Msd 8973

This is going to start a big discussion again. Oh Boy. Ok my advice is to do a search on this forum on 8973 and you will get all the past discusiions. I will say this that the vast majority (if not all) of all those racers that are using them right now (today) are not having problems. It appears that some small amount of racers had problems in the past due to unknown reasons.

Lots of theories such as electromagnetic interference from the ProMag generating random pulses being pickup up by unshielded cranktrigger cables and making it appear at though the 8973 was changing timing by itself. My put is that if you use a shielded crank trigger cable from MSD like it specifies or one from Leahy you will not have problems. I know of no one that has ever had a problem on an 8973 that does not use a crank trigger.

 

Use it with confidence. It works great.

 

fair and balanced coverage of the 8973....

before this turns into an 8973 cheerleading section, let me weigh in with a dissenting opinion, in an effort to provide fair and balanced coverage of the issue (tongue in cheek)

i'll be the first to say if this deal worked like it was supposed to, it would be a neat box with a lot of features. without touching base on the 'ghost' problems this box is prone to have, let's look at a few pro's and con's of the box itself.

the very first thing you notice when if you changed from a six shooter to the 8973 is the first time you want to make that last minute adjustment. now instead of a pocket full of chips, you have to lug a laptop around the staging lanes to make those last minute adjustments. for someone who is pretty quick with the program and a computer, you might be able to make a change as late as two pairs back. normal computer users had better make that change 3 pairs back in the lanes. that becomes problematic if you're the first or second pair.

the user interface isn't very user friendly. i'm a computer person, and it took me a little while to get it down. there's a lot going on with that box, and it's not all black and white what's on and off. i think there's close to 79 features the box can do. 95% of alcohol racers will probably only use 3-5 of those features. a KISS (keep it simple stupid) version of the box might be better suited with simple timing retard vs. time, shift lights and rev limiter. starting line 2 step for those who use that.

IF you set something wrong, I can personally vouch this box will throw a monumental $hit fit. Here's where the phantom showed it's face to me. With the box having "37" different flavors of timing management, if you have two retards going off at once, they are supposed to be cumulative. I did not realize that timing retard at 0.0 seconds was also how much timing was out when the transbrake or clutch switch was applied. so I also had 11 degrees out on launch retard, 11 degrees out at 0.0. When you hit the transbrake, the motor went silent, poped a few times and sounded very off key. this was on the jackstands, so when we did a racepak pull, the timing was a flat line on 75 degrees. the trigger was set to 28 degrees. As soon as I got rid of the launch retard stack, the box did return to some normalcy. I only made 11 runs with the 8973. If we hadn't left all the 6 shooter stuff at the shop, it would have been reinstalled at the first race, before we had the above mentioned jackstand issue.

I know Mick Snyder and Marty Thacker both post here. Maybe they can share their experience and problems. They both hurt motors with the box, went through several boxes, went back to six shooters and the problem went away. Ken Perry told me in Indy last year at one of the divisional events he burned holes in two pistons, unpluged the box, no tuneup changes, no more holes in pistons, and I think he won the race. I haven't checked back in with Chris Demke to see if the 8973 had anything to do with his engine woes, but I know he grenaded two motors at the world finals and winternats, and I haven't heard him having such problems since.

These are pretty smart racers. In fact, Perry is the quickest BAD in history. Thacker and Snyder are multitime Division Champs. These guys have experience and obviously have attention to detail. These aren't the only racers to have these problems. I know TD racers Mike Manners and Troy Stone both attribute major engine damage to the 8973.

Why these boxes throw a fit is unknown. However, it appears that MSD is supporting the line that the racers must have messed something up, rather than actively investigating the problem. Maybe it's more prevalent in the alcohol ranks due to more tireshake? Mounting proximity to the mags?

So my train of thought is more of a bottom line analysis rather than an engineering approach of why. There's a very real threat that if you accidently mess up on a setting it will kill a motor. If you plug the wrong chip in your six shooter, more than likely you won't kill a motor. There's also a very real threat that these boxes go skitzo and will kill a motor. No matter how you spin it whether it's user error or equipment malfunction, the lowest common denominator in many of these engine failures is the 8973 box. I can personally vouch that the guys that have had the problems are very smart guys. I wouldn't be so quick to write them off as electrical dummies. As a matter of fact, Perry makes electrical interfacing equipment.

So what's my recommendation? It's pretty easy to use tried and proven analog equipment from MSD to utilize the few features most racers use and eliminate the threat of a phantom problem toasting a motor for you.

For starting line control, use the two step. If you want to get fancy, use a soft touch rev box.

For timing control, use a six shooter with the digital leahy controls. If you want to get real fancy and make smooth timing curves like you can on the digital box graph, run two six shooters in sequence. That should give you more than enough stages to effectively do the job.

I think both MSD and Autometer make variable shift lights if you want to have different RPMs for different gears, and there is stuff out there to set up launch light's as well.

With the analog setup, all you will need is a little box full of chips and be able to make changes much more easily, and feel more confident that your last minute change went through.

That's my dissenting opinion. You decide. But you can't say you haven't been warned....

 

This is like the presidential race: