Which is the best CAS?

I always see different posts referring to different CAS. Some referring to a green CAS. Are there multiple CAS options for our cars? Just don't want to get a crappy one if I need another in my troubleshooting process.

FYI, If you are going to pm me to sell me one, please make sure it works and that you are selling it to me below what the going price for one is. At this point I think that I will have to resort to parts changing to fix my problem. /ubbthreads/images/graemlins/frown.gif

Thanks

 

[G]

/ubbthreads/images/graemlins/rofl.gif Just sell the car already.

 

Thinking about it...anyone else? f***er /ubbthreads/images/graemlins/mad.gif

 

[Boostin_AWD]

They are the same. They do the same thing. You have the green top and black top. I believe the black is rebuildable.

 

Thanks for the info.

 

[alansupra94]

I was under the impression that the black one offered better resolution.

 

[turbowop]

I don't remember the exact difference. I think the black one is a hall-effect sensor and the green one an optical sensor. They both accomplish the same thing. I've heard pros and cons for both. I've used both and have noticed no difference between the two.

 

[prove_it]

You do get better resolution with the black top CAS. It will pick up small variances in the rpms quicker and more accurately. It's not necessary and if you can get one for less than $75 it's worth it. Like WOP said though, you won't notice a difference. You'll see a slightly smoother rpm line graph in a datalog and that's about it. No power to be made, nor will it limit your power.

For some reason the black top will sell for over $50 more than a green top. Some people think they are gold and the only way to go. I've also seen some people paint the cover and pass a green off as a black top. In reality it's like the difference between a smooth valve cover and a stock valve cover.

Also there is a difference between the pre 91 and after 91. Pre 91 sensors have a pigtail on them and post 91 have the connector right on the body. Try to find a post 91 as it will be a straight bolt on.

 

Thanks all.

 

[rmontalvo23]

The true black top cas is far better for when you have an engine that revs above 7,000and or goes through the rpms faster.

For example with my AEM and the green top cas it would read 7,000 rpm. Then at 7,500 the log showed 9,000 at 8,000 it showed 12,000 and at 8,500 was giving 20,000 rpm. The green cas could not send the correct rpms fast enough. The AEM did not understand what was happening and car would break up big time.

Borrowed a friends black top and it revs all the way to 9,500 with perfect readings. AEM gets the exact readings through the rpm range and you can tune perfectly.

Any high HP 4G63 will have a black top cas. If youre not fully modifying your car
For high hp and revving passed stock redline you wont need it. In the past months i have purchased 4 black top ones just incase I need an extra.

 

[alansupra94]

Your AEM EMS probably would have been happier with this:

click

 

[cheekychimp]

I don't like posting information I cannot verify but in the hope that it might at least vaguely benefit someone to be aware of a possible issue, I was told that one of the two CAS models was far more susceptible to electrical interference than the other. I have no idea if this has any correlation to what a member above posted about high power applications (which may or may not be using COP and a CDi).

As I said I have no idea if this is true or not so take it with a pinch of salt but I was warned to be wary of the fact as I intend to use a CDi on the project car and was told it could cause issues.

Paul.

 

[mitsuturbo]

I've come across MANY green top CAS units that have failed and are no longer working. I've gotten one wet and had it fail. I've also had one go flaky on me and not work right. I've bought cars with a bad CAS for next to nothing. So have friends of mine. They all had the green top CAS. I've not yet actually seen an example firsthand of a blacktop CAS that has ceased to function. I still keep a spare of each, along with a spare ECU, Power TR unit, and coilpack. I'd recommend anyone else with 89-94 4g63 keep a spare CAS, PowerTR unit and ECU. It's not a bad idea to keep a main MPI relay (aka fuel pump relay) as well. It certainly makes troubleshooting a lot easier if something goes wrong when you have known good parts hanging around.

For instance, when a friend of mine wanted me to go look at a $700 DSM with him, i brought these things along, because the seller couldn't figure out why the car wouldn't run. I pulled a plug wire off each coil, had my buddy crank it over... no spark. Plugged in a CAS, spun the mechanism with my finger, and whaddya know... sparky spark spark. Buddy paid $600 for the car after telling the guy it was going to take a lot of work, we installed the CAS, and he drove away in the car. Sold it less than a week later for $2300.