Sequential Fuel Injection and Electromotive - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


ECUs and Tuning Discuss Engine Management, Tuning, & Programming

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 10-11-2012, 03:41 PM   #1
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default Sequential Fuel Injection and Electromotive

Looking for some help with sequential fuel injection for a 1.6 engine.
I just picked up an Electromotive Gt and plan to run it on my FP miata.

I need to provided a camshaft angle signal to the ems for sequential fuel injection. I am looking at modifying a cas to do the job. My first question, is there one cas that is preferable to modify? I have not seen the inside of a 94-97 cas. For signal I thought about having a plate machined to provide the rising edge to trigger the signal, and making the appropriate modifications to the housing of the cas to hold the sensor. Does this sound like a viable solution? This stuff is a bit over my head, but will be worth the trouble and headache as it will allow my tuner to trim the injectors and even up cylinder temps.

One of the other reasons I have chosen to go with the electromotive is the ability to use a potentiometer to control mixture on the fly. If the car is running a bit rich or lean of target AFR adjustment is as simple as moving a slider one direction or the other. I lost a qual session at RA due to a miss calculation on fuel, the electromotive once properly configured, will prevent this from happening.

Any ideas, pics, or dyi instructions on modifying a cas to provide the needed signal are greatly appreciated.

Last edited by hingstonwm; 10-11-2012 at 06:56 PM.
hingstonwm is offline   Reply With Quote
Old 10-11-2012, 07:43 PM   #2
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

I'm honestly not sure it's possible anymore to make a distinction (by year) as to which engines are going to have the optical style sensor (with a slotted flat plate) as opposed to the magnetic sensor (with two concentric cups with teeth stamped into them.)

If you can find a magnetic-style sensor, you can easily cut one of the two teeth off of the CMP cup and not have to machine any fancy new parts.



You can see that the larger, outer cup has four evenly-spaced teeth. That's the "Crank" signal.

Barely visible beneath it is another cup with two teeth. That's the "Cam" signal, and if you slice of one of those teeth, you'll have an absolute phase reference.


HOWEVER:

None of this should be necessary.

Regardless of whether they had an optical or a magnetic CAS, the '90-'97 engines all produced exactly the same CAS pattern.

One of the two CMP teeth is longer than the other, such that it's high during an entire rise-fall cycle of CKP, whereas the other CMP tooth is high during a CKP rise, but low during a CKP fall:




This is enough information for most ECUs to figure out the difference and run fully sequential. The stock '94-'97 ECUs worked this way, as do the MS2/3, the Hydra, etc. I don't know anything about Electromotive, but it's worth investigating whether it can run sequential withou havig to modify your CAS. When speaking to the Electromotive crowd, you may find that they refer to our CAS pattern as "4G63", as that was the Mitsubishi engine which it was originally installed on.
Attached Thumbnails
Sequential Fuel Injection and Electromotive-miata_cas_96_172.jpg   Sequential Fuel Injection and Electromotive-4g63-trigger-pattern.gif  
Joe Perez is offline   Reply With Quote
Old 10-11-2012, 10:57 PM   #3
Senior Member
 
Join Date: Aug 2010
Location: Maumelle, AR
Posts: 618
Total Cats: 2
Default

This might work with the optical cas, I bet electromotive can read a 12 tooth https://www.miataturbo.net/ecus-tuni...upgrade-57770/
ianferrell is offline   Reply With Quote
Old 10-11-2012, 11:02 PM   #4
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

Electromotive at least up to the Tec3 needed a single pulse somewhere from 90 to 3 degrees before TDC.

If I remember correctly, I had to modify the NA CAS quite a bit to get that to occur. I used the inner wheel and removed one of the teeth maybe. Then I drilled a hole for the tiny little locating pin on the center shaft rotor thing to reposition it so it would fall in that 90-3 degree range. You only have to get it close because you do get some adjustability on the CAS for timing.

oh hey I found a pitcher:



https://www.miataturbo.net/megasquir...e4/#post785458

The four-tab wheel is keyed to the shaft which is keyed to the cam. The inner/bottom/smaller wheel is keyed via a pin to the top/outer/bigger wheel. Drilled the new hole in the top wheel to relocate the bottom one. Smaller wheel has the second tab removed.
Attached Thumbnails
Sequential Fuel Injection and Electromotive-imag0924.jpg  
y8s is offline   Reply With Quote
Old 10-11-2012, 11:03 PM   #5
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

