JP84Z430HP

I'm bumping this thread to the top due to the number of posts lately that relate to this same thing.

I'm still waiting for N* crank trigger wheel dimensions to finish the drawings, then I will get rollin back into gear on this! I'm going to try again this next week to come up with something!

rattle

well then here ya go, this should be what you need, attached a file that shows how cranks and cam sensors and crank trigger wheel are setup.


Crankshaft Position Sensors and Reluctor Ring
The two crankshaft sensors are located on the front bank (BANK 2) of the engine block between cylinders 4 and 6. Crankshaft position A sensor is located in the upper crankcase and crankshaft position B sensor is located in the lower crankcase. Both sensors extend into the crankcase and are sealed to the engine block with O-rings. The crankshaft position sensors are not adjustable.

The magnetic crankshaft position sensors operate similar to the pickup coil in a distributor. When a piece of steel (called a reluctor) is repeatedly moved over the sensor, a voltage will be created by the sensor that appears to go On-Off-On-Off-On-Off. This On-Off signal is also similar to the signal that a set of breaker points in a distributor would generate as the distributor shaft turned and the points opened and closed.

The reluctor ring is cast onto the crankshaft between the #3 and #4 main bearing journals. The reluctor ring has 24 evenly spaced notches or air gaps and an additional 8 unevenly spaced notches for a total of 32.

As the crankshaft makes one complete revolution, both the A and B sensors will produce 32 On-Off pulses per revolution. In addition, the A sensor is positioned 27 degrees of crankshaft revolution before the B sensor. This creates a unique pattern of On-Off pulses sent to the ignition control module so that it can recognize crankshaft position.

JP84Z430HP

Dude, read the thread, and check out the links. I've gotten that far, I just need some dimensional data.

I've been spinning my wheels here. I've had others say they can help, but that's been months. As stated in my last post in this thread, I'm gonna find what I need one way or another.

rattle

Dude, it dont get any more accurate than that, bust out your protractor, read some angles and make a trigger wheel. could be 5 inches diameter, could be 10 feet, dont matter, look at the size of the notches and the angular placement, all that matters is the correct output signal which looks like this..

JP84Z430HP

What I'm saying is that the size of the notches need to be proportional to the diameter of the wheel. Therefore, I need to know the diameter of the factory wheel, along with the size of the notches. If I had a crank to look at, I could also get a grasp on the relationship of the notches to #1 TDC......

I'll get the info and get this thing firing sometime soon!

Thank for that second pic with the scope pattern. That's the first I had seen of that one, although I have seen the crank/cam sensor live scope captures.

ED89

Check out the northstar dis.pdf in moates misc section.

89 Iroc Z

I am bringing this post back from the dead…

Back when this thread started I did not have enough knowledge of how everything worked to actually be able to work on using Northstar DIS with 7730. Now a few years later I know a lot more, still not nearly as much as a lot of guys on here, I am putting some work into it trying to make this a reality.

I bought a Northstar crank on E-bay some time ago but never actually got it CADed out until now. My roommate did the CAD work and I figured out the measurements.

Here are the measurements taken for my post in this thread (I think the information is more relevant in this thread):

Each of the 32 notches on the crank trigger wheel is 7/30'th of an inch in length and 1/5'th of a inch deep. There are 16 small raised area's which are about the same length as the notches, they are 13/60'th of a inch. There are 16 large raised area's which are about 3 times the length of the notches and measure in at 41/60'th of a inch.

So calculating in a percent of error for machining tolerances, each notch and small raised area are the same length. The large raised area is three times the length of the notches.

The above broken down into degrees:
- 32 notches 3.75 degrees in length
- 16 small raised areas 3.75 degrees in length
- 16 large raised areas 11.25 degrees in length

The thickness of the trigger wheel is 4/15'th of a inch. The diameter of the trigger wheel is about 6 & 15/16 inches. Sorry about the weird numbers I left my measuring caliper at home and am using 1/60 engineering scale engineering ruler.

The CAD is perfectly accurate of the original crank. I have printed out and compared it to the crank and it is accurate. If you want a copy of the AutoCad file check out my website: http://www.lukeskaff.com/car/northstar/design.html

89 Iroc Z

Here is a picture of the crankshaft trigger wheel. This is a mirror image of the above CAD image because you are looking at the trigger wheel from the back side of the engine. The crank was cut in order to get more accurate measurements.

89 Iroc Z

Not many people know this but some mid 90's Mastercraft boats came with a LT1 and Northstar DIS ignition, it was an option on some boats in the Prostar series. They did not use an opti-spark optical pickup; it used a crank trigger wheel. They also used a marine EFI computer, pretty much just a marine version of the ECM that comes with the ramjet create engine and such from what I have read.

If anyone has access to shop manuals, service diagrams, part numbers, or pictures on how they went about mounting the crank trigger on the LT1 crank, please let us know. My plan is to mount the trigger wheel after the balancer and before the crank pulley. I would use a corvette crank pulley since it is shallower and machine an aluminum spacer to space it out to factory spec.

Here is a picture of a LT1 Mastercraft boat engine with the Northstar ignition setup.

Also take a look at this pic

EDIT: I updated the picture to one taken at a better angle

JP84Z430HP

From my understanding, the boat pieces are from the LT5 vette engine. Similar, but not at all the same. Simpler trigger wheel, but more expensive parts (By a LOT!)

This was all commented on earlier on in the post, but the pic link was bad, glad to see pics of it again!

89 Iroc Z

I highly doubt it is not the LT5 setup or similar to it. For one the LT5 ignition module looks completely different. Also in the Mastercraft sales paperwork it says "Northstar Ignition system"

Also check out these links to see the northstar ignition mentioned:
Check the 5.7L LTR engine
http://www.boatingworldonline.com/Bo...?CD=17&ID=3644

I also found a PDF manual a while ago that said the northstar ignition, but I can't find it anymore.

JP84Z430HP

You're talking about 2 different engines!

The LT1 version, from what I've heard, nothing definate, is said to have the LT5 system. It's really a trivial issue. It would be nice to know how they trigger it if it is the N* setup, but not all that big of a deal.

edit: With that said, that DOES look like the N* setup. I'm pretty sure the older picture that I saw had the LT5 setup on it.

89 Iroc Z

I was also referring to the LT1. You can see in the pics I posted above, the LT1 uses the northstar ignition too. There may be other boat brands or models that use the LT5 but mastercraft never seemed to use it for all the research I have done.

wake77

would someone be able to send me a copy of the autocad file for the trigger wheel i'm having a go at setting up this ignition module on the 808 ecu

Thanks Ross

JP84Z430HP

I'll see if I can in a few days after I get the rest of the software (Cad) re-installed on my computer after last weeks crash....

jwscab

See if this works. Here is a link to the other thread regarding northstar stuff. I posted some pictures of that I have running on my bench. Please read through it, it goes into details about how I made mine, and the dimensions that are critical.

https://www.thirdgen.org/forums/diy-...ight=northstar

wake77

JP84Z430HP any luck with the cad files?
well my module finally turned up and i am about to start putting it all together. does anyone know where i can get some connectors for the module i have found some on the net but they are expensive, secondhand would be fine the only thing is i'm in australia and can't find anything down here with the same connectors

89 Iroc Z

I have put up some info on my website but haven't worked on the project for sometime. http://www.lukeskaff.com/car/northstar/design.html

Attached is a copy of the cad file I made.

wake77

thanks for the cad files i finally got around to getting a disk cut out
and i set it up on the bench for a test. i found that you do need the 2 crank sensors hooked up to get spark, maybe if you have a cam sensor you can get away with 1 crank sensor but i definately needed both connected for it to work
i'm still fabricating brackets to mount it on the car but hopefully i should have it up and running this week!

