Dougs951S

I'm getting pretty close to finishing the preliminary build of my car (Read: Until I blow the 2.5 liter up) and I'm really strongly considering going with a microsquirt stand alone. I have access to one right now already stuffed into an old N/A DME. Both the n/a dme and the 951 dme are 35 pin so it should fit into the connector, even if it takes some wire swapping to get things where they need to be. Its setup to run speed-density tune with just a 3 bar MAP sensor. Microsquirt has native support for dual ignition inputs so it works with the factory S&R sensors and ignition system. I've been told that I would also be provided maps that would get the car driving, though it is only mapped for 1 BAR absolute. I don't know that much about mega/microsquirt or speed-density tuning. Obviously the 951 DME is not the same as the n/a, plus the ignition goes through the KLR in the 951 so that would have to be addressed. It'd be simple to delete the KLR, but I like its functionality with respect to monitoring knock and I think I'd like to keep that function if possible. For all I know, the microsquirt ECU may be perfectly capable of handling overboost and knock protection with stock hardware. Obviously it would take some rearranging of wires to make it work in a 951, but I'm really interested in it. This is going on the same car that will likely be getting a prototype ITB manifold soon, and eventually a hybrid stroker engine so it is fairly radical. Does anybody have anything to say about it? Anyone know where I could get some maps for it? How much dyno time is needed to get a solid tune? Obviously it is unlike a MAF tune and is not readily self adapting to engine modifications and boost levels since it relies on a VE table lookup to estimate airflow, so any mods that change VE like a new intake or exhaust would require a retune. Does this mean I am also locked into tuning for one boost level, since the other main variable besides VE is MAP?

jlturpin

Pm sent

Dougs951S

I've got the MS wired up and installed, and all the sensors work properly. However, I'm having issues getting a good spark. I'm running with the KLR powering the coil, but my ignition and tach signals during cranking are not right. They are way too fast, its picking up 7k-8k rpm during cranking and my tach redlines. I'm running the MS tach output to DME pin 21 which is also tied to the MS ignition output going into the KLR, but i'm not sure that is right. I assume the proper way to set up the squirt to work with the stock VR sensors is by setting it up to read the starter ring gear like a reluctor wheel, but I can't seem to find settings that work. I know the turbo ring gear has 132 tooth and the sensors are located at 58.6 degree BTDC. Does anybody have any tips on how to configure tunerstudio MS to pick up the twin crank VR signals? I'm getting pretty frustrated with this, I feel like I'm on the cusp of getting it started. Does anybody have a .msq file from a running car that was using the stock sensors

Edit: I've just been informed that the KLR is not capable of directly driving the coil so I'll be returning to the bosch BEP373 high current driver setup and ditching the KLR (again).

Dutch944

Hi Doug,

Friend of mine has a perfectly working Megasquirt with all the mapping already done for the 951. Sent me a PM and i'll give you his contact details, if you're interested! At the moment his car is not running but that's only due to the broken turbo..

Grtz,
Bas

Dougs951S

I have spark again, using the bosch high current driver. I set the ignition settings in tunerstudio to run with a missing tooth wheel, 120 teeth with none missing, tooth #1 at 58.6* BTDC. I know the ring actually has 132 teeth but I get a tooth count/number of cylinders configuration error if I try 132 or 130; I'm not really sure what that means. I picked 120 because it was a nice round number that 4 went into evenly, and I'm getting a much more normal crank signal now. During cranking the highest spike I saw was 270 rpm vs 8k before, and I confirmed it is sparking. However I am still not getting the spark when the compression is, and now I definitely know its just an ignition settings issue.

Dougs951S

I have NOT gotten it running yet and too my knowledge, only ONE person here has gotten their car to run well to redline using microsquirt and the stock sensors. Other attempts have met with noise issues above 3500 rpm that cause MS to loose the crank signal. I will be going to a 60-2 setup eventually with LS1 COP once I get everything ironed out, but I REALLY wanted to get the car at least up and driving with the stock sensors for a short while before going through the hassle of welding a reluctor wheel to my crank pulley and fabbing a mount for a sensor. Fords are a ready source of 60-2 wheels so it isnt like the cost is a factor, I just simply didn't want the hassle and I specifically went with the microsquirt and not the similarly priced and more powerful megasquirt v3 board because only the microsquirt natively supports twin VR crank triggers.

I feel pretty confident that some clever use of diodes and resistors should be able to keep the crank signal clean to redline if I could just figure out the proper way to make tunerstudio read it in the first place. I just wish somebody who managed to get their car to start with stock sensors would post their ignition settings or a .msq. I've tried to find information from other cars that use dual crank sensors with no cam reference but the only one I could think of was the BMW M20 engine. Amazingly, I was not able to find anything useful.

Dougs951S

*sigh* and the stock DME does it so well...
Looks like I might be upgrading to a reluctor wheel a bit sooner than I thought. The 944 crank pulley is 126mm in diameter and I'm not running AC or power steering, so I'll need to find a ~126mm diameter reluctor wheel. Not sure how big the 36-1 wheels off the fords are, I'll have to find out. I had the idea of taking one of the stock sensors and extending the harness to reach the crank, and seeing if I could get microsquirt to run using the starter ring gear as TDC reference and use the front mounted wheel for speed signal. I dont plan on exceeding 6400 rpm so I dont need amazing resolution.

The wheel from the ford escort appears to be 5" diameter, that might be perfect to attach to the spare crank pulley I have laying around..

Dougs951S

The thing here is, I don't want this to become an engine out operation..and lucky for me with the way I've got everything wired up, its still all hotswappable and I can have the car running on the DME and KLR in ~10 seconds. My desire to use the stock sensors is 100% based in wanting to keep this ability to swap if need be. I never DREAMED it would be this complicated.

Dougs951S

Fascinating, can you tell me a bit more about that? Does it work along side the built in conditioning circuit, or does it replace it? With everything being surface mounted and sealed water tight in the microsquirt, if the later I dont know how I'd wire that in. Sounds very promising though, I like the idea of an add on board much more than pulling the motor to weld on the crank.

At 28 bucks and some solder, the price is certainly right. I wonder if this logic is similar to how the DME derives a clean crank signal?

Dougs951S

I dont think any other components are needed, from what I've gathered reading the thread, you just need to solder in a few jumpers to configure the board the way you need it, then put it inside an insulated case and run the wires to the microsquirt.

Dougs951S

You are correct, I sent him an email asking a few questions so it's definitely an option. I am still looking into a few others, I'm still holding out for a way to make the stock sensors work since I know for certain that it is possible and that it can be made to work well. I am keeping my options open though and I expect this to develop more in the next few days as I gather more information and weigh the costs/benefits.

86 951 Driver

Has anyone thought about using a LS 1 based computer on a car like these? Off topic. Sorry.

Cool stuff in this thread. It could open a whole open source stand alone.

86 951 Driver

Doug have you checked Pelican parts forum. There was a guy ding this exact thing in there. I believe he got the car to run as well. It was an NA though.

67King

FWIW:
https://rennlist.com/forums/944-turb...squirters.html

https://rennlist.com/forums/944-turb...ck-wiring.html

https://rennlist.com/forums/944-turb...read-pics.html

pa951

My sensor is on the front. The most easy place to mount it imho.