mag vs MSD

at what point with blown alky do you need to go to a mag. How far can you go with a MSD 7AL-3

 

they say a MSD 10 plus is good to 2000 hp on alk so a 7 would be less

 

many moons ago
i went 6.90's with an Autotronics 7C box
took it off and went to a mag when the battery came loose and ruined a firesuit and trans blanket from the acid

so you know
Autotronics was the company that Chrysler had build their
Multiple Spark Discharge ignitions
the MSD 7-AL is the after effects of
the Chrysler (Mutiple Spark Discharge) 7C

Autronics now known as MSD

 

I am having the same questions. I have a MSD 7AL3 in 1471 Blown Hemi. It runs but cannot cut through the cylinder pressure. I went to an MSD 10 because I had one laying around. It started breaking up and the data logger RPM graph looked terrible. (I sent it back to MSD which seems to be common on these MSD 10's but it's a lot of energy so it would not surprise me that you have to do this frequently.) I then went and got a Mallory Mag IV and the car sounded much much better and cleaned up my fuel problem. I think once you go to a mag, you will get rid of the capacitive discharge ignitions. The mag seems to be much better suited for blower cars with alot of boost. I'm running 40 plus lbs. I think if you have low boost the 7AL3 will get you by for a while but your car would like a mag better. The mag appears to work almost the opposite of the Capacitive discharge ignitions. It's lower voltage but high amperage (That's why you can't gap your spark plugs too far apart)... Of course the MSD 44 mag would jump just about anything but I am just running the Mallory Mag IV at 4 amps. That's my .02 cents...

 

Did you have a 10 or a 10 Plus? There different. The 10 Plus is actually a marriage of inductive and capacitive ignitions. They took the benefits of each and built it into the 10 Plus.

The 7AL3 puts out 160 millijoules of energy to the plug. The Digital 7 delivers 190 MJ's and the MSD 8 delivers 315-345 MJ's.

The ProMag 12 delivers 300 MJ's and the ProMag 20 is 600 MJ's.

The two top ones are the MSD 10 Plus at 700 MJ's and the ProMag 44 at 950 MJ's.

With the 7AL3 you'll never get it to burn the fuel volume potential (more power) of the 10 Plus or ProMags. Sure, it will run just fine if that's all that's important.

Blessings........Ron Clevenger

 

i am looking at running in the 20-30 lb boost range with 12.4:1 static compression.

Is the 10-plus worth the investment

 

i would put at least a mag 20 in it.....just my 2 cents

 

I run a 10 Plus on a big chief chevy blower motor. We run a PSI 14/71 at 26% OD makes 35 lbs of boost... no problems. HOWEVER I run the ten plus because it's a little tough to get a Mag on the front of a chevy, I know about the pioneer drive but it's still a pain. If I had a 481X or a Hemi.... Mag 44!

 

I've never had experience with anything but Mallory mags,,, but Dean Stumme in New Hampton, IA runs a turboed BBC I beleive in the 50 psi range and fires it with a 10+. Once upon a time he ran Msd 8's. He would be good to talk with.

To the best of my knowledge, many of the turboed alky pulling tractors run 80-90 psi and use 8's and 10+. Some are making upwards of 800 HP/cylinder

Why they don't run mag's I don't know, it maybe for some other reason. Like most of them are 6 cylinders and maybe that can't be made to work???

 

if you can put a alternater on it, run the msd 10 +

do you need the onboard starting function , or have remote starter ?

 

my 16v V-Battery shows 17.35 volts on the alternator. I don't think voltage will be a problem. Just looked at the plugs from my buddy running a mag and they were alot cleaner, but burned nice. That is why I was asking.

Where do you guys like to run the timing mark on the -9 NGK plugs. I run a 5671-A-9 plug.