wake77

ok i got all the gear mounted to the car this weekend and it is half working, it controls the timing fine up to about 3000 rpm and then cuts out the ignition all together. i'm not sure if it would make much difference but the trigger wheel i got made up is smaller than an original the outside diameter is about 5.5 inches but i scaled all the notches, also the sensors i'm using are not from a northstar and i wasn't sure if they might be my problem.
if anyone has any ideas that would be great
thanks

jwscab

As far as scaling the notches, how wide did you make them? The notches need to have enough gap to allow the sensors to fire correctly. Its hard to explain, but the notches have to be wider than the small metal tip on the sensor end, so that there is a clean transistion on the leading and trailing edge of the notch. The way this system works, the notches do not provide any duration information (like, so many degrees wide), they are used to give a relative position (like, positioned at 30 degrees). the actual voltage spike that is measure is in the transistion from negative to positive voltage, if you take a closer look at the waveforms, you'll see it's kind of like a sideways Z kind of picture. the circuitry triggers on the center 'zero-crossing' so if the gap is too narrow, and the wheel is fast enough, I can imagine that the sensor is getting messed up.

there is also the issue of making sure you're max and min spark retards are set-up properly. There is some information here in threads, I can't think off-hand, except there is a guy running one in a fiero (northstar engine running on '730 ecm).

I haven't gotten this running yet, so it's hard to say if its the first issue or the second, but I do know there was some concern about the notch widths, and it's really not as critical about the width provided its WIDE enough. That's the straight-up elctro-mechanical physics, regardless of the fact it's a automotive application. You can search on variable reluctance sensors and find out more info, if you are interested.

wake77

i pulled the module off the car and set it up on the bench whith the wheel and sensors on the car and guess what it also looses spark at about 3000 rpm, i wanted to prove to myself it didn't have anything to do with the ecu in the car.
i also checked all of my wiring and i had the vr sensors wired wrong the positive and negative were around the wrong way on both the A and B sensor so i fixed that up then i couldn't get it to run on the bench, when we first set it up we had a little trouble with getting the angle of the sensors correct it didn't seem to work at 27 degrees we put them closer and we got spark so i didn't wory about it, so i started to adjust the sensors again after i corrected the wiring and got it to fire up again but the sensors were now at 30 degrees but it still looses spark at about 3000 rpm

so i then hooked up a Oscilloscope to the sensors on the bench and the signals from the sensor looked ok but i don't know how sensitive the module is.

the notches on the wheel that we made are 5mm wide and about 4mm deep and the tip of the sensor is about 5mm also so i will widen the notches a bit.
do you think they could also be deeper.

so i will try again and let you know how i went

jwscab

well, I'm not sure on the depth, since you aren't using the stock sensors, if I read your post above correctly. I would make them as deep as they are wide, at a minimum. If the sensor tip is about 5mm, I think I would shoot for around 7mm min. definitely deeper will be better, but it really depends on the physics of the sensor. if you have the original application for the sensor, you could study what they used for a notch. That's kind of odd, I'll have to fire up my bench and take it as high as I can with the motor I'm using to spin it(gets a little shaky), see if I see the same phenomenon.

wake77

ok i finally got it working it turned out to be the angle between the 2 sensors, by changing the angle by less than about 0.5 of a degree it now revs to injector cutout which is set to 6200.
i didn't think it would be so critical but looks like it is i haven't pulled the brackets off again to measure the angle i now have but when i do i'll post it up.
thanks for the help

jwscab

wow, sounds touchy. How close to you have your sensors to the trigger wheel? thats great you got it working though! Can I ask what your combo is? engine? ecm? code? changes?

wake77

i think the sensors are about 3mm from the wheel
the engine is a 5.0L V8 in an australian commodore it has been stroked to 5.7L and am running a T-Trim Vortech supercharger with a 1227808 ecu i'm using the standard code but have rescaled to use a 2bar map sensor and the only code change i had to make for the dis module was the spark referance angle.

jwscab

thats a very cool combination ya got there. 3mm sounds about right, maybe a touch too far away, but if its working, thats awesome. So I'm guessing you put the sensor where the cadillac sensors are(relative to TDC), and set the reference angle. That would be about 30 degrees or so? From what I'm measuring, thats where I think it should be, but its just running on a bench right now.

wake77

i mounted the sensors where i had space and then just mounted the disk to suit the sensors, the referance angle in the software was 70 degrees.

