My official testing of several different aftermarket CDIs

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

  1. lazylightning

    lazylightning New Member

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    Venice Bikes wrote: 'I just did several hours of testing all the CDIs in my race bike by blasting it a couple of miles on each one... I'm choosing the Gas Bike 'Super Charge' CDI for the race on Saturday. Many of them were very close in performance, but this one was just a hair faster & ran a few degrees cooler.'

    Venice also posted that the timing at top rpm is more retarded than the Jaguar CDI is. I have two thoughts on that:

    1. He didn't make use of the adjustability of the Jaguar CDI because he talked of it like it was set and not adjustable. (It doesn't arrive with the most retarded timing.)
    2. More retarded lets the engine wind out farther (more speed/rpm) but at the expense of less acceleration and less grunt going up hills. The curves on the Jaguar CDI are all centered around what normal performance motorcycle CDIs have, not too advanced or retarded. Just right for good acceleration and good speed. Unfortunately Venice picked the CDI that gave the fastest speed at the expense of the best acceleration. But at least he admitted he is a rookie racer. Jaguar himself is not a rookie and definitely knows more on the subject than anyone I've come across and all his competitor CDI makers.

    Timing differences of 5 degrees makes little noticeable difference. Let's assume the difference is 5% of 2hp which is .1hp. Who in the world can feel the difference of .1 hp?
    Over the last year or so the Jaguar competitors have made their timing curves more retarded to be in competition with the Jaguar Performance CDI, and some even more retarded. Looking at all of them I still think the Jaguar is the best because of the quality components used which guarantees reliability, the most correct timing curve which is also adjustable, the documentation (no one else posts the graph of their CDIs ignition timing from idle to 10,000 RPM), and the customer support. The Jaguar CDI is made to be compatible with high output coils like those from a Honda CR from any CR motocross bikes so you can get the best spark using it. So you can just buy the Jaguar Performance CDI by itself and order a coil from E-Bay or somewhere else. Also it is the only one that automatically adjusts timing depending on the temperature. It's slightly more retarded in the summer and slightly more advanced in the winter.
     
  2. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Jaguar!!! It's so good to see you here using a different name! :)

    Fortunately for me, I'm a very good racer & engine tuner... (as I've proven with many years of actually racing these bikes).

    Unfortunately for you, your product wasn't as good as the competitions, (if it was, I'd be using it) :(
     
    #62 Venice Motor Bikes, Jul 16, 2016
    Last edited: Jul 16, 2016
  3. lazylightning

    lazylightning New Member

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    Sorry guy, it's not him. Just one of his fans. I guess there will always be some competition amoungst racers and producers though and you can angle someone's product for whatever reasons. At least try the different settings on his CDI though. If you really want to compare CDI's. The settings really make a huge difference, especially for a performance engine. I left the lower rpm jumpers off for more advanced timing at lower speeds and all of the high rpm jumpers on. It runs really well at all rpm's. With my new porting, passage expansion, high compression and torque pipe, it won't even run well on a stock CDI. The Jaguar CDI was the first and in my opinion is still the best. I wouldn't mind trying the other CDI's you mentioned for the sake of knowing first hand. The new Jaguar CDI's have 5 jumpers/micro-switchs now. It's great to be able to tune it with a choice of different settings. Guarantees and customer service are a great plus as well. I guess I just don't like the idea of dumping a faithful friend that has always come through. And to be honest, I really don't believe you found something better.


    xct2
     
  4. exokinetic

    exokinetic New Member

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    BAHHHHHhahahahahHAHAhHAhaHAhHAHAHAHAHha!!!!11!!!!!111!!!!!11


    Wow.


    "But at least he admitted he is a rookie racer. Jaguar himself is not a rookie and definitely knows more on the subject than anyone I've come across and all his competitor CDI makers."

    You know what I remember?

    You, JAGUAR, built an engine for JN Motors to race at the SMBR Race at Grange.

    I was there, and that is what the guys at JM told me.

    So, then they raced...

    And not only did they not win (surprising right? I thought Jaguar knew more on the subject than ANYONE...)

    But it was even more surprising who they lost too...

    I distinctly recall that a very good racer by the name of Sander won the day.

    I also helped Sander work on his engine that weekend.

