MSD and an 81SC Distributor Hall Sensor

[Dizzy]

Greetings!

Im just about to install an MSD ingniton system into my 81 SC.

Can anyone tell me if the MSD unit can interface with the Hall unit in the distributor?

If so, how did you choose to wire it up?

Cheers

(Installing Webers, SSI and M&K 2 in 2 out)
(I am aware of the advance limitations with this distributors)

[Dizzy]

I just called the MSD supprt line.

They said the MSD unit would not work with the sensor in the SC Distributor.

Yet I see vague reports here that it does. Can anyone confirm?


Thanks

[Jeff Higgins]

It works just fine; I'm running that combination right now. Use the two wire pickup from the MSD rather than the single wire. The shielded wire from the SC distributer need to be wired to these two with the proper polarity. It will run either way, but if it's backwards it will run very poorly. If that's the case when you first fire it up, simply switch the wires. Sorry I can't remember which way it goes; I'm nowhere near my car to go look, either.

[Dizzy]

Originally Posted by Jeff Higgins

It works just fine; I'm running that combination right now. Use the two wire pickup from the MSD rather than the single wire. The shielded wire from the SC distributer need to be wired to these two with the proper polarity. It will run either way, but if it's backwards it will run very poorly. If that's the case when you first fire it up, simply switch the wires. Sorry I can't remember which way it goes; I'm nowhere near my car to go look, either.

Thanks very much for the info Jeff. Muchly Appreciated.

I think the polarity is pretty straight forward.

Cheers and thanks again!

[911Freak]

I put this setup in mine and compiled notes from various threads here..here's a sampling:
I installed the MSD box by using spade connectors on the MSD leads and connecting to the original 6 pin connector so no splicing into the harness was necessary and it can be easily switched back at any time.

A short lead was made to run from the Tach output on the MSD unit and plugs into the 6 pin connector at terminal TD, no adapter is necessary.

The thin red wire is hooked to terminal 15 this is a switched 12V source.

The orange wire is connected to terminal A this is the positive coil lead (white wire for coil)

The black wire (thin) is connected to terminal 31-1 which is the -ve coil lead (brown/red wire for coil).

For the distributor trigger the green wire goes to terminal 7 and the violet wire goes to terminal 31d .This is important as if the car is hooked up the other way it will run but very badly, ask me how I know

For the 12V power I ran the heavy red wire from the MSD unit to the +ve terminal on the starter, the heavy black ground wire is connected to the ground lug behind the fuel filter and accumulator on the body.

I opened up the plug gaps to 0.045” as I believe are recommended by
Steve W. The car idles and runs very well. I highly recommend this upgrade.


"The 3.0's green wire from the distributor is coaxial, it has a sheath and a

core wire, these connect to the violet and green wires of the MSD...

Also, the white wire of the MSD is not used but can be connected with a

normally open switch to ground as a kill/anti theft switch.


Also, the Green wire from the distributor goes to the Green wire on the

MSD and the outer shield part of the green wire goes to the purple lead."

[mb911]

yeah 1 would think the polarity is pretty straight forward but triple check with a timing light at idle and 4000 rpm otherwise its possible to get it all messed up.. And yes it works just fine when correct as that is the same basis as mine

[stlrj]

Originally Posted by Dizzy

I just called the MSD supprt line.

They said the MSD unit would not work with the sensor in the SC Distributor.

Yet I see vague reports here that it does. Can anyone confirm?

Thanks

Maybe MSD misunderstood your question because you called it a Hall unit. The SC distributor contains a VRT ( variable reluctance transducer ) type sensor.

[mb911]

Originally Posted by stlrj

Maybe MSD misunderstood your question because you called it a Hall unit. The SC distributor contains a VRT ( variable reluctance transducer ) type sensor.

Yes my thoughts as well as it works fine for me.. MSD sometimes is hard to deal with I tried to have them make porsche plug wires for years. they sent me samples and when we had set that would work great they flaked out and never followed up

[Steve@Rennsport]

Dizzy,

The SC's distributor uses a magnetic pickup with a 6-tooth reluctor and that triggers an MSD very nicely.

If you need wiring instructions, drop me an e-mail and I'll send that along for you.

[911Freak]

#1. if Steve at Rennsport says it works...it works!

#2 I did exhaustive research on MSD and my 81SC before buying and installing..works VERY well!

#3 MSD as any corp is in CYA mode when a consumer asks specific questions etc...

Finally,
If you do a search (as I did) you will find "real" pro's and con's" about using MSD on a basically stock 911SC, some believe it un-neccesary other swear by it...
I went for it, and after realizing I wired the dizzy backwards, correctly wired as per many install procedures here and have enjoyed it ever since!

Just my .02

[Dizzy]

Originally Posted by 911Freak

I put this setup in mine and compiled notes from various threads here..here's a sampling:
I installed the MSD box by using spade connectors on the MSD leads and connecting to the original 6 pin connector so no splicing into the harness was necessary and it can be easily switched back at any time.

A short lead was made to run from the Tach output on the MSD unit and plugs into the 6 pin connector at terminal TD, no adapter is necessary.

The thin red wire is hooked to terminal 15 this is a switched 12V source.

The orange wire is connected to terminal A this is the positive coil lead (white wire for coil)

The black wire (thin) is connected to terminal 31-1 which is the -ve coil lead (brown/red wire for coil).

For the distributor trigger the green wire goes to terminal 7 and the violet wire goes to terminal 31d .This is important as if the car is hooked up the other way it will run but very badly, ask me how I know

For the 12V power I ran the heavy red wire from the MSD unit to the +ve terminal on the starter, the heavy black ground wire is connected to the ground lug behind the fuel filter and accumulator on the body.

I opened up the plug gaps to 0.045” as I believe are recommended by
Steve W. The car idles and runs very well. I highly recommend this upgrade.


"The 3.0's green wire from the distributor is coaxial, it has a sheath and a

core wire, these connect to the violet and green wires of the MSD...

Also, the white wire of the MSD is not used but can be connected with a

normally open switch to ground as a kill/anti theft switch.


Also, the Green wire from the distributor goes to the Green wire on the

MSD and the outer shield part of the green wire goes to the purple lead."

Firstly,

Thanks to everyone who responded! This is great information and its truely a great thing when folks help each other out like this.

However I have a question about the green wire running from the Dizzy.

In the quote above, he states the outter shield of the green wire goes to the positive purple wire on the MSD unit.

This seems bass-ackwards to me.

The Dizzy wire is a single conductor wire with a braided shield. The braided shield should be there to protect the inner wire from stray signals couplinig into it via crosstalk etc.

It would be my assumption that the center wire would be the positive wire with the signal, and the outter braid, ground. i.e. the center wire would be connected to the purple wire and the outter shield connected to the green wire, which is ground.

Anyone else agree?

Heres my Car. It the process of 40mm webers, SSI, M&K dual in dual out and the MSD upgrade.



Cheers

Dizzy

[Dizzy]

Double post deleted