3,0 SC with EFI system - Which ignition system to choose - any ideas ?
 

I'm planing to remove my CIS system from my SC engine, and mount a 3,2 system which i recently bought. I will not use the DME, but any aftermarket management system.

With regards to the ignition system, i am bit in doubt about what kind of system i would like
to go with. I do not have the 3,2 distributer, and i do not like the visual thing about using 6-coil pack.

Can the CDI ignition be combined with the engine management system, or does it even make sense ?

What is the advantage of the CDI ignition compared to the newer systems ?

If i would like to with a system like what was std. on a 3,2 Carrera, i assume an empty SC
distributer (without spool, and with locked advance mechanism) ?


Another crazy thought is to have 6 "coil on plug" coils from a 996, and the make a cam position device instead of the distributer. Then run a complete sequential ignition / injection system. I know this will require some fancy valve covers to fit the coils, but this is a minor problem.

Please let me hear you ideas :-) !

COP has been done, believe it was a guy in South America that had a thread on it here. I have no idea how to make use of the 3.2 system on a 3.0L SC motor without the Motronic setup and all the sensors it uses. Sounds like a nightmare to me! I would either stay with CIS or go with ITB's and an EFI setup.. and then there is always PMO carbs but they should go along with other upgrades to maximize them..

You can't use the 3.2 distributor anyway. Your SC crankshaft has a different drive gear and the original SC distributor therefore spins in the opposite direction.

One guy I can think of off the top of my head is billjam from Australia who did a 3.6 Megasquirt with coil on plug.

Take a look at the tbitz kit.. you of course will be using a 3.2 manifold and fuel rails presumably. Aren't the 3.2 injectors low-z? In that case get some appropriately sized high-z injectors; you can use megasquirt to control the fuel and keep your stock SC ignition.. You shouldn't really expect any gains in power, but perhaps reliability will improve over your aging CIS system...

Injection electronics
 

I was just thinking about te use of Megasquirt (MS3) as engine management, but can the CDI system be used in conjunction with the MS3 ? .. letting the MS3 control the advance curve if this is blocked in the distributer ?

MegaSquirt - Electronic Fuel Injection Computer by Bowling and Grippo ©2010

Greetings,
The M'squirt manual, ignition section, provides information related to CDI, direct coil, etc.
Also, the support forums (there is a link within the manual ). Good luck with your project.

regards,
al

Megasquirt is a great system. Very versatile and highly capable.

I think MS3 is more than you need for your conversion. The MS2 runs just as well but does not have all the extra peripherals (add-ons) that you will not use.

If this were my build I would suggest the following.

3.2 manifold (you already spec'd this).
some type of Variable Reluctor (VR) crank trigger. Buy the crank pulley, VR mount and trigger wheel from many of the suppliers (GSF, Clewett, Rothsport, Dzug, etc).
Send the VR signal to MS.
Output signal for ignition is 3 channel, wasted spark. This can be either an EDIS style coil pack or COP. If COP use a self powered coil and send logic-level trigger signals. Pair 1,4; 6,3; and 2,5 to the same logic signal.
Control timing through MS.

For fuel just buy external injectors. I like the Seimens Deka EV6 injectors. Fast response time. Pick them up used from a Mustang or similar car. I suggest high-Impedance (high-Z) injectors. Low-Z injectors (like stock 3.2) require some modifications to better control the injectors. Its just more soldering.

Wire the injectors to the crank rotation. (1,6,2) for Channel 1. (4,3,5) for channel two. Run them alternating fire for smoothest idle. The only benefit to true sequential is idle quality with big cams and emissions related. Your car will not have big cams and at its age, it will run cleaner than CIS when tuned properly.

You will need to tune the car and a wide-band O2 sensor is needed.

BTW, EFI is SO MUCH better than CIS. So worth the effort of conversion.

Jpnovak, do you have any specific COP you would recommend?

Great reply JP! To the OP, another big advantage of the Megasquirt system is its popularity. You'll likely be able to grab a decent base map from someone here or on the MS forums for your 3.0.

