This has happened several times over the past couple of years. It is completely random and very infrequent.

When I leave the starting line (currently footbraking) the shifter will immediately shift into high gear. It shifts right after the hit. Right after means approximately .1-.3 seconds after the hit. Unfortunately, I didn't have a SD card in my Sportsman when this happened yesterday.

I thought I was spinning the radial slicks and it was shifting on RPM like it should. Luckily a friend was videoing with his phone yesterday and I could watch the video in slow motion. The tire did NOT spin at all.

I'm sure I have spun before causing the shift, but that was not the case yesterday proven by the video.

My shifter setup is the electric solenoid that is spring loaded. The solenoid holds back the spring and releases the spring to shift.

I am using a 30 A relay to to power the shifter. I think grid supplies a ground to shift so the relay is NC if I recall correctly. (Maybe I should switch to a solid state relay?)

I should've checked if the solenoid had released to shift yesterday or if the shifter somehow moved on its own. Unfortunately, I didn't think of that at the time. It did not happen again on the next two runs.

Also, any wiring connection that had a problem could cause the issue also. I tried shaking all the wiring, tapping on the relay, tapping on the solenoid, etc. Everything seems secure and did not initiate a shift when testing. Almost all of my connections are crimped, soldered, and shrink wrapped. I'll check the wiring some more soon.

I am using the Grid shift light trigger wire to shift on RPM.

Any idea what could cause this? Could it be a Grid malfunction? That seems doubtful. Thoughts?

If I can't find the problem I have to replace/change everything. This can't happen again!!!

Thanks!

Are you using the Shift Light, “Launch Light Low” feature in Grid to shift with when foot braking?

If Yes, What is the RPM value in Launch Light Low set to?

What does the RPM flash to (don’t guess) at Launch?

Distributor trigger or Crank trigger?

This message has been edited. Last edited by: markemark,

I put the HD card in my Racepak after this happened and made two good runs (at least for gathering data, lol). I should be able to pull the data and answer all these questions tonight.

I have never tried using logging capability of Grid. I've really never had a need to and stay way too busy with jr dragsters to mess with it. It might be necessary to help figure this out though. Frankly, I can't afford to lose another round because of this. I need a proactive solution.

Thanks,

Personal opinion, throw the spring loaded crap in the trash and put a solenoid either electric or air on it. Like I said, personal opinion so don't bash me. If the rest of you love them then keep running them.

Racepak isn’t Grid.

Grid controls ignition and the outputs you decide to program through it. What those outputs do is dependent on what Grid sees from the inputs like Ignition Trigger, Launch, Step Retard and your program values.

The Grid .dqi Data Acquisition file from your problem run can very probably show the error that is causing your intermittent problem. Even a good run in Grid dqi might lead to showing the problem.

Grid will share some data with Racepak if selected in Grid Data Acquisition.

quote:

I am using a 30 A relay to to power the shifter. I think grid supplies a ground to shift so the relay is NC if I recall correctly.

Brktracer, If Im reading that right - thats your problem. Use the 87A terminal on the relay for the solenoid ground wire (relay is used on ground side of solenoid). Run your 12V + switched/fused power straight to solenoid - no relay. The Brown/White wire from the MSD grid (or digital) is used to trigger the relay.

I understand Grid and RP difference, but appreciate clarification. Always.

Just clarifying that I have never logged using grid. If I had the grid log we could figure this out easily. Hindsight is 20/20.

Converter flashes 5,800.
Yes Launch light low is set to 6,500 rpm.
Crank trigger.

The video is from iPhone and frame by frame shows no tire spin whatsoever. Car is deadly consistent for a setup like this running gas. I know everyone says that though. Lol.

I’m really wondering if the shifter could possibly move independent of the solenoid.

I agree on using the other type shifter solenoid. Please recommend one for quarter stick forward shift pattern. It’s time for an upgrade. I’ll order one today!

This has GOT to get fixed!!!

Thanks!!!

Jerry:

Thanks for your response. I really appreciate it.

Yes. That is how it’s wired. Exception is I’m using the yellow wire from Grid. This is the shift light wire recommended by Mark for accuracy.

I use 2 relays. First relay turns on hot to the solenoid when ignition is turned on. Second relay is activated by Grid yellow wire to (edit) remove ground from (edit) the solenoid using pole 87a.

This message has been edited. Last edited by: Brktracer,

To clarify the shift works properly 98+% of the time. It is very intermittent problem that’s why I thought it was spinning but the video does not show spin.

However, how many frames per second does I phone do? I would think it would take at least an entire turn of the tire to be 700 rpm above flash. But?

Look at graph in the grid.

