Ignition Boxes

Louie L.

Habitual Line Stepper
Staff member
May 24, 2001
With the current popularity of the distributor swap, I like to see what you guys think about whats available out there in CD boxes.

I know the majority are using the 7al2. This box appears to be bullet proof and is probably the only thing MSD sells that actually works.This box has no real features and when looking at the numbers ..Like spark output and coil voltage it looks a little low. Plus this bastard is 400.00 new !

In comparision the the mallory VII s has 2 built in rev limiters, digital display on the unit with selctor buttons. There is no need to buy anything xtra for it, unlike the 7al2. It has both higher spak output and coil voltage than the MSD.

The Crane HI6R box looks pretty stout when used with their LX92 coil. It has a built in rotary switch selected rev limiter. It has way higher spark output than both units and equal coil voltge to the MSD. It also appears to be more compact...Both coil and box can be had for less than 350.00

Im afraid to ask this ...But any opinions?

I rather not give MSD any more of my money after the DIS 4 fiasco.. :frown:
MSD has done their home work with the Digital 7 Ignitions. I have installed many of these without problems. Furthermore, with all of the options that can be tuned into this box, it has been a great tuning aid for all types of power adders. Some of the fastest cars on the planet are using the Digital 7. I have even put one on a 2 stroke snowmobile with N20. We have gone 8.22 @ 160 mph using this ignition.
I hope this helps
John Wilde said:
Motec :eek:


Duttweiler has used them to make over 3300HP.

BTW: I am still mad at you for not sending me pics of your car with the MTs! ;)

After buying these wheels I dont have any money for a high dalla Motec box.. Im working on the pics for ya.. ;)

Ref to the MSD 7 digital. I know this box works, but it has too many toys I wont need,high$$$ and again is a digital..Just like the Dis4 :mad: Ive read of some issues in the Mustang boards with these.
msd 7

louie, i went to a swap meet in indy sunday and saw serval 7 al 2 for sale from 100 to 250 for a new one still in the box, they all were for a v-8 but you send them to msd and for 30 bucks plus shipping they can change them to a v-6. the msd 6 there were serval there you can change them from a 8 to a 6 your self, they were about the same price, good hunting oc,
Sure, try a different brand than MSD. Won't hurt anything. Don't get too caught up in the spark energy slight of hand numbers game. I'm with you- I'd rather not hand them my cash either.

Thanks for the replies. For the money the Crane box and coil seem to be the best buy. Never seen any issues with these. Its compact and appears lighter than the others.

Im going to give this one a try.. :cool:

OD, Thanks for the info.. :)
I have read some of the other boards about people having trouble with the Digital 7 Ignitions, as well.
I even answer a lot of questions about the Digital 7, on YellowBullet.com. http://yellowbullet.com/v-web/bulletin/bb/index.php, I have a section over there, even on race weekends I get calls from racers who have questions and/or need help with this Ignition.

Sometimes I have to scratch my head?? :confused:

But, when I look at the racers who are running these Ignitions, with the races they have won or the records they have set, I often ask myself, is it an issue with the Ignition box or is it an installation issue? I installed one of the first Digital 7 Ignitions MSD made available for Bill Glidden in 1999, it was installed in the black car and is still in the car today, it's never been sent out nor had a problem. Billy has run bad fast with a Digital 7.
Since then I have installed a ton of Digital 7's and out of all them installed, I have sent only one back for repair, because the owner neglected to disconnect the ignition while they were welding on the car.

The Fastest 10" tire, twin turbo car in the country, (Lynch/Petty) relies on a Digital 7 Ignition. Prior to me rewiring the car, Steve Petty discussed with me about an “Ignition problem” that he felt they were having. I rewired the car and we used the same Digital 7. The so called "Ignition problem" isn’t there anymore. Since I rewired the car it has run 4.46 @ 172mph in the 1/8th and 6.86 @ 209.8 mph, It has set records in both 1/8th mile and ¼ mile and has been on quite a winning streak.

