[Jason Rouillard]

Hi,

I try my resistor and it's work good for start and survive at high rpm like 5000. But, when I have this resistor, the motor doesn't exceed 5200 rpm... but when i remove the resistor, it goes to 6400 rpm...

I don't know how i can make a good setup with this. I don't want to need to put a resistor for start and remove it after...
Do you have an idea ? My resistor it's directly between my crank sensor wires and for now it's only twisted on both wires (for tests).

I also have an other question. What do Speeduino if duty limit of injectors are reach ?

Thanks !

[AlainNotHere]

I vote for trying to have as clean signal as possible to start with, I did wrap the cables for the pickup in my setup with aluminum foil all the way to the connector on the speeduino.

The other thing, depending on the conditioner and the VR sensor you can pick noise when there is vibrations in the engine, if I use an impact driver on the engine the speeduino will report 10,000 rpm.

If I understand correctly the duty limit is what percentage of the time do you want to have the injectors open, if you say 80 percent and and top rpm/load/throttle you have 5ms to perform the fuel injection your injectors should be able to do that in 5ms*80% = 4ms... if you exceed the 100% that means at that point the injectors are open the whole time.

[Jason Rouillard]

Thanks for your response Alain,

I already wrapped my crank sensor wires with aluminium foil. It's ground directly to battery.

My VR conditioner is from speeduino based on the max9926. I thought about replacing it by this but i don't know if it will fix my problem.
https://wtmtronics.com/product/dsc-dual ... tioner-vr/

I saw in my log that i have a dwell time of 8 ms. I did a calculation yesterday and i think speeduino cannot make a spark at good time with this value. It's too short
I have wasted spark, so my coils fire at every turn.

I will try 4ms today.

I also saw that my injectors are at 90% of duty at 6000 rpm. I don't know if speeduino reacts like rev limiter when duty cycle are reach or if speeduino only limit open time.

[AlainNotHere]

Thanks for your response Alain,

I already wrapped my crank sensor wires with aluminium foil. It's ground directly to battery.

My VR conditioner is from speeduino based on the max9926. I thought about replacing it by this but i don't know if it will fix my problem.
https://wtmtronics.com/product/dsc-dual ... tioner-vr/

I saw in my log that i have a dwell time of 8 ms. I did a calculation yesterday and i think speeduino cannot make a spark at good time with this value. It's too short
I have wasted spark, so my coils fire at every turn.

I will try 4ms today.

I also saw that my injectors are at 90% of duty at 6000 rpm. I don't know if speeduino reacts like rev limiter when duty cycle are reach or if speeduino only limit open time.

I'm using the other one https://wtmtronics.com/product/mini-max ... tioner-vr/ not sure if the other one could fix the problem or the conditioner is not the problem...

Another thing, what's your configuration for the pins on the board where you select if routing through the conditioner before going into the digital input of the board?

And another thing... my VR sensor is run with the negative connected to the board, not to the battery, in the case of the VR sensor used on the honda J30 it's a 2 cable setup, so it's configured as mention on this board

https://github.com/noisymime/speeduino/issues/168

"When you say grounding on the sensors, do you mean the shield on the sensor wires or are you actually running one of the VR signal pins to ground?

Each VR sensor should have 2 wires (and optionally a 3rd one for the wire shield). those 2 signal wires need to be connected to VRx+ and VRx- on the board (Where x is either 1 or 2 for primary or secondary). You shouldn't be running either of those signal wires straight to ground."

If you are using the same injectors that came with the car, then those same injectors should be able to work, do you have an idea on how many cc at what psi? for example the toyota 4 runner and the honda cb500 injectors are 250cc/min @43 psi

There are some calculations that can be done but this are some excel data that I calculated

and as you see at 80% duty cycle 6 injectors at 250cc/min is enough for 200hp in the 4runner

| Injector Size (flow rate in cc/min) | Injector Size (flow rate in lbs/hr) | Engine HP at flywheel | bsfc | # injectors | duty cycle |
|-------------------------------------|-------------------------------------|-----------------------|------|-------------|------------|
| 47.25 | 4.5 | 6 | 0.6 | 1 | 0.8 |
| 164.0625 | 15.625 | 25 | 0.5 | 1 | 0.8 |
| 240.625 | 22.9166666666667 | 200 | 0.55 | 6 | 0.8 |
| 360.9375 | 34.375 | 200 | 0.55 | 4 | 0.8 |

[Jason Rouillard]

Hi,

I have a jumper #2 on VR.

