MSD 8973 lessons learned...

We've had some headaches the first few outings with this new box...it has a lot of stuff that can get you in a lot of trouble. here's a few of our experiences...

LAUNCH RETARD - STAY AWAY.

- Rather than using the launch retard setting, use your time retard curve. MSD informed us this weekend that whatever retard you may have at 0.0 seconds on your retard curve is what retard you have when your activation switch (clutch or tbrake) is armed. We initially started by using the launch retard setting for the timing we wanted out on the transbrake button (clutch switch for clutch cars). When we figured out how to drag the timing retard down at 0.0 seconds, we thought that retard curve started once the transbrake button was released, starting the 'time' retard curve. What really was happening when we did that was both settings were cumulative.....so only use one or the other. I would advise only using the time retard curve.

CYCLE the system -

Whatever switch you use to start timers (clutch/tbrake/etc), be sure to cycle the button during the warm up to check the proper timing. We spent the better part of an hour trying to figure out why our shift light wouldn't work, when we found we had to arm the button to make it think it was starting a run.

LAPTOP required

Don't install the 8973 unless you have a laptop with a good battery. Any last minute changes will need to be made via laptop in the staging lanes. The MSD system has to be powered up prior to opening the program on your laptop or it will not recognize it. Also, when making last minute changes, use the much shorter transfer 'pc to msd' on the individual setting you are working with rather than doing a complete file transfer from the main menu. ie if you're changing your retard curve, use the transfer option in that window rather than going back to the main menu and transferring all info.

Walk thru with MSD

Everybody has different applications and uses for this product. I would advise a phone call or visit to MSD with the lap top in front of you and go over exactly what you do and don't want this box to do, to save the 'oh by the ways'. we found out about the retard problem after wasting a day of testing fighting it on the jackstands. luckily we have timing monitoring on the racepak, and found that when it was throwing it's little fit, it was ADDING 50 degrees of timing when i hit the transbrake button.

Monitoring timing

If you're going to be playing around with the timing, you need to be monitoring it on your data logger. Derry O'Donovan makes a unit that can monitor timing with nearly any data logger for about $700. Yes he's a advertiser on the site, and if you think I'm making a cheap plug, keep thinking that while your competition that monitors timing get's a jump on you. If you're playing with timing, you need to know what exactly is going on. That being said, the next thing you need is a crank trigger. We were hard headed when we started and ran off the mag. The first race with our new racepak w/timing monitoring, we had a crank trigger the next race. You're really pissing in the wind trying to chase the timing around off the mag. Especially if you're moving it around. In other words, don't get the box until you have a crank trigger. Don't buy MSD's trigger, go with Leahy's unit. If we didn't have timing monitoring, we would have never saw it adding 50 degrees. It's also a very handy tuning tool to overlay timing to wheelspeed...

I haven't played with the boost retard or individual timing settings yet....

I encourage any other racers that have played with this system to add their experiences.

 

Rickey, email me at mike.c@mindspring.com about your MSD 8973 problems.

 

transfer & cable

chris,

yes if you transfer within a window, only that data is transferred. not only does this work for doing retard windows, but ie, changing shift light...just click save to msd, and it goes straight to the box.....

here's another tip that took some digging off the msd site in regards to a usb to serial adapter...copied from the msd site:

Today you’re hard pressed to find a laptop or notebook computer with an RS232 / DB 9 pin connector or Serial connection. Most all computer manufactures have made the move to USB connections varying from one to as many as 5 USB connectors.

One would assume these connection ports would be an easy “plug and play” connection unfortunately they NOT. Some of these adapter cables “USB to 9 pin / RS232” fall short of simply making the connection or keeping the adapter cable “awake”. In some cases if the adapter cable goes to “Sleep” or “hibernates” a complete shut down and restart of the computer is necessary. To date we have found an adapter cable that just simply works and does NOT require any Software or drivers to run it, just plug it in.

The adapter cable is available from “IOGEAR” www.iogear.com part number is GUC232A
IOGEAR calls it a “USB to Serial / PDA Converter Cable”

 

don't know

we run what most would consider base timing on the trigger, nothing exotic. i just think that thing threw an absolute fit with both of those retard settings on top of each other. added together, it's outside the normal retard range, so it could have retarded it so much it showed 50 degrees more than our base setting.

it would fall flat on its face on the jack stands when i hit the transbrake button. we kept on disconnecting wires until we disconnected the trigger wire from the brake switch to the msd, and it acted just fine. hook it back up, and trouble. we then went ahead and stalled it to stage rpm and took a computer reading....the results kinda scared us, timing in the 70's. we was about to load it up when we decided as a last ditch to down load a tuneup file from houston where we had no such issues and not touch the file, just upload it. the car immediately sounded better and acted just fine...

 

Just as a reminder when thinking about a minimum setup on the 8973. You ALWAYS need the blue wire that runs to the 8973 hooked to a 12 volt reset device either to the transbrake switch, a button on the dash or a clutch switch. The MSD 8973 must have a 12 volt momentary input through the blue wire at staging time that tells it that you are getting ready to make your run. This momentart 12 volt resets everything including the staging light, the shift lights and any retard curves.