These are just a couple of examples of the success racers have had with the Digital 7 Ignition, I have many more.
It isn’t a fluke thing or that MSD has some good boxes and some bad boxes.
I attribute the success I have had with these ignitions boxes to the installation methods I use.
Paying attention to component layout, understanding the abilities and function of the Ignition, supplying the Ignition with a proper power supply and practicing proper grounding methods, which have made racecars I have wired some of the most consistent racecars in competition.

Cool. So what do you consider proper power supply and grounding techniques for them? Just curious.

That's some good info there Sparky. I was in ATL and saw the mob lay down that string of 4.40's. I have heard alot about your work.

I am currently wiring my car using a 7al-2 with FAST XFI and am paying more attention than ever to routing, proper grounding and wire sizing than I ever have. Hopefully to avoid any issues with igntion problems.

First question for you. I have the 7al in front in engine compartment, battery in rear. The car isn't running yet but just testing some voltages I lose around 2.6 volts at the ignition box during cranking. Drops from 12.8 to 10.2.. Is this normal or is there something I need to look at? I have read in the FAST manual the voltage should be 12 during crank and run position. I do have my XFI power run from a painless circuit block with relay but haven't checked cranking voltage to the FAST yet.

All power is fed from the Flaming River disconnect in the trunk. I have cleaned the frame down to metal at all grounding points. I have two #4 grounds from engine to frame and battery is grounded to frame with 1 #2 wire in rear. All critical ignition and FAST grounds are run to the frame.

I also checked out the pics you put up of Lynch's ride and noticed most of the wiring run in one large group. I have been trying to run all my ignition and critical FAST sensor wires with some distance between them to avoid any possible interference. After seeing the pics, is this really necessary?

Thanks for the help, nice to have you around.
Clone311v6 sent me a link for this site. I am currently wiring his Syclone, it is sick!
It surely should be one of the fastest Syclones in the country. Hopefully, Mike will post some pics when I am done.

Anyway, I really enjoy the site.

To answer your first question, I have a question for you. Is this a drag application and/or street application?
The voltage drop you are experiencing is not uncommon, I would imagine if you’re only seeing 10 volts at the ignition, more then likely you’ll see the same at the Fuel Injection too. I have seen a fair amount of problems when running 12 volts with EFI. Especially if an alternator is not putting out enough voltage.
If your car is for a Drag application, I would recommend running a 16 volt battery, although you will still have voltage drop, but it will only be in the 14 volt range while cranking.

As for your second question, yes space between components is very important. Component location and harness layout is an integral part of laying out an effective electrical system in any type of car. Understanding what types of components generate noise and keeping them isolated is value added in the electrical system. The whole consistency part of a racecar begins with its electrical system.

Although the pics I posted of Lynch’s car may look a bit deceiving. The harness you see that runs across the dash bar, doesn’t contain any sensitive signals (EFI or Ignition). Most all Fuel Injected cars I do receive an engine harness. All of the Fuel Injection signals are in this Harness and is isolated from the rest of the car. Same goes for Ignition signals. They are isolated from the rest of the car. This helps rid the car of any EMI or noise that may linger throughout the car.

I hope this helps,
Thanks for the reply.

Actually I know Mike with the syclone. He is local here to me. I remember it well from the street racing days and saw it under construction at the chassis shop. I look forward to seeing it completed. He is sparing nothing on the build.

My car is 90% drag, really a turbo V8 car for drag radial. I do plan to cruise it occasionally to various events. A 16 volt system is an option. Right now I am working to get it started and you know the situation with turbostart. We have used several voltage boosters in the Buick world for years with good luck with voltages under boost at WOT around 15 or so using the stock 12 volt alternators. I am trying something similiar to see how it turns out. If it doesn't then I will definately go to a 16 volt system. Hopefully by then a vendor will take up the turbostart business if it hasn't happened already.

I've tried keeping the wires from the 7al to the coil away from everything else as well as the crank signal away from the plug wires. The cam sync signal is pretty much away from everything anyway. Anything else that needs attention.

Yes you did help. Much appreciated.