Nissan CAS

[seishuku]

No, it's not another post about using the 360 window trigger disc.

I've been doing some R&D on making a good+proper trigger disc for running MS on Nissan engines, and the attached PDF is what I've come up with so far.
It's a 24+1 (24 primary inner windows, plus 1 secondary reset window), which could be changed to a 24-1-1+1 and set as a 12-1 on the decoder.

Anyone have anything else to add? Post it up!

[seishuku]

Slight correction, the reset window should be 3.75 degrees AFTER the 60degree trigger window.
Should also note, that it's 60degrees crank/trigger angle, which is 30degrees on the cam (in the case of the CAS).

Edit:
Bah, I screwed up more than that.
*work in progress*

[Matt Cramer]

We've started mass producing a similar design ourselves. I opted to use the missing tooth decoder so installs that don't need the second trigger can use a similar sensor.

[seishuku]

Yeah, I noticed... And duplicated... Sorry Matt, I'm cheap and have access to a waterjet.

I just feel that there should be more public info on this, for people trying to get things set up.

EDIT:
My goof up is that the reset window should be on the other side of the d shaft, since that would be BTDC, it's ATDC in that PDF... Minor issue. lol
I cut out the corrected one today at work, so I'm going to give it a go and see how it works.

[seishuku]

Oh, while on the subject... How did you come about that design?
Do you have any trigger angle/wheel decoder settings for it?

[Matt Cramer]

Oh, while on the subject... How did you come about that design?
Do you have any trigger angle/wheel decoder settings for it?

Measured an SR20DET CAS with a set of calipers. I used to work for Amada Laser and have a bit of experience with laser cutting, as well as a list of contacts at laser job shops. (Which is why the MSPNP uses a laser cut case instead of an extruded one like most aftermarket ECUs.)

[seishuku]

That's cool, I sometimes wish we went with a laser, but I'm pretty happy with the waterjet.
I meant more along the lines of the trigger pattern though.

[Matt Cramer]

That's cool, I sometimes wish we went with a laser, but I'm pretty happy with the waterjet.
I meant more along the lines of the trigger pattern though.

Here was my reasoning for it:

1. A 24-1-1 will enable wasted spark in 1/2 CAS revolution and no second trigger needed.
2. Making the second trigger as wide as the missing tooth gap will allow using MS3's "poll level" cam sync mode.
3. Using the inner ring for the main trigger wheel would allow existing KA24DE installs to use this wheel with no rewiring.

[seishuku]

True, but couldn't you get the same with a single 36-1 on the inner track, and support everything with out a 2nd trigger?


Edit:
With that one, I'm getting pretty decent results with these settings:
A - 33/3
B - 6/12
C - 15/21
D - 24/30
With a 60 deg trigger angle.

Though I don't know if the order is correct, since I'm on a distributor. I'll set up my COP again and see how it runs with that.

[Matt Cramer]

That would take twice as long to sync up however if you are running a distributor or wasted spark. It's a judgment call there.

[mtnickel]

Matt,
You site says that wheel won't work for the RB engine? I'm pretty sure I have a D slotted wheel @ 50mm.
I really like this solution as I have heard a lot of issues attempting to use the high resolution (360 tooth) sensor in any fashion (with a 24 tooth wheel or otherwise) due to noise from the logic circuit.
Is there any reason that wheel would not work on a 6 cylinder using wasted spark?

[Matt Cramer]

The pattern is OK. And RBs do have the right 50 mm diameter. However, they normally locate the CAS using a round center hole and a set of 3 surrounding holes instead of a D-shaped center hole. So you'd need to do a bit of modifying the disc to use it on most RBs.

[r20xm]

Did anyone MS'ed Nissan VQ30DE(T) engine?

It has 2 crank sensors (POS and REF) and CAS (reads marks on left head's intake cam sprocket).

It has timing CHAIN (closed by timing chain cover) and no distributor or other places to install D-holed 24+1 trigger disc.

is it possible to learn MS to understand stock CAS to manage sequential sparking and injection?

CAS reads groups of marks (1 mark, 2 marks, 3 ... 6 marks, in specific order) cast on sprocket.

[jsmcortina]

VQ35DE is already a supported pattern in MS3 - it is totally different from the "Nissan CAS" being discussed in this topic.

James

[FricFrac]

Someone already made one for the L28ET dizzy....

It's http://forums.hybridz.org/index.php/topic/102280-ms3-w-ms3x-install-l6-turbo-sequential-injection-boost-control/page__view__findpost__p__957516