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any thoughts on cam-mounted trigger wheel?
Posted: Feb 21, 2016 4:03 AM
by 12valves
I want to be able to remove the distributor cap, rotor, and dust shield from a Motronic M20/M30 and install a trigger wheel that bolts to the rotor adaptor, as well as a plate that bolts to the front of the timing cover with mounting boss for a VR sensor. Wouldn't that be the perfect thing for standalone setups? I can 3D print the parts in plastic for a test fit. And I know someone who had parts produced on a computer-controlled mill, so I could see about getting my own models produced in the same fashion. I'm thinking about a 24-1 crown wheel like this...
100mm diameter. 5mm thickness?
Re: any thoughts on cam-mounted trigger wheel?
Posted: Feb 22, 2016 10:50 PM
by marc79euro645
Cool project. I would like to get rid of the diz on my motor also (m106), because when it's cold or battery low the vr pulse can be weak.It makes sense to me to have the vr on the crank since it spins twice as fast (like b35). Hall sensor or optical might be better for cam drive. Or I could be completely wrong, been known to happen.
good luck
Re: any thoughts on cam-mounted trigger wheel?
Posted: Feb 22, 2016 11:35 PM
by EventuallyAyrton
Interesting. I look forward to hearing about/seeing your findings
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jun 19, 2017 7:14 PM
by Nebraska_e28
Any update?
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jun 28, 2017 12:57 AM
by 12valves
I got sidetracked messing around with the 3D modeling software. Then I started working on a design for a cover plate (in place of the distributor cap) but then I crashed my car so this project went to the back burner. Now the car is running and I'm thinking about it again. The poster above brings up a good point. I'm not sure if a VR sensor would work reliably with a relatively small and slow moving trigger wheel like this. I'm also not sure if it would be worth it to use a crown wheel shape instead of a normal flat trigger wheel which is easier to produce.
M52s have a trigger wheel on the crankshaft (inside the engine) and that's only about 100mm diameter isn't it? Has more teeth though.
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jul 04, 2017 9:46 PM
by M. Holtmeier
I just used the stock VR crank sensor (since it plugged into the harness), a stainless clean out plumbing cover from Lowe's and a bolt to make a single tooth cam sensor and wheel. Set it up about 90* back from TDC and it synced just fine and I've never had issues with it since. I would like to add a mounting boss to my distributor block off plate in lieu of the stack of crush washers I used to set the correct gap, but it would be purely for aesthetics.
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jul 06, 2017 9:49 AM
by downforce22
Is this what you are looking for? I don't understand its purpose
https://www.r3vlimited.com/board/showth ... p?t=408966
EDIT: here is a quote I found from DIY autotune website
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Support Articles » FAQ » MegaSquirt Tech » Don’t I need sequential injection to make big power? Does the MegaSquirt offer this?
Don’t I need sequential injection to make big power? Does the MegaSquirt offer this?
Sequential injection attempts to only spray fuel while the intake valve is open for the cylinder that is about to fire, which in most cases is only possible at low engine speeds between idle and low speed cruising. Benefits can be seen in emissions, drivability, and fuel economy at these low engine speeds.
Batch injection (which is what the MegaSquirt-I and and most MegaSquirt-II versions do) does not attempt to spray only when the valve is open. It’s a fact that at higher engine speeds you won’t have enough time to spray all fuel while the valve is open, making this somewhat pointless, particularly for a performance oriented application. At these higher engine speeds 99% of sequential systems (exceptions being race only systems with super massive injectors) cannot spray all of the fuel needed while the valve is open Anyway, and sprays it both while the valve is opened and closed, very much like a batch system such as the MegaSquirt I and II. We’ve dyno tested several cars with using batch fire and sequential injection on the same motor. Peak power was the same without using individual cylinder tuning. However, the sequential fire setup did run a bit more smoothly at idle and at light throttle angles.
The MegaSquirt III system with the MS3X Expansion board or MS3-Pro will do full 8 cylinder sequential fuel and ignition. If you’re looking for the absolute best possible emissions and fuel economy, as well as the ability to fine tune each cylinder individually, then the MS3 system is the way to go.
There is generally no significant performance difference with a sequential system over a batch system unless you use individual cylinder tuning. There can be minor emissions and fuel economy benefits at very low speeds though. If your tuning budget allows for individual cylinder tuning, it may be possible to pick up 3-4% more power depending on how much cylinder to cylinder variation your engine has.
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jul 07, 2017 7:57 PM
by Shadow
Seems like just another thing to fuck with with no actual performance.
If you daily it then it would be worth it for me, I guess.
Re: any thoughts on cam-mounted trigger wheel?
Posted: Jul 08, 2017 5:10 AM
by 12valves
The benefit of knowing the camshaft phase is mainly for throttle response and fuel milage. (But it's not necessarily about squirting when the valve is open, that may not turn out to be the ideal time)
I could go the "one-tooth" route... I currently have the v2.2 PCB and daughterboard with dual VR inputs for using the crank/reference sensors. Still, it would be nice to get a complete trigger wheel on there and run everything with one sensor.