WOT gear change...0-60 times....

[Mark_123]

So I've played around a little with the stock tunes on the Gryphon. At WOT, when the truck shifts from first to second, there is a stutter (delay, not really sure what to call it). The RPM's hit the rev limiter I'm guessing, then there is a pause and the RPM's fall slightly, then the RPM's hit the limiter again before shifting to second gear. Remember, these are the canned tunes. I'm guessing this will be resolved with the custom tunes. Anyone else experience this?

So I haven't really made an effort go to a perfectly level area to do a 0-60 time yet, but I did so on an on-ramp merging onto the highway. There was a slight decline, so these numbers I'm sure aren't exactly accurate since gravity probably gave me a little assistance. Anyway, the truck is a 2007 F-150 4x4 SCrew with stock tunes (87 tow) from Gryphon, stock 20inch wheels with the stock Pirelli's, AEM dryflow filter, and Magnaflow 5x8x18 muffler replacing the stock muffler. 0-60.1 mph was 6.78 seconds. Again, I was going slightly down hill on an on-ramp merging onto the highway when I checked this. I still thought this was very good and I'm extremely satisfied!!! I can hardly wait to get the custom tunes. The custom tunes will hopefully resolve the stutter at 1-2 gear change and I'll check a true 0-60 on perfectly level ground. I'll get some 1/4 mile numbers then as well.

VERY SATISFIED CUSTOMER

[Jackpine]

Mark, you might want to go into the "Custom Options Menu" and check what the Gryphon is loading for your gear ratio and tire size. If I'm not wrong, I think it loads a default setting for each that may have nothing to do with what you've got on your truck. And if you've done all this, forgive me. I read recently somewhere that an incorrect gear ratio can cause symptoms similar to what you describe.

In "Custom Options" for your chosen tune level, first go to "Load Previous Settings" so that what is in the PCM gets put into the Gryphon. Then check and adjust your Gear Ratio and Tire Size if necessary. If your tire size is not right, use Bill's "Gear Ratio Calculator" (part of Pegasus under "Tools"). Put your tire size in the first box like this: "275/65-18" (which is what my tires are) and you'll immediately see your tire circumference in mm with a 5% "squish" factor, which is a good starting point.

I think even with the custom tunes, you're going to have to check and reset your tire size each time you change your tune level. (At least I have to do this with mine).

- Jack

[Jackpine]

I just thought of something else. The Gryphon manual says your MAX RPM must be at least 150 above your WOT shift points or you might experience erratic shifting.

Somewhere, in what's left of my feeble brain, I seem to remember Bill saying this figure should actually be 300 (or was it 400?) RPM. I know my WOT shift points are in the 4900-5000 range and my MAX RPM is at 5400 (I don't race and I don't want to balloon the Torque Converter, so my values are probably lower than yours).

Anyway, you might check these values too.

- Jack

[Mark_123]

Thanks for info Jack. My Gryphon, Speedo, and GPS all read the same at 60mph (the GPS is an aftermarket Garmin and is not connected to the truck's speedo). I was assuming the original pcm file had the stock tire size/wheel size info already programmed, and the Gryphon built on that file. I haven't played with the custom tuning options. I'm going to let Bill do that for me. If I don't know what I'm doing I'm afraid I might damage something :scream: I agree with you about the rev limiter. I bet that is the issue. I'll recheck it after I get the custom tunes.

Mark

[Jackpine]

The Gryphon and speedo will always read the same (actually, the speedo will be about 2 mph higher due to a quirk in the way Ford does things, according to Bill). They BOTH get their input from the PCM, which has been programmed by the Gryphon to interpret axle revolutions to determine speed and distance. The fact that they agree with a GPS, though, says the overall effect of the gear and tire circumference settings is producing correct speed and odometer values.