    So I remember exactly what he had going on:

    66cc China Girl Engine

    - Stock CNS/ NT type Carb

    - Stock Cast Intake

    - Stock Cylinder (mild porting)

    - Stock Head

    - Stock Piston

    - Stock Crank (no truing/ balancing)

    - Stock Exhaust (end cap removed)

    - Stock CDI

    ......and somehow with all this STOCK equipment, his bike did not just beat the Jaguar powered bike, piloted by JN Motors, it left them in the dust.


    And, by the way;

    Venice Motors Bikes may have 'said' he is just a rookie.

    He is being modest.

    He has been participating, SUPPORTING, and racing in the SMBR Racing series, for MANY years.

    The only Motorized Bicycle racing series I know of that races on actual tracks, 3 times a year, EVERY YEAR, for the last 6 years and counting.

    He is not Rookie.

    In fact he builds some of the strongest China Girl engines currently in the SMBR Paddock.

    So go ahead and keep 'talking' Jaguar.

    And for reals, do you seriously think you are going to win over ANYONE when you just come in here to bash people that decided a different CDI than YOURS is what works best for THEM?

    You have to accept that not everyone is going to look at things the same way you do.



    And to spread a little more information as to the CDI advance curve.


    You correctly state that "advanced" timing (relatively) will yield better low end torque, and acceleration.

    And, "retarded" timing (relatively) will yield better HIGH RPM performance.

    But you then seem to believe that you can only have one or the other.


    If your timing curve starts at a certain 'initial' advance, and can only ADD timing from there... then this is true.


    You can decide to start with a lower 'initial' advance. Or you can decide to have the 'curve' add LESS timing as it advances through the curve.

    Either way, you have to sacrifice at the bottom to gain at the top.

    These curves look like this, more or less:

    [​IMG]


    But you CAN have your cake, and eat it too!


    If you have a curve that STARTS with HIGH advance. Then, it advances the timing VERY slightly as the RPM's rise, UNTIL the curve reaches the Torque PEAK RPM.

    AT THIS TORQUE PEAK RPM, the CDI curve then begins to start "retarding" the timing, and it continues to take timing OUT (further "retarding") as the RPM's climb to you current engines Red Line.

    This kind of CDI curve would look like this, more or less:


    [​IMG]


    If this kind of curve interests you, then I have a discovery to share.

    A Yamaha PW80 CDI (MUST BE PRE-2003) will work as a DIRECT replacement for our China Girl Engine.

    Yamaha OEM Part Number: 21W-85540-20-00

    -You must also use an external coil:

    [​IMG]


    If anyone wants to use this CDI, and has any question about how to wire it up to work with the China Girl, PM or email me (see signature).
     
  5. lazylightning

    lazylightning New Member

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    Hi! Like I said, I'm just a fan of Jaguar. I guess JN Motors was probably to blame for having a bad driver that day. Races are funny though, things can happen, luck, skill, chance, Divine Intervention.
    The Yamaha CDI you are offering sounds interesting too. I'm interested in any avenues.
    So what about this testing of the Jaguar CDI without using the different jumper positions? That's kind of lame to mis-represent Jaguar's CDI's performance by not utilizing it's functions. Maybe Venice just didn't know about the jumper positions in the Jaguar CDI?
     
  6. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    That was awesome!! Thanks! (^)


    It's kinda funny... I never once bashed the Jag CDI or even gave it a bad score!
    All I did was give a honest test & evaluation of it (& he got all butt hurt)!

    This goes right back to what I said earlier in this thread... Every vendor likes to get on here & bash the competitions CDI but will never offer any kind of hard proof that theirs indeed has the best performance!
    (this is another perfect example of that) :rolleyes:
     
    #66 Venice Motor Bikes, Jul 16, 2016
    Last edited: Jul 16, 2016
  7. lazylightning

    lazylightning New Member

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    But Sir, I think that his and definitely my only discontent was in that you had made no mention of or even comparison of the multi-settings regime capability of the Jaguar CDI in your CDI testing. This in itself is something of a misrepresentation of the product, which could be mis-construed as bashing it. Why would someone bash a product? Like you said, perhaps it's vendors or agents of vendors trying to position a product as being better than another one. Which automatically raises some concerns as to why the Jaguar CDI had been compared in the testing in a way that excluded it's multi-settings functionality. This goes without mentioning the comparison of different things like the guarantee or customer service that may or may not be available with other products. Actually, I am personally interested to see the real dyno results of using different CDI's and at different port timing tunes. Even if someone discovers something that is somehow better, I am sure that Jaguar as the first great friend to motorized bicyclists will surely imprve his product. From the other side, where is the multi-functional timing setteings in the competitors products?
    Well hey, we all love to ride these things. It's an addiction that's hard to shake. We could all just stop the war of words, you guys could be friends with Jaguar and everybody could enjoy some peace and good vibes. r.ly.
     
