Homemade Cdi box ?

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Joshbus

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Hi. Who out there has made a cdi box to run a standard dirt bike coil ? I got a performance ignition from gasbike , and my other bike loves it. I can get just the coil for under $10. I'd like to make my own cdi setup , thanks for any info,Links , or diagrams , Josh
 
Jaguar's CDI is slightly modified KX200 CDI

http://www.dragonfly75.com/moto/CDI.html

if I recall he puts a 1 uF capacitor in parallel with the 4.7 uF capacitor and changes the 1.5 uF for a polypropylene film type, but don't quote me on that.

it's the only design worth cloning in my opinion. the stock cdi works well but is shy on features and so cheap it doesn't make sense to roll your own, the HD-Lightning is nice, but as far as I can tell it itself is a clone of Jaguar's CDI with some other minor changes, and pretty much everything else on the market is trash.

a few years ago we were mulling over an arduino based CDI that would adjust the timing dynamically depending on load, engine temperature, and RPM but nothing ever came of it. it's been kicking around in the back of my mind ever since though.
 
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j car have a diy cdi kit I got one but need a coil .it has 3 different timing curves. It's $20
 
Jaguar's CDI is slightly modified KX200 CDI

http://www.dragonfly75.com/moto/CDI.html

if I recall he puts a 1 uF capacitor in parallel with the 4.7 uF capacitor and changes the 1.5 uF for a polypropylene film type, but don't quote me on that.

it's the only design worth cloning in my opinion. the stock cdi works well but is shy on features and so cheap it doesn't make sense to roll your own, the HD-Lightning is nice, but as far as I can tell it itself is a clone of Jaguar's CDI with some other minor changes, and pretty much everything else on the market is trash.

a few years ago we were mulling over an arduino based CDI that would adjust the timing dynamically depending on load, engine temperature, and RPM but nothing ever came of it. it's been kicking around in the back of my mind ever since though.
Jaguar's CDI is slightly modified KX200 CDI

http://www.dragonfly75.com/moto/CDI.html

if I recall he puts a 1 uF capacitor in parallel with the 4.7 uF capacitor and changes the 1.5 uF for a polypropylene film type, but don't quote me on that.

it's the only design worth cloning in my opinion. the stock cdi works well but is shy on features and so cheap it doesn't make sense to roll your own, the HD-Lightning is nice, but as far as I can tell it itself is a clone of Jaguar's CDI with some other minor changes, and pretty much everything else on the market is trash.

a few years ago we were mulling over an arduino based CDI that would adjust the timing dynamically depending on load, engine temperature, and RPM but nothing ever came of it. it's been kicking around in the back of my mind ever since though.
Jaguar's CDI is slightly modified KX200 CDI

http://www.dragonfly75.com/moto/CDI.html

if I recall he puts a 1 uF capacitor in parallel with the 4.7 uF capacitor and changes the 1.5 uF for a polypropylene film type, but don't quote me on that.

it's the only design worth cloning in my opinion. the stock cdi works well but is shy on features and so cheap it doesn't make sense to roll your own, the HD-Lightning is nice, but as far as I can tell it itself is a clone of Jaguar's CDI with some other minor changes, and pretty much everything else on the market is trash.

a few years ago we were mulling over an arduino based CDI that would adjust the timing dynamically depending on load, engine temperature, and RPM but nothing ever came of it. it's been kicking around in the back of my mind ever since though.
Thanks. It seems to me that flaws were designed on purpose to meet state law requirements as far as speed regulations go. California emissions pretty much screwed things up with the whole catalytic thing. Definitely the first mod seems to be upgrading the exhaust. I think no matter what improvements made something will always be a bottleneck along the way. The stock cdi does performance well , but I think it limits the r.p.m. potential that all our other mods could achieve. Has anyone ever tried using a pw 50 cdi module? Look at this on eBay http://www.ebay.com/itm/251876380830
 
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I had to ditch the jaguar cdi for a stock one to reach 11500 RPM. there are things you can do with timing other than swap the CDI. I'm running a manic mechanic adjustable magnet to retard the timing by 8 degrees to support my RPM requirements. it's a compromise, with a different CDI I may be able to hit 12 grand or higher. I still don't know how far I can push my oillite bushing.
 
That magnet sounds like a good idea. Could a setting on that improve bottom end torque , while another setting could increase top end ?
 
it could, but not significantly so. any engine, especially a 2 stroke, is a balancing act. everything's gotta be synced up for your intended operating speed. a CDI with a timing curve prevents the need for adjusting timing for operating speed, but there are a hundred other factors involved that can't easily be changed on the fly. variable valve timing and variable valve lift (think honda vtec) means you don't have to change the intake or exhaust duration for an intended operating speed either, but that's not a system that's within reason for a 2 stroke engine. exhaust cutoffs (think lamborghini) marginally prevent the need for adjusting the exhaust system on the fly too, but it's far from a perfect solution and very costly to implement.

not like you could change it while you're moving 40 miles an hour anyway.
 
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