My both wires are connected to board and i already checked if they weren't reversed. My shield is directly grounded to the battery.

It's oem injector. They are 17lbs/hour at 43 psi. I not use my cam sensor, so my injectors are paired and I increased my AFR at 12.5. I think it's why i reach duty limit. The temperature is cold (-5 C), so more gaz are injected.

[AlainNotHere]

My both wires are connected to board and i already checked if they weren't reversed. My shield is directly grounded to the battery.

There is something on the design of the board, I didn't read it explicitly but one day looking at the board I notice

There are 2 ground systems let's call them, there is the ground provided by the battery chassis, which you use as well as the 12v to power the speeduino and the other one is the one supplied on the sensor side of the board, and I was like... why there is a sensor negative? if you see the diagram of the board, that negative is not directly tied to the negative pin input to power the speeduino, the sensors, anything that is "sensed" and that means, read by analog to digital conversion need to have a stable reference, that's the sensor ground.

in fact everything in the right side, the "sensor side" negative comes from a pin on the arduino.

connect the negative of the VR to the -VR1 and the other one to rpm1, notice how the -vr1 on the diagram is not tied to the ground https://github.com/speeduino/Hardware/b ... .6_pcb.png

in fact, check any sensor connected to the board should NOT be connected to ground or the battery, this introduces noise and ADCs doesn't like that

It's oem injector. They are 17lbs/hour at 43 psi. I not use my cam sensor, so my injectors are paired and I increased my AFR at 12.5. I think it's why i reach duty limit. The temperature is cold (-5 C), so more gaz are injected.

17lb/hr is like 30hp per cylinder at 80% duty, asumming 4 cylinders that's 120hp at the crank, which engine is? I'm lazy didn't read the first post

forgot to mention, this is under the vmax area

https://wiki.speeduino.com/en/decoders/Yamaha_VMax

Hardware modification

"The signal from the pick-up is quite noisy. Therefore, it requires 10K resistors on the VR+ and VR- line (before getting to the VR-conditioner), and the R10 on the VR-conditioner to be equipped with a 220nf ceramic capacitor to filter the generator noise."

[Jason Rouillard]

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TOPIC REVIEW: VR CONDITIONER NOISE WHEN CRANKINGEXPAND VIEW
RE: VR CONDITIONER NOISE WHEN CRANKING
by AlainNotHere » Thu Mar 21, 2024 8:38 pm
Jason Rouillard wrote: ↑
Thu Mar 21, 2024 8:02 pm

My both wires are connected to board and i already checked if they weren't reversed. My shield is directly grounded to the battery.
There is something on the design of the board, I didn't read it explicitly but one day looking at the board I notice

There are 2 ground systems let's call them, there is the ground provided by the battery chassis, which you use as well as the 12v to power the speeduino and the other one is the one supplied on the sensor side of the board, and I was like... why there is a sensor negative? if you see the diagram of the board, that negative is not directly tied to the negative pin input to power the speeduino, the sensors, anything that is "sensed" and that means, read by analog to digital conversion need to have a stable reference, that's the sensor ground.

in fact everything in the right side, the "sensor side" negative comes from a pin on the arduino.

connect the negative of the VR to the -VR1 and the other one to rpm1, notice how the -vr1 on the diagram is not tied to the ground https://github.com/speeduino/Hardware/b ... .6_pcb.png

in fact, check any sensor connected to the board should NOT be connected to ground or the battery, this introduces noise and ADCs doesn't like that

If i understand, i need to ground my shield directly on speeduino to remove some noise ?

It's a 2200 sfi from a chevy cavalier 2000. The car is for a demolition derby. I want to use speeduino on many demolition derby car, so i try to make a "plug and play" for each model. I make wiring harness for each model, so i only want no big modification on hardward. Only like changing a jumper.

I already try a 10k shunt, but i have noise when i crank engine. I don't know if problem will still persist with shield grounded to speeduino.

[Jason Rouillard]

I did a thoot logger without any modifications to wiring or hardware :

See pictures and csv

My trigger pattern is GM7x

[Jason Rouillard]

I found this on Megasquirt doc. This is what you tell me with your two grounds (one ground it's battery and other is into speeduino ground) ? So i need to connect my shield to speeduino ground that used for ground sensor ?

Can i use same ground that a another sensor ? I think i already use all ground pin on my speeduino..

[JHolland]

The shield should only be connected to ground at one end, so if it isn't connected to the body of the VR sensor then it should be connected to the Speeduino ground. The VR- should be connected to the CKP- input of the Speeduino not to ground.