  8. lazylightning

    lazylightning New Member

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    Hi again, as it turns out, Jaguar did not build an engine for JN Motors. He was supposed to, but they never sent him a 66cc. They only have 48cc engines in Ecquador. JN Motors built that engine themselves and it may just have been stock. He sent them a pipe which they did not use and a CDI, which they used. That was the only thing that Jaguar had to do with that engine. It's common that different rumours lead to disinformation on the grapevine. Maybe you guys will make up and be friends? It's not so prductive to bash each other and all......we.
     
  9. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Jaguar.... Just so you know, I did test all the different settings on your CDI & it tested well, but the others still provided better slightly performance; so I continued down the path & focused my efforts towards testing the two best performers.

    You should take this opportunity to 'rise to the occasion' & concentrate your time & effort towards making a new product that is truly better than the others & then let the new product speak for itself... (because the cream always rises to the top). ;)

    I give you credit for what you have accomplished & I will be more than happy to test your next CDI against the others & report back here with the results. :)
     
    #69 Venice Motor Bikes, Jul 17, 2016
    Last edited: Jul 17, 2016
  10. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    The reader is left hanging. Was there a Jag build engine or not?
     
  11. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Let's keep my thread on track here... This thread is about CDI systems (not engines).
     
  12. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Point taken.

    MB Racing results are about 90-95% rider.

    For the record we no longer sell CDI's.
     
  13. exokinetic

    exokinetic New Member

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    So how is it again you know all this information as 'fact', when you are 'supposedly' not Jaguar...?

    If you wanted to be CONSTRUCTIVE...

    You could have asked Venice what jumper position he had the Jaguar CDI in when he did the testing.

    You could have also asked why Venice decided to test the Jaguar CDI in the jumper position he did the testing in.

    You could probably also have asked if he would be interested in testing the Jaguar CDI with ALL potential jumper combinations, and add that information to the first post of the thread, so that everyone that reads this thread would have that much more information with witch to make an informed purchase.

    THAT would have sounded like someone that was just interesting in getting the most information.


    INSTEAD, you impugned his testing methods, his results, and his level of competency.

    And then you directly promoted your product.


    If you think ANYONE is buying this story that you are not Jaguar, you are delusional.


    Guess what, honesty is ALWAYS the best policy.
     
  14. salorr33cc

    salorr33cc Member

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    to Venice from Jaguar

    from Jaguar via a friend:

    Venice I wasn't hurt and I haven't bashed anyone, just filled in the missing information of the topic. But every time I do that all kinds of people come out of the woodwork to criticize me and put me down before getting the facts straight.

    Exo, your understanding of a typical 2 stroke timing curve is not quite right. You should visit my site to read up on the subject and look at the timing curve graphs. I think you are referring to an older type of CDI of a different design.

    I didn’t build the racer for JNMotors. I was in Ecuador at the time and I only had a 48cc engine. The 66cc cylinder they used won't fit on the cases of a 48cc. For me to of built an engine for them I would of had to build, adjust, and tested it in Ecuador. But I couldn't of because there are no 66cc engines in Ecuador. The distributor only stocks 48cc. I sent them a torque pipe which they didn't use and a CDI which they did use. Other than that I had no input about the engine other than giving recommendations for port durations which I don't think they followed. I don't know why JNM said that was my motor.

    Any way the biggest advantages to CDIs for these engines are in this order: reliability, spark strength, and having the timing curve match the needs of the engine (which is why mine is adjustable for all engines both stock and modified). Power differences are very minor.

    The reason a stock CDI can be OK for racing on a closed track is that most of the track is curves so the engine is always accelerating or slowing down between curves and only gets into top RPM once a lap on the straight. The stock CDI timing is more advanced (less retarded) and so lends to better acceleration out of corners. Unfortunately that also contributes to higher engine temps and more stress on the connecting rod bearings. For track racers the most advantage from an aftermarket CDI is reliability and increased spark strength.

    As with design aspects of a 2 stroke engine the user should always strive for a balance between extremes.
     
  15. exokinetic

    exokinetic New Member

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    I have read everything on your site, multiple times.

    I have also read most of what Gordan Jennings has written, as well as books by Graham Bell.

    I have researched SAE papers written by the engineers at Honda, Suzuki, Yamaha, and Kawasaki.

    I have also found a forum where the Aprilia factory engine builder for their MotoGP team in the late 80's and 90's when they were heavily developing the 2 stroke engine was answering questions.


    What exactly is not quite right about this 'understanding' of 'typical' two stroke timing curve:

    1. A two stroke engine favors high initial advance.

    (Even the image you attached shows the RM250 CDI is already at 15 degrees advance @1800 RPM's)

    2. A two stroke will generally favor a slight increase in advance as the RPM's rise towards the Torque Peak RPM.

    (Again, the image you attached shows the RM250 CDI continues to add advance as RPM's rise, in fact hitting about 22-23 degrees @3500 RPM's)

    3. A two stroke will favor a CDI Curve that RETARDS timing after the Torque Peak RPM.

    (Again, the image you attached shows the RM250 CDI does in fact RETARD timing, starting @3500 RPM's -witch I can reasonably assume IS the Torque Peak RPM of an RM250- It continues this retarded curve until it is only adding 3 degrees of advance @10,000 RPM's -witch I can reasonably assume is the Red Line RPM of an RM250-)



    This is because of two dynamic effects.

    1. The position (in degrees, or in mm's before or after TDC) the piston is in when the spark fires determines where the 'heat of combustion' is going to go.

    -A. If the timing is sufficiently advanced, the entire combustion event will happen INSIDE the cylinder, and the CYLINDER will absorb all of this heat. This will create a scenario where the CYLINDER receives more of the 'heat of combustion' than the expansion chamber.

    Because the expansion chamber is 'relatively' cooler in this scenario, and gas travels SLOWER when temperatures are LOWER, an ADVANCED timing curve is preferable at lower RPM's.

    At lower RPM's, the gas travelling SLOWER through the expansion chamber, LOWERS the tuning frequency of the expansion chamber, witch means you get 'on the pipe' earlier. I.E. Low-End Torque.


    -B If the timing is sufficiently retarded, the entire combustion even will NOT be completed INSIDE the CYLINDER. SOME PORTION of the combustion process will continue burning INTO the expansion chamber. Thus, a scenario is created where the EXPANSION CHAMBER receives more the 'heat of combustion' than the cylinder.

    Because the expansion chamber is 'relatively' hotter in this scenario, and gas travels FASTER when temperatures are HIGHER, a RETARDED timing curve is preferable at higher RPM's.

    At higher RPM's, the gas travelling FASTER through the expansion chamber, RAISES the tuning frequency of the expansion chamber, witch means you 'stay on the pipe' longer. I.E. Top-End Run Out.



    I am completely open to a better understanding of the dynamics going on here, you just have not provided one.



    If you see any flaws in this understanding of the 'typical' two stroke timing curve, please let me know.




    1. Correct, I made an assumption, and I was off as to the number, but you will notice the the curve is indeed RETARDING after the 7k Torque peak as well. Suffice to say, we can agree, a 2 stroke engine would not prefer MORE advance, beyond the torque peak (like the grubee CDI). Obviously, one curve (the RM250 as our current example) does not represent the only 'right' way. The specific RPM that the CDI begins Retarding will be determined by the manufacturer based on MANY variable. But that does not change the dynamic I described; optimal results will be achieved with a timing curve that begins to 'retard' at some point in the mid-range, and will continue to retard all the way to Red Line.

    - I also did not say it MUST be most advanced at the Torque Peak, I don't know where you got that from.


    2. Did you notice the term 'relatively' ?? OBVIOUSLY the expansion chamber is hot while the engine is running (REGARDLESS of ignition advance) it is about relative heat.


    3. "The speed of the pressure wave from the exhaust pulse varies very little with different temperatures." Absolutely wrong. This represents a complete misunderstanding of the laws of thermodynamics. The gas speed absolutely changes to a significant enough degree to effect the exhaust system tuning frequency. A straight pipe still experiences resonance effects. And obviously a straight pipe will still be effected by the laws of thermodynamics. So OBVIOUSLY you will still experience the effect with a straight pipe.


    4. Yes, gas turbulence during the intake charge effects burn characteristics. But you have not explained HOW retarding the timing effects intake charge turbulence. You have also NOT explained how the changes in intake charge turbulence effect power output. Or why the turbulence change that results from 'retarded' timing is beneficial as RPM's rise.

    -Are you talking about the turbulence of the 'intake charge' or the turbulence of 'combustion'? Your statement makes perfect sense if you are referring to the turbulence of 'combustion'. But the 'intake charge' event has already happened by the time the spark is ignited. And further retarding the timing means the spark event happens even LATER; WELL after the 'intake charge' event has taken place.

    5. Who cares if it was 7 or 3, the point is, it continued to take timing out all the way to Red Line.


    6. No, it was not from an analog CDI, why does that matter? It was a common 4 stroke curve that showed the curve advancing all the way to Red Line, witch demonstrated my point sufficiently.


    AND as a matter of fact, the PW80 CDI I gave you the part number for in the forum thread IS an ANALOG CDI, and as you can see it has multiple steps that are anything but 'gradual'. Yamaha apparently figured out how to create such a curve with an analog CDI. They have since gone to digital (Post-2003), with a Hall Sensor added to the magneto in order to send the trigger signal.

    Our China Girl magneto (obviously) does not have a Hall Sensor, so you must use the Pre-2003 ANALOG Yamaha CDI, if you want it to work with the china girl stock magneto.


    “a little knowledge is a dangerous thing”


    Indeed it is.

    And your 'presentation so far' demonstrates your misunderstanding of thermodynamics, witch thus leads to a misunderstanding of the dynamics involved.

    You have provided no evidence to support your belief that: "The speed of the pressure wave from the exhaust pulse varies very little with different temperatures."

    "I’ve measured around a 33 degree increase in exhaust temps for every 1000 rpm increase."

    This statement is a complete non-sequitur. It does not disprove my assertion (that of thermodynamics) nor does it support your assertion.

    You have also provided no description of the dynamics that demonstrate: "Timing is retarded at high rpm because the rate of combustion is dependent on the turbulence the intake charge experiences which rises with higher rpm."

    You have provided me with NO REASON to change my understanding of the dynamics involved.


    But please provide an explanation of the dynamics involved in this statement: "Timing is retarded at high rpm because the rate of combustion is dependent on the turbulence the intake charge experiences which rises with higher rpm."

    You have not explained HOW the turbulence changes as a result of ignition timing (I.E. Advanced VS. Retarded)

    You have not explained HOW these changes in turbulence effect power output at high and low RPM's.

    If you do not understand these effects yourself, how do you expect me to just 'take your word for it'???
     
  16. exokinetic

    exokinetic New Member

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    And the Pièce De Résistance:



    AND now he wont answer any more of my questions.

    Sad Panda.



    I find it humorous that when he was not able to articulate his beliefs, he resorted to directly insulting me, and then shut down the conversation.
     
  17. exokinetic

    exokinetic New Member

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    And for anyone reading this thread (if they leave this post up)...

    A server administrator at this Forum just banned my local IP address.

    Luckily I am not retarded, so I can mask my IP all day long.

    Seems they did not ban my user account...

    Kinda odd if you ask me.

    I wonder how long this post will stay here.
     
  18. sbest

    sbest Member

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    Exo, one of the best descriptions of the pipe / timing interaction. Wonderful!
    I don't usually get into describing that connection because eyes glaze over long before I get there. You did a great job of describing it.

    Please keep this thread up and keep testing Venice!

    Thanks all, Steve
     
  19. 2door

    2door Moderator
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    You were not banned. We have been watching this thread but so far it hasn't reached a point to warrant intervention.

    I don't understand why you would say you were banned or even imply it. No action has been taken against you by any staff member. Would you explain the above post for us?

    Tom
     
  20. exokinetic

    exokinetic New Member

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    Surely.


    I get a 102 error (ERR_CONNECTION_REFUSED) when I attempt to connect to "motorbicycling.com/" from my home IP address.

    This happened while I was posting yesterday.

    I made two posts while I could connect.

    In the middle of my third post I began to get this error while attempting to preview that post.

    I then checked the home URL and saw that I could not connect to the website at all.


    Here is a screenshot of what I see when I attempt to connect with my home IP address:


    [​IMG]



    -If I spoof my IP address to anything else I can connect just fine. I am making this post from a spoofed IP address.




    The only time I have ever seen this is when I have been IP Banned from the server hosting the website (forum, gaming, wiki, etc.)

    For SOME reason my home IP address went from granted access, to REFUSED access.

    Hence I referred to it as an "IP Ban".

    Witch confused me, as my forum account was unaffected.

    I suppose I could be totally jumping to conclusions here.


    Do you know why my home IP address is being "REFUSED" connection?
     

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