BA XR8 Speed limiter.. - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Kypez · 05-08-2003, 07:58

Hey all,

well, I know that the speed is limited to 230kms... in my testing of the car, I cant seem to get the car over 210-215km/hr... is something wrong with the speed limiter?! whats the deal?! Any suggestions welcome....

cheers.

Thought: I changed the wheels to 19's and havent recalibrated the speedo... could this cause the 15-20km/hr speed difference?!

WBT56 · 05-08-2003, 14:28

VSS info comes in via the ABS circuit. There is no sender in the driveline. Does your cruise control work in all gears?

Jase_ELXR8 · 05-08-2003, 16:27

Quote:

Originally posted by WBT56
VSS info comes in via the ABS circuit. There is no sender in the driveline. Does your cruise control work in all gears?

BA's still have the transducer in the extension housing for the speedo!!!

05-08-2003, 18:48

Unless the 19's are exactly the same diameter as the original wheels that is likely the cause. Sit one of your stock wheels next to the new ones.

Pete.

Aussie Pete · 05-08-2003, 20:02

Wheel and tyre diameter is irrelevant. The computer senses wheel speeds meaning the indicated speed on the speedo, the speed seen by the PCM etc are all the same. Unless you're measuring the lower speed via a separate source?

Rusty · 05-08-2003, 20:26

If you replace wheels on the car for a different size, you actually need to recalibrate the PCM configuration. The transducer is the primary source of speedo output. