CIS to EFI Conversions?

[Wrecked944]

I've stumbled upon a couple of sites on the internet claiming to offer "bolt-on" CIS to EFI conversions for 911's. Here is a picture of one on a turbo:




Is this idea as nutty as it seems or might it be a cost effective (and potentially "greener") alternative to carbs? Has anyone actually tried any of these products?


------------------
Janus Cole
1980 911SC & 1987 944

[matt_d]

Couldn't get to the page listed at the top of your pic? Any ideas?

Any other links?

Sound like a good idea to me, but I need to see more. With all the efi tuners out there now, an affordable efi system seems doable - maybe not in the carb cost region, but you can't beat the performance.

Matt

[Wrecked944]

Well, I found the following three websites...
http://www.injectionperfection.com.au/

http://www.pem.com.au/

http://www.sdsefi.com/



I'm definitely not qualified to evaluate any of their claims. I sent an email to the first company - I'd expect it will take a while to hear back because of the time zone differences. I am curious mainly for environmental reasons - I've avoided carbs because of the emissions issues. A halfway decent alternative to CIS could make me very happy. I'll keep you posted if I get a reply.



------------------
Janus Cole
1980 911SC & 1987 944

[Wrecked944]

I just tried the links and found that I was getting some extra html tags at the end. They don't appear in the message - but they appear in the address bar when you click on the link. So I think you'll have to delete the "br" stuff appearing at the end of the address when you clik on it.

And just in case, here they are again without line breaks. Maybe this will help...

http://www.pem.com.au/
http://www.sdsefi.com/
http://www.injectionperfection.com.au/

[CamB]

Janus

It is about midday when I type this in Australia. If they get off their butts you should get a quick answer.

I got something from them once, took a couple of days. Price for a pair of triple throat throttle bodies was pretty reasonable, I think. I cant find the info though (and it is pissing me off!).

Cam

[RarlyL8]

I am not aware of any complete ready to bolt on systems for the 911, but there are many EFI systems out there that can be used.
Here are a few, all are priced at less than a set of new PMOs:
Emtech (Haltech of Australia)
Haltech
Electromotive
DFI (Digital Fuel Injection)
EFI Technology
Zytech

[Natchamp]

Autronic is also a good unit that I have heard good things about. I am running a Haltech E6K.

------------------
Mark
The Beast
mark@hargett.com

[rfix'n]

Excuse me for butting in on this post with a question but what is required to change to a Haltech type system from CIS. Controllable injectors, air box?

------------------
Rob Fix
'78 SC Targa

[Wrecked944]

Hey, I just checked out the website for "The Beast". It is a beauty !! Awesome job.


------------------
Janus Cole
1980 911SC & 1987 944

[Natchamp]

Thanks Janus.

Robfix, I'm not that familiar with the CIS but what you would need to do is install regular type injectors, supply them with fuel pressure, and then control them with the ems.



------------------
Mark
The Beast
mark@hargett.com

[RoninLB]

to my narrow point of view, it's a carb eat carb fuel world, unless you are spending big bucks.

[dwil]

I remember someone fitting a 4 barrel
carburetor to his 911. Why couldn't one
of the aftermarket 4 barrel throttle body
systems such as the holley projection
be adapted to the existing cis runners?
It would be tuneable for engine mods and
forced induction. Has anyone tried these
systems on their muscle cars?

[beepbeep]

I'm planing to install SDS-system on my car.

triple throttle bodies per side is a bit of overkill, at least for a turbo...it's so much easier to pick up plenum-chambers from more recent 911 Carrera together with holes for injectors and fuel-rails. N/A engine might respond better to multiple throttles tough.

EFI is *much* better solution than CIS, and more simple too...

I'm dreaming about throwing out all CIS-maze, with modern EFI you can put air-filetr directly on turbo intake, connect the turbo directly to throttle and voilá...it works.

all you need is dump valve and throttle-body potentiometer.

You can throw out several kilograms of CIS-rubbish out of the engine bay.

CIS is cumbersome, complicated and power-robbing system with air-flow meter sitting directly in the airflow....

EFI is cleaner, more fuel-efficient and simpler solution.

[Doug Zielke]

Originally posted by beepbeep:

EFI is *much* better solution than CIS, and more simple too...

That's the way it is now. But when Bosch introduced CIS, there was no EFI and DME's as we know them today. The CIS was a good system for the times. It *was* simple compared to some other existing mechanical FI systems.

Actually, with a lot of reading on the subject, along with help from this BBS, I feel quite at home with CIS. On my car, it's working just fine.

BTW...if you want a good overview of how CIS works, take a look at the article in the October Panorama (Pg. 86).

------------------
'81 SC Coupe (aka: "Blue Bomber")
Member: SCWDP
Canada West Region PCA
The Blue Bomber's Website
"If it ain't broke...we'll help you fix it 'til it is!"

[This message has been edited by Doug Zielke (edited 11-04-2001).]

[Matt Smith]

...or what about 6 individual electro-mechanical injection plungers linked into a MoTeC brain? New World meets Olde World in a spectacular synergy of horsepower, sound and processing grunt....

------------------
'72 911 TE

[Nickshu]

A guy in our local PCA chapter removed his CIS from his 79 SC and installed the DFI system. He was never happy with its performance gain and felt that the CIS did just as well. He ended up selling it saying the benefits were not worth the cost and work involved.

But that may be just the DFI system...not sure how others compare.

Nick

------------------
_ _ __ _ _
Nick Shumaker
1982 911SC Coupe
nickshu@yahoo.com

[beepbeep]

CIS is wide-a***d, complicated way of doing things.

It cannot compensate for air-pressure or air temperature, and as generally cumbersome way of doing things. MFI was much better, altough dirtier way of doing things. EFI rules...

It was probably a good solution 20 years ago...but by now it's obsolete.

Even if i dont get a single horsepower from conversion (which i strongly doubt) , i would welcome additional MPG-increase with EFI.

[koenig911]

beepbeep - what system are you using to control injectors? Are you also replacing ignition?

[Matter]

We use SDS on our 993 race car and on my 3.2L. On my carrera I have TWM throttle bodies with the SDS system. SDS is very reliable, easy to install and a fraction of the cost of most other managment systems. It uses a standard bosch style injector harness and has a driver for each set of three injectors with fuel mixture adjustment. All engine timing and fuel is controlled by computer and the engine map can easily be adjusted with the LED display at any time.

[rvanderpyl]

The problem with using a 4 barrel carb is ensuring that the fuel distribution is the same to all the cylinders, to do that you need equal length runners , the CIS manifold doesn't have that so you would need to fabricate one yourself.

There was an interesting article in one of the Up-Fixin the Porsche issues that was written when Porsche first introduced the Vario-Ram system. It explained how Porsche motors has gone from a tuned intake on the Weber carbs that allowed for a 'full' cylinder charge (a ratio of 1, or the actual volume of the cylinder chamber at bdc) to less than 1 with the first CIS to greater than 1 with the vario-ram system. Any replacement manifold that isn't fed by a turbo charger needs to take into consideration this ram tuning effect or you can seriously impair the ability of the cylinder to fill properly.


Robert

[This message has been edited by rvanderpyl (edited 11-05-2001).]