60-2 crank and optical pickup on PNP
 

Looking to run a 60-2 trigger wheel and optical pickup off the crank instead of CAS with my PNP. I was speaking with Matt Cramer today, and he believes all I would need to do is make some software changes. Anyone have a clue where I need to start? Thx

Do you think the CAS isn't accurate enough with the MS, and you need to run a trigger wheel?

Why?

Speaking from recent observations, the CAS isn't accurate enough even with the stock ECU. This has nothing to do with my recent trigger trouble- it's a universal problem. The CAS is driven by the timing belt, and the timing belt has some degree of slack in it by design. As you rev the engine, the CAS jumps around slightly relative to the crank.

Ben, I am *very* interested in this. What do you have in mind with respect to mounting the wheel, and where are you getting it?

*need*? No. But I think it's a good idea.

Joe, I got it second hand from Frank who's pulled out his 1.8 and motec in favor of an LS1. Actually, it's in transit and I won't have it until next week. I understand that Vishnu originally offered the items for use with the TECII. Will know more in a few days.

Are you sure about this? Nearly every car made today comes with a cam-mounted position sensor, and I know the amount of work that OEM's put in to get a clean signal from the position sensor. I have myself seen several SAE papers about the subject.

LOL, don't you think there's a reason why mazda went to a crank trigger in 96? ;)

32-tooth crank trigger in my OTM..

Good luck with this Ben, keep us posted!

This is new information, I thought even the NB's came with a cas?

They have a cam position sensor to identify #1 TDC (this is a totally different unit from the NA CAS), however the primary firing trigger is on the crank. A little jitter doesn't matter on the cam reference.

Most modern cars are like this.

Ben- keep me posted, I'm primarily curious about how it attaches to the crank pulley. I do have a lathe that can turn up to about 3" (limited by the chuck at the moment), however drilling accurately spaced holes around a circle can be a bit of a challenge. If I can't come up with a new CAS soon, I may make the leap to a crankwheel as well.

Could one of the wheels DIYautotune is currently offering possibly work? I need to research crank triggers, I know nothing about the MS side of using one nor why you need certain numbers of teeth or spacing.

http://www.diyautotune.com/catalog/t...eel-p-181.html

http://gallery.y8s.com/d/237-3/DSC00756.jpg

It is the Vishnu piece--was offered as part of the Tec3 kit actually. The wheel is an Electromotive wheel mounted to a custom hub that bolts to the four crank pulley bolts and has a big hole through the center. The sensor is mounted to a T-shaped dealie that you can kinda see in the photo.

Note that I tossed the 3/8 sensor as EM deemed them unreliable and made a new 1/2" sensor mount out of square aluminum tubing.

Pretty much any wheel will do. Tooth config looks pretty easy. The trick is mounting it properly- with a sensor gap of 0.7mm - 1mm, they have to be really concentric. I was hoping maybe Ben had found a source for pre-fabricated adapters.

I found one wheel in particular that really looks slick. Go to this webpage and scroll down to "5.75" lightweight trigger wheel": http://trigger-wheels.com/store/index1.html The 1.5" center hole and pre-cut slots should make it uber-easy to install and adjust. Just gotta figure out what to do in terms of a center hub...

ATI damper

If only that wasn't a $500 option. Unless FM has them marked up an extra $400 that probably wouldn't be my preferable option.

There has to be a way to make an aluminum adapter that bolts into the space in the center of the crank pulley and provides a surface for the wheel to mount on. If it weren't for the diameter required, I'd turn one myself...

Joe, you can't reverse the jaws in you lathe to turn larger stock? Every lathe I've ever seen had reversible jaws.

His lathe is pretty tiny, like super tiny, i bet that max diameter he is talking about is with the jaws turned around.

Even if so, does it have provisions for a faceplate? If so you can use support the work on centers and use a lathe dog to drive it.

not bolted but pressed:


https://www.miataturbo.net/forum/sho...highlight=edis

My lathe has a 7" swing, but the chuck I have in it presently will only accommodate a maximum 3" stock, and that with the "outside" jaws installed and fully extended- from a practical standpoint it'll only hold about 2.5" with anything resembling decent clamping force and stability. A 5" chuck with plate is only $100, I should probably buy one...

I think a more practical approach however would be to have the pieces made by a small-run prototyping shop. I just did an ultra quick-n-dirty sample drawing with the emachineshop software, and it quoted me $39 ea in qty 10, $27 each in qty 25. So if a group buy came together, it would be pretty darn affordable. The trick would be to make sure we have a design that'll fit both the 1.6 (long & short) and the 1.8 pulleys. I'm thinking of a mushroom-shaped piece that replaces the flat washer-like thing that holds the pulley on, and is retained by the same four bolts. It would also probably be specific to a particular wheel, so we'd have to agree on that. If we could find something domestically like the one I linked to above (with the slots) that would be cool- or we could have those custom-made too...