Quote:
Originally Posted by ianferrell View Post
This might work with the optical cas, I bet electromotive can read a 12 tooth https://www.miataturbo.net/ecus-tuni...upgrade-57770/
It works with either setup. Just put some opaque tape over the holes in the optical CAS and/or drill new holes where you need them. HVAC aluminum tape is cheap and easy and you probably want some anyway.
y8s is offline   Reply With Quote
Old 10-12-2012, 01:10 AM   #6
Senior Member
 
Join Date: Aug 2010
Location: Maumelle, AR
Posts: 618
Total Cats: 2
Default

I would recommend against tape on something that spins at double crank speed in a race car, but maybe I'm paranoid :-)
ianferrell is offline   Reply With Quote
Old 10-12-2012, 01:33 AM   #7
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

Quote:
Originally Posted by ianferrell View Post
I would recommend against tape on something that spins at double crank speed in a race car, but maybe I'm paranoid :-)
Half crank speed.

The aluminum tape might work. Honestly, I've never really checked to see how much clearance there is between the sensor and the plate. If it's wide enough for a piece of tape to fit comfortably, then by all means have a go at it.
Joe Perez is offline   Reply With Quote
Old 10-12-2012, 03:07 PM   #8
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

If you don't want tape, get the other type of sensor. Maybe see if hustler will sell the one I made to you.
y8s is offline   Reply With Quote
Old 10-12-2012, 04:36 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

I'd do the tape and wouldn't look back.
Braineack is offline   Reply With Quote
Old 10-12-2012, 05:03 PM   #10
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by y8s View Post
Dat my CAS. I'm still not sure if I want to use it or just cough-up $200 for a cam gear and simplify my life.
hustler is offline   Reply With Quote
Old 10-12-2012, 05:06 PM   #11
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

What two "additional wires" are you using for the injectors?
hustler is offline   Reply With Quote
Old 10-12-2012, 05:17 PM   #12
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by Braineack View Post
I'd do the tape and wouldn't look back and I'd take it like a man.
hustler is offline   Reply With Quote
Old 10-12-2012, 05:26 PM   #13
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default

I will send a pm to Hustler, to see if he is interested in selling. I am running a 60-2 crank wheel, so I only need the cmp signal. I will need to index the cas and see if I can just rotate it and trigger the signal within electromotive's parameters. If not then I will need to index, unless Hustler is willing to sell his.
hingstonwm is offline   Reply With Quote
Old 10-12-2012, 06:34 PM   #14
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

your stock cas has too many tabs/slots. Electromotive can't tell the difference between short and long.
y8s is offline   Reply With Quote
Old 10-12-2012, 07:02 PM   #15
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default

I should have said that I would index, then make the modification to the CMP wheel by removing a tooth, and see if I hat a good signal. If I don't I will index as was previously described.
hingstonwm is offline   Reply With Quote
Old 10-18-2012, 06:09 PM   #16
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default

Quick update, I picked up a cas off eBay for 90 bucks. Luck was on my side as it is the magnetic pickup type. I will have to go through my wiring harnesses, but I'm sure I have one that has the cas connector. I am running electromotives 60-2 trigger wheel, so I won't need the cmk signal. The cas that is currently on my engine is gutted, the new one will be modified and take its place, so I can setup sequential fuel injection. I am hoping that sequential fuel injection will also give me a more accurateafr readout on my uego.
hingstonwm is offline   Reply With Quote
Old 11-09-2012, 04:31 AM   #17
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default

Update. after reading the manual I need a signal between 180 and 6 degrees btdc. It looks like I can acheive this without modifying the timing in the cas. I took a few pics, not sure if the pulse is triggered as the tooth enters the magnetic field or after it passes.
the goal of the pics is to shoe relative position of the tooth on the cas as compared to crank angle. let me know what you think. The crank position wheel was removed so I could see the timing on the cam wheel.


Attached Thumbnails
Sequential Fuel Injection and Electromotive-utf-8bsu1brza5ntquanbn.jpg   Sequential Fuel Injection and Electromotive-utf-8bsu1brza5ndguanbn.jpg   Sequential Fuel Injection and Electromotive-utf-8bsu1brza5ntiuanbn.jpg  
hingstonwm is offline   Reply With Quote
Old 11-09-2012, 11:15 AM   #18
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

Other than not knowing what pic 3 is, it looks fine. You may have to move the tab around to get it where you want it, but the tolerance zone is very large.
y8s is offline   Reply With Quote
Old 11-09-2012, 12:13 PM   #19
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2010
Location: Denver
Posts: 909
Total Cats: 14
Default

Pic #3, picture of the crank timing gear on my small nose crank engine. Taken to show relationship of crank angle to sensor.
hingstonwm is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM
"Chimney Ethanol" E100 MiataGarage Engine Performance 5 09-30-2015 12:04 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:07 AM.