Before I order the Dyna CDI I have one question that seems to get danced around in every previous post I have read.

Will the Dyna CDI give as much or more extreme low end power as the module or not???
I know it reallly helps mid and top but I am mainly concerned with dead stop and hitting WOT power.

 

I don't have one but in order to do that it would have to advance your timing at idle or before your stall kicked in.
its all about the timing. so all you have to do is match your stall (rpms before your bikes moves)and what rpm the timing advances on your cdi and bingo. if it (bike) moves after the cdi advance kicks in yes! (more power)

 

schl48a: I have ordered a dynatek cdi, but I really don't know what it does. In other words, I don't understand timing. I have used a timing light and timing marks a long time ago, getting a car to run, but I really didn't know what I was adjusting. Do you have a short definition of timing? I hope I'm not the only guy on the forum who doesn't know this. My background is in engineering also, but not mechanical engineering.

 

Let me give this one a shot.

First of all, with my stock CDI and no mods on my Prairie 700 other than a winch and my big a$$, if it hit it WOT from a stop, the bike would go 3-4 feet then smoothly pull the front end up. It would go over past the balancing point if I didn't let off of it.

With the new CDI, if I hit it WOT from a dead stop, it brings the front end off of the ground within the first 6" or so. It comes up a lot faster too. I have never had a module, but I can tell you from first-hand experience that the CDI adds a tremendous amount of power to the bike right off the line from a dead stop.

I have to paint a mental picture to describe ignition timing. In the perfect world with fuels that ignite and burn instantly, there would be no need for advanced ignition timing. When the piston went down in the cylinder and sucked in the fuel/air mixture, then went back up to the top and compressed it, the spark plug would fire when the piston reached the top of the cylinder and the resulting explosion would force the piston back down, creating power.

Since in the real world the fuel/air mixture doesn't ignite instantly, you have to fire the spark plug while the piston is still traveling up. You have to try to picture this hapening at very high speeds. As the piston almost reaches the top of the cylinder, the plug fires. By the time the mixtures ignites and starts making pressure, the piston has topped out and is on its way back down. There is an optimum time for this to occur depending on RPM. If you spark too early, you are making pressure too soon and fighting against the piston that is trying to get to the top. If you spark too late, your piston is already on its way down in the cylinder before you start making any pressure.

What Dynatek has done is change when this spark occurs for any given RPM. In this case, they have made a CDI that makes this spark occur a little sooner for a given RPM than what the stock one did. In this application, it adds more power to the bike all the way through the RPM range. They determined what the optimum timing setting should be for any given RPM, and designed a CDI that makes that spark happen at the optimum time each time.

That is it kinda in simple terms. Hope that helps.

 

FYI: I currently have a DG holeshot module, and I ordered the new Dyna CDI on 3/22. As soon as it arrives (in a few weeks [img]i/expressions/face-icon-small-sad.gif[/img] )...I plan to do timed tests at 100' and 300' and top speed runs to compare the performance of the module to the cdi. I will report back here with my results afterwards...come on UPS man!

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

 

the timing is when your spark fires your spark plug. thats what before top dead center and
after top dead center refer to. btdc means your spark fires in your cyl, before the piston comes
up to the top of the cyl and atdc means after your piston is past top dead center when it fires.
starts out with your crank,where your crank trigger (pick up) is getting a signal every rotation of your
crank,next your rod hooks to your crank and your piston hooks to your rod. this is 1/2 of what you need to
fire your motor.next you have a cam and valves which are also hooked into your crank with a chain,
thats were timing chain comes into play.your cam has a gear which hooks to the chain and when the
cam turns the valves open and close. now the object is to get the valves to open and close at a percise time
so advanceing your time is gonna let your spark at a certain degree. so on the 650 i don't know for sure but lets say it advances to 28 degree when you take off and idles at 5 degrees before you'll start out at 5 and advance to 28 and go no higher on your advance and i think at 5000 rpm they go back with the timing . so we know that your timeing fires your spark at 28 degrees and no more and starts to go back (retard) with your timing.
the cdi everyone is talking about advances to 33 degrees before tdc. which lets your motor run better with power and heat etc, number2 the cdi doesn't retard( let your timing go backwards) period. so after 5000 rpms
tour timing is still making power where before it (by retarding) was actually taking power away.
hope this helps. any questions ask away.

 

Gentlemen,

Let me tell you this much. I have seen both of these in action and I would tell you that if you don't have a CDI on order you are missing the boat! You will be getting beat by 650 Prairies and hating life! Order it today and thank me when you get it. We tested the CDI in a bone stock 650 against a 700 prairie with a hole shot module and HMF exhaust. I will tell you that at the end of 300' it wasn't even close! The 650 won. If I hadn't have rode it and seen it, I wouldn't have believed it. Let me tell you, I BELIEVE!!!! I tried to wipe the smile off my face, but it wouldn't come off. When you call Dyna tell them that FD Racing told me I wouldn't be dissappointed! It's a must have [img]i/expressions/face-icon-small-happy.gif[/img]

Racinaki
FD Racing

 

Racinaki;;;;;; Thats the best report Ive heard yet, Seriously, I want to hear real time like this , not nessessarly dyno charts. Ive always said I would give some up on the hole shot to have more mid to high end, reason being my 650 will come right over on me with the dg and it sounds like this unit has it all for the time being. Thanks again. Jim @jhmach

 

schl48a & 2prairie700s: Excellent info...thanks. Just one more question: degrees indicates what? OK, 2 questions: is the # of degrees always btdc?

 

Prairiedust,
On other posts this has been discussed. With the OEM cdi it has be fooled to advance the timing by way of the module to get more timing at an earlier rpm. The OEM system uses the pink wire with speed input to determine amount of timing advance to be used at the proper speed,( timing ramp ). The old system takes time to determine from the input of the module or the pink wire then it is supposed to set the timing for that rpm, this takes a minimum of 3 rotations to get an average. Normally this would be all right except the module pushes 28* it is to abrupt of a timing advance from 1100 rpm. Timing has to be increased at a set ramp to fully utilize volumetric efficiency. When the module is used it enhances the bottom end but with a slap stick boost that is to drastic for initial take off. Sure it helps a lot but it does not get full potential that a gradual timing ramp can produce. The old system has to go through its programing which takes time. The new Dyna cdi doesn't have to think all it needs is the input from the crank very simple then delivers the predetermined timing for the set rpm. Doesn't have to rethink itself like the old system. I haven't used the old cdi for almost 2 years now and will never go back. We have been asking for a cdi for a long time and no module will ever compare. There are other benefits to a complete plug and play system bottom end is just part of it. It has been discussed by Kawi engineers that 32* is optimum on pump gas where the new cdi attains 33* from 4000 rpm to 9500 roughly, very simple and the best of all it works. I haven't seen any timing curve from the other cdi makers like Procom for instance I wonder what they are trying to use. Dyna has been forth coming with their specs a straight up approach to let people now what is happening. I hope this helps