Cough Cough.... I HAVE A LATHE. 18x60 gear head Clausing that cuts standard and metric threads, 3 and 4 jaw chucks, steady rest, follower rest, lathe dogs, face plate, live centers, etc. :) Gotta get a 3 phase rotary converter to run it though. It has a 4hp 3 phase motor. Motor is apart on my bench. I have new bearings for it, just need to reassemble and get 3 phase. It's the first thing that's getting fixed when I get out of school for summer in 2 weeks. I'm gonna be making a few things this summer, such as brake brackets for the RX7 calipers and a NB fuel rail. Might could do this too.

Well then, since you've volunteered, I call dibs on the first hub. :D

I also might have a cool job at a facility with an excellent machine shop so... there is that possibility as well.
Lets discuss hub design. Do we want to make a single piece hub or would it be ok to make standoffs out of like .75" round stock?
The solid hub should have the center bored out of it for the sake of saving weight. It could have just about any pattern of holes drilled in it depending on what gear you wanted to use.
The standoff design would utilize the stock 4 bolt pattern so the gears would have to work with that, i'm not sure how standoffs would like 7-8krpm though(for the high reving engines).
3" aluminum stock isn't too aweful expensive. Lets hear your design ideas.

Assuming a wheel such as this:

http://trigger-wheels.com/store/cont...ightweight.jpg


I was assuming a piece of 4" or so solid bar stock, lathed and drilled to make the following:

http://img216.imageshack.us/img216/80/image1pv7.jpg


It's not to scale, but the idea is that you remove the washer-thing with the four holes that holds the pulley on, and replace it with this using four longer bolts. On the wheel side, the bolt heads are recessed below the surface, and then the wheel bolts over top of them into the three threaded holes. In the center is a raised lip to center the wheel.


Question- are the basic dimensions (diameter of center bolt, size and pattern of the four smaller bolts) the same on all Miatae?

Hmm not sure where you want to put that now. Wish I had pictures now. Here is how my NB crank assembly is laid out from the rear of the engine forward.

Crank - Timing belt gear - Pully hub - Crank Bolt - Crank sensor wheel- Pully

My pully hub is held onto the crank with the large 21mm crankbolt. My pully and crank sensor wheel are held on with four bolts that thread into the pully hub.
Is the 1.6 laid out the same because it doesn't sound like it.

Looks like several of us are having the same idea...

Jim

I think the electromotive wheels aren't much different than $39 each anyway. if you can make both parts....

Must MS have a 60-2 wheel? On a Link wire-in install I just used the OE 99 trigger wheel and sensor for spark trigger with the OE cam sensor for coil phase. The ecu just needs to "know" the location of spark triggers.

no, the ms doesn't need it but there is accuracy to be had for the early cars without crank triggers. I'd venture a guess that a 4 tooth crank trigger is probably just as good as a 60-2 for most applications. does the later wheel/sensor bolt right up to the earlier cars?

No, it'll take just about any wheel you can find. The "popular" choices just seem to be 36-1 and 60-2.

In theory, the more teeth you have, the better the resolution. Although I expect the difference between 36 and 60 is trivial compared to the difference between two and 36.

Of course, as the number of teeth increases, the frequency of the sensor signal increases and becomes slightly more difficult to deal with from an electronic standpoint.

IIRC the sensor bolts to a boss on the 99+ oil pumps- not the block. I think I have both the wheel and sensor - though I'd imagine been does too with his collection of engines.

Yeah, the sensor bolts to the oil pump, and that's a good spot for it.

CJ, so far as I can recall, the 1.6 setup looks like this. I'm I bit hazy on the shield/spacer thing that guides the timing belt, but it's not important:

http://img373.imageshack.us/img373/8...k16acadai5.gif


The big bolt does not hold the main pulley on. It holds the timing belt gear on, then the main pulley goes over top of it and bolts to the timing belt gear. Four bolts and a big washer-like thing hold the pulley in place.


My idea is to replace the washer with an aluminum hub, and use longer bolts in the same four positions to hold the hub and pulley to the timing belt gear. Then, the wheel bolts to the hub:

http://img508.imageshack.us/img508/4...b16acadmb6.gif


Here it is assembled. (There should be more space between the timing belt gear and the main pulley, just imagine a spacer in there. I can't remember exactly what it looks like)

http://img371.imageshack.us/img371/8...sembledqx6.gif

Btw, those of you with an MS1, a 60-2 or a 36-1 offers absolutely NOTHING compared to a stock CRANK-mounted 4-teeth wheel. Only the MS2 decodes every tooth. If you are using the stock CAS on the head, then there is some benefit in switching due belt stretch.

