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View Full Version : Miata CAS and Crank Sensor?



networkingdude
02-03-2009, 11:14 AM
i have a fwd bp which is in my 1998 protege. I ill be using the miata CAS in place of the stock distributor so i can run coil over plugs. Will i need to use the crank sensor as well as BOTH signals from the CAS? Or just the CAS? Or one from the CAS and the one on the crank?

And are there any differences between the Miata and 2nd Gen Protege crank sensors?

I will be running sequential injection and ignition by the way.

Any help would be great!

mx-3_4evr
02-03-2009, 11:18 AM
are you running the sock ECU?

323driver
02-03-2009, 02:52 PM
Are you using MS? You can't run sequential injection with MS, there is only 2 drivers. For ignition, you can use the protege 4-1 cas with COPS.

networkingdude
02-03-2009, 04:31 PM
its going to be a haltech e11v2 or a platinum sport 1or 2k

i know about megasquirts limitations and thats why i want a haltech but I am unsure what I will need for triggering

Does the miata just use the cas and no crank signal because the cas has 2 signals?

atomicEGT
02-03-2009, 05:36 PM
Bleaugh, Haltech.

The year Miata you're talking about changes what is going on. 94-97 had the distributor-style CAS and no crank sensor. 99+ moved the CAS to in front of the crank, and removed the old cam-driven sensor.

networkingdude
02-05-2009, 11:58 PM
so its just the cas that i need? no cam sensors or anything more than the cas? I just need to make sure guys. I want to do it once do it right.

EDIT: I'm thinking i should use the crank sensor for my main signal and one of the 2 outputs ( CKP or CMP ) of the cas as my secondary.

Lex
02-06-2009, 10:05 AM
The protege crank wheel has 4 teeth, so that is twice the resolution you need for finding TDC on the cylinders. If you want sequential firing or spark or ignition you also need a cam position sensor so that you know where TDC of cyl 1 is. Or you need a missing tooth crank wheel.

For true COP and sequential firing the Miata CAS and crank wheels won't help you because you won't be able to tell when cyl 1 is at TDC. The Miata/Protege system are meant to run batch fire and wasted spark. When people run COP on the Miata, they run the COPs in wasted spark mode. So they still fire 2 COPs at the same time.

The 4-1 Disty of the older protege will help you locate cylinder 1 because it has just 1 extra slot in the cam wheel for cyl 1. So you actually can run full sequential COP and injection on a 4-1 cam wheel if the haltech allows it BUT your engine speed resolution is as poor as it can be.

I recommend using a missing tooth crank wheel for the higher resolution and ability to identify TDC of cyl 1. You will have to retrofit this to your crank pulley.

networkingdude
02-06-2009, 11:29 AM
ok, so if i just want to do batch firing can i do sequential ignition?

can i use the protege crank sensor and the miata cas together?

can i use just the cas by itself for batch?

if i get the missing tooth wheel do i still use the miata cas?


i'm really tiring to figure out all the options i have and I relly do appreciate the help guys.

EDIT: I also have a dizzy from an EGT and would prefer not to use it for ascetic reasons

networkingdude
02-06-2009, 12:09 PM
also, what are the effects of having poor resolution? Bad timing?

323driver
02-06-2009, 12:10 PM
protege has no crank sensor. Just use the protege disty as a cas and it should be enough for COP sequential ignition and batch firing. Just remove the cap and rotor off the dizzy.

networkingdude
02-06-2009, 12:14 PM
protege's DO have a crank sensor

and removing the cap would leave it exposed to the elements

networkingdude
02-07-2009, 10:47 AM
well can someone at least point me to an article or other post that discusses miata cas's and crank sensors then? I can't seem to find any :wtf2:

atomicEGT
02-07-2009, 04:48 PM
Miata.net and Soloracer.com both have information about them.

networkingdude
02-07-2009, 08:54 PM
thanks for the help

could still use some more input on options

Lex
02-07-2009, 11:08 PM
Ask Haltech tech support if they support sequential injection and sequential COP using only a 4-1 cam wheel on a 4 cylinder 4 stroke motor.

networkingdude
02-08-2009, 02:34 PM
i will ask and post my results back here in case someone else wants to go the same route

ftjandra
02-08-2009, 03:00 PM
I am pretty sure that the Haltech can use a 4-1 cam trigger for sequential inj/ign, but as Alex already said, the timing resolution at fast rpm changes would be horrible.

--Ferdi

networkingdude
02-08-2009, 07:03 PM
I am pretty sure that the Haltech can use a 4-1 cam trigger for sequential inj/ign, but as Alex already said, the timing resolution at fast rpm changes would be horrible.

