My official testing of several different aftermarket CDIs

Discussion in 'Lighting and Electrical' started by Venice Motor Bikes, Mar 17, 2015.

  1. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    I got really sick of all the BS about who's CDI is best.... So I've been testing several different aftermarket CDIs (head to head) for highest spark voltage & total advance degrees at full throttle.

    There's a lot more testing to be done but my first results are posted on my VMB/facebook page.

    You can click here & see what I have so far. :)

    https://www.facebook.com/VeniceMotorBikes
     
  2. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    This is my home made testing bench... I'm using a coil voltage tester for the CDIs along with a timing light & a fixed degree wheel bolted to the crank to check the spark advance.

    I'm also using a digital voltage tester on several different magnetos.



    image-838428865.jpg

    Below is the largest spark I was able to make... (It came from one particular stock chinese CDI)... It is a whopping 20 full turns!!



    image-143721470.jpg
     
    #2 Venice Motor Bikes, Mar 17, 2015
    Last edited: Mar 17, 2015
  3. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    Here's some of the different aftermarket CDIs that I tested with the results...

    *edit*>>> The numbers posted are the total advance degrees @ 3000 RPM, & the 'number of turns' is the total outward turns on the coil voltage tester.

    All the CDIs that I tested (even the stock Chinese black boxes) have a advance curve of roughly 25-30 degrees.

    Most of the stock Chinese boxes maxed out around 5-10 turns, (but one particular Chinese box maxed out at a whopping 20 turns)!!!

    My 12v timing light was having a bit of trouble reading the 6v sparks at low RPMs, but I was able to see quick flashes of where the timing curves started.

    image-3758718735.jpg



    image-3150630639.jpg



    image-4289475941.jpg



    image-386973151.jpg
    Gas Bike just re-named this the 'Super Rocket' CDI


    image-504095877.jpg
    Gas Bike just re-named this the 'Thunder' CDI.
     
    #3 Venice Motor Bikes, Mar 17, 2015
    Last edited: Mar 20, 2015
  4. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    From my testing, the two GasBike CDIs have the exact same spark power as the HD Lightning, (& also the same retarded timing at 10 degrees BTDC).
    These would work best for a really 'hot' running (high revving) engine with a large expansion chamber pipe... (the 'Super Rocket' is a killer deal)!! (^)

    The Screaming Roo has the same spark power as the first three, but has the same spark advance as a stock Chinese CDI (20 degrees BTDC).
    This would be the best choice for a moderately modified street engine.

    The Jaguar CDI has the weakest spark (but still way stronger than most stock CDIs), & the timing is in between the others at 15 degrees.
    This is a good choice if you want to change the timing curves for use on different engines.
     
    #4 Venice Motor Bikes, Mar 17, 2015
    Last edited: Mar 17, 2015
  5. bluegoatwoods

    bluegoatwoods New Member

    Joined:
    Jul 29, 2012
    Messages:
    1,577
    Likes Received:
    0
    Why thank you, VMB.

    It's good of you to investigate, document and share your findings. It could be useful.
     
  6. cannonball2

    cannonball2 Active Member

    Joined:
    Oct 28, 2010
    Messages:
    3,472
    Likes Received:
    0
    Yes, thanks for getting into something that there is little hard info on! My question is are these values ultimate advance starting from a lower degree base point or is this a fixed value?, if variable where does the curve begin?
     
  7. YesImLDS

    YesImLDS Member

    Joined:
    Jun 29, 2013
    Messages:
    951
    Likes Received:
    0
    Interesting finds! So there is an advantage of these CDI's over a stock unit and it's not all snake oil?
     
  8. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,294
    Likes Received:
    11
    Norm,
    Are you planning some actual road testing in addition to the bench? Timed/speed trials over a specific distance? It's okay to know voltages and advance curves but I'd be interested in seeing real world results along with them.

    Same engine, same bike, same rider, same fuel, tire inflation, etc. Same engine temperature as well as the same weather conditions. Humidity and temperature will play into performance as you well know.

