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Thread: ESE's works engine tuner

  1. #19261
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    Quote Originally Posted by Frits Overmars View Post
    That is a good approach. However, theoretically the object is not to drop back closest to peak torque through every gear change, but to change gear at the rpm where the power before the gear change and the power after the gear change are equal. Or to express this graphically: where the current gear's rear wheel thrust curve intersects the next gear's thrust curve. Remember: power is not only torque x revs, it is also force x velocity.

    The graph below shows the acceleration of an Aprilia RSA125 over a distance of 800 m from an initial speed of 50 kmh. The Y-axis scale is determined by the grip coefficient of the tire.
    In first gear the clutch is slipped at 12517 rpm which is the rpm of maximum torque. By the way, slipping the clutch will be favourable each time the revs drop below max.torque-rpm after a gear change, provided the clutch can take the heat and the rider can spare the concentration. But with a racing gearbox this won't be necessary after first gear.

    In both the graph and the numeric picture you may notice that in the higher gears the engine is revved a little bit beyond the intersection point, as a compensation for the loss of velocity due to the air resistance because of the power interruption during the gear change. You'll notice this loss between the final velocity in a gear and the initial velocity in the next gear.
    Attachment 315342Attachment 315343Attachment 315344Attachment 315345
    Hi Fritz,

    Thanks for that gem of information!

    A quick question, do the GP bikes have shift lights that have different RPM settings for each gear to give the riders the optimal.

    Interestingly, I did have a quick go at figuring out what would be the best RPM shift by finding the best polynomial curve fit to my power curve (ok at best but the limit of my math skills!) for the RPM range that I was interested in. By integrating that polynomial between the relevant limits (the sweep of RPM in a given gear) I then got the area under the curve for that range. I shifted this range of RPM values until I converged to a maximum area thus hopefully giving me the optimum sweep for that gear. Looking at it now it seems obvious that as you mentioned that if I shift where the where the power before and after the gear change are equal then that will be the same!

    If I were to make a shift light that gave me unique shift RPM values for each gear that could be worth some free lap time!


  2. #19262
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    Quote Originally Posted by Sketchy_Racer View Post
    Hi Fritz,

    Thanks for that gem of information!

    A quick question, do the GP bikes have shift lights that have different RPM settings for each gear to give the riders the optimal.

    Interestingly, I did have a quick go at figuring out what would be the best RPM shift by finding the best polynomial curve fit to my power curve (ok at best but the limit of my math skills!) for the RPM range that I was interested in. By integrating that polynomial between the relevant limits (the sweep of RPM in a given gear) I then got the area under the curve for that range. I shifted this range of RPM values until I converged to a maximum area thus hopefully giving me the optimum sweep for that gear. Looking at it now it seems obvious that as you mentioned that if I shift where the where the power before and after the gear change are equal then that will be the same!

    If I were to make a shift light that gave me unique shift RPM values for each gear that could be worth some free lap time!
    Remember those cascades charts the Japanese used to have in the road tests in the 70's as far as I know that's what they were for.
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    I reminder distinctly .




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  3. #19263
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    Quote Originally Posted by Sketchy_Racer View Post
    do the GP bikes have shift lights that have different RPM settings for each gear to give the riders the optimal.
    The two-strokes didn't. The current lawn mower class and the honda standard class, otherwise known as Moto3 and Moto2, probably won't; technical innovation seems to be a deadly sin there. MotoGP will probably have them.

    By integrating that polynomial between the relevant limits (the sweep of RPM in a given gear) I then got the area under the curve for that range.
    Be careful with this area under the curve-approach, Sketchy. You may want to take a look at the power range concept:


    http://www.kiwibiker.co.nz/forums/sh...post1130525788


    http://www.kiwibiker.co.nz/forums/sh...post1130526279

  4. #19264
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    Quote Originally Posted by Frits Overmars View Post
    The current lawn mower class and the honda standard class, otherwise known as Moto3 and Moto2, probably won't; technical innovation seems to be a deadly sin there. MotoGP will probably have them.
    Frits, a few weeks ago, I thought of something along these lines. Probably dreaming though:


    “While the initial & impact that the Ryger (and other new engine concepts) might have in karting is being considered, one might also expand this through to GP bikes.

