Rocket racing CDI

Discussion in 'General Questions' started by 570rm47, Jun 22, 2014.

  1. 570rm47

    570rm47 Member

  2. Fabian

    Fabian Well-Known Member

    I would be thrilled to bits if you decided to make your own CDI with more features than the Jaguar CDI.

    I have a wish list if you happen to be good with electronics; design and manufacture.
  3. 570rm47

    570rm47 Member

    Im just a tinkerer but when i get to that level i am aiming *drools profusely while looking exceptionally dumb a moment* for a mosfet bridge rectifier hooked to a dc-dc digital cdi and an injection system two injectors oil and fuel, petrol to my homemade methanol/ethanol with the flick of a switch.

    Im real sorry man wish it could be tommorow but im a bit slow two years of tinkering so far has me at an ok homemade cdi based on the rommel roll your own cdi with my engine running on my homemade methanol/ethanol i am just beggining my journey into how to make my poor old 46cc have dc-dc cdi
  4. jaguar

    jaguar Well-Known Member

    with a dc-to-dc CDI you will need a trigger circuit to tell the CDI where the flywheel is in its 360 degree rotation.
    you will also need a battery.
    why unnecessarily complicate things?
    the stator/magneto of the chinese engine generates enough voltage for a hot spark when feed to a non-standard CDI.
  5. Fabian

    Fabian Well-Known Member

    That's exactly what i want, but with the addition of being able to plug the CDI in to a laptop to give total adjustability of the ignition curve; as well as being able to upload ongoing software improvements to the programmable CDI.
    Modern lithium high capacity battery packs are light enough and reliable enough to power a single spark CDI for a long period of time. Besides, the original magneto can still be used to keep the lithium battery pack charged up, thereby allowing the use of the battery pack to recharge electronic devices, like a laptop or phone or tablet etc.
  6. jaguar

    jaguar Well-Known Member

    Fabian, what you want is already available. You just need to devise a trigger circuit and have the pickup with adjustable position.
  7. Fabian

    Fabian Well-Known Member

    I have done enough modifications and fabrication. I just want to be able to purchase an advanced technology ignition kit from someone who can make it available as a turn key option.

    As you very well know, i have a Jaguar CDI strapped to my bike, but i want more technology. I want to be able to control all parameters of the CDI and the ignition curve through an interface with my laptop.
  8. jaguar

    jaguar Well-Known Member

    What you want would have to be very customized.
    Best CDI control is
    1) digital
    2) variable timing dependant on throttle position
    3) variable timing dependant on intake vacuum (reflecting engine load)
    and of course a customized trigger pickup at the magneto.
    In other words what you want is the equivalent of a date with the hottest Hollywood star there is. won't ever happen.
    Learn to be content with what you have since it is much better already than what most people have.
  9. OCCStingray

    OCCStingray Member

    Isn't all that stuff available over the counter at cart shops?
  10. Fabian

    Fabian Well-Known Member

    Well get cracking and turn your Jaguar CDI into the hottest Hollywood star there is, then i'll be even more happy with the Jaguar CDI.
  11. HeadSmess

    HeadSmess Well-Known Member

    im over the whole hoo ha. as long as i can overtake L platers, and generally keep up with traffic on a pushbike, im happy :)

    all experiments have pointed to one thing...nothing seems to beat stock parts, except for the exhaust.

    everything else is fooling yourself, and wasting time trying to convince the few people that come on here... better carbs, better ignition, better this, better that. all nonsense. just gimme my tuned pipes and im happy now...

    all the main supporters of these silly "hop up" parts...i havent seen ONE of them fabricate a tuned pipe to the same level of accuracy as mine. just constant "innovative experiments" with no comparisons to the REAL DEAL. why does a ktm 65 with no pipe run like :9898:? despite having racing level carb, reeds, intakes, wheels, ignition systems, and all the works? because its the FREAKING EXHAUST THAT COUNTS.

    take the exhaust off a cr500, replace it with a straight pipe, and tell me its better than ever. just try it.

    why hasnt anyone contemplated revising the whole freaking ignition system, magneto, stator coil and all? because at that point, you might as well revise the entire engine. and noone is about to do that...commercially at least :) and seriously, its not worth the hassle.

    day off tomo. i have a certain device to work on, i guess :) before the surface rust takes hold :eek:
  12. Fabian

    Fabian Well-Known Member

    From my experience (using a stock exhaust system), the reed valve intake improves low and midrange torque (has virtually no effect on max power over stock) and the CR Machine Manufacturing cylinder head gives improvement everywhere in the rev range (though not a huge improvement in power), but the cylinder head cooling improvement is tremendously good over a stock cylinder head.