The other bit that has me puzzled is earlier in this thread there was mention that you only need 1 sensor for it to work and they only use 2 sensors for faster startup, the thing is i could not get it to work with 1 sensor, and with 2 sensors connected it is always the same coil that sparks first no matter where the disk starts from. now that doesn't sound like a fast start to me.
do you think that you might need the cam sensor for fast start?

jwscab

cool, thanks for the info.

I doubt the cam reference would make it start any faster, but who knows. I suppose it does spin faster at the cam, so it might be an interesting thing to try(though probably difficult). I think I read that it could limp home with a single sensor going bad, so it might be a combination of any 2 of the 3 that they refer to. maybe? that might be where there was a 'single' sensor reference.

does it have a long crank time?

Rocket-Doc

iTrader: (11)

Anyone heard anything on this? Been dead for a while, still hoping that someone will strike gold........

Forgive my Ignition ignorance, if the LT1 optispark is nothing more then a front mounted optical distributor, why can't we get the TBI setup equivelant to that and just use the Opti to DIS conversion? I dont remember the Opti needing 2 crank sensors in the block..... http://delteq.com/Manual_r3.pdf

jwscab

you could build a distributor that houses an opti-wheel and trigger. then you could use a delteq conversion. Its about the same amount of work to build a trigger wheel thats crank mounted, with the Nstar sensors on a bracket, as modifying a distributor to house the opti. There is one major flaw with this: the set-up talked about here is still controllable (with no extra hardware) with a '730 type ecm (OBD1, TPI). when switching to the opti-wheel, you now need to use an LT1 style ecm, which in itself isn't a bad thing. Of course, if you can write our own code, you can use just about anything you want.

wake77

i've been playing with this for a while now and still haven't got it reliable, and am pretty sure it is to do with the sensor gaps, i can close the gaps up close and it will start fine but it won't rev, then i can make the gaps larger while the car is running and it will rev fine but if i turn off the car it wont start again. now i'm thinking it could be a case of my cranking rpm isn't fast enough it's only about 170rpm. could someone tell me what the cranking rpm of the northstar engine is.

Thanks Ross

Corner Worker

hmm....

wake77

I have had it working reliably for a while now it turned out to be the wheel size the first one i made i scaled down to 140mm and it just wouldn't work 100% so i made some more modifications so i could fit a bigger wheel which was 175mm and now works fine.

???

iTrader: (5)

did you use one of the cad drawings in this thread? or just cut up a stock crank and use that.

wake77

yeah i used the cad files and had the wheels laser cut.

???

iTrader: (5)

sweet.. i had a friend check out the file and all looks like a go for making up a test wheel very soon. but...


one thing i need to know is the clocking of the wheel to the sensors. well which sensor too since there's 2 of them. i see that the drawing is numbered 1 and 2 but i doubt its as simple as just setting the motor at TDC and lining the tooth thats numbered 1 in that pic with sensor #1. i need to figure this before i can have my friend add the 3 holes to bolt it on the balancer with then cut it out.


i'm pretty sure i understand the code changes, as with this project it seems to be the easy part. but here's the link with the info about it that makes sense to me.

http://www.diy-efi.org/twiki/bin/view/Gmecm/DISdist

wake77

if the engine is at TDC and you line up the notch labeled 1 to sensor A it should be fine. and that should give you the base timing at 10 degrees BTDC for startup before the ecu takes over.

???

iTrader: (5)

sweet... thank you.

???

iTrader: (5)

to update this thread, my buddy's 93 lt1 with northstar coil packs and a 727 ecm running $8D(soon to be $59 for a turbo build) started and ran last night.


as for that 70* reference angle, this post says thats all that was done to the .bin. but this one seems to need more. i'm guessing more along the lines of changing the min and max spark values like the diy-efi link talks about . figured i'd ask if you had to do that and hope the e mail notifaction goes thru.

next i'm going to go find the S_AUJP_V4 thread and see if anyone knows the address to the min spark value. it doesn't seem to be definded in my .xdf for it.

afgun

Video? Details?