But, and this is a big but: Both gear and tire size COULD be wrong. I'm positive the default values in the Gryphon have nothing to do with what's in your truck. On the f150 forum, someone had 3.55 gears and the Gryphon said he had 3.73 gears (and he had "funny" shifts). I think 3.73 might be the default gear ratio. The tire size on mine always defaults to 2356, but my actual tire circumference, accounting for "squish" is about 2481. Since my gears ARE 3.73, if I don't set the tire size manually, my speed and distance values are about 5% lower than actual.

And, I don't recall the MAX RPM default in the canned tunes but I know it was lower than 5400. The MAX speed is set to 99 MPH, by the way.

All these things are adjustable in the custom options menus. You select something, such as Tire Size and hit Enter. You'll be shown what the Gryphon is going to insert into your PCM when it "tunes" it. If you don't like what you see, just use the up or down arrows to change the value, then hit Enter to set that new value.

I doubt you can hurt anything unless you do something stupid like advancing the spark on low octane gas, or, possibly setting the Rev Limit to a very high value and then standing on the gas pedal.

You can actually go through all the settings without changing anything just by hitting Enter at each and then hitting Enter again to accept the value once you've seen it. When you're through looking or customizing, hit Enter on the "Done" option and you'll be told to turn the key off and then back on.

If you've gone through the custom options and looked at any of them (or changed them) the programming process will take quite a bit longer than if you just skip the Custom Options step. Don't worry, just make sure your battery is healthy and that your headlights, AC blower and radio are off to minimize battery load. Don't do it in really cold weather either.

Hope all this information helps. I'd be more afraid of damaging the truck through hard acceleration and high speed, rather than through playing with the Gryphon.

And, I hope Bill chimes in here sometime to say I haven't been leading you astray.

- Jack

[Power Hungry]

Originally Posted by JackandJanet

You can actually go through all the settings without changing anything just by hitting Enter at each and then hitting Enter again to accept the value once you've seen it. When you're through looking or customizing, hit Enter on the "Done" option and you'll be told to turn the key off and then back on.

If you've gone through the custom options and looked at any of them (or changed them) the programming process will take quite a bit longer than if you just skip the Custom Options step. Don't worry, just make sure your battery is healthy and that your headlights, AC blower and radio are off to minimize battery load. Don't do it in really cold weather either.

- Jack

With the exception of the tire size and gear ratio (TS/GR), everything displayed in the custom options should be correct. I've mentioned this elsewhere but I'll post it again here for reference.

The F-150 PCM is broken down into 3 sections: RTOS, Strategy, and Calibration. There is also a small (256 bytes) section called the VID block that stores the vehicle specific parameters like tire size, gear ratio, and VIN number. It looks a little like this...

0x1:0000 - RTOS
|[VID]
|
|
|
|
|
|
0x50:0000 - Strategy
|
|
|
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0x58:0000 - Calibration
|
|
|
|
0x60:0000 - Memory End


When our programmer modifies the memory, we only read and write the Calibration section of the memory. Ford, in its infinite wisdom, saw fit to not only put the TS/GR in the VID block but also have values that are located in the Calibration portion of memory.

In normal situations, the PCM uses the VID block for TS/GR information. If you have stock tires or gears we don't bother that setting.

When it is necessary to make changes to TS/GR, we have to make those changes to the Calibration because we do not access the VID block which is stored in the RTOS.

The confusion comes when we grab the default values located in the Calibration. These values have no relationship at all to what TS/GR is actually in the truck and are simply place holders for arbitrary data values. Some trucks are 3.55, some are 3.73, and we've even seen 3.31. When we change TS/GR, we write the values into these spaces and then set a switch that tells the PCM to ignore the VID block and use our new values instead.

Since we assume that neither value in the Calibration is accurate, this is the reason we always say to set BOTH TS/GR values. Don't change one or the other and expect it to all be correct.


One other note about custom tuning... Viewing the custom options sets a flag that tells the programmer to write those values to the PCM even if you didn't change it. We recommend that if you don't plan to change it, do not go into it. You may take a 20 second reprogramming session and easily turn it into 2 or 3 minutes. Shifts are especially slow to process so use those sparingly.

Does any of this make sense? I hope so.

Take care.