I've got a 2005 G.T. I have 4.10 gears in place of the factory 3.55's. I also have a CL7140 Diablo Predator tuner, but I am still running the stock airbox. Car is all stock except the gears and BBK underdrive pullies. My question is, can I fix the speedo error with the tuner without having to install a tune from it or a CAI? I may get a C&L kit down the road, but it's just not in the cards now. If this can be done, how do I do so? The car was just reflashed with the latest Ford IDIS setup at the dealership, so the tune is stock now.

 

Yeah just tell the programmer you want to change the parameters and it should let you change the gear ratio.

 

I went into "Modify Stock" and did nothing but fix the axle ratio, loaded it into the car, and it went into failsafe and would not start until I reloaded the original backup.

 

I did the same thing with mine when i went to a 3.73 rear gear. I tried to change it myself but for some reason the tuners dont allow it without have a custom tune written.

 

I think the easiest option is to get the C&L Street Kit and just install that tune with the kit. Bad part about all this is that I had a Racer Kit on the car, and sold it when premium fuel got so expensive. Thought I was being smart, and could just change the axle ratio and use the factory tune and airbox. Guess I was wrong. If I get the Street Kit, I can use 87 octane fuel with it, then go in and adjust for the 4.10's, I suppose.

 

you should have performance tunes preloaded into the predator that are used with the stock airbox. You can also try copy the stock file to your pc, change the name (xxx.frg) and load it as a custom tune.

 

The Dealership should have been able to set it for the gears when the PCM was reflashed.

KC

 

Arnt the stock gears a 3.31?

 

3.55 Was an option in 07

KC

 

05 & 06 stock was 3.55's. In 07 3.31's became stock and 3.55's were an option.

 

I had a first gen Diablo programmer and installed 4:10's way before I changed out the stock airbox. I was definitely able to change the gear parameters in the tunes that came with the predator. I doubt you can change the stock tune, but the tuner should have 3 (I think) canned custom tunes. I used to run the 91 octane performance tune that came with the programmer and modified the gear ratio to correct the speedometer. I no longer have that programmer, so I can't walk you through the steps, but I can definitely confirm that at least at one time it was in fact possible.

 

I have the same tuner and was able to do it for my 410 gears.

You can also adjust the revolutions per mile of the tires
if you have larger than stock as it also affects the speedometer.

I believe the manual that came with your Diablo shows you how to do it.

 

For the gear change (Speedo Fix) you were able to tune for just the speedo fix. Is that correct? If so, how long did that tune take and did you use a battery backup during th eprocess?

thank you for your help/info.

 

It appears more than obvious your unaware that the last activity on this thread was from over 11 years ago.. Therefore, I wouldn't count on getting a response from Barricade anytime soon

 

His most recent activity on the site was back in 2020.

 

Exactly 100% spot on with his most recent site activity.. 2020 lol.