    Currently we have the combined result of Honda and Dorna, giving us Moto3, Moto2 and MotoGP, all 4 strokes. Looking simplistically at the 3 classes, particularly with respect to the engines:

    Moto3. Constraining overall limitations on capacity, bore, max revs, pricing and changes
    Moto2. Sealed CBR600 engine, no touchies
    MotoGP. This is split into two main classes, with the short term intention to achieve some form of time parity, but with the long term intention to phase out the difference so that only a single set of rules would apply:
    • Factory bikes: capacity maximum, ability to control ECU software, # engines and 20 litre fuel allowance
    • Open bikes: more engines, tyres, limited ECU access, 22 litre fuel allowance
    There are tech developments from the MotoGP class which do rub off to road bikes, which must be seen as a good thing. One big one being fuel consumption, hence consequentially CO2 emissions, the latter being the world index criteria of energy usage.

    I see the Moto3 class as being ripe for absorbing and demonstrating alternative technical opportunities. Thinking about the Ryger, other 2T and alternative performance opportunities, wouldn’t it be good to be able to demonstrate these in the world arena somehow, perhaps for the betterment of the world.

    How could this work?

    Initially I considered that, instead of contracting teams for a whole season, just set the max number of bikes on the track. Qualifying times determine who could start. However, this probably would have a negative effect on sponsorship, who would want to sponsor a team that doesn’t make the grade.

    So, instead of this and taking into account the current contracted 34 bikes, say reduce this to 30 bikes that must conform to current M3 rules. Then allow the remaining 4 places open to:
    a. Fledgling new technology bikes that choose to enter, subject to meeting some minimum qualifying time. No-one wants to see the class become a circus.
    b. Any other wildcard M3 bike, should the above 4 places not be taken up by new technology bikes
    However, only the four fastest of the a. & b. bikes can be eligible to race.

    Overriding all this though, would be a maximum class fuel allowance, say 12 litres, to pick a random figure. If this can be controlled in MotoGP, then surely it could be repeated in other classes. This would clearly mean performance in conjunction with fuel consumption and, therefore, CO2 emissions.

    Depending on the success of this, the percentage of new technology bikes could be gradually increased."

    Not too sure how one could ever advance such a proposal. I would imagine a brick wall if approaching Dorna directly. Maybe through influential and hopefully sympathetic journalists, say Alan Cathcart, Michael Scott to name a couple. Could be heaps more over the world in many countries
    "Success is the ability to go from one failure to another with no loss of enthusiasm.”

  5. #19265
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    Quote Originally Posted by ken seeber View Post
    ... a maximum class fuel allowance, say 12 litres, to pick a random figure. If this can be controlled in MotoGP, then surely it could be repeated in other classes. This would clearly mean performance in conjunction with fuel consumption and, therefore, CO2 emissions.
    In principle I'm all for it, always have been. In practice, starving a two-stroke engine of fuel could hurt its rider and others. So, as there is a fairly tight relation between power and air/fuel ratio, I chose to control the inlet diameter instead. It works fine for the Dutch 50 cc SOBW races. And I'd like to see Dorna apply this approach too (the 125 cc 70 hp Ryger breathes through a 30 mm carb. Oh, the joy of seeing a small two-stroke single wipe the floor with those 600 cc four cylinder Moto2 Hondas).

    Not too sure how one could ever advance such a proposal. I would imagine a brick wall if approaching Dorna directly. Maybe through influential and hopefully sympathetic journalists, say Alan Cathcart, Michael Scott to name a couple. Could be heaps more over the world in many countries
    You're damn right about the brick wall. In my opinion Dorna already lost control when they had to issue new MotoGP rules almost weekly, so they will certainly not welcome any outside interference.
    As for influential journalists: I don't think there are any. They may well influence the opinion of their readers, but this will hardly have an impact on TV cash flow, which is the only thing Dorna is interested in.

