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Thread: ESE's works engine tuner

  1. #25081
    Join Date
    18th March 2012 - 08:35
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    Homebuilt chassi, Kawasaki 212cc
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    Sweden
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    438
    Quote Originally Posted by wobbly View Post

    FCR carbs were designed for 4T, and the biggest issue on a 2T is that the slide is set at a 1.5,whereas a normal 2T Keihin would be a 5.
    This gives very rich transition response,and cant be tuned out - but on Meth this may not matter.
    For simple gravity feed you need at least a 4.2 float jet,and I believe that Meth needles are available, but the tube is fixed,so will have to be drilled or be part of an alky kit
    to get sufficient flow at 1/4 to WOT with a thin point on the needle tip.
    Nice, Thanks!,
    Ill check that slide issue if having problems.
    Yes i figure the needle need some job, as is it almost has no taper at all.
    The carb came from a big KTM 4t.
    And i plan to use a mikuni fuelpump from a snowmobile.
    I have also designed the fueltank to give slighty higher gravityfeed during hard acceleration.
    Will measure the floatjet later today, my first impression is that is is quite huge already as std.

    Rgds.

  2. #25082
    Join Date
    12th March 2010 - 16:56
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    TT500 F9 Kawasaki EFI
    Location
    Hamilton New Zealand
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    2,017
    [QUOTE=Nath88;1131031730]Hi All,
    Thought Id drop by to share the findings of my YZ250 EFI project. It has a 2009 CRF450R 50mm throttle body, 3D printed polyurethane throttle boot to a Boyesen RAD valve. Fuel system is returnless with a Walbro GSL-414 pump controlled by a Madhu PWM pump controller/pressure sensor. Fuel filter is a Sytec mini bullet. Injector is the CRF450R 12 hole injector (440cc/min @ 4 bar). Its controlled with a Microsquirt V3 running MSextra code, triggered by a 20-1 tooth wheel welded to the ignition rotor and a crank sensor from a YFM350.

    Its tuned in Alpha-N strategy (TPS vs. RPM table), with barometric pressure sensor and intake air temp sensor for compensation. It uses a Wideband O2 and logs either EGT or Fuel pressure.
    First start was about a month ago, have put 3 tanks of fuel through it so far. Most of the tuning has been automatic based on AFR targets, except idle, light throttle and overrun where it needs to be tuned manually. 50mm throttle feels just as linear as the 38mm carb. I havent used any accel pump fuelling yet, so Im hoping that will sharpen the throttle up a bit more.

    Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value. I tried tuning a ledge into the fuel map, it was better than before but still hit and miss, fast roll on was ok, slow roll on or steady part throttle would still flood.
    Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isnt firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
    Therefore the fuel required for a cycle can be predicted by whether or not the engine fired on the previous cycle, in addition to engine speed and throttle position.
    So my solution is to check whether the cylinder has fired, then adjust the fuel table for the next cycle. The throttle body MAP sensor is connected to the exhaust port and samples the pressure during blowdown. Ive set up a 2nd fuel table in the ECU with a multiplier for when the pressure is above a threshold, corresponding to the cylinder firing. When the exhaust pressure is high, the main fuel table is unchanged, when low, it is reduced by 50% (will need to be dialled in for various RPM, but seems to work so far). The main fuel table is tuned with the wideband when the motor is firing, then extrapolated into the non-firing low throttle/overrun area. On closing the throttle, once the motor stops firing, fuel flow drops to match the airflow, so the motor doesnt flood. On opening the throttle, the mixture is correct to initiate firing, then after the first fire fuel flow goes back to the main table value.

    I think with some tuning I should be able to get the transition pretty much seamless. At the moment I'm working on getting the fuel table just right around the transition area, then I'll work on the switch threshold and multiplier values. That said, it's pretty decent already, but I'm a perfectionist.

    Nathan

    https://www.youtube.com/watch?v=4Zsz26QmfAU

    That goes alright! There has certainly been a lot of thought put into this project, thank you for sharing this.

