MSD ON THE RX7'S ---( ((><)) )-->
 

I was wondering if anyone has a MSD ignition setup on their first gen. I currently have a few bolt on's on my seven and am considering installing an MSD ignition system next. Could anyone tell me which ignition box I need to buy and also if the MSD really does do a noticeable difference in terms of performance. Check out my seven at car domain and let me know if a MSD ignition system would make a difference with my current setup. http://www.cardomain.com/memberpage/656571

I've done a MSD 7AL install on a carb'ed and distributor-based 13B. To get the timing split, we ran two 7ALs in parallel. The drivers and coils are better than the stock equipment; I don't know by how much.

Just remember that if you're using the stock-style transistor-based ignitors to trigger the MSD driver(s), you need to wire up to the MSD like you would a points-style ignition (i.e. ground contact triggered). I've never seen this mentioned anywhere (e.g. MSD docs, general online banter).

MSD makes for a smoother idle, better driveability, and probably a small hp gain. I use 6a's cause I see no need for more expensive ones. Also if your only using one box, a rev limiter chip wont work as the trailing ign will still function. Best way to trigger it is directly off the mag pickups. Go check www.mazspeed.com in the facts section for more info.

I concour with Carl, the MSD 6a on your leading side has a very positive impact on your car.

There is 2 things I do not agree with in the write up:

1. "Go ahead and hook up your plug wires for the trailing now. Its just the same as they always have been."
WHy not: Since your plugs for the leading are firing directly off their own coil, move the tailing coil wire and plug wires to the leading locations on the distributor cap. The trailing ignition design requires the coil spark to jump gap 2 times where as the stock leading only required the coil to jump gap 1 time. Get double miles out of distibutor cap/ rotor.

2. This picture is why I was reserve about doing the MSD install in the beginning.
http://www.mazspeed.com/distributor.jpg


I gutted a old spare ignitor and jumped internally the terminal connections. That make the connection between the MSD box and stock distributor much better set up. Also get a spare factor harness to solder in your wiring connection to it, so its 'plug in and play'

http://www.rhinoracing.com/images/ga...gniter_msd.jpg


John

I totally agree about moving the trailing, although admittedly jumping air gaps at ambient pressure isint all that bad.

And definately do an igniter like John showed (try to find a burned up one though please. good ones are getting harder to find as time goes on). Thats how I did mine. Much more positive connections and more secure. Also allowed me to switch back and forth between different setups very quickly for testing at a track day. :bigthumb:

so banana man the ignitor doesn't need to be working if u wanna do wat john did?

Agree find a 'dead ignitor' I have a few and could do the soldiering for you. I am sitting on about 175 good ignitors in my safety deposit box, so I can keep my car running for ever. :D

Using junk ignitor is only for a connect point, you remove back cover, gutting the contents the insulating gel and solder in 2 short jumper wires re-glue back cover.


John

so instead of gutting out the ignitor and doin it ur way wat would u have had to do?

Here is my gutted ignitor with color coded wires soldered to the pins. Notice how the pins are jumpered. This allows the red and green wires to stay in the same positions. In other words, when the gutted ignitor is installed, the red wire will be on the right-hand side of the T shaped connector at the top of the ignitor, which is the same side as the pickup plug the fits into the back of the ignitor. Red on the right. This is my prefered wiring method and is very easy to remember.

https://www.rx7club.com/forum/attach...chmentid=71855

As for the MSD's purple and green wires, I can quite easily remember that MSD purple goes to green and MSD green goes red. Again, it's very easy to remember which goes where if the ignitor is gutted as shown above.

As for the rev limiter, if you want to use it, simply wire up a switch to turn trailing off from the comfort of the driver's seat. This may complicate things if you have an '84-'85 though.

I've never found a need to glue the cover back on.

I was not impressed with my MSD 6AL hooked to two coils, as mentioned in the instructions. I found DLIDFIS worked better. I'll try my MSD hooked to one 2nd gen leading coil next.

Mr BiG G, maybe someone here will send you a gutted ignitor for your MSD. Or you could file down the connectors as shown in the picture and maybe fab up a smaller holder so the wires won't fall out, if you're worried.

Iotus and i have our MSD running through our ignitors using the white wire, works very well

yes, and you can use splice the white wire to run the trailing as well.

hmm srry to revive from dead, but in the 2 gutted ingnitors, why is it they are both hooked up differently. hmm i guess if u did the wiring opposite on one then itd be fine, but wich way is actually right...

ROFLMMFAO!

My method was based on level-headed thinking and logic. It corresponds with the markings on the ignitor and the wire positions relative to the connectors. In other words, I think my wiring style makes sense. It's basically idiot-proof. If you ever have a question as to which pickup wire goes to which terminal, the deepest you'd ever need to dig would be to pop off the cap, pull the rotor, lift off the aluminum cover and look at the red and green wires. Red is on the right, and green is on the left. Everybody knows the MSD's purple and green wires seem to hook up backwards to the Mazda pickup wires, so that has never been a point for confusion. Just hook them up; easy as pie.

The other method is a little easier to solder, I guess. I've aurgued this aspect before, but nobody could give me a good enough reason to switch.

By the way, the MSD white wire is only supposed to be used with points. If you hook it to an intact ignitor, the signal will not be as clean as if it were coming straight out of the pickup. In other words, use the MSD green and purple magnetic pickup wires hooked to the red and green Mazda pickup wires for the best results. And yes, you don't need to kill a good working ignitor just to feed the pickup signal out of the dizzy into the MSD. Use the wiring harness that comes with it and file the connectors down so they'll fit in the pickup plug. It's what I did. Besides, you'll have an extra ignitor laying around should your trailing ever die. Oh, and pick yourself up a 2nd gen leading coil so you don't have to make do with lower amperage to two seperate coils. It's what I did. :D