Need help with 930 motor swap

[rudy]

I am putting a 78 euro 3.3 turbo motor and trans in my 71T. I already have the fuel lines, oil system, motor and trans fitted in the car, so all that is left is the wiring. I am using a MSD ignition and a mechanical boost gauge. So basically I need some help with the electrical end of it. I read on some other posts about fuel pumps needed something done special. I don't know what needs to be done for any of the CIS and speedo wiring.
Also I need help with how the clutch arm goes onto the trans and the propper clutch adjustment. Does the clutch pedal need to be changed as well? I have heard mixed things about this.
Let me know if I am forgetting anything. Any help would be really appreciated. I need to get this car going by thursday since I am moving from Indiana to Washington state this comming weekend.
Thanks alot, Mark

[RarlyL8]

The 930 CIS systm requires 2 fuel pumps. One goes in the stock front location, the other in the rear near the engine. You really need the entire fuel system to make everything work optimally. This includes the 930 fuel accumulator.
The factory overboost switch shuts off the fuel pumps at 1.1bar while the factory rev limit switch shuts down the ignition at around 7200rpm.
These are good devices to have in place to protect your investment.

There are a few on this board who have put 930 engines in early cars. Hopefully they will see this and chime in. If not do a search. About 5 years ago there was a fellow down in Florida named Rich Boylan (screen name rboylan) who did the same thing you are.

[dean]

If I were you I would use a high pressure aftermarket fuel pump up front. I would also get a turbo manual and compare the wires in 14 pin connectors. They are different. Like Rarely said overboost is good. I would also ship my car instead of hurrying to finish it. If done right it takes some time.

I would also dump the CIS and go EFI. But that is me If you do that then the overboost is not nessacary.

[rudy]

both pumps and accumulator are installed already. everything came off the 930. All that is left is the engine wiring harness and a few small things about a days work.


By the way the car is going inside the Uhaul truck.

[beepbeep]

have you already installed he engine/tranny combo? Post 77' 930 transmission has long clutch bellhousing, which means engine sits litle further back in the body. It usually requires that you either modify front transmission mounts or rear engine mounts.

How did you solve this?

[RarlyL8]

I ran the wiring for the front pump through the stock configuration relay.
Ran the rear pump trough an empty relay spot on the rear electrical panel. This one is tied into the overboost switch.

The wiring harness needs to tie into the 14 pin connector. You need the electrical schematric for the exact engine you have and the car it is going into. This is a good time to minimalize your CIS and eleminate a few electrical connections. It is important all CIS equipment gets power after the initial start up. The various time devices will cut the power to the individual components when needed. A CIS schematic also helps at this point.

What tranny are you using?

You've probably got your hands full with the move. I would consider waiting until you are settled to finish this project.

[slammed1000]

Originally posted by beepbeep
have you already installed he engine/tranny combo? Post 77' 930 transmission has long clutch bellhousing, which means engine sits litle further back in the body. It usually requires that you either modify front transmission mounts or rear engine mounts.

How did you solve this?

both the front and rear mounts were modified to get the engine tin sitting in the correct area. about 20mm on the crossmember and 10mm on the rear.

[rudy]

It is a 78 long bell 930 trans. I cut the front trans crossmember and moved the ears back around 3". Not sure because I did it several times since I could not get a good measurement from the front of the trans to the torsion bar tube. Kinda eyeballed it. I got it really close to the distance from the drive flanges to the ears on the crossmember on my 911 trans. The rear crossmember I cut the bend at the top of it and pushed the ears forward till the bolt fell through, around 1" or less. So basically the motor sits back less than 1". I also cut the shifter rod 3/4" since the trans went forward so far. It was pretty easy after I got all the measurements correct. The stubs on the trans I machined 2 of the bolt holes out so the dowl pins in my 4 bolt 2 pin CV's would fit.

As far as beeing busy moving, My wife is taking care of it. I've been on a 20lb weight restriction since Oct 04 for a neck injury, so I can't do much. She is in the military and we knew this was comming so we don't have much stuff to move. I figure I could have the car wrapped up in a day or so. It's taken me less than a week to get this far on it.


I'm going to the local Porsche dealer in the morning to try to get some wiring diagrams. I was in there a few weeks ago to get my VW GTI worked on and the service manager seemed like a nice guy. I should have it sorted out tomorrow. I was just trying to get a jump on things and see if anybody here could give me some shortcuts as far as which wires on the 14pin connector needed to be changed.

[rudy]

I went to the local porsche dealer and they never heard of a 930. It was quite funny. I ended up going to another shop and got a diagram. Looks like the only thing I have to change is the red and white wire #10 on the connector. Same as putting a 78 3.0 in my car. I took it out of the connector, cut the end off and connected it to the fuse that gets power with the key on. There was other wires for the fuel shut off and boost gauge, but I'm not worried about those. This should at least get it running. I think I am going to try to wiring the the MSD box to the over boost switch. So instead of shutting the fuel off it will cut the ignition. It seems alot safer than cutting the fuel from to much boost and causing a even more lean condition.

I worked on it yesterday but ran into problems with the throwout bearing, so I had to pull the motor back out and fix it and put it back in. Looks like the only thing left is wire the MSD, mount oil cooler, and lines. I'm still waiting on a fitting so I can run the return line into the tank. It should be here tomorrow. It shouldn't any more than a couple hours to finish it up.

[RarlyL8]

Good deal.
The harness on a '78SC is the same as a '78 930. My swap was made very simple by using the same year motor and car. I'm not as familiar with the early cars and cannot help on that end. Sounds like you have it under control.

I need to add something. Overboost control - I would not wire the ignition side. If you shut down the spark at high rpm and allow the CIS to continue dumping fuel bad things could happen. It is better to cut the fuel for a second or so. An overboost event should only last a very short time before you lift the throttle.