    The Walbro style diaphragm carburettor doesn't give any power improvement over the stock NT carburettor, however it's external jetting method, makes for convenient air/fuel ratio adjustability and leak free operation (both air and fuel); henceforth physical cleanliness, unmatched by float style carburettors.

    The Jaguar CDI makes marginally more power than the stock CDI, but it significantly extends the life of the connecting rod bearings.

    I wish someone would offer a billet reproduction engine, using a one piece cylinder and cylinder and using a well designed horizontally split crankcase system, thereby allowing you to conveniently change the crankshaft (if it needs changing) without having to pull the whole engine out of the bike.

    I'd have no issue with an $800 price tag, because you if the thing is reliable for 15,000 miles then it's paid for itself over a conventional Chinese 2-stroke engine that you've spent about the same money on; purchasing "reliability upgrade" parts.
  13. butre

    butre Well-Known Member

    what's wrong with wanting more? if it weren't for people wanting more we'd be lucky to be out of caves by now
  14. Fabian

    Fabian Well-Known Member

    I was really hoping that the "Lightning CDI" developed by Jaguar's competitor would take the Jaguar CDI to the next level, encompassing many of the features described by Jaguar himself:

    Best CDI control is
    1) digital
    2) variable timing dependent on throttle position
    3) variable timing dependent on intake vacuum (reflecting engine load)
    and of course a customized trigger pickup at the magneto.

    Sadly, the developers and manufacturers of the Lightning CDI made a product which has none of the features of the Jaguar CDI, yet call their CDI a better product, which is completely false marketing.

    Lightning had the chance to build in a whole new level of technology into their CDI, and they could have done so; eclipsing the Jaguar CDI by means of a technological masterpiece in a black box, yet sadly they just made a technologically inferior product.

    There is no reason why the Lightning CDI couldn't be built with USB connectivity, allowing it to connect to a home computer, giving possibility of updating the CDI software or allowing the user to modify the ignition parameters (including an adjustable "soft rev limit") through a PC based program.

    Secondly, it would give users the ability to share their ignition parameters with other people, by listing ignition parameters on websites like this, thereby allowing others to try out different ignition settings based on different engine setups i.e. specific cylinder heads or compression ratios or fuel types or spark plug heat ranges etc.

    A person could look for someone who has an engine configuration similar to their own, then simply copy the other persons ignition settings into their CDI.

    This is exactly the level of technology the manufacturers of "Lightning CDI" should have built into their CDI.
    I am terribly disappointed that they chose to make a product which was (and still is) inferior to the Jaguar CDI, when they had the chance to build something really special.

    I completely agree with butre:

  15. HeadSmess

    HeadSmess Well-Known Member

    whats wrong with wanting more...

    hmmm, when the electric windows only wind down but not up.

    when the keyless entry and ignition mysteriously wipes its codes and no longer works.

    when the bank turns around and charges 3.75 for using someone elses ATM.

    give me a 1960s rattler and im happy :) air con...thats what the windows (with handles that rotate) are for ;)

    why work all your life to pay off that luxury car and massive mansion when youre too busy WORKIN to enjoy them? ill take a shed and 40 acres before a masserati and a landscaped postage stamp in the city.

    all these people wanting more, and never realising what they missing out on by keeping it simple...