Hopefully MS is a better system than what this guy paid $2200 and 15mpg for. My CIS still gets mid-20s mpg. Yes, I realize modern EFI is the way to go especially with lots of mods but that's a lot of money to have less MPG on an unmodified engine. I'm sure it's all in the tuning. What do MS guys get mpg wise?

http://forums.pelicanparts.com/porsche-911-technical-forum/621680-finally-back-game-10.html

tbitz is an easy conversions to do and works out of the box. Then as you progress (as I did) it's the easiest thing to swap the MS1 ECU for a MS2 unit and get an EDIS coil pack. You can swap the distributor for a 36-1 wheel and VR sensor to fire system whenever you are ready, or not. Cheap parts and easy to set up and configure. Good luck

Btw I got 26 mpg on my last longer trip. 70-80 mph

@jsveb - I hear that Toyota Tundra COPs work well. I have not tried to fit them myself. I typically go the coil pack route though my upcoming build has not progress far enough to solve the COP issue for myself.

Tom is correct that there are base maps available. These will likely get the car started. Each car is different and you will need to optimize the individual fuel and timing maps.

@manbridge. Interesting interpretation.

I seem to read that (post #184) he was getting 15mpg mixed driving with CIS and this improved to 18mpg mixed driving (post 188) with EFI.

Seems like an improvement to me.

Now, I must say that the EFI allows you to tune for economy if you know what you are doing. air cooled heads do not like to run lean - unless you can control ignition timing. Look at the 3.2 Motronic and 964 timing maps and you will see very advanced timing when driving at low load bins on your fuel maps. This timing allows you to lean out fuel mixtures and this gives you economy.

my 3.2SS with big cams and ITBs was getting about 24mpg on the highway - and still put down nearly 300hp to the wheels.

Its all about efficiency. Its all about the tune.

Thank you very much all of you for great inputs !!

The decision about choice of ignition system is still not taken, but the engine management will
be the latest MS equipment from MegaSquirt | Engine Management System | Electronic Fuel Injection - DIYAutoTune.com - think i will buy it as a kit and brace things together by my self. The great thing with the MS, is that i got company of my brother and a friend who is making the same stuff this winter with their two T1 VW engines, so there will for sure be a lot to talk about during the Christmas holiday when it comes :-) !

If a COP system will be the end, i have looked at Beru 0 040 100 036 this should be a 996 one, and with 2 mounting holes for M6. I am doing 3D modeling mostly every day, so to design a state of the art valve covers to accept COP's would be a great challenge !

At a later moment i will keep you updated with some photos from the project as things moves on.

Stay tuned !

You can leave your current ignition system in place and do only fuel with your EFI. I would highly recommend wiring in anticipation of sequential injection and COP to simplify potential future upgrades.

Manbridge 74,
My car has gone from averaging 15 mpg with a well tuned CIS city/ highway to over 18 mpg driving the same conditions. Over 20 on the highway, 10% better then factory ratings.
I still have a lot of room to play in my ms to improve it more. I'm running a little rich on purpose for performance running regular 87 octane gas.
The real gain has been in the performance aspects.
The car has had a dramatic improvement.
For example:
This Sunday I was casually driving up a high incline twisty road near home the other day when a new BMW came up on my tail and wanted to push me, I stepped on it in third and he couldn't keep up. At the stop sign at the top of the hill a mile later where I waited for him, he was honking and flashing me both thumbs up. :)
Not bad for a 35 yr old car...

Mileage gains were secondary to the EFI install, the performance gains are terrific with the SSI's and Dansk muffler added to the formula.
I'm still running the stock Bosch CDI for spark.
My car is now a daily driver and I just jump in, turn the key and go... Every time!

This is the Bosch injectors i already have : 0280150731 they have an impedance of 15,9 ohm and
a flow volume of : 201 cc/min @3bar according to this great page : Microchips TuningInjector Data - Microchips Tuning

The Bitz site specs out a set of high impedance injectors suitable for a Megasquirt controller.

sfj911 - Good point to at least prepare the wiring loom for eventual later COP upgrade. The idea with using the CDI ignition parallel with the MS is interesting, but here i was thinking - If the CDI ign. is kept, would it then be possible to lock the mechanical advance system in the distributer, and have the MS to control that part ?
I saw Al mentioned that the MS manual is providing information related to CDI, but i haven't been trough it yet.

timmy2, wasn't trying to slam your EFI deal as I'm sure your still tuning it as you go. It is a superior system in every way if one has the coin. I would've guessed higher MPG before and after EFI though.

