HEP + Megasquirt, someone made it work.
http://www.msextra.com/forums/viewto...512053#p523969
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I have an 87 Shelby CSX that has been mothballed for two decades because I was chasing one electrical gremlin or another. I ordered an eMS-Pro last fall and yesterday I just got it running. I'll be reading over your build and progress and following your links, because I'm sure I'll have to deal with 90% of the same battles you have overcome so far.
I will say I managed to get the MS to use the hall effect pickup as the trigger input. It is possible. Once I get a little further into tuning and getting most of the functionality out of this ECU I'll post my own write-up on what I did. In a nutshell, I called tech support a few times and got some help with the HEP. The tech was reading margin notes from some file and gave me dip switch settings and some potentiometer tweaks. Basically, it doesn't see the input as a hall, but will see it as a VR input. I had to set my unit to enable (and NOT invert) the VR with a 5V pull up signal. Also, we did some testing with the stock turbo distributor and HEP. The turbo has a square hole in one of the shutters, and two HEPs about 170 degrees away from each other. I had assumed that one sensor was getting 4 triggers per rotation and the other was getting 1 trigger from the window per rotation, this is not the case. Both sensors see 5 triggers per rotation. The factory ECU must be configured to decipher this input.
I used a non-turbo distributor and HEP, with the settings close to what was given to me by the tech, it fires right up and idles. A turbo HEP will work, just use the black connector and not the white one. The non-turbo has 4 solid shutters and one HEP. I'll absolutely agree that using this as a trigger input won't be anywhere near as precise as a trigger wheel, but I want to use as many stock parts as I can. My goal with this car was to get it running and just enjoy driving it. Fabricating a trigger wheel on the crank pulley is logistically one of the only means of getting something like that mounted to this engine, but I wanted to try the factory HEP first. I can always get another HEP, cap, rotor, etc., but if anything happens to that trigger wheel, you are going to be down for a while.
So once again, good job on keeping the turbo Dodge lineage going. It warms my heart to see someone still interested in these things. I hope you keep us updated on your progress.
Re: HEP + Megasquirt, someone made it work.
Where there's a will, there's a way! :-) That and the right tech info and experience!
I've always wondered why Chrysler was so enamored with the HEP, and not an inductive type of trigger, etc.
I'm sure there's a reason, just not clear on what it would be, given their dubious reputation for failure...
Just cheaper/easier? They started with the mag pick-up like the older engines, but changed. Why?
Mike
Re: HEP + Megasquirt, someone made it work.
Most engines that I see these days use hall effect sensors on cam and crank.
Re: HEP + Megasquirt, someone made it work.
That's pretty awesome. I might try that sometime.
Re: HEP + Megasquirt, someone made it work.
I'm glad somebody got it to work, but this invites back in a few problems that a crank trigger eliminates.
Re: HEP + Megasquirt, someone made it work.
It gives people options if they can't weld. My friend sold maybe fourteen 36-1 wheels for welding to the crank pulley.
I found 23 psi is about the limit of my factory single coil setup while I can go 28 psi (MAP sensor limited) on the junkyard 420a coil/spark plugs wires with waste spark with no problem.
Re: HEP + Megasquirt, someone made it work.
I'd say that it opens up the option of adapting a hall-effect from another application too.
I kind of like how they did the shutter wheel on the flywheel/flexplate on the cloud cars, TIII. That's one seriously big trigger wheel, which should bring inherent accuracy/tolerance of machining error, I would expect anyway.
Mike
Re: HEP + Megasquirt, someone made it work.
You can just install a 64-2 wheel, much more accuracy and reliable up to 12,000 rpm.
with megasquirt the best way to go is run a crank trigger and make a half moon style shutter wheel for the distributor based hep- you get all the accuracy of a crank trigger with all the cool features having a cam sensor brings.
Re: HEP + Megasquirt, someone made it work.
Quote:
Originally Posted by
tryingbe
It gives people options if they can't weld. My friend sold maybe fourteen 36-1 wheels for welding to the crank pulley.
I found 23 psi is about the limit of my factory single coil setup while I can go 28 psi (MAP sensor limited) on the junkyard 420a coil/spark plugs wires with waste spark with no problem.
are you Harry Lui ? I bought one of those just in case. Nice Piece
weird you had an issue @ 23psi . where is coil mounted ?
I ran a factory coil on the block 4-6" from the distributor and no miss fires up to 31-32psi
Re: HEP + Megasquirt, someone made it work.
Quote:
Originally Posted by
contraption22
I'm glad somebody got it to work, but this invites back in a few problems that a crank trigger eliminates.
I agree , I was actually ready to jump ship for this reason and tunability on the charger
The Seth Butchbinder and Chris Cummins talked me into an Ostrich
FIgured I'd give the factory tuning a try since it's evolved so much over the years
but as soon as I run out of good HEPs I'll probably swap out to the Megasquirt