???

iTrader: (5)

we snapped some pics, but no video, really should have. he couldn't get the cad file in this thread cut, so he laid the wheel out by hand and mounted it behind the crank pulley. it turned out well. the details are, its a 93z28 that the opti went out on, instead of buying a new one, the coil pack idea came up. so he used the info in this thread to build a wheel, hit the junkyard for sensors, coil packs, 727ecm and icm. I found a wiring diagram for a 727 tpi vett and the 93lt1 and made up a repin text file. he then repinned everything, dropped my prominator in, loaded up s_aujp, sorted out a injector ground I missed and bam, it started and ran. I think I've figured out a work around for the code for timing. I'll head over and try it in a few days(he lives 45mins away, so most of this has been done over the phone), because just changing the ref angle to 70* is not it lol. I found some stuff on the code59 board about getting some 3.8 buick's to run 59 and going to try that.

???

iTrader: (5)

here's a quick cut and pasted from a local thread about it. it has some pics

RBob

iTrader: (1)

For the 70* BTDC offset in the initial timing need to change three calibration parameters. These are the Initial SA, the maximum SA, and the maximum retard (sometimes called minimum SA).

For the maximum values just need to offset them by the 70* of original initial value. The trick is that these two parameters are two bytes each in 2's compliment. So a value such as 65508 is -10*

65536 - 65508 = 28, 28 * .352 = 10, which is really a negative number, so make it -10*

So either need to have the ECU/XDF entry correct (most are not), or just edit the BIN by hand.

As an example for a DIS set up running at 60* BTDC initial timing, here are the values:

This shows the hex value, the decimal value, and the converted value.

RBob.

???

iTrader: (5)

i think i follow you, but in the xdf i have, there is no min spark definded. so i would need that address to input the max retard values you've giving, right? how would i go about figuring that out.


but while your answer sounds like the diy_org link. whats not fully making sense to me is the 70*BTDC thing. judging from how the car ran with 70 in the referance(and i tried 0) then finding this thread on getting 59 to work with a dis. http://www.code59.org/index.php?opti...=5960&catid=12

it almost seems like the 70* is ATDC and you have to add back 70* (setting the referance to 0* and adding 70* to the max SA) to make it end up at the number you put in the spark map being BTDC.

i'm not seeing it at the moment but your way does seem like its the right way to do it. and i'm pretty sure you've done it and it works. since i know very well from reading this board, that you understand this on a whole other level than most people. the other way seems like a work around. but i don't see how both things end up working, since more than one person reports the adding timing thru bias and timing tables works.


i'd try both before asking, but since i can't without knowing where to put the min spark value in? i'm tying to understand what i'm doing.

???

iTrader: (5)

i may have found the address from searching around the gmecm stuff.



i'm thinking L8028: is the location i need to know to add this to my TP xdf? disassembling a bin and hand editing is still something i haven't tried yet and not really sure how.

syntax terror

??? Any progress with getting this running on s_aujp_v4? I am using a1 code set up Running a Northstar on a 1227730 ECMbut would like to try the nvram on the *star.

???

iTrader: (5)

no i haven't had a chance to get over to his house. he works early and i work late shifts. so this weekend will be my first chance.

so you have it running on the 730? only using the bin from that site. i may download it just to take a look at the reference angle and stuff.


anyways, i have 2 ways i've found to throw at this. i'm going to try the way that seems right and if that doesn't work, i'm going to try the other way. one of them should work.

i have found a $8D .xdf and .bin for a dis v6 that is said to work right. if you have quick access to your car and want to try changing the number of cly's and dump it in and see what happens. i'll forward you the link. i was going to wait till i tried it to post it here.

i don't know much, but it does atleast look like the .xdf has the max spark retard defined right. along with a different formula for max spark, than the S_aujp. i don't know which is right yet.

so looking at that site, the A1 code is hacked for logging a wideband too? if all else fails, i may have to go that way. so thats cool.

syntax terror

Ryan Hess did that bin. He also has bin set that will go to 8500 rpm the north star likes to rev. I don't have the engine running yet .

junkcltr

iTrader: (1)

Is there a PDF, GIF, BMP, JPG floating around with the dimensions of that trigger wheel in post #143? One that could be printed out actual size on a piece of paper.