Count the turns on the band screw to 72 inch lbs as well while you're at it, should be right around 3.5 turns.

If it's more turns than than that, put a band in it. Or reset it 3.5 from 72 keep a eye on it.

Changing the shifter doesn’t fix the problem imho. Low current Spring loaded shifter coils are used today with no problems.

If it were me, I’d start by using a single relay. 86 + 87a to ignition ON +12v, 30 to shifter +12 wire, 85 to Grid Yellow wire. Ground the shifter coil wire to an appropriate ground.

I’d also use a relay with an internal diode (Bosch 0332209158 ) to remove the flyback voltage from the relay coil. These need to have the proper coil wiring polarity as shown on the relay body.

What a Grid DA will show you is if the Shift Light Output activated, providing a ground signal, energizing the relay coil. Because you’re foot braking, you need to start the recording with the Line Lock during burnout or a momentary toggle with +12v of a Step input.

If you prefer Racepak, assign the Grid Shift Light to one of its inputs and activate in Data Acquisition /Racepak tabs.

I have never been able to get RP and Grid to communicate. I finally gave up. I suppose I could use the 12v event (orange wire) on RP. It would require another relay (or 2) to reverse the ground polarity though.

Only problem is getting this data requires another failure to take place and I really need to be proactive. It really has to work 100% of the time moving forward.

I’m going to inspect all this wiring closely. It looks great at a glance.

I’ll look into the Bosch relays also.

Ordered Bosch relays and Biondo solenoid. Will go through the wiring with a fine tooth comb.

In thinking more about it, there is really only a few things that could be happening:
-loss of 12v power to solenoid
-loss of ground to solenoid
-Spinning and rpm exceeds launch light low SP
-Something in yellow wire circuit is going to ground

The only thing I know to do at this point is:
-shake wires, tap on things to see if I can get it to shift in the shop. This would narrow down the problem to a specific connection, relay, etc.
-Throw parts at it - Rewire and change everything in the circuit.
-Set up grid to log for future troubleshooting
-Always log with RP for future troubleshooting

Having the data might be critical to solving this.


Thanks Mike for mentioning the band adjustment. I adjust it about every 3 races but I'm a little behind so I'll verify.

Yes Sir, no problem.

You're gonna love your new electric shifter, it's a copy of the original electric shifter, Dixie.

When I bought this Dixie out of the back of national dragster in 1994 or 1995, when everyone was on air shifters, they all laughed and said that won't work.

Everyone has one now, I got the original. Flawless performance, you're gonna luv it.

Install the SD card in Grid and clear the card of any runs. Choose the pertinent channels in Data Acquisition to record. Attach the Light Blue Burnout wire to your line lock PB and program Grid to start recording with this input. Let it record. When you have a problem the information will be there. Because you will need to record each event at a longer period of time, the first of every month attach to Grid and clear the SD card. Or remove the card and plug it into your computer and clear if easier. The overwrite feature in Data Recording does not work well.

I’d also update to the newest firmware version in Grid if you have not already done so.

Yeah, ya gotta have the record feature working, no need for racepak to monitor the converter. The most important part to monitor, bracket racing. Torque converter.

You have a great tool to diagnose 12 volt electrical issues as part of your Racepak Sportsman. It's called the trans brake activation channel, but can be used for any 12 volt event.

So if you take the orange wire coming off your DS plug (disconnect it from TB if in use now) and tap into the solenoid activation wire as close to solenoid as practical. This will give you a vertical line in your graph when the shift is commanded.

Here's the resulting data log with the the yellow line showing 12 volts present on the shift wire starting at 6700 RPM for approx .3 of a second.

The most popular use of this is in diagnosing nitrous activation issues with full throttle switch etc. Awesome tool.

Greg:

I think I can easily do this with what I already have by hooking up one wire and setting up the channel. I have USM because I use some custom sensors. It looks like USM can record a GROUND event. Assuming that's true, this is a piece of cake. I can simply connect the USM to the yellow Grid wire to log the output from Grid in RP.

I would do it this way because my relay is on the negative side of the solenoid. Otherwise I'd need to rewire some stuff.

Shouldn't this work?

I'll also set up Grid logging feature just in case I need it in the future.

Thanks,

Why make this information sharing so hard? Grid will share up to 13 channels with Racepak through V-Net. All you need is a V-Net Tee. Don’t have a Tee, order one from Greg and he’ll walk you through the set-up. It can’t be that hard.

Grid users….. Here’s a cool feature (Monitor Plot Screen) that is in Grid that’ll display up to 12 channels in real time. You can activate this even when not attached to Grid in the software to see how it works prior to using. The path to using it is in the picture.