  6. #19266
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    Dorna seems to have a more than passing interest in honda's well being as well.

  7. #19267
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    Quote Originally Posted by Sketchy_Racer View Post
    it seems obvious that as you mentioned that if I shift where the where the power before and after the gear change are equal then that will be the same!
    assuming symmetry pre and post peak

  8. #19268
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    What I don't get is four strokes use to be able to race with 2 strokes. Why can't 2 strokes race with 4 strokes now?

  9. #19269
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    Quote Originally Posted by Frits Overmars View Post
    In both the graph and the numeric picture you may notice that in the higher gears the engine is revved a little bit beyond the intersection point, as a compensation for the loss of velocity due to the air resistance because of the power interruption during the gear change.
    And not to compensate for the higher leverage in the lower gear?

    Or is that value included in the "total resistance" figure?
    Go soothingly on the grease mud, as there lurks the skid demon

  10. #19270
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    Quote Originally Posted by Ocean1 View Post
    And not to compensate for the higher leverage in the lower gear?
    Quote Originally Posted by Frits Overmars View Post
    Remember: power is not only torque x revs, it is also force x velocity.
    Leverage does not need to come into the equation. If you have a given amount of power at a given speed, this defines the rear wheel thrust, irrespective of the gear you're in.

  11. #19271
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    Quote Originally Posted by jonny quest View Post
    What I don't get is four strokes use to be able to race with 2 strokes. Why can't 2 strokes race with 4 strokes now?
    4 strokes sound better

  12. #19272
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    about new technology bikes and open rules : a couple of years ago I had the idea of having just one single rule : only the amount of coolant would be limited. power means heat and coolant is used to keep heat under control. by limiting the allowed amount of coolant you indirectly also limit the amount of power.

    where the power would come from is of anybody's choice. 2 or 4 strokes, diesels, electric motorcycles, turbines, you name it. capacitiy and fuel consumption/stored electric energy also free.

  13. #19273
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    Or a minimum level of alcohol the rider had to consume at the end of each lap. Finally the Irish and the Czechs could present world teams, but perhaps a cheeky Aussie would be in with a chance as as happened so many times before.
    Don't you look at my accountant.
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  14. #19274
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    Quote Originally Posted by mr bucketracer View Post
    4 strokes sound better
    Really? Moto3 sounds like lawn mowers, Moto2 sounds like the bike from the kid at the end of the block (the kid thinks it's the other way around) and MotoGP sounds the same, just a bit louder and with a bit more revs.
    In case you are referring to classic four-strokes: they sound better because of their megaphones. But I guess you never heard a two-stroke racer with megaphones.
    Now there is a sound that would make the four-strokes crawl back into their caves. When the pre-war supercharged DKWs were racing at the Isle of Man, you could not only hear them anywhere on the 60 km long TT course, but even on the British mainland.
    Click image for larger version. 

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  15. #19275
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    Quote Originally Posted by JanBros View Post
    about new technology bikes and open rules : a couple of years ago I had the idea of having just one single rule: only the amount of coolant would be limited. power means heat and coolant is used to keep heat under control. by limiting the allowed amount of coolant you indirectly also limit the amount of power.
    Engine cooling is not limited by the amount of coolant, Jan. Increasing the coolant circulation velocity will counteract a reduction of the amount.
    But whatever the amount of coolant and its circulation speed, ultimately the heat has to be carried away by air. And how would you control the air flow through a radiator or through a set of cooling fins? It's not the air volume that you would need to control, but the air mass. Not so simple...

    where the power would come from is of anybody's choice. 2 or 4 strokes, diesels, electric motorcycles, turbines, you name it.
    Agreed.

    capacity and fuel consumption/stored electric energy also free.
    Nope; we need to stimulate fuel efficiency.

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