EARLY sc VS. Late sc Induction sys differences

911 tweaks · 07-23-2006, 05:03 AM

Can anyone help me figure out ALL of the diferences of the 78-79 vs. 80-83 911sc induction system differences.
early intake runners are larger
early system did not have o2 set up
early fuel dist = euro fd?
early air box is different
early fuel injector size vs. late?
early fuel metering plate vs late?
early plastic fuel injector lines work with either fuel dist or
injectors? vise versa on late cad steel fuel lines?
any and all other elements?

Basically I am unable to fine an early sc induction system except one that went swimming in Katrina and I am wondering if I should pass on it or get it and can use some of my late sc induction system to cobble it together. I will be using the early sc heads thus I need the early induction system otherwise I will obviousley limit air intake to more breathing early heads.
Thanks, Bob

Rick V · 07-23-2006, 06:10 AM

Why not just use the Bitz system? If I ever run into one of those expensive (over $1500) repairs I am going that route. Just a thought.

911 tweaks · 07-23-2006, 06:16 AM

thanks rick v- if you are using this set up, can you tell me your complete engine set up; performance +/- vs. cis; what is needed touse the tbitz system... maybe pm me and I can call you to go over my situation and how your suggestion may help me out. Thx Bob ps I will be away from the computer till mid PM today but I will check in then.

Gunter · Gunter's Garage

early intake runners are larger = True
early system did not have o2 set up = True
early fuel dist = euro fd? Bosch # ’78-‘79= 0 438 100 031 (Make sure you get the right WUR)
early air box is different = True, mainly the runner boots are larger.
early fuel injector size vs. late? = They are the same
early fuel metering plate vs late? = Not sure
early plastic fuel injector lines work with either fuel dist or
injectors? = 99% sure but..........

Anyone wants to chime in?

911 tweaks · 07-23-2006, 10:38 AM

thx gunter for the info!!
If anyone else can chime in to help me figure out how I make this early set up work, I would greatly appreciate it! Bob

Eric-325I · 07-23-2006, 11:05 AM

Rick is talking about the Bitz Racing CIS to EFI upgrade. The word is that it's fairly easy to install, very clean, and good for a little more hp... The link is here: http://bitzracing.com/products/Complete_kit/index.html

I will do this when I need to or have a little extra cash...

Eric

Rick V · 01:53 PM

Quote:

Originally posted by Eric-325I
Rick is talking about the Bitz Racing CIS to EFI upgrade. The word is that it's fairly easy to install, very clean, and good for a little more hp... The link is here: http://bitzracing.com/products/Complete_kit/index.html

I will do this when I need to or have a little extra cash...

Eric

Yup.
Simply do away with the CIS alltogether and enjoy. I think you misunderstood my post, I still have the CIS on my car but will change if the repair cost ever gets to the replacement cost of the Bitz

911Mac · 07-23-2006, 04:23 PM

Bob,

If you decide to use the Tbitz CIS to EFI kit you will still need intake runners, air box, and throttle body. Some cut up their air box and add an external air filter for a cleaner installation. Check out the Tbitz web site at http://www.bitzracing.com/ to see samples of various installations.

You'll need to weld a bung (included in the kit) on your exhaust for the O2 sensor.

I've been running the kit on my 82SC for several years and love it.

Good luck getting your car running.

Mac

Gunter · Gunter's Garage

I like CIS.
Just finished a SS 3.2 with CIS from a '78 and the bottom from an '82 with 964-cams, SSI's........................
Be more specific about what parts you have and what you want to do so I can give you my 2cents worth.

Eric-325I · 07-23-2006, 05:57 PM

Mac, would you care to elaborate on your experience with the kit? Did you install? Horsepower gains?

Thanks.

Eric

911Mac · 07-24-2006, 01:52 PM

Eric,

I installed the kit myself, the instructions provided with the kit are very thorough and everything is included.

I've put almost 50,000 miles on the car since installing the kit, I upgraded the O2 sensor to a wideband about a year and a half ago.

As far as hp increases, I haven't had it on a dyno either before or after the conversion so there's no real concrete data. Feels stronger, but you know how accurate the butt-dyno tends to be. I believe Tony had some before and after dyno numbers on a car that had been converted, try a search on "CIS TO EFI Conversion".

I do get better fuel milage, went from an average of 22 mpg to about 25, mostly highway driving.

The mechanical skills needed to install the kit aren't that great, some people drop the engine for the install, some don't.

One thing to consider is that once the kit is installed, you can't just take the car to your local mechanic and ask him to fix something EFI related. You need to have a certain comfort level with your diagnostic and troubleshooting skills and then take the time to read the megasquirt manual to understand the system and how it works. If that makes you uncomfortable, then maybe you should investigate other options. Don't get me wrong, it's a great system, just not for everyone.