Hello,
I own a 78 911SC with 157,000 miles on it. I just had my mechanic install a MSD 6AL CD box, super blaster coil and tach adaptor. Before installing the ignition system, they car ran great except it would idle hi when warm in traffic, 3,000rpms. After installing the new ignition system many more problems began to occur. Detonation, and stumbling over 3,000 rpms. Took it back to my mechanic and he found the probem to be the wire between the 6AL and the dirtibutor were crossed. He also reset the timing. The detonation went away but the car will not rev over 3,000 rpms and will hold idle between 2 and 3,000 rpms. He checked the vacuum lines and claims there are no leaks. Problem with the distributor?

 

Your mechanic should review the installation,....

Make sure the wire under the black "button" on top has been cut for 6-cylinder operation.

Make sure the power wires and grounds are properly done as these ignitions draw a lot of current.

Make sure the trigger wires are correctly connected (yes, I see he fixed that) and checked for continuity from the distributor to the MSD unit.

Make sure a 6500 RPM module is plugged into the MSD unit.

Hope this helps,

 

Sean,
I've been thinking about doing the same to my 79 SC. I hear the installation is pretty pricy. What was your total investment? Do you think it was worth it.? Is this a track or DE car?
Andy

 

thanks for the help. I only have 3, 6, 7, and 8 rpm modules. The 6 is in there now. I tried the 7 with no change. He said the wire was cut for 6- cylinder operation.

 

Andy, the total investment was about $1000. $650 for labor and $350 for the CD box, super blaster coil, and tach adapter. The car is a street/DE car. The most expensive part of the install was mounting the the CD box in the same place as the bosch unit. He had to fabricate a custom mounting bracket. I switched to this box because i might do some more DE events, but am planing on more engine performance upgrades in the future. Once I get it sorted out, I will let you know if it is worth it. Sean.

 

Sean,
Thanks! I was told the same $1,000 bucks for maybe 10 hp. Look forward to hearing about your upgrades.
Andy

 

I have a similar system on my 3.2 (overbored 3.0). The spark plug gap should be increased to 50 thou. You may want to drill two small holes in the distributor cap to allow the excess ozone to escape. These tips are usually included in the MSD literature. I don't remember, but they may also suggest different timing. The signal wire to the distributor must be pristine - checking for continuity is not a guarantee of good performance. Good luck!

 

"I was told the same $1,000 bucks for maybe 10 hp."

10 HP, from what???

 

I don't often agree with Loren, but in this case he's right.

You'll not get anything close to 10HP on a CIS car.

MSD's really pay dividends on carbureted and MFI'ed cars when the plug gaps are opened up.

 

There is a good writeup on this mod (with a number of seemingly useful tips) in the book, '101 Projects For Your Porsche 911'. I have no relationship to Penguin, but just recall reading the chapter on this mod.

 

Well sometimes I may not understand what I read or am told but here goes....

Project 24 from 101 Projects. Performance Gain: 10 or more horsepower increase on lower-end and non-CD911s (1965-1968)

Page 99 of the Performance Products/Automotion Spring 2010 catelog. "Our chassis-dyno testing showed a 10 hp improvement on a 912E"

Am I confused? I'd rather find out now then $1,000 later!

 

"Project 24 from 101 Projects. Performance Gain: 10 or more horsepower increase on lower-end and non-CD911s (1965-1968)"

You can't always believe everything you read, especially given the source,
i.e. Who copied info from another unreliable source without verification.

 

Penguin, Pelican, they all look the same.

 

First, I'd preface my comments by telling you that I am a huge fan of MSD's and have been using them on a wide variety of 911's since 1975. On many of these cars, they make a big difference in starting, drivability, and overall manners. In some cases, we saw measurable power improvements on the engine dyno.

Note the statement: '65-'68 non-CD equipped cars. Those cars had the old-style Kettering ignition (points & condenser) and were prone to plug fouling, so when the addition of an MSD was completed, it made a very big difference.

On a 912E, I would expect to see little or no difference with an MSD unless the engine was using oil at a prodigious rate: 10 HP no way,...

 

Good thread.