Jim

Hmmmm......

(thinking hard)

How thick is the '96+ crank plate? I'm wondering if it'll fit under the '90-'95 pulley without upsetting the alignment of the accessory belts?

Or....

Getting a new plate of comparable thickness laser-cut would be relatively inexpensive- that would allow "normal" even tooth spacing and the elimination of the cam reference altogether.

:werd:
Seeing a tbelt on the dyno during a run makes you wonder how the CAS trigger works at all.

I think most use the CAS because it's simple. I did.

Just measured: .070" thick

info I have/used on the NB crank wheel:
http://i158.photobucket.com/albums/t.../NBtrigger.jpg

the 96+ crank plate is just thin sheet metal.

The "Big Boost Kit" for the Jackson Racing supercharger does a similar thing with the crank pulley, maybe you could get some ideas from it.

With a 5 volt Hall effect crank sensor, using a crank trigger with an MSPNP is pretty much a matter of wiring up the sensor and changing the wheel decoder settings (one of the things the manual says not to touch on a typical install).

http://www.msextra.com/manuals/MS_Ex....htm#wheeldecr

If you post how many teeth away the sensor is from the missing teeth, and if it's ahead of or behind them, I can post the settings that should get it working.

There were many threads regarding the accuracy of the stock CAS vs the crank trigger wheel back in the old miatapower mailing list days. Not sure if there is an archive around. Shiv was an active participant back then. Jason Cuadra probably remembers them and could shed some light.

Frank

I need a measurement
 

I think I've figured out how to do this on my lathe, but I need some data. Can somebody who has a spare 1.6 or early (pre-96) engine laying around take a few measurements for me?

First, with regard to the image below I need to know the outside diameter of the plate which I've highlighted in red. It's the one that goes on the "outside" (front) of the crank pulley, with the four bolts that basically hold the crank pulley on. I simply can't get close enough to mine with the calipers to get an accurate measurement.

http://img29.picoodle.com/img/img29/...ym_3c819b0.gif

Secondly, with just the bare pulley sitting face up on a table, I need to know the depth of the dish (with the washer thing removed) relative to the uppermost lip. In other words, if you lay a ruler across the front-most lip, how far is it to the flat surface where the washer-thing goes?

http://img26.picoodle.com/img/img26/...hm_cd18485.gif

For that matter, if anyone has a complete crank pulley assembly (ideally the whole enchilada including the timing belt gear) that they could loan me, I'd be hugely appreciative.

That is basically the same as the 99s crank pulley assembly.
Replace 11-414 with the timing wheel and remove 404 and 408 they don't exist on a 99.

Im going to the junkyard right now, might be something laying around that could answer your questions.

There's a 1.6 on the forklift in the back right now, but I have no way of taking precision measurements.

It doesn't have to be micrometer-accurate, I'd settle for a ruler marked in 16'ths. I just need to know what size piece of aluminum stock to purchase- the biggest bar I've got on the metal shelf right now is 2.375", and I know it's bigger than this. The question is between 2.625" and 2.75" diameter and I need depth of dish to the nearest 1/4" or so. Just trying to buy the smallest piece of pre-cut stock I can, to minimize the amount of machining necessary.

I don't want an NB wheel, quite honestly. I'd still have to use a cam sensor, and I'm really just trying to go with a proper 36-1 wheel setup. I've decided that I can use the 4" wheel that DIY sells, and make the center hub the same diameter as the big washer, then use the four bolts to hold both the hub and the wheel on. It'll give me less adjustability (basically it'll need to be close to dead-on-balls the first time, all adjustment will be in the sensor rather than the wheel) but it means I can build the whole thing at home with the lathe that I have.

I was comparing the two just for the sake of filling this thread with information for all to read in the future. I am going to the junk yard though, they have 1.6 motors and i have a vernier.

Hey- if they've got a longnose 1.6 at the yard you're going to (we don't locally) could you buy the whole pulley assembly for me to use as a reference? Ideally, I'd like everything from the timing belt gear all the way to the outer washer with the four bolts, including the big bolt that holds the package to the crank. (I hate to keep using you as a parts bitch, but our local yard is slim pickens and you appear to have a goldmine on your hands)

Looks like they're all short nose in this yard. I know a guy in east TN that might be able to help though. He sells most his stuff on ebay. miata_godfather at yahoo dot com
Send him a message, he replies same day most the time. I know he has quite a few miatas around.

Can we do a groupbuy on the 1.6 longnose version of the adapter, maybe from emachineshop? Assuming Joe has been able to make a drawing of it?