--Ferdi

you guys say the resolution will be poor? I thought that the resolution would be good as long as the ecu was fast enough. Now comparing the resolution you would get using the 4-1 on a megasquirt IF it could do sequential would probably be poor... I get that... BUT since the haltech is quite a bit faster would is still pose a problem?

networkingdude
02-08-2009, 07:30 PM
and are there any books or websites that go in to ridiculous detail on crank triggers/cam triggers that tell you everything about this stuff?

ftjandra
02-08-2009, 07:31 PM
I don't think the MS is slow and I don't particularly think my E6X is fast.

Basically, the ecu can't detect fast rpm changes because there are only 4 teeth that are spaced very wide apart - equal to 2 teeth on the crank. The ecu measures the time between each tooth to figure out the rpm. So, obviously the more teeth you have (spaced closer together), the faster the ecu will be able to figure out that the rpm is changing. Whether this has a real affect I can't say.

You see how it has nothing to do with processing speed of the ecu, but more with that it doesn't get enough info?

Btw, I fitted a 60 tooth wheel onto the crank and used the cas sensor for the sync event. I am running sequential injection and waste spark ignition because that's all my E6X can do.

--Ferdi

networkingdude
02-08-2009, 07:37 PM
the e6x compared to the ms would be similar however the platinum 1000/200 are much faster

but i get your point and understand what you are saying

I am just confused as to what negatives poor resolution would have?

and if i need to end up fitting a trigger wheel who makes a kit? Do you have pics of your setup Ferdi?

ftjandra
02-08-2009, 07:49 PM
Well, if the ecu doesn't know what the exact rpm is in 'real-time' how will it know when to send the spark (timing) or how much fuel to inject? If the rpm is changing fast, like on the drag strip, the ecu would always be lagging behind just a few milliseconds. Like, I said, I have no idea how much of a difference it really makes.

I am using an aftermarket crank pulley (ATI) that I fitted a 60-2 trigger wheel onto.
http://www.ferdster.com/94ProLX/misc/ati_damper_trigger_tm.jpg (http://www.ferdster.com/94ProLX/misc/ati_damper_trigger.jpg) http://www.ferdster.com/94ProLX/misc/ati_damper_installed_tm.jpg (http://www.ferdster.com/94ProLX/misc/ati_damper_installed.jpg)

Btw, how do you know the processing speed of the Haltech ecus? Do they list what processors they use inside?

--Ferdi

networkingdude
02-08-2009, 07:56 PM
wow... I was thinking of using the ati damper as well. Did you make that trigger wheel? And how do you have the sensor mounted? Is that custom as well?

As for the Haltech you have is 16bit and 16mhz, the newer ones are 32 bit and 56mhz Motorola processors i believe

networkingdude
02-08-2009, 07:58 PM
I also dont see the ati FIX on you pulley, did you omit this in your install?

Lex
02-08-2009, 08:08 PM
What I was getting at with poor timing resolution was that if I were to improve my ignition system, I wouldn't consider anything more than wasted spark until I was able to detect changes in RPM faster than what a cam wheel on a belt could.

That being said, the higher resolution of modern cars greatly helps in terms of emissions improvements during engine transients and fault detection (misfires, etc)

ftjandra
02-08-2009, 08:17 PM
The trigger wheel is one from electromotive. I bored out the center and drilled the mounting holes. The sensor mount I made myself. You are right, those pics don't show the 'fix' because I was one of the first guys to get one. I later added the fix, which required the center of the trigger wheel to be machined down. This (http://forum.miata.net/vb/showpost.php?p=2971682&postcount=11) post on miata.net has pics with the fix isntalled (you must be a member there to have known about the fix?).

Ah, interesting about the processor speeds. I wish that the communication between the E6X and the laptop would be faster, but that's the only time I feel that it is slow. I think a lot has to do with the Halwin software, which from my experience with it does not seem very well written.

--Ferdi

networkingdude
02-08-2009, 09:00 PM
well... you guys have me convinced! I'll see about getting a trigger wheel made up.

If i can't find a shop or sutable trigger that i can fit to the ati do any of you provide such a service?

Now to clarify why i want to go through all this trouble when i know wasted spark or a dizzy would work is because I love to tinker, i need to learn, and it just seems to be a better way to do things. I still may even end up with a MS depending on my budget.

Haltech has new software for their newer units and they use usb so it will be much faster

EDIT: which part number or what specs are for that trigger wheel? And how much did you have to machine it?

ftjandra
02-08-2009, 09:17 PM
I used the 6" diameter 60-2 trigger wheel (electromotive part# 230-72660). I don't have the specs of how much I machined off, but once you have the ATI pulley you should be able to easily measure it. Another option I have seen is to mount the trigger wheel on the front of the stock crank pulley. It's not as exact, though, because the front of the pulley can move in relation to the back...it is a damper afterall.

Yes, I wish Haltech would come out with updated software for the E6X as I hear that the software for the newer units is much better. But, I doubt that will ever happen.


Now to clarify why i want to go through all this trouble when i know wasted spark or a dizzy would work is because I love to tinker, i need to learn, and it just seems to be a better way to do things.
Same here.

--Ferdi

networkingdude
02-08-2009, 09:24 PM
do you have pics of the crank sensor mount?

ftjandra
02-08-2009, 09:41 PM
do you have pics of the crank sensor mount?No, unfortunately I do not (I usually have pics of everything...). Make sure to make the mount out of non-magnetic material, like aluminum, otherwise it'll mess up the sensor.

--Ferdi

networkingdude
02-08-2009, 10:54 PM
I will :thumb:

Thanks for the advice. I actually am now looking at the megasquirt manuals because they show this theory very well

atomicEGT
02-08-2009, 11:32 PM
Ah, interesting about the processor speeds. I wish that the communication between the E6X and the laptop would be faster, but that's the only time I feel that it is slow. I think a lot has to do with the Halwin software, which from my experience with it does not seem very well written.

--Ferdi

Ferdi- does the E6X rely on a serial cable like the E6K? If so, that's likely the cause of the slow communication between the Haltech and laptop- I've seen a few other ECUs that also have this sort of problem.

ftjandra
02-08-2009, 11:56 PM
Ferdi- does the E6X rely on a serial cable like the E6K? If so, that's likely the cause of the slow communication between the Haltech and laptop- I've seen a few other ECUs that also have this sort of problem.Yup, it does and it hates usb->serial converters. I had to purchase a serial card for my newer laptop when my old laptop with the built-in serial port broke.


Thanks for the advice. I actually am now looking at the megasquirt manuals because they show this theory very wellThe back of the E6X manual is pretty good too, it even has a couple oscope traces to help you visualize the trigger timing.

--Ferdi

Beerizfood
02-09-2009, 07:49 AM
Here is a so-so pic of the 36-1 trigger wheel i installed on my z5 pulley.
Its from ebay ~$20.
Sensor is the stock protege one.
I also had to machine the pulley .There was a clearance problem with the plastic front cover which had to be cut

networkingdude
02-09-2009, 10:41 AM
Here is a so-so pic of the 36-1 trigger wheel i installed on my z5 pulley.
Its from ebay ~$20.
Sensor is the stock protege one.
I also had to machine the pulley .There was a clearance problem with the plastic front cover which had to be cut

what bolts are you using on your dampener?


As for the Haltech... Did you set your baud rate at 19200 in Halwin and the windows device manager?

networkingdude
02-09-2009, 10:46 AM
do you guys have any tips for getting the trigger wheel aligned perfectly? And are you guys machining it at home or having it sourced out?

networkingdude
02-09-2009, 11:05 AM
Here is a so-so pic of the 36-1 trigger wheel i installed on my z5 pulley.
Its from ebay ~$20.
Sensor is the stock protege one.
I also had to machine the pulley .There was a clearance problem with the plastic front cover which had to be cut

how much did you have to machine to make it clear the plastic? Did you machine the wheel or the pulley itself?

networkingdude
02-09-2009, 11:39 AM
Ferdi - When you got your fix for the ati i noticed you mounted the fix over top of the wheel like a sandwich. On the revised ati's is this piece integrated or removable? If its not then wouldn't i have to mount the wheel even closer to the block than you did because it would rest on top of the fix??

networkingdude
02-09-2009, 12:10 PM
also if you guys could send me your maps for your haltech's that would be perfect!

ftjandra
02-09-2009, 01:41 PM
Ferdi - When you got your fix for the ati i noticed you mounted the fix over top of the wheel like a sandwich. On the revised ati's is this piece integrated or removable? If its not then wouldn't i have to mount the wheel even closer to the block than you did because it would rest on top of the fix??I don't think the new ones are any different because the later Miatas (Miatae? lol) use a crank trigger wheel mounted the same way. You need to machine the trigger wheel on a lathe, otherwise you'll never get it perfectly centered. The clearance to the sensor is only like 30 thou.

--Ferdi

networkingdude
02-09-2009, 02:55 PM
ok, just need to find someone with a lathe around here


so how about those maps ;)

swalltr207jg
02-09-2009, 06:18 PM
its a little off topic, and might be a little more pricy than ms, but I have a microtech lt10s, it has sequential, and direct fire 1 coil per cylinder off the stock cas sensor....this is another option if u dont want to run the ms stuff...or you could run a hydranemasis

Beerizfood
02-09-2009, 07:27 PM
how much did you have to machine to make it clear the plastic? Did you machine the wheel or the pulley itself?

Im sorry i dont have the spec on how much was machined off the pulley as i did it a bit at a time.I used our brake lathe at work LOL.i removed the 4 tooth plate that was part of the crank pully assembly and replaced it with the 36-1.
The stock plate was thinner for sure so i machined a little off the the pulley and a little off the 36-1.
I centered it and drilled holes to secure the plate 6mmx1 if memory serves.
The holes in the pulley were tapped and the holes in the plate not.