    Tom
     
  9. YesImLDS

    YesImLDS Member

    Joined:
    Jun 29, 2013
    Messages:
    951
    Likes Received:
    0
    Might be worth while to just set up a bench test using the same speedometer on the rear wheel so you don't have other things tainting the results like humidity, temperature, and wind fluctuations
     
  10. Davezilla

    Davezilla New Member

    Joined:
    Mar 15, 2014
    Messages:
    2,708
    Likes Received:
    0
    Still no substitute for real world road testing... there's one important factor missing from bench testing.... engine load. It needs to be able to perform under load in equal conditions by making each run at a specific distance then check the speed or time it takes to get from point a to point b then the test needs to be done going this distance then on the return so you record both directions then average the results to compensate for variables of unlevel road, wind, etc... the temperature isn't a huge factor and wont change a whole lot between runs enough to make a difference... unless a cold front is on its way... humidity can also remain the same long enough to run several tests.
    several units can be pres installed on a single bracket and swappdd out either by switches to select which unit will be active or unplugging one andnplugging in the next so all the runs can be done in a very short timeframe like under an hour to test 5 or 6 units on a 1/2 mile to 1 mile out and back run.
    the quickest way to switch which unit is active would be by wiring them all to a common plug and using either a selector rotary switch or a switch on each unit and turn off everyone except the one intended for each run, then its just a flip of the switch and the next cdi is active and all others are inactive. A row of toggle switches or a single rotary selector would make switching units take just a matter of seconds, and with a rotary selector you could switch from onento the next without even shutting off the engine.
     
  11. frank66

    frank66 New Member

    Joined:
    Jan 15, 2015
    Messages:
    207
    Likes Received:
    0
  12. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    Yes, there will be more bench testing & some road testing. :)
     
  13. roadrash

    roadrash New Member

    Joined:
    Feb 11, 2015
    Messages:
    21
    Likes Received:
    0
    brnotI have tried a few different cdi's an wasted a lot of $. The last one was recommended by a friend.was the supercharged cdi. Well it would not run my bike it just back fired.so i tried it on my other 2.same results. So i tried my friends an it would drop at 7k an the bike tested on was cr machines top motor so i no what works an don't far as cdi's. finally i tried the lightning and to my relief it worked excellent an the lightning did exactly as advertised.i have 2 other bikes an bought one for them an they perform very well also.personally i would recommend the lightning to anyone.brnot
     
  14. FFV8

    FFV8 New Member

    Joined:
    Oct 29, 2013
    Messages:
    552
    Likes Received:
    0
    What crankshaft RPM are you testing at?
     
  15. roadrash

    roadrash New Member

    Joined:
    Feb 11, 2015
    Messages:
    21
    Likes Received:
    0
    My daily roll is a easy 9300. This motor will let u no how good your components are because of the pm range it has.
     
  16. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    I've been a member of this (& other) forums for many years, & over the years, we've seen many shifty vendors posting here using fake names to give fake testimonials slandering other vendors products just to sell more of their own parts!

    So Roadrash, you'll have to forgive me when I say that I'm highly suspicious of a newbee member who's only been here 1 month & his only 7 posts on this entire forum are praising CR Machine & HD Lightning (who are known shifty business partners) & slandering their competitions products.

    I have nothing to gain, & I firmly stand behind my test results of these other CDIs being equal to the HDL.
    I'll be doing even more detailed testing (including actual riding tests) & posting the results (good or bad) here.
     
    #16 Venice Motor Bikes, Mar 19, 2015
    Last edited: Mar 19, 2015
  17. allen standley

    Joined:
    Oct 22, 2011
    Messages:
    700
    Likes Received:
    4
    Thanks Much! VMB
     
  18. MotorBicycleRacing

    MotorBicycleRacing Active Member

    Joined:
    Jul 28, 2010
    Messages:
    5,595
    Likes Received:
    11
    Fred is a stand up guy that runs a straight business.
    Fred really has nothing to do with HD Lightning except that he sells them.
    Calling CR Machine shifty is out of line.
     
  19. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,149
    Likes Received:
    3
    Really Neil?? You're a pretty good detective yourself when it comes to these kinds of things...

    The 'newbee' doesn't seem at all suspicious to you??
     
  20. YesImLDS

    YesImLDS Member

    Joined:
    Jun 29, 2013
    Messages:
    951
    Likes Received:
    0
    I think Fred can get a little full of himself at times, but I believe he sells a good product that he makes himself. I haven't had any problems with Huffy Davidson either, but like Fred I think they can be full of themselves. It's pride, but when it comes to there products as long as they do what they say they do I won't complain. It's when people make carbon copies of others products and sell them as there own when it's crossing the line. Talking down someone else's products is just something that has sadly became the norm when it comes to advertising. Look around it's everywhere.

    You might not think you've done it, but you have yourself on your facebook page when talking about the fred head in comparison to your new head

     
    #20 YesImLDS, Mar 19, 2015
    Last edited: Mar 19, 2015

Share This Page