SuzukiSavage.com - EFI Project.

klx650sm2002

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less I know.

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Cumbria,England
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Re: EFI Project.
Reply #15 - 06/04/05 at 05:53:53

Also I forgot,
as Greg says "do the exhaust too", I am presuming he is refering to that "nasty exhaust port". Anyone who has seen inside the ex port will know what I mean.
It apears that the circular "restriction" can be opened up to 38mm without worry, but the flat part at the top of the port can not have much taken off and needs carefull measuring. See Exhaust port.

Clive W Cheesy

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PRH111

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Re: EFI Project.
Reply #16 - 06/17/05 at 08:54:33

I want to do this simply for the challenge of it. It will also give me a nice big fat line on my resume if I ever decide to get out of RF theory and go into the embedded design/ microcontrollers field.

I am going to try to start on a Microchip PIC 16F88 chip (8 ADC I/O pins, 16 I/O pins total, CCP, PWM, UART, MSSP, 20MHZ, 4K memory, 352bytes of ram space). If need be I'll go to a more powerful chip later but the 16F88 runs about $4. The most expensive part (other than my time) would be the PCB...on small orders it can be as high as $60 per circuit board on a 6" X 7" circuit board.

I plan to do my testing as such: Drive in the morning when it is cool, then day when it is warmer. Then I'd do a morning drive to a nearby mountain (you can get to 7000ft elevation by vehicle on mount rainier). Followed up by the mid-day warmer drive back down the mountain. Final tests would be me riding every single time we get rain here (quite often) to make sure the electronics are sealed up well against humidity. I figure 3-4 months to program the MCU, 3-4 months to put it all together and another 2-3 months of testing.

The only problem is I can't do miniaturization of the circuit as I have very little experience dealing with surface mount components so if there are any electronics assemblers with that type of experience out there I'd like to make arrangements with you...I'll engineer the system but you slap it together. Other than that the circuit board will be somewhat large (6" X 7" is what I envision currently)...

I am avoiding closed loop to keep it simple. If desired maybe I'll build in an option to accept input from a wide band bosch O2 sensor but that is a hefty project in itself.

Lucky for me I'm not married so my free time away from work is my free time to work on whatever projects I want and I'm sure my kids would love to be involved anyways.

Tentative start date is September.

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PRH111

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Re: EFI Project.
Reply #17 - 06/17/05 at 09:01:36

Just to add:

I am hoping that I can keep the cost of the ECU under $250 completely assembled and tested .

I'm still not sure if I want to keep all of the other components on hand though...but I don't mind testing a bunch of different sensors to see which ones are compatible to find the cheapest units that can meet the full requirements. (definitely won't stock the fuel components but I may get a bunch of the sensors because my experimentation may find that there are only a select number of sensors that work for their output signal and the space requirements on the engine).

Warranty on the ECU would be lifetime of the bike...just please don't crack open the case and spill a beer on the circuit and ask me to repair it for you!

As I said previously I plan to do this work all open source (helps me by having others troubleshoot my work for added features or to correct anything that could be done more efficiently since I am still quite green as an electronics engineer)...as long as people give proper credit when using my code or circuit.

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PRH111

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Re: EFI Project.
Reply #18 - 06/17/05 at 09:04:20

The ECU will probably be designed for in circuit programming or I will socket it and leave the code un-encrypted just to make it easier for me to add updates and features. I could even have a list of everyone who has the ECU, send out a chip when I make changes and then the owner replaces the chip and sends back the old one (because I really don't want to buy a billion chips) which I can then reprogram in the future.

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Kaishaku

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Re: EFI Project.
Reply #19 - 06/17/05 at 17:59:43

PRH111 wrote on 12/31/69 at 16:00:05:

I will be using the stock components to account for where in the rotation the engine is and it will therefore be "wasting" gas by injecting when the intake valve is closed at BDC since the stock ignition fires twice (not knowing when TDC occurs...only when TDC and BDC occur).

Isn't this a big deal?

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Mr 650

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The LS650- Classic
style & 4-valve
engine

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Re: EFI Project.
Reply #20 - 06/17/05 at 22:18:56

Homebrew EFI; Shocked

more power to ya.
It could really make a difference in performance.
We will let your bike be the guinea pig for the initial experiment. I like Bobo's idea of modifing a tried and true ECU (vs. home brew) & integrate aftermarket ignition, if you are looking for a market.
The watercooled 650 EFI BMW thumper makes 50Hp but the compression is at least 2 points higher, something the Savage design may not handle w/o knock sensor.
Still is is a cool project and having a bike that cranks and idles instantly w/o choke would be great.

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SilverBlue '01,K&N,Snorklectomy,125mm NOS carb, 1/2 spacer & 155, 'Trapp, NC flyscreen, Suzy GelSeat, Osram H4
later..putt. Putt, PUtt, PUTT! 8)
HelmetLawsSuck

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PRH111

Ex Member

Re: EFI Project.
Reply #21 - 06/19/05 at 20:50:40

Kaishaku wrote on 12/31/69 at 16:00:06:

Isn't this a big deal?

No, many multi-port batch fire automotive injection systems do the exact same thing. Only true sequential fired multi-port injection fires at the exact necessary time and the improvement in gas mileage is really only marginal (though there is no difference in power if I remember correctly).

A stock EFI from another vehicle requires all the sensors off of that vehicle and I have no access to their code for making modifications because obviously there is more than just the compression giving it more power (I'm guessing the a/r ratio is more favorable for high rpm as well as the cam). The injection would still provide fuel for a 50hp engine even though the savage makes only 1/2 of that. You could reduce fuel pressure or put in a different injector size to compensate but you have to hope that you can find an injector using the same impedance of appropriate size with the same style of feed (side or top).

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bobo383

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Arlington, TX
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Re: EFI Project.
Reply #22 - 06/20/05 at 04:24:43

Very true. It's definitely worth experimenting with.

PRH111 wrote on 12/31/69 at 16:00:06:

No, many multi-port batch fire automotive injection systems do the exact same thing. Only true sequential fired multi-port injection fires at the exact necessary time and the improvement in gas mileage is really only marginal (though there is no difference in power if I remember correctly).

A stock EFI from another vehicle requires all the sensors off of that vehicle and I have no access to their code for making modifications because obviously there is more than just the compression giving it more power (I'm guessing the a/r ratio is more favorable for high rpm as well as the cam). The injection would still provide fuel for a 50hp engine even though the savage makes only 1/2 of that. You could reduce fuel pressure or put in a different injector size to compensate but you have to hope that you can find an injector using the same impedance of appropriate size with the same style of feed (side or top).

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Arlington Texas
Used to have 98 & 88 Savages

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