CIS to EFI = long term happiness?

kwc98 · 09-24-2008, 02:05 AM

I am seriously considering installing an EFI kit on my 82SC. I see a huge advantage just getting rid of all of the CIS plumbing, but I was wondering about people's experiences and thoughts on the swap.

thanks,
Ken

Porsche_monkey · 09-24-2008, 05:06 AM

What EFI are you considering? I that will make a big difference in the feedback.

kach22i · kach22i's Garage

Don't carbs have a sweeter sound than either?

kwc98 · 09-24-2008, 06:12 AM

I am considering the bitzracing EFI kit.

MatthewBrum · 09-24-2008, 07:00 AM

CIS is very reliable and runs well when set-up properly. I don't really think you will gain anything in performance with going to efi. The good thing about CIS is all it needs is fuel pump pressure to operate.

With you car you have the o2 sensor so your gas mileage will not get better with efi.

kwc98 · 09-24-2008, 08:12 AM

thanks for all of the input. I am getting rid of the CIS for various reasons, but I am still interested in getting the opinion of someone who is using the EFI kit. Are they still happy? Greatest thing since sliced bread?

MURF · 09-24-2008, 08:46 AM

i was very satisfied with my bitz racing kit.. i have since moved on to a megasquirt 930 efi in my 83 cab

danielt · danielt's Garage

I converted my 81SC to SDSEFI with good success. Simple to operate and a complete system. I used a late 80's Carrera intake. Here is a link to my documentation of the conversion:

http://home.roadrunner.com/~tisserand/SDS_Install.htm

Hope this helps.

Porsche_monkey · 09-24-2008, 12:39 PM

Have you checked out the megasquirt forums?

kwc98 · 09-25-2008, 03:01 AM

I have looked at the megasquirt forums, but they are kinda all over the place. I like the step-by-step install of the btizracing. Is there another EFI that is as simple to install. The tbitz also looks good when complete.

Porsche_monkey · 09-25-2008, 06:23 AM

There was a place in Calgary, anyone remember the name? Their stuff looked very good.

Mysterytrain · 09-25-2008, 06:26 AM

Have you seen this? Scroll down to the EFI
http://www.pmocarb.com/products.htm#EFI_Throttle_Bodies_for_Porsche®_911® _Engines

Jeff Alton · 09-25-2008, 06:30 AM

SDS mentioned above are based in Calgary.

Cheers

911st · 09-25-2008, 07:16 AM

Just thought, sell the SC motor and get a Motronic 3.2 or 3.6. With a chip and cat bypass my 3.2 is pulling 215+RWHP or 250+FWHP. Might be better for resale than a car w with most aftermarket conversions unless done really top notch.

jcunning · 09-25-2008, 07:18 AM

I don't have actual experience with installation, but I have spent enough time investigating the different systems to offer a little bit of advice.

Make sure you have a local contact for troubleshooting issues. You don't want a system where the support is in different time zones. This makes is very difficult to work through a hard to diagnose problem.

Be sure to line up a local Dyno place to dial in the system. No system is perfect out of the box and there is about 5-10+ hours of dyno time required to make sure everthing is good. Also be sure to budget the dyno time as well, it's not cheap!
You can try to use a friend and a laptop to dial in the car, but this is much harder due to speed limits and traffic.

Hopefully you are a technical, computer savvy person. All of the systems usually require some type of laptop connection for code uploads and system tuning.

1100sport · 09-25-2008, 08:01 AM

EFI on CIS cars allows you to get rid of the "metering system" which is very restrictive on the air flow. Expect at least 10 more bhp by moving to EFI (all things equal). Some have reported a gain of 20 bhp with perfectly tuned EFI and early style exhausts on 3.0 SC.

Quote:

Originally Posted by MatthewBrum

CIS is very reliable and runs well when set-up properly. I don't really think you will gain anything in performance with going to efi. The good thing about CIS is all it needs is fuel pump pressure to operate.

With you car you have the o2 sensor so your gas mileage will not get better with efi.

afterburn 549 · 09-25-2008, 08:22 AM

What I think I know. CIS to EFI you will loose some weight. But,Have a reason to do so..as mentioned is a very reliable good sys.
EFI will give you more flexibility if you are going in the direction of more CR and timing issues.
I always say carbs are for cave men LOL but some are in love with them....for the money....to me EFI would be it, JMO

RWebb · RWebb's Garage

Quote:

Originally Posted by afterburn 549

I always say carbs are for cave men

Unh!

Grog like!

kach22i · kach22i's Garage

Quote:

Originally Posted by RWebb

Unh!

Grog like!

Me like too,

kwc98 · 09-25-2008, 10:32 AM

Looking at the plumbing for CIS makes my head spin. Every problem that cannot be located is a vacuum leak, but of course you can't get to very many of the CIS pieces to check them. I am hoping for something that is less voodoo like. My technical skills are quite high, but I don't want to have to fiddle with the EFI every day either, so I was hoping for someone to proclaim that EFI is the one true road to happiness. I know a backdate on the heat and EFI woud really clean up the engine compartment!