Also, my CIS mileage figures are not what most guys can get due to altitude giving better MPGs. I'm usually between 5200-9000ft.

The reason for me to go with EFI, is that i'm not happy about CIS during the warm up period, and i feel that the engine compartment is a mess with CIS - ok the last thing is only an optical thing - How it looks do also have it's right in all this :-) ?

But most important in the first place, is that i will get a fully programable system, that can be really fine tuned, and at the same time is a good basis for my further thoughts about - raised CR. 964 cams , twin plugs and perhaps 98mm cylinders if the budget will last when i get so far !

First, i will get the engine running with the EFI and what ever ignition (learn about it ) , before any deeper hardware change to the engine will happen.

I was just clarifying what looked like a loss in MPG from the post you made.
(I bought my system used, so I'm into it for a lot less, I posted the new price for reference)
Very easy to spend $2k on all new CIS components if you can find them...
I have the ability now to expand to ignition/timing control with the Megasquirt and may go down that road some day. ITB's are another option! Spent a few hours drooling over Rothsport's system a couple of weeks ago. :)

I'm down a lot closer to sea level here in western Oregon.
Usually around 400-700 ft.
The original mpg rating for my '78 was 18mpg and that was probably optimistic back in the day!

I went through a similar process. I bought the TBitz kit about 5 years ago and did fuel only for a while. Upgraded it to MS 2 to be able to do an Idle Air valve and get rid of my AAR to help cold starts. Turned out that I had trashed exhaust valves and guides. So, while the EFI was a real improvement, I had mechanical issues that were keeping me from getting to the next level. I decided to drop the engine and do a top end rebuild. I took advantage of the engine being out to add a trigger wheel and hit the local junkyard to get Ford EDIS parts which provides an ignition module, coil pack and a VR sensor that is an easy add to MS2 Extra. I also upgraded my cams. The car is totally transformed and I don't have what I consider to be a real good tune yet. It's a long process working through the MS manuals and forums to figure out everything, but the view is worth the climb.

As soon as my schedule permits, I will spend an afternoon on the dyno with a guy who knows tuning and Porsches and get it fully done.

K Sykes,
What idle air valve did you use? I wouldn't mind tossing the AAR as well....

I've used the original AAR, a GM stepper with a Clewett 3.2 adapter, and the 3.2 OEM 3-wire Bosch. The AAR was more predictable than the GM stepper but the 3-wire OEM gives the best performance although requires an add-on board for MSII to control. It is also the cleanest install with the 3.2 manifold.

M'squirt of choice
 

MegaSquirt-II EMS System - SMD PCB3.57 w/ Black Case DIYAutoTune.com

This is my M'squirt of choice. I buy them fully assembled and tested from DIY Autotune. They are knowledgeable and helpful. Should meet your requirements and this surface mount version is, to my mind, a better choice for auto (vibrationnnnnn) apps.

dig in and have fun with the project

koz77911's channel - YouTube

regards,
Al

I used the DIY Autotune machined block which fits a jeep Cherokee IAC. Think the part # is listed on their site. Need to solder 4 jumpers to energize and run it. Specific wiring is in the manual. Need to have at least an MS2.

sjf911 which add on board and where did you get it? Also do you mind if I pm you about tunes.

Glen's Garage sells the board to adapt the 3-wire to the FIDLE output of the MSII.

Glen's Garage

You can also control a 3-wire valve with "external" modifications:

http://forums.pelicanparts.com/uploa...1382719091.jpg

MS2-Extra Hardware Manual

Feel free to PM me, I'll be happy to help in anyway I can.

He actually hasn't sold these for a few years, and it took me several attempts to order from him or contact him to learn this. Wasted several weeks on this back when I was doing an MSII install on my BMW (I was using the same Motronic 3-wire idle valve).

You can certainly build his circuit and use it. I built mine into the gutted base of the GM 3-coil ignition module I used for the wasted spark install. Good heat sink available and didn't have to add another small box anywhere.

Interesting, it's still in his menu for sale.

There's a long thread on the MSExtra forum about Glenn's Garage. Unclear if he is still in business or not. Lot's of unhappy people.