Engine Management help

In reply to Taiden:

So, now you have a wheel, and a pully, and a sensor, in 3 parts.

How that is easier than using the original or OEM like hardware and working with the software is what I don't get.

6 of one, half dozen of another.

If you are going to tune it, properly, you have to know the software anyway.

You and I are stuck on the fact that I said "use a 36-1 trigger wheel."

All I am saying, is that one can use a 36-1 trigger wheel. It will work for just about any setup. However, there is no reason why someone cannot use their OEM trigger wheels.

My point in saying 'use a 36-1' trigger wheel was that, like everything else I mentioned, it's straight forward and will work for most setups. Like the Bosch 2 wire PWM idle solenoid. Sure, you can use your stock stepper motor, or 3 wire pwm, but the Bosch 2 wire is proven to work well and is extremely well documented and easy to setup.

So again, I'm not saying that getting a trigger wheel machined is easier than using stock hardware. I'm saying that in my mind, it is the most straight forward way to get working trigger if your OEM stuff isn't straight forward.

And I can promise you that our "conversation" didn't make Megasquirt any more simple for those out there who are already afraid of it.

What I did for the trigger wheel: (the simplest part of my build actually)

First I got a 72 tooth spur gear from Car McMaster and remove two teeth. (making a 72-2)

Then you mount it where the cap and rotor was and add a pickup from a RX7 Like So:

And one of it running:

Kind of funny that the plug wire #'s are still in the cam gear housing LOL

That is amazing. What was total cost on it?

Is the shaft keyed?

Did you just tell megasquirt that it was a 36-1 crank trigger?

Taiden wrote: That is amazing. What was total cost on it? Is the shaft keyed? Did you just tell megasquirt that it was a 36-1 crank trigger?

Yep. Because the cam spins at half the crank speed you need a 72-2 when mounting to the cam or if you put it in the dizzy. MS never "sees" it. The EDIS unit sees it as a 36-1. It sends the PIP and SAW to the MS or in my case a MJLJr.

People bashed me saying that it was inaccurate due to the timing belt but I venture to say it is more accurate than a timing chain or a gears dizzy driven by gears off a cam. It works excellent!!! Probably not as accurate as a trigger wheel on the crank but the simplicity of the install made it a no brainer.

There is a key on the piece that mounted to the cam that the rotor use to mount to. I mounted the gear to it and got it aligned with tdc and the sensor and then welded the gear to the piece that the rotor use to mount on that holds the timing belt gear on the cam. The most finicky part was truing up the gear to get the least amount of clearance between it and the sensor. A small plastic dead blow hammer did the trick once you mark the gear while it is spinning. Takes about 5 minutes. I have been running this setup for about 3 1/2 years with the MJLJr EDIS control. It has been dead on reliable. I basically took the entire ignition system from a 1993 escort wagon and grafted it on to my Porsche. I ended up using the ignition wires from a 1994 mustang V8 I get two sets of wires for the price of one. I can replace my entire ignition system now for less than 1/2 the price of a set of OE replacement Porsche wires.

Cost? The gear was 40+/- (shipping was something like $7) for the gear and 35 for a pile if ignition parts from three escorts. I probably could have got what I needed for $15 if I had only got a single set but I was in a picking mood and wanted spares. Another $7-10 for misc bolts and hardware. I got two RX7 sensors from he local P&P for $10. That was about it.

I just checked McMaster Car and the gear is now listed at $47 for a 1/4" wide gear. I ended up calling the supplier as I wanted a 3/8" wide gear and they gave me a local stocking supplier and I got it for a little less than McMaster Carr.