Thread: Alternative CAS

I have come across a Cam Angle Sensor that looks like it will work on our engines and ecu's with some modifications. If that word scares you, leave now. Anyways, this sensor is from a 96+ suzuki aerio and sidekick. This sensor costs about $60 on ebay. It uses and optical 360 degree trigger wheel with a secondary crank position trigger. Exactly like the SR uses. There are a number of differences that have to be addressed in order to get this working properly. So while this looks very promising, I am not telling you it will work. So if you want to pursue it, by all means. So here we go.

This is the P12 CAS I used as reference.


This is the Suzuki CAS. At first glance it is very similar.



First difference:

This is the OD of the distributor pilot (same dimensions as the p12) for the SR20. The measurement comes out to 33mm.




This is the pilot for the Suzuki CAS, the measurment comes out to 36mm.

So, the biggest problem so far is the pilot OD is too large. BUT, removing metal is easy.




Second difference:

In this pic we can see the drive is very similar aswell, offset and all. However the Suzuki CAS drive teeth are too narrow, this would lead to timing deviations, maybe on decel.
The mounting ears are also very close. And during a mock up, it looks like at least one ear will bolt. I wont know this until I get the pilot turned down.

Third difference:

This is the sr20 trigger wheel. The outside tick marks represent 1 cam degree. There are 360 total. The inside row is the crank position that represent 180 degrees with a reset which is a little larger.




This is the Suzuki CAS trigger wheel. Same count 360 degree trigger, however the inside row uses an increasingly larger gap on the tick marks.




Here are the two trigger wheels on top of one another. What we see here is the alignment between the inside tick marks (180 degree crank) is out by 360 degrees. This is just how the suzuki ecu measure crank and cam position. However the important thing is while they are out by 360 degrees, the relationship between the guides and the rotations is qualitative. THIS IS GOOD.
Not pictured is the relationship between the flat spot on the shaft and the drive. They are slightly off. But I will cover that in the next few days when I get the shafts out and mic'd.
Moving on.



Here is the Suzuki CAS with the sr20 trigger wheel. There wires you see connected are my power wires and scope. I have verified that this does produce a signal that the sr20 ecu can use. Further testing is needed.
Oktoberfest beer is the shit btw, get some.


Here is Tator Nuts holdin' it down.

Now the biggest tell tale for me was the pin out and the connector are the SAME. It is exactly like the p12 CAS. EXACTLY.

The similarities between the two CAS are way to many to be a coincidence.

Take this post with a grain of salt. This is the testing stage and we are far off from testing.

Follow up:
The pilot needs to be turned down to 33mm.
The trigger wheel needs to be swaped.
The drive and maybe the shaft have to be swapped.

I was able to turn the pilot down to just under 33mm today. I also swapped over the drive and test fitting it on a stripped down head. So far so good. In car testing should take place in the next few weeks. So far I have spent $65 on the Suzuki CAS, and maybe 2 hours of my time swapping and shaving down the pilot.

Pretty cool, would be cool option for us AEM guys

Its crazy that I have just seen this post. I too have also been working with the Suzuki CAS to make it work. It too is the closest one I have come across. I too have turned down the pilot. I did notice that when the Nissan pawl is attached to the shaft... The pin hole is not in the same place. I'm not sure if it will make a difference. We will have to see when its installed.

My idea was to turn down a standard Nissan dizzy shaft to the same dimensions of the Suzuki shaft, except the end of the shaft that holds the pawl.

Suzuki also has one from the vitara i think. It is a magnetic speed sensor with a gear inside. It is much smaller and only has one ear for mounting. It would be good for a standalone system.

4 years @LANCESR20, 4 YEARS the people have waited. Haha, anyways yeah it looks to be very promising. Here are a few pictures of why swapping shafts will not be needed. It has to do with the mounting alignment in relationship to the sensor location. This difference is actually accounted for in the relationship between the paw and the trigger wheel.

You are correct in that aspect. What i meant was the pin hole distances from the pilot on the shaft. The suzuki has a greater distance than the nissan. I am unsure if this distance will cause interference with the camshaft.

OOOH, I see what you mean now. I didn't catch that at first. That could be an issue. I'll have to get back to you on this one by this weekend. I have a spare head I can mock everything up on. If its an issue, maybe during the pilot machining surface a shoulder should be left to push the paw away from the cam. Good catch.