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-   -   CIS to EFI Conversions? (http://forums.pelicanparts.com/porsche-911-technical-forum/10077-cis-efi-conversions.html)

emcon5 11-07-2001 10:54 AM

Also, I see you are in California, any smog legality issues? Do you just count on Goober down at the Smog-Pro's not knowing what he is looking at?

Tom

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82 911SC Coupe

BenWillis 11-07-2001 12:04 PM

The suspense is KILLING me!!!!!!!

Ben in SC

stlrj 11-07-2001 01:02 PM

The donor car was an 85 Cavalier V6 stationwagon. Reason I used the 85 system was because the input signal from the stock 3.0 distubutor was compatable in order to trigger the ignition and injection.

If you look close, you can see how I butchered an old air box with a little imagination.

Smog was a breeze since I got very skillful at removing it and putting the stock CIS back in less than 30 min.

Probably the most challenging part was machineing a cylider head to accept a 914 head temperatue sensor.

Joe

beepbeep 11-07-2001 02:00 PM

smog? what smog? EFI is much better at holding the right mixture (compared to CIS)...put in a lambda and a cat and you're ready for Greenpeace http://www.pelicanparts.com/ultimate/smile.gif

wckrause 11-07-2001 02:06 PM

I think the smog issue is more about laws against modifying emissions equipment than meeting specific emissions levels. Some states don't allow you to modify anything, no matter what the result is.

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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

emcon5 11-07-2001 02:13 PM

Quote:

<font face="Verdana, Arial" size="2">Originally posted by beepbeep:
smog? what smog? EFI is much better at holding the right mixture (compared to CIS)...put in a lambda and a cat and you're ready for Greenpeace http://www.pelicanparts.com/ultimate/smile.gif</font>
You poor misguided soul. You must remember, this is California we are talking about. The fact that the car actually produces less emissions has absolutely nothing to do with it. If you put on an aftermarket part that the California Air Resources Board hasn't given their all-knowing stamp of approval, it should still fail a visual inspection. If all that mattered was lower emissions, CARB couldn't collect money from manufacturers seeking approval for their parts.

Everything that is not expessly permitted is forbidden.

In their defence, CARB is a hell of a lot better than they used to be. Ten years ago, almost nothing was CARB approved, now lots of things are.

Tom



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82 911SC Coupe

Wrecked944 11-07-2001 02:15 PM

I just spoke to my P-tech on the phone and he agreed that in theory a properly bolted 3.2 litre induction system could be put onto an SC engine (preferabley with the 3.2 litre cylinder upgrade) for short money with nice results. He said there might be some fanagling required with the flywheel. But nothing huge. Again, this is all in theory.

But clearly STLRJ has captivated our collective attention. I suspect you're going to be inundated with requests for pictures, specs, diagrams, FAQ's, graphs, etc ad infinitum. Heck, I'm barely able to contain my own curiousity.


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Janus Cole
1980 911SC & 1987 944

Jcon 11-07-2001 03:56 PM

OK In yet another display of my unending ignorance....Why would the fly wheel be involved in such a conversion?

Jeff C

BenWillis 11-07-2001 04:13 PM

The DME system used magnetic triggers on the flywheel. 3 if I remember right....

I do hope that we can get a little more detail on the GM FI, like part numbers, maybe a few pics of the installation etc. Heck I am already calling the local junk yards looking for an 85 Wagon http://www.pelicanparts.com/ultimate/smile.gif

Ben in SC

Wrecked944 11-07-2001 04:51 PM

OK In yet another display of my unending ignorance....Why would the fly wheel be involved in such a conversion?

Well, if you're ignorant then so am I. My P-tech explained it and it sounded something like what Ben said. Aside from that, I just nodded and said, "Oh, okay. Something about a sensor." It didn't seem like a show stopper.

And since we're already all searching for 85 Fords in the bone yards (myself included), let's add Audi's and VW's to the list. I did some research on Bosch K-Jetronic (aka CIS) systems and found out that Bosch upgraded the system to be essentially an EFI system in the late 80's. Seems they added everything we CIS guys could want - mass air flow sensor, pulsed injection, etc. And they did it all within the same throttle body/fuel distribution unit. The system is called KE-Jetronic and it looks to be about as "bolt-on" as "bolt-on" gets. Pull the fuel distribution unit off, replace it with an almost identical unit (with electronics inside), add some sensors and you're good to go. And presumably, if you get one from a wrecked VW, then the price would not include the "Porsche Tax" and might be reasonable. I'll keep digging and present the results once I have more. Stay tuned.


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Janus Cole
1980 911SC & 1987 944

II6 11-07-2001 06:13 PM

Sorry for the long wait for the reply.

Beepbeep; I'm still shopping around for an adjustable fuel pressure regulator at a decent price. I'm also waiting for my TB's to come in first.

BenWillis; Some basic mapping is done when you receive the SDS system. I also bought most of the sensors from SDS, as I didn't want any electrical gremlins. Go to their website, they have a ton of info. They've done 911 before, look at their project cars.
I'll be fine tuning with an Air/Fuel meter, done by none other than me, I got the plans from the Pelican tech area. (I modified the plans slightly, to better suit my needs.)

The main reason I chose individual throttle bodies is because I wanted instant engine response. But I know I could probably have saved 1000$ easy if I had taken a used 3.2L intake system. I don't intend to put a blower on the engine either, so TB's it is.

PS: Wckrause, my sc already had a computer for the 02 sensor. Also, my car is not a collector car, it's got plenty of mileage and dings, it's my weekend semi-street-legal project/go-kart http://www.pelicanparts.com/ultimate/wink.gif

emcon5 11-07-2001 07:27 PM

RE: KE-Jetronic

You got me curious, so I dug out my Bosch FI book and read up on KE-Jetronic. From the description, it sounds pretty similar to the standard CIS with Lamda, except the WUR is removed, and an electronic unit to control fuel pressure and a coolant temp sensor are added. Unfortunately the biggest chokepoint of the old CIS is still there, the sensor plate.

Too bad, as it can be found on Audi 4000S & 5000S, Mercedes 190E, and VW Cabriolet, Golf, Jetta, Quantum and Scirocco. Should be easy to find parts.

Tom

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82 911SC Coupe

[This message has been edited by emcon5 (edited 11-07-2001).]

Wrecked944 11-08-2001 06:36 AM

it sounds pretty similar to the standard CIS with Lamda

Yes, I believe you are correct. On further investigation, I learned that Bosch has developed a number of incarnations of the "Jetronic" system (K-Jetronic, KE-Jetronic, KE3-Jetronic, D-Jetronic, etc, etc). So I am certain that I have them confused. I'll keep researching to determine which, if any, could provide a genuine upgrade to our K-Jetronic systems. I still have a lot of interest in this option. I just need to sort out the various options. And did I understand correctly that the later Porsche turbos and maybe the 993(??) used variations on the Jetronic theme? If so, then these might provide clues or upgrades as well. Lots of research to be done here and I'm, working on it.


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Janus Cole
1980 911SC & 1987 944

stlrj 11-08-2001 08:12 AM

Ben,

Forget the wagon. Just about any 85 with a 2.8 V6 will do.

Pick up an 85 Chevy manual at the Goodwrench place and then head off to your nearest boneyard.

That was basically my approach.

And be prepared to do a lot of reading...

Joe


KTL 11-08-2001 09:26 AM

Joe and jadams are right on. All sorts of GM models run the 2.8L V6. If 85 was a special year, so be it. There's Cavaliers, S-10 trucks/Blazers, Sunbirds, Fieros (did it get the GT-V6 that early? because you'll need a GT for the 6), Celebritys, Buick Skyhawks, Cadillac Cimmaron (oooooh a Caddy had one too!), Olds Cutlass Calais and whatever else I forgot.

Point is, most (probably all) of the above cars are some serious piles of poo at this point in time and should be readily available at your local donor yard!!!! Good luck.

Joe (strlj) knows much better since he did the conversion, but I imagine more than just 1985 stuff will apply. GM hangs onto tech. stuff for a little while (e.g. TPI for the F-body cars and Vette was mostly unchanged from 86-90 [85 & 86 had different PROMS]and changed a little 91,92 [went to speed density from MAF I believe] before introducing the LT-1 motors).

Great topic. Interchangeability from different manufacturers is always fun to read about.

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Kevin
87 Carrera coupe

[This message has been edited by KTL (edited 11-08-2001).]

beepbeep 11-08-2001 09:34 AM

But hey, if you are using GM Cavalier EFI, how do you trigger injectors in right moment?

Ignition timing is different for boxer-6 compared to V6...do you spread sensors around flywheel in different way or what?

stlrj 11-08-2001 09:46 AM

Kevin,

If you go beyond 85, you'll be dealing with a crank position sensor as part of the crankshaft...too complicated.

If you stick with the 85 TPI you can use the signal from your stock distributer to the EFI computer to trigger the injectors.

I think the solution to the cylinder head temp sensor installation, if I did it again, would be to find one that fits under the spark plug like they do in general aviation.
That would eliminate machining a head for a 914 sensor and save $$$.


Joe

[This message has been edited by stlrj (edited 11-08-2001).]

BenWillis 11-08-2001 11:21 AM

Joe, In an email I got from you you mentioned converting the CDI? What are the other options, could a MSD be used in place of the stock CDI?

Ben in SC

KTL 11-08-2001 11:31 AM

jadams,

Is Motronic batch fire also? That is, non-sequentially injected.

Joe,

I figured you mentioned only 85 for a reason. I'm no parts manipulator, just a little (very little) informed about GM stuff. Thanks for the correction. I imagine the CPS is why the TPI eproms changed from 85-86?

All of you guys rock! Building a CIS to EFI upgrade out of Cavalier electronics.... That's slicker than whalecrap on an iceberg.


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Kevin
87 Carrera coupe

stlrj 11-08-2001 12:37 PM

3.2 Motronics are batch fired. Sequential did not start until the 993's if I'm not mistaken.

I wouldn't know if MSD is compatible but then why make it more complicated than it is?

Besides, HEI will blow the electrodes off CDI any day and no manufacturer I know of uses CDI today for good reasons.

Joe

Speaking of slick, you should have seen the expression on the Chevy technician when he plugged his scan tool into my diagnostic test connector and read the data stream...it was hilarious!

[This message has been edited by stlrj (edited 11-08-2001).]

[This message has been edited by stlrj (edited 11-08-2001).]


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