the stock CDI. Seems like nyroc mentioned the starter kicking back on him but dont hold me to that. Im sure he will input today sometime.

 

This "kickin back" doesn't sound like a good thing...........

 

Seems like it would hard on the starter but thats about it. Maybewe should ask Scott from Dyantek about it. Mine should be here tomorrow.

 

I always run 93 or better octane in all my bikes. It's not from shi**y gas, unfortunately.