Motronic from a 3.2 on a 3.0 SC

[BernieP]

Has anyone installed a complete Motronic unit from a 3.2 onto a 3.0 in an SC? Would this not be a good replacement for a failing CIS system?

Thanks

[PcarPhil]

Good question. I'd like to know the answer to this myself...

[Scott R]

I looked into this last week, there is a company that makes a kit in fact, Clewett engineering:

http://www.clewett.com/products/engnmgmt/emsys.htm

Biggest issues that steered me away were, having to cut the bellhousing for the reference sensor bracket. Changing the flywheel out again, meant another engine drop me. And dealing with the ignition system, the SC distributor in manual advance, the 3.2l is motronic of course, and controlled by the DME. I couldn't find reference is using a 3.2l dizzy on an SC, I bet you can, but I couldn't find any info on it.

Next and last deal killer was the cylinder head temp sensor, you would have to machine the head to accept it, or find some cleaver workaround.

[Scott R]

I wanted to mention on other thing as well, you could use the 3.2l intake and get the BITZ fuel rails and Megasquirt setup to drive it. You get the benefit of the 3.2l intake design, and more programmability.

[sjf911]

Originally Posted by Scott R

I wanted to mention on other thing as well, you could use the 3.2l intake and get the BITZ fuel rails and Megasquirt setup to drive it. You get the benefit of the 3.2l intake design, and more programmability.

This is what I have except I have the 3.2 fuel rails and FPR. Using the Motronic almost necessitates using a 3.2 engine/tranny combination unless you want to do lots of modifications. The 3.2 intake is great but you need 3.2 heads to optimally mate them to. You can modify 3.0 heads to fit but this is not perfect. Megasquirt or other aftermarket ECU setups offer much more flexibility in designing your EFI system.

[Bill Douglas]

Scott, you car sounds like a nice setup. How does it perform?

[Scott R]

Originally Posted by Bill Douglas

Scott, you car sounds like a nice setup. How does it perform?

Did you mean Steve? He has the 3.2 intake. I had Bitz EFI up until yesterday when I went back to CIS.

[Bill Douglas]

I was looking at your footer "1980 911 SC TBITZ EFI 10:5:1 JE's SSI's 964 CAMS Heater Backdate " and thought it sounds like the sort of setup I'd like to have.

[Scott R]

Originally Posted by Bill Douglas

I was looking at your footer "1980 911 SC TBITZ EFI 10:5:1 JE's SSI's 964 CAMS Heater Backdate " and thought it sounds like the sort of setup I'd like to have.

Oh, ok. Well if you read my dyno thread so far it's only made 141 hp, which is why I switched back to CIS. I'm going back on Saturday for another set of pulls. Can't exactly say what was going on with the EFI post rebuild, but so far I have far better response from the CIS system.

[Roslin]

I'm planing to do the same conversion ( Motronic on SC)
- Do i need the 3.2 distributer, as the advance curve is controlled by the DME ?
- SC distributer is so far i know rotating the opposite direction?
- If the 3.2 distributer is used - can it rotate backwards, with the gear mounted from an SC distributer ? .. have hoped not to open the engine to change the distributer drive :-/

Thanks Roslin

[Tspringer]

Why would want to do this?

Motronic is very complicated, has tons of things that frequently go wrong, is a pain to diagnose and repair (not to mention expensive) and does not give any sort of great power advantage.

Browse threads here on Pelican... I bet 3.2 motronic problems are the single biggest category of problem posted here. Why anyone would volunteer to go down this road when carbs and a re-curved distributor offer so much more power and simplicity is beyond me.

[SteamWolf]

Originally Posted by Tspringer

... when carbs and a re-curved distributor offer so much more power and simplicity is beyond me.

You damn kids. Get off my lawn.

[boyt911sc]

Originally Posted by Tspringer

Why would want to do this?

Motronic is very complicated, has tons of things that frequently go wrong, is a pain to diagnose and repair (not to mention expensive) and does not give any sort of great power advantage.

Browse threads here on Pelican... I bet 3.2 motronic problems are the single biggest category of problem posted here. Why anyone would volunteer to go down this road when carbs and a re-curved distributor offer so much more power and simplicity is beyond me.

Really? You probably have not owned or driven 3.2 Carrera Motronic car for you to come to this conclusion. My two- cents.

Tony

[timmy2]

Bitz EFI and my ROW mechanical advance only dizzy on my '78 is working great with proper tuning.

Key words, proper tuning.

Reliability greatly improved with a slight improvement in fuel mileage as well.

I don't understand Scott's issues, maybe he needed to change injectors for the changes in the engine? More flow needed? Completely different AFR map for sure...

[JeremyD]

I know Nippy had a 3.2 Intake on his SC {and Motronic}

My $6K Porsche 911

[Roslin]

Originally Posted by Tspringer

Why would want to do this?

Motronic is very complicated, has tons of things that frequently go wrong, is a pain to diagnose and repair (not to mention expensive) and does not give any sort of great power advantage.

Browse threads here on Pelican... I bet 3.2 motronic problems are the single biggest category of problem posted here. Why anyone would volunteer to go down this road when carbs and a re-curved distributor offer so much more power and simplicity is beyond me.

I would like to have a full program able system where i'm really able to fine tune things
The engine compartment look's like a mess, with CIS ! don't like that - ok this is only a visual thing, but like 3.2 setup from that point of view.

[Roslin]

Originally Posted by JeremyD

I know Nippy had a 3.2 Intake on his SC {and Motronic}

My $6K Porsche 911

Thanks Jeremy - i will contact him, to get some details.

Roslin

[will hung]

Lots of guys, in particular the 930 guys, have gone the route of replacing the CIS with a Carrera intake and megasquirt. You should explore that path too.

[Kremer#2]

Will the injector bushings that come with a Bitz kit work with the 3.2 minifolld? Also do I have to modify my 3.0 sc heads? I already have the crank fire XDi.

[will hung]

To fit a Carrera intake to SC heads, you would need to modify the heads. Turbo Kraft sells an adapter kit that makes it a bolt on affair. I can't comment about the Bitz injector bungs, but the Carrera already has proper fuel injectors. I plan to use the factory fuel injectors/rails that came with my Carrera intake when I convert to megasquirt. Having said that, I'd imagine that the fuel injectors the Bitz kit is set up will plug into the Carrera intake.