Suzuki DR-Z400S

[marauder1441]

Hi everyone,

I'm planning to convert my motorcycle to fuel injection. It's a Suzuki DR-Z400S with a single cylinder carbed engine.

I want to do it in 2 step. The first one is to replace the CDI by rusEFI and get it working with the carb on. The second step is to replace the carb by a throttle body.

I have scope trace from both crank sensor. the first sensor give 6 pulses per turn and the other one give one long pulse before TDC and one on TDC.

(This trace aren't from me. I'll take some recording on thoses pulses while cranking, and running later.)

For the firing, i don't think it's a big problem because I can firing on each rotation. But I don't think I can do that with injection. To identify the aspiration cycle, I plan to use MAP sensor reading or the pulses on flywheel to detect deceleration of angular speed on compression cycle (maybe just a dream ).

Any comment or hints are welcome!

[AndreyB]

The Suzuki DR-Z400 is a dual purpose motorcycle manufactured by Suzuki. It is powered by a single-cylinder, 398 cm3 (24.3 cu in), liquid cooled four-stroke engine.

What is the source of these two signals - are these real sensors used for ignition? Someone not-electronically-challenged should comment if MAX9926 would work here.

[rus084]

To identify the aspiration cycle, I plan to use MAP sensor reading or the pulses on flywheel to detect deceleration of angular speed on compression cycle (maybe just a dream ).

i think about it too . i have one cylinder 4stroke engine like you , but it smaller .

[kb1gtt]

Do you know what kind of electrical generation you can support? Does your magneto or alternator or what ever have a watts rating, or an amp and voltage rating? Often these bikes have small abilities to generate electrical power. If the fuel injectors draw more electrons than you generate, you'll eventually kill the battery.

[marauder1441]

The Suzuki DR-Z400 is a dual purpose motorcycle manufactured by Suzuki. It is powered by a single-cylinder, 398 cm3 (24.3 cu in), liquid cooled four-stroke engine.

What is the source of these two signals - are these real sensors used for ignition? Someone not-electronically-challenged should comment if MAX9926 would work here.

These 2 signals come from sensor in the flywheel casing. There are 4 wires (2 by sensor) going directly to CDI. I have a max9926 on my table...it's my plan to use it with those signal. I'll make a small circuit on protoboard to evaluate the output of MAX9926.

[kb1gtt]

I'm a bit concerned with 8V at very low RPM. I would raise some caution as you start to get a higher RPM. The VR might be generating more energy than your 9926 circuit can handle.

[marauder1441]

Do you know what kind of electrical generation you can support? Does your magneto or alternator or what ever have a watts rating, or an amp and voltage rating? Often these bikes have small abilities to generate electrical power. If the fuel injectors draw more electrons than you generate, you'll eventually kill the battery.

Damn good question. A quick look on net give me 180-200W of output for the 3-phases AC Genarator. I have headlight (55/60W), tail light (5w), brake light (21w), turn signal (21W) and CDI (unknow...). Probably 70-75w left for fuel injection. Converting some light to HID or LED could help a lot.

I don't have any idea of comsumption of fuel injector. I read 1A at 13.5V for a Yamaha R6 injector (13.5W) but the injector won't be always open, only pulsed...sometime, I release the throttle too ;o)

For the fuel pump, some people use a pressure sensor on fuel line and use PWM to drive de fuel pump to get the right pressure. This way is simple because I don't have to fit a return line to tank, I don't need a fuel relief valve to controle the pressure and use less energy since the pump only draw what it need to maintain the pressure. The drawback of this method is when idling, fuel temperature rise at the output of the pump.

[kb1gtt]

I've got a motorcycle fuel pump, it both resides inside that tank and returns in the tank, then puts out one line at around 50 PSI. I forget the pumps flow, but if you know the flow, and pressure you can calculate the watts needed to generate that pressure which is the min watts you'll need. The actual watts will be increased by the efficiency factor for the motor. You'll get different inefficiencies over relief vs. PWM. I expect the PWM would be less electrical watts. On-line calculator found here http://www.engineeringtoolbox.com/pumps-power-d_505.html

Looks like around 60 watts for the fuel pump is common for fuel injected motorcycles. I think you should plan for LED's and such energy efficiency enhancements.

Also running 100% of your generators rating usually shortens it's life significantly. I would aim for 80% or lower if you can.

[marauder1441]

I've got a motorcycle fuel pump, it both resides inside that tank and returns in the tank, then puts out one line at around 50 PSI. I forget the pumps flow, but if you know the flow, and pressure you can calculate the watts needed to generate that pressure which is the min watts you'll need. The actual watts will be increased by the efficiency factor for the motor. You'll get different inefficiencies over relief vs. PWM. I expect the PWM would be less electrical watts. On-line calculator found here http://www.engineeringtoolbox.com/pumps-power-d_505.html

Looks like around 60 watts for the fuel pump is common for fuel injected motorcycles. I think you should plan for LED's and such energy efficiency enhancements.

Also running 100% of your generators rating usually shortens it's life significantly. I would aim for 80% or lower if you can.

I didn't think to this issue but I'll keep a note on that. I think ac generator is enougth powerful but I'll need to save some watts elsewhere

[marauder1441]

This afternoon, I plut the scope to the crank sensors and take some reading. The CDI have a impedance ok 10K for sensor #1 and 55K for the sensor #2. I put the respective load on sensor and capture the trace. I got some proble to save screen capture but CSV work well. There is the results:

https://www.dropbox.com/s/hkusp90opy0ar8d/DR-Z400%20-%20Crank%20Sensor%20%231%20-%202015-02-15.jpg?dl=0
https://www.dropbox.com/s/rrfu23utd1rkpm6/DR-Z400%20-%20Crank%20Sensor%20%232%20-%202015-02-15.jpg?dl=0

Currently, I don't understand how they do that, but it's look like a "special" pattern on sensor #2 on every 2 complete crankshat turn. I was not able to to capture both signal because one of my probe is defect...2 new one are on the way.

Very interresting!!!!

[marauder1441]

To identify the aspiration cycle, I plan to use MAP sensor reading or the pulses on flywheel to detect deceleration of angular speed on compression cycle (maybe just a dream ).

i think about it too . i have one cylinder 4stroke engine like you , but it smaller .

Where are you now with this project?

[rus084]

i started engine and looking for ecu box .

[Yuri_Y2K]

any updates? ))