I still have my old TECII wheel (Shiv) kit and bracket (now uses a GM sensor) from my old car. I'm all ears to this thread, it would be great to use it versus a CAS in the future.

I also might have some pulley assemblies at home. Hopefully I did not throw them out last year.

Well, if there is a huge outpouring of support (I think we'd need at least 10 confirmed orders to make it worthwhile, the more the cheaper) then I'll be happy to design the part and manage the order. We'd probably need to all agree on a specific trigger wheel for it to really work as a bolt-on. Looking at the parts diagrams, I think it might be possible for one hub to fit all the NAs, but I'd need people to donate a complete shortnose assembly, a complete '94-'95 assembly, and a complete '96-'97 assembly to verify that. Everything from the timing belt gear to the four 6mm bolts.

For the moment, I am moving forward building one for myself. I think I've figured out how to do it with 2.75" diameter 6061 stock which will fit my lathe. The metal should be in tomorrow, along with some longer bolts. (Have you ever tried to find class 10.9 M6x70 bolts locally? It's impossible.) The sensor is going to be a Ford part, either a mid '90s 1.9 Escort or a mid '90s V6 Taurus. They are electrically the same but have a different mounting scheme. I've ordered one of each to see which fits best.

On a happy note, two packages arrived today. The first is a ChinaCo Model 2090 40Mhz 2-channel USB-based PC oscilloscope. I got tired of fighting with the old Tektronix TDS-420A that I've been using. It was a truly awesome scope in its day (even used they sell for up to $2,000) but it's absolutely friggin' massive, it won't run on batteries, the floppy drive is dead, and it doesn't do logging. The new one, despite costing a paltry $240, seems to work pretty well. The software is pretty easy to use, it seems accurate, and it even came with a very nice set of 1x/10x probes that, apart from having only a 60Mhz rating, are damn near indistinguishable from a $300 set of Tek P3010s.

The other big ticket item is my new crankwheel from DIY. It's the little one- only four inches. I'd have preferred a 5" wheel, but couldn't find one anywhere (in the US) in 36-1 and from an electrical standpoint I didn't want to deal with 60-2. Once I saw it, however, I couldn't believe how small it was:

http://img31.picoodle.com/img/img31/...dm_f33c800.jpg

On the plus side, it should clear my BOV (which is right next to the pulley) with no problems and it'll hopefully make fabricating the sensor mount just a bit easier. We'll see when the time comes how that goes. I'm just hoping I can get a clean signal out of such small teeth. Once the hub is semi-complete, I'll spin the wheel on the lathe while scoping the sensor to make sure I've got a usable signal before proceeding further.

Ok. I thought 60-2 was the preferred one over 36-1. Any reason not to go that route? I also saw some Tec 60-2 wheels on ebay.

How about setting up a group buy in the classified to gauge interest.

would it be worth swapping my 9093mspnp to the crank trigger on my 99 motor?

MS1/Extra doesn't gain any improvement from a 60-2 over a 36-1. For an MSPNP, you'd need an optical or Hall effect sensor rather than a VR sensor.

I dont want to be a gunea pig, but if a "kit" comes out of it I definitely want in. Even if the extra accuracy is only worth a couple hp than it is worth it on my setup.

The higher the toothcount of the wheel, the higher the fundamental frequency of the signal you're working with. All else being equal, it is easier to work with a lower frequency signal, particularly when you're in a noisy environment trying to do accurate threshold detection.

Indeed. Technically, a 4-1 wheel would be ideal, only nobody makes one that I can find.

Wait a sec... Matt, would I be crazy if I ground all but three of the teeth off the wheel I just bought from you? I mean, how critical is the balancing situation? Nah... Stupid idea.

Insofar as the Hall vs. VR situation, I am planning to build the VR circuit for my system in an external box. The primary driver in my case is to make it easier to probe and modify, but adapting this concept for others would permit MSPNP owners to use a traditional VR sensor, simply by using this circuit as an external logic-level converter. They'd have to snip one wire in the factory harness (CKP), and splice into two others (VREF and GND).

Also, FWIW, I'm pretty sure the stock NB crank and cam sensors use open collector output, just like the NA CAS.

Everyone involved will be a guinea pig. And I still haven't figured out exactly how to mount the sensor. I know approximately where mine is going to go, but the actual mounting scheme is probably going to look like quite a hack-job. Not something I'd want to sell to others.

http://cgi.ebay.ca/Mazda-Miata-MX5-C...QQcmdZViewItem

Very cool idea.. I like this..

Hell, I finally finished all the machine work last night for my very complex crank wheel, and now I see this... :cool: