MegaSquirt trigger wheel sensor solution, What's your design?? Options

[draganc]

Hi guys!

I’m planning to upgrade my D-jet system on a 75 2.0 (2056) with a MegaSquirt system.

I’m still debating how to mount the trigger-wheel-sensor and would like to see some of your solutions.

Thank you for your input,
Dragan

[DNHunt]

Trust me, I really don't want to have to screw withMS, because I still have scars from it.

Here are my experiences with MS failures. I had 2 failures with wires coming loose because of solder failures at the DB 37 connectors to the Megasquirt board. Both times I was stranded. I had 1 injector driver go up in smoke on an MS1 board but that was in the garage and I hooked stuff up wrong.

And, I had the king of all failures on Jake's dyno where I could not get a tach signal for some unknown reason. When he said he has the scars from it, he's telling the truth. He got some nasty burns on his hands. He grabbed a 12 gauge wire we ran from the battery that shorted to ground on the dyno. His fast thinking and action may have saved all of us from going up as the wire ran across fuel lines. I hate to remember it, that was a really bad day. I never did look for what caused the problem, cause I never unpacked the MS I shipped back home.

That system is only as good as the builder and installer. I think the the weakness is all the soldering and the hodgepodge of used parts people use.

Since then I have run SDS. It is OK for the most part. I don't like the tuning module/ screen. I miss tuning on the PC. It is simple for sure. I had problems at altitude at Tahoe for WCR where it over compensated for elevation gain and ran lean. I had to bump the fueling by using the tuning knob. I also had starting problems that disappeared when we got back down the hill. The acceleration enrichment has been impossible to tune and I live with a bogging down at really low rpm. I'm not often down there but, on the occasional AX course it is a pain cause it forces 2 extra shifts. I would say it is a pretty good electrical carb.

Dave

[JamesM]

Trust me, I really don't want to have to screw withMS, because I still have scars from it.

Here are my experiences with MS failures. I had 2 failures with wires coming loose because of solder failures at the DB 37 connectors to the Megasquirt board. Both times I was stranded. I had 1 injector driver go up in smoke on an MS1 board but that was in the garage and I hooked stuff up wrong.

And, I had the king of all failures on Jake's dyno where I could not get a tach signal for some unknown reason. When he said he has the scars from it, he's telling the truth. He got some nasty burns on his hands. He grabbed a 12 gauge wire we ran from the battery that shorted to ground on the dyno. His fast thinking and action may have saved all of us from going up as the wire ran across fuel lines. I hate to remember it, that was a really bad day. I never did look for what caused the problem, cause I never unpacked the MS I shipped back home.

That system is only as good as the builder and installer. I think the the weakness is all the soldering and the hodgepodge of used parts people use.

Since then I have run SDS. It is OK for the most part. I don't like the tuning module/ screen. I miss tuning on the PC. It is simple for sure. I had problems at altitude at Tahoe for WCR where it over compensated for elevation gain and ran lean. I had to bump the fueling by using the tuning knob. I also had starting problems that disappeared when we got back down the hill. The acceleration enrichment has been impossible to tune and I live with a bogging down at really low rpm. I'm not often down there but, on the occasional AX course it is a pain cause it forces 2 extra shifts. I would say it is a pretty good electrical carb.

Dave

I will through a few thoughts in here for the sake of anyone looking to go with Megasquirt in the future.

Relay board - If you have not done a megasquirt install before, use the relay board. It will make things a lot easier, cleaner, and it has everything already fused in case you miswire something.

On the DB-37 connector/cable - This is in my opinion probably the weakest link hardware wise on a standard Megasquirt install and for that very reason has been eliminated from the boards that I use. It is not at all suited to what it is being used for. The gauge of wire that Megasquirt should be using is much bigger then this connector was designed for. It is a connector used for data transmissions, not passing current for injector circuits. That being said, ways to make it more useable....

Don't use the solder cup style connectors, only USE ONLY CRIMP PIN CONNECTORS and buy wires that have already been machine or professionally crimped if possible. I have no idea why they show it done this way on the Megasquirt site, it’s just a bad idea. This is an automotive application and vibration will kill hard joints at the end of a wire in no time flat. To make the problem worse the size of wire you need to use is to large for the solder cup, and most people are not going to be able to get the proper heat to the metal to form a proper solder joint without melting the plastic in the process.

Which brings me to my next point...

SOLDERING
Really the only soldering you should be doing is on the board itself, as stated before automotive wiring harnesses should not have soldered joints in them. If you are going to attempt to build your own board, DON'T use your typical RadioShack 15w/30w soldering iron to do this. Get a good fully temp adjustable soldering station and multiple tips that are able to apply a lot of heat to a concentrated area fast. This makes a world of difference in terms of the ease of assembly as well as the quality of your joints. As for the joints themselves, you should be melting the solder on the pins/pads when you are soldering not on the tip of the iron. If you can’t get enough heat in the joint to melt the solder on the pins/pads then you will have a bad joint. To much heat can also be a problem for the components, which is why you need a good adjustable iron.

Hopefully anyone building a Megasquirt should already know these things, however as I have seen more then a few bad/scary Megasquirt builds I am posting all this here for the sake of anyone who doesn’t.