  3. #25083
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    27th October 2013 - 08:53
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    Quote Originally Posted by 41juergen View Post
    So based on the output of the EngMod simu I made a first "test" cylinder. The timings are : main ex 198, aux ex 195 start open, A port 129, B port 131, C port 131 CA. That all as a road going bike with the (nozzle) modified stock exhaust (not too bad in the dimensions) at 11000 rpm peak. The question is: are the large aux ex ports the right way to go? Or shall I better use the "tear drop" shape getting a potential better flow with compromising on the (at that engine setup with 56,0mm bore and 50,7mm stroke) already hard to get blow down TA?
    The first pic shows the stock setup, the other pics the current status of my porting.

    Attachment 328681 Attachment 328682 Attachment 328683
    maybe your aware already but take care not to make the aux window too big if there isn't sufficient material around the passage to make it appropriate size also. I see a lot of amateur guys make this mistake on other websites. what happens is their aux port looks like a hour glass shape. the window is large but the passage gets small then it gets large again where it intersects with the main passage

  4. #25084
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    20th April 2011 - 08:45
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    Raalte, Netherlands
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    Quote Originally Posted by Nath88 View Post
    I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isn’t firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
    Therefore the fuel required for a cycle can be predicted by whether or not the engine fired on the previous cycle, in addition to engine speed and throttle position. So my solution is to check whether the cylinder has fired, then adjust the fuel table for the next cycle. The throttle body MAP sensor is connected to the exhaust port and samples the pressure during blowdown. I’ve set up a 2nd fuel table in the ECU with a multiplier for when the pressure is above a threshold, corresponding to the cylinder firing. When the exhaust pressure is high, the main fuel table is unchanged, when low, it is reduced by 50%
    I like your approach very much Nathan.
    But looking at your third picture, I wonder how much radiator heat will be picked up by the fuel. Some fuel components have a boiling point around 50 C ....

  5. #25085
    Join Date
    20th January 2010 - 14:41
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    husaberg
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    The Wild Wild West
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    Quote Originally Posted by Nath88 View Post
    Hi All,
    Thought I’d drop by to share the findings of my YZ250 EFI project. It has a 2009 CRF450R 50mm throttle body, 3D printed polyurethane throttle boot to a Boyesen RAD valve. Fuel system is returnless with a Walbro GSL-414 pump controlled by a Madhu PWM pump controller/pressure sensor. Fuel filter is a Sytec mini bullet. Injector is the CRF450R 12 hole injector (440cc/min @ 4 bar). It’s controlled with a Microsquirt V3 running MSextra code, triggered by a 20-1 tooth wheel welded to the ignition rotor and a crank sensor from a YFM350.

    It’s tuned in Alpha-N strategy (TPS vs. RPM table), with barometric pressure sensor and intake air temp sensor for compensation. It uses a Wideband O2 and logs either EGT or Fuel pressure.
    First start was about a month ago, have put 3 tanks of fuel through it so far. Most of the tuning has been automatic based on AFR targets, except idle, light throttle and overrun where it needs to be tuned manually. 50mm throttle feels just as linear as the 38mm carb. I haven’t used any accel pump fuelling yet, so I’m hoping that will sharpen the throttle up a bit more.

    Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value. I tried tuning a ledge into the fuel map, it was better than before but still hit and miss, fast roll on was ok, slow roll on or steady part throttle would still flood.
    Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isn’t firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
    Therefore the fuel required for a cycle can be predicted by whether or not the engine fired on the previous cycle, in addition to engine speed and throttle position.
    So my solution is to check whether the cylinder has fired, then adjust the fuel table for the next cycle. The throttle body MAP sensor is connected to the exhaust port and samples the pressure during blowdown. I’ve set up a 2nd fuel table in the ECU with a multiplier for when the pressure is above a threshold, corresponding to the cylinder firing. When the exhaust pressure is high, the main fuel table is unchanged, when low, it is reduced by 50% (will need to be dialled in for various RPM, but seems to work so far). The main fuel table is tuned with the wideband when the motor is firing, then extrapolated into the non-firing low throttle/overrun area. On closing the throttle, once the motor stops firing, fuel flow drops to match the airflow, so the motor doesn’t flood. On opening the throttle, the mixture is correct to initiate firing, then after the first fire fuel flow goes back to the main table value.