    "anyone can make it complicated, it takes a genius to make it SIMPLE." albert einstein.

    if 7 and 8 string guitars were better, simply because they had MORE, everyone would be playing them. rather than just steve vai and that cruddy metal band, meshuggah. reminds me of that guitar from spinal tap with a full array of humbuckers....

    this is almost a fitting time for a bible quote, too :)

    "think not that with your endless repetitions you shall be heard" somewhere in matthew...

    tuned pipe.

    fabian, id send you one, but you fail to realize that to develop POWER requires MORE RPM. and as you seem to live in this self deluded belief that theres gobs of power to be had at 4800 rpm, and any faster will cause instant failure, i wouldnt bother. i know that if you dared RISK FAILURE, that if you tried a 7500rpm pipe, fitted to a STOCK STANDARD ENGINE you would become my main advertiser, supporter, whatever. id send you one for free! and i also know you would experiment with all your silly lil accessories, only to remove them the next day... (also dont bother saying anything about laws or police or fines... be sensible and they TURN A BLIND EYE. youre already ILLEGAL as it is. if they can see a mobile phone and no seat belt from 500 metres, they know exactly when someone has an engine attached.)

    you would require a 1800mm pipe at your foolish speeds. and, well...power being based on RPM, you arent going to experience anything, even if one could somehow wrap all that pipe onto a bike somehow.

    you once mentioned that a 30cc brushcutter would fail to be capable of producing any reasonable amount of power. in YOUR hands, yes, of course. they run at 9000 rpm, not 4.

    but, as they blow up at 5210 rpm in your situation because you think they run slow like a mack truck engine, why bother at all?

    maybe some one else is willing to RISK BLOWING AN ENGINE BY DARING TO EXCEED 5220RPM...(yes, im offering a free pipe to whoever pays postage!) ;) then therell be two of us up on this soapbox! :)

    4800 is where my powerband is just starting :)

    end pointless repetitions :)

    oh, thats right...i had a go at making the FREELY AVAILABLE CIRCUIT for jags cdi. in fact, i tried just about every schematic available, plus an alternative or two of my own...

    back to a stock coil again. strange that...
    Last edited: Jul 2, 2014
  16. HeadSmess

    HeadSmess Well-Known Member

    and what exactly do you expect to PAY for this box of goodies?

    less than 100? less than 500? less than a grand?

    how many do you seriously think these people are selling? maybe jag can give us an idea of total annual sales in his case...i reckon, at most, one a day. internationally. worldwide.

    i have a feeling that jag requires an alternative income to just selling CDI units...

    then start tacking on overheads...government cottons onto the fact your manufacturing and exporting? stocking PCB. stocking components. labour. R&D. business insurance. packaging. advertising. middlemen taking their cut.

    even with discount parts in bulk, i also reckon jag realizes about $30 profit per unit, MAX.
  17. Fabian

    Fabian Well-Known Member

    I would be happy to pay $400 for a decent CDI system that plugs into my home computer, allowing me to adjust every single aspect of the ignition curve as well as providing a selectable "soft rev limit".

    Better still would be a GPS enabled and temperature controlled CDI with internal clock, enabling me to preset specific ignition curves for specific parts of my journey at specific ambient temperature and at specific times of the day. This is """must have""" technology for the motorised bicycle rider.
  18. Fabian

    Fabian Well-Known Member

    I have never said that. Please show me where i have mentioned such words.

    I have never said that. Please show me where i have mentioned such words.

    Please prove such a statement where i fail to realise that POWER requires MORE RPM.

    I cannot afford to risk failure when travelling to some of the locations i've been to. My only option is absolute reliability.

    Unfortunately a 7,500 rpm pipe is not compatible with long term reliability and is also not compatible with police perception of a motorised bicycle, and when it comes to police perception of a motorised bicycle, perception is everything, not to mention the public perception of a motorised bicycle who are all to quick to get on the phone to police, particularly when it comes to people ripping up and down the street with a 7,500 rpm pipe.

    A powerband starting at 4,800 is not compatible with flying under the radar, nor is it compatible with long term reliability, nor is it compatible with the law stating that a motorised bicyc le must not travel faster than 12.54 miles per hour.
    You'd be hard pressed to explain to a police officer (and have him believe) that you were unable to travel at/or under 12.54 miles per hour because your powerband started at 4,800 rpm.
  19. butre

    butre Well-Known Member

    I'd love more than anything to have an adjustable soft rev limiter. it might even be fairly easy to do with an arduino and more brains than I've got.
    Fabian likes this.
  20. OCCStingray

    OCCStingray Member

    I honestly thought all this was available over the counter for go karts, I doubt it would take much for you to wire one up to a HT in a bike frame...