MY CDI comparison results are posted in swap and shop..

GoldenMotor.com

mapbike

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Mar 14, 2010
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http://motorbicycling.com/showthread.php?t=54074&page=7

The first 4 minute of the video is when I was doing the actual speed test, the rest is just cruising around and then back home... should have shut camera off, but had no idea the quality was going to be so bad.

I did a comparison testing of three different CDI units today and made a horrible 12 minute video when I was running the Rocket CDI on my bike, the link above will take you to the thread and a link to the video.

again, video is horrible people.... highest quality setting on youtube makes it sorta bearable (720P HD )

Map
 
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Davezilla

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Yeah, youtube does compress the filesize which effects the video quality, they can also detect a shaky video and smooth it out for you but it also drops some of the quality again. If you can mount the camera to a helmet it'll also smooth out the video because mounted on the bars it'll move with even the smallest bumps in the road. I'm just glad that someone is giving honest and un biased results on these
 

greaser_monkey_87

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So it would seem, based on your results, that the "HD Lightning" CDI performs about the same as the stock CDI. This is good data-based info, as opposed to those who say they can "feel" a difference in power with the HD CDI. Thank you for sharing this. I'm sure it will help many people make a wiser decision with their money. Why spend $70 when you can have the same thing for $15?
 

mapbike

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Mar 14, 2010
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Central Area of Texas
Yeah, youtube does compress the filesize which effects the video quality, they can also detect a shaky video and smooth it out for you but it also drops some of the quality again. If you can mount the camera to a helmet it'll also smooth out the video because mounted on the bars it'll move with even the smallest bumps in the road. I'm just glad that someone is giving honest and un biased results on these
Yeah when just peddling a bike the handlebar camera mount does pretty good but at high speeds it stinks, and the fact that my little Samsung 14 mp camera isn't good at canceling out some of the shake doesn't help any either, I plan to either get a better camera down the road or make me a mount that will work better with what I have.

Map
 

mapbike

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Mar 14, 2010
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Central Area of Texas
So it would seem, based on your results, that the "HD Lightning" CDI performs about the same as the stock CDI. This is good data-based info, as opposed to those who say they can "feel" a difference in power with the HD CDI. Thank you for sharing this. I'm sure it will help many people make a wiser decision with their money. Why spend $70 when you can have the same thing for $15?
I just wanted to do an honest test for my own questions about whether or not my bikes benefit from a high dollar ignition vs the stock kit ignition, as I have said my engines have several mods to them, high compression, jugs ported , pistons ramped to change port timing, carbs well tuned and exhausts the flow freely, that is the reason my bikes easily do top speeds in the mid 40's to close to 50mph and even with all these mods the "custom CDI's added zero performance gains that I can detect and added no increase in top speed over what my bikes will do with the simple and inexpensive stock cdi unit.

Some may be offended by what I have done and said here but that is not my intent, I just want to honestly seperate fluff from facts on things that can cost people money they may not be able to really afford to spend on something they hope to add performance but doesn't, if someone has the extra to spend and wants the extra bling bling from custom made parts I say go for it, but vendors should not be leading people to believe that a part is gonna add power and speed a china girl engine when in reality they have not done any honest comparison testing to prove their claims.

I was very disappointed with the Rocket CDI, it looks like a rigged up mess being its in a pill bottle that looks like you would find in the garbage and then it decreased performance compared to the stock unit it has been advertised to be better than, it does work and on a basically stock engine build it should work just fine and give the engine all it will need to do ithe best it can.

The HD's Lightening CDI looks good, has a nice on and off switch on the cdi box, it showed identical performance to the stock cdi on my bikes, so I have nothing bad to say about it at all, it does a nice job of doing exactly the same thing as the stock unit does but adds a custom built look and a key switch, if someone is willing to pay the extra to have that look and the switch then the HD's Lightening will be what I will always recommend, but dont expect any big power or speed gains because you wont get any in my experience and testing, you get a neat looking black box and a remote ignition coil that looks good and will do anything a stock unit will do and does have a bigger stronger coil that may be better for realy high compression engines in some cases.

Map
.wee.
 

Davezilla

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I got the same results you did with the Rocket CDI unfortunately and I was hoping it would stay strong on top but the power does fade off with it installed. The real reason I wanted that CDI was because I could use a better more reliable coil instead of the tiny integral coil in the stock CDI.
I was going to get the HD lightning setup because so many people claimed it ran better, maybe it does depending on engine setup etc, but really there's no way to make a high performance CDI without having some way to adjust the timing curve to match the engine setup because it may rock on a stock engine but not give any gains or even lose power on a built engine. Jaguar tried to address that problem but made all the curves way too mild for any kind of performance use. Now if someone could make a CDI unit that's as agressive as the stock or the HD lightning with a way to fine tune it to each individual setup that's the one I'd buy... something with a 10 turn precision pot instead of preset jumpers to change the resistance or capacitance would really be nice...
 

mapbike

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Mar 14, 2010
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Central Area of Texas
I got the same results you did with the Rocket CDI unfortunately and I was hoping it would stay strong on top but the power does fade off with it installed. The real reason I wanted that CDI was because I could use a better more reliable coil instead of the tiny integral coil in the stock CDI.
I was going to get the HD lightning setup because so many people claimed it ran better, maybe it does depending on engine setup etc, but really there's no way to make a high performance CDI without having some way to adjust the timing curve to match the engine setup because it may rock on a stock engine but not give any gains or even lose power on a built engine. Jaguar tried to address that problem but made all the curves way too mild for any kind of performance use. Now if someone could make a CDI unit that's as agressive as the stock or the HD lightning with a way to fine tune it to each individual setup that's the one I'd buy... something with a 10 turn precision pot instead of preset jumpers to change the resistance or capacitance would really be nice...

Yeah, Dave I agree, I'm not electronics savy on all this stuff myself but I have talked to some others who are members and more on this forum who do have a lot of knowledge on the stuff and they have also told me that there is no way that any of these preset CDI's can possibly live up to the Hype and Claims being made about them.

No doubt in my testing the HD's Lightening shows to be the best compared to the jag or the Rocket CDI, but as far as performance gains it still does not add anything beyond what the little stock unit does on my engines, it looks good and works good, just doesn't add performance that I have been able to detect over what the stock unit gives, I'll say again that under certain circumstances of extremely high compression, it is possible that having the larger stronger coil is an advantage, but I have no proof of that and I have seen no proof from anyone else on it either, just an assumption that may or may not be valid.

Map
.duh.
 

Davezilla

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I do have some electronics experience and I also have an associates degree in electronics, but I hadn't workid in the electronics industry in over 20 years so I'd need to really read up on stuff to remember exactly what to do if I was to make my own from scratch, but buying one that's easy to modify like the Rocket cdi, I can find out which caps and resistors control the timing advance and swap them out.

The biggest problem with any aftermarket CDI is that you can't change teh timing curve to match your engine and tehy won't perform if they don't match the engine they're on fairly closely. I'm sure tehy do perform on the engines they were designed around, but once we change something about the engine like port timing or duration etc, the timing curve needs to be modified to match the engine's new mods in order to get the most power from the engine without detonation.

As far as using a bigger coil goes, the magneto only puts out a certain amount of energy that can be converted to higher voltage, but as voltage goes up, current goes down, so to really get a hotter spark you'd need an external power supply like a small battery or stronger magneto to create more energy. And so far, like mentioned, even the stock coil is up to the task at the higher compression ratios some of us are running.

Of course, having a separate coil and CDI box can have some advantages for custom builds where the builder wants a really clean looking install or wants to locate the CDI in a better location, and the dual fire version of the HD lightning setup does have an advantage of detonation prevention since running 2 plugs at opposite sides of the combustion chamber burns the fuel quicker, it does mimick higher timing but since the spark doesn't actually happen sooner, there's no further risk of detonation... If you or anyone remembers the Nissan NAPS-Z engines, they were 4 bangers with dual plug hemi heads and their initial timing was set at only 3 degrees BTDC because of this effect of mimicking higher timing by burning the fuel twice as quickly, they were able to reduce emissions by retarding the timing without killing the performance too badly, and advancing the timing to normal settings while still firing both plugs has little effect, but the advantage was less risk of detonation at low rpm where both plugs were firing, and better emissions by retarding the timing back... as for performance tho, they were dawgs... really good bottom end torque but very lacking on the top end, but the engines were also designed to redline at around 5500 rpm.