    I think with some tuning I should be able to get the transition pretty much seamless. At the moment I'm working on getting the fuel table just right around the transition area, then I'll work on the switch threshold and multiplier values. That said, it's pretty decent already, but I'm a perfectionist.

    Nathan

    https://www.youtube.com/watch?v=4Zsz26QmfAU

    That goes alright! There has certainly been a lot of thought put into this project, thank you for sharing this.
    Overun over fueling, Cagiva had the same issue. Yours is a bloody neat set up though.
    https://www.kiwibiker.co.nz/forums/a...hmentid=301602
    https://www.kiwibiker.co.nz/forums/a...hmentid=301601
    https://www.kiwibiker.co.nz/forums/a...hmentid=301600
    https://www.kiwibiker.co.nz/forums/a...hmentid=301599
    https://www.kiwibiker.co.nz/forums/a...hmentid=301598
    https://www.kiwibiker.co.nz/forums/a...hmentid=301597

    The cagiva used to keep pumping in fuel on over run, then bog whth its rich mixture and then chime in with a potental highside causing burst, when the unburnt fuel finally cleared out of the crankcase.
    Pumper carbs can do the same thing, not an issue on karts as they tend to keep on the gas.
    I think What you have done is you have compensated for lower airflow and incomplete combustion on over-run, which was creating a richer mixture in the crankcase, which is what a conventional vacum metered carb does.
    Neat solution.



    Kinky is using a feather. Perverted is using the whole chicken

  6. #25086
    Join Date
    21st March 2014 - 22:00
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    RZ350, TZR250 3XV
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    Hanau, Germany
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    OK, so will start with the 2CA lower aux ex ports... And thank's for the head up peewee, I believe the passage is currently big enough as it has more than half of the overall aux ex port area...

  7. #25087
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    27th October 2013 - 08:53
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    Quote Originally Posted by 41juergen View Post
    OK, so will start with the 2CA lower aux ex ports... And thank's for the head up peewee, I believe the passage is currently big enough as it has more than half of the overall aux ex port area...

    your doing good job . will your exh exit be 75% of exh area at bore face ?

  8. #25088
    Join Date
    7th June 2009 - 13:29
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    Norton Manx
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    Over the Rainbow
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    Quote Originally Posted by Nath88 View Post
    Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value.

    Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isnt firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
    Great stuff, TeeZee will be very interested.
    Factual Facts are based on real Fact and Universal Truths. Alternative Facts by definition are not based on Truth.

  9. #25089
    Join Date
    27th June 2013 - 05:29
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    Suzuki RG500/Aprilia RS125
    Location
    Norway
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    Quote Originally Posted by FastFred View Post
    Great stuff, TeeZee will be very interested.
    My thought too. Waiting for TeeZee now.

  10. #25090
    Join Date
    2nd March 2013 - 15:04
    Bike
    CBX125F NS50F NS90F NS-1
    Location
    Lower Hutt
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    317
    Quote Originally Posted by husaberg View Post
    At highspeed it doesn't even have to rotate at all. As long as it stops in the open position. Its only needed at lower speeds isn't it?
    Quote Originally Posted by F5 Dave View Post
    Rotate? Why not just open and close guillotine?
    Guillotine implies reciprocating, i.e. back and forward or up and down, the killer motion.
    Rotate is better than reciprocate, even in stop/start stepper motion, and the stepper only needs to have two positions: Opened and closed, being 90 apart.
    Or, the disk could have a number of "fingers", each a bit wider then the port, and the stepper could just move however many degrees required to move to the next open or closed position.
    If there were, say, six such fingers (and six gaps, obviously), the stepper would only need to move 30 per step (open to closed or closed to open), or 60 per rev.

    Such demands might be within the reach of a stepper motor at 15000 RPM. I don't know.
    The load on the motor wouldn't be huge: discs don't weigh much although the starting friction (stiction) could be high with the disk surface stationary against the port, with pressure in one direction or the other.

    Having the port completely open and unobstructed for its full duration sounds ideal, but I wonder if the very sudden closing and opening would have repercussions down the tube?

  11. #25091
    Join Date
    16th February 2017 - 14:26
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    2002 Yamaha YZ250WR
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    Brisbane, Australia
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    Quote Originally Posted by Frits Overmars View Post
    I like your approach very much Nathan.
    But looking at your third picture, I wonder how much radiator heat will be picked up by the fuel. Some fuel components have a boiling point around 50 C ....
    As it turns out, a not insignificant amount... The fuel starts to boil in the pump when water temp exceeds 70C, and the fuel pressure drops, it can be awkward in traffic. I am installing a return line to the tank, bleeding off about 8L/hr to move fuel through the pump. The pump will draw extra power and the fuel in the tank will be heated, but it should do the job until I redesign the system. Fitting the parts on the bike cleanly is most of the battle. In-tank pump would be ideal!

  12. #25092
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    18th May 2007 - 20:23
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    RG50 and 76 Suzuki GP125 Buckets
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    Quote Originally Posted by oktrg500 View Post
    Quote Originally Posted by FastFred View Post
    Quote Originally Posted by Nath88 View Post
    Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value.

    Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isn’t firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
    Great stuff, TeeZee will be very interested.
    My thought too. Waiting for TeeZee now.
    Yes, very interested. Thanks Nathan, for the great idea of using a MAP sensor to measure the pressure changes in the exhaust system so as to see the changes in bulk air flow through the engine, I wish I had thought of that ages ago.


  13. #25093
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    16th February 2017 - 14:26
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    Brisbane, Australia
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    Quote Originally Posted by husaberg View Post
    Overun over fueling, Cagiva had the same issue. Yours is a bloody neat set up though.
    https://www.kiwibiker.co.nz/forums/a...hmentid=301602
    https://www.kiwibiker.co.nz/forums/a...hmentid=301601
    https://www.kiwibiker.co.nz/forums/a...hmentid=301600
    https://www.kiwibiker.co.nz/forums/a...hmentid=301599
    https://www.kiwibiker.co.nz/forums/a...hmentid=301598
    https://www.kiwibiker.co.nz/forums/a...hmentid=301597

    The cagiva used to keep pumping in fuel on over run, then bog whth its rich mixture and then chime in with a potental highside causing burst, when the unburnt fuel finally cleared out of the crankcase.
    Pumper carbs can do the same thing, not an issue on karts as they tend to keep on the gas.
    I think What you have done is you have compensated for lower airflow and incomplete combustion on over-run, which was creating a richer mixture in the crankcase, which is what a conventional vacum metered carb does.
    Neat solution.
    I found with my system it would never clear once it bogged, just 100% dead until the revs dropped. They must have been using some method of clearing it.
    I guess that's why injected snowmobiles and boats don't have the issue, as soon as the throttle is cut the revs drop.
    Nice article on the Cagiva too, I hadn't seen that one.

  14. #25094
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    18th May 2007 - 20:23
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    Quote Originally Posted by Nath88 View Post
    I found with my system it would never clear once it bogged, just 100% dead until the revs dropped.
    Exactly my problem too.


  15. #25095
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    12th May 2011 - 23:52
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    razor scooter(pink)
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    Quote Originally Posted by Nath88 View Post
    Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value. I tried tuning a ledge into the fuel map, it was better than before but still hit and miss, fast roll on was ok, slow roll on or steady part throttle would still flood.
    Same problem everyone else, from Cagiva through to Suter last year at the IOM the longer time at full throttle the worse it will be.

    That overlay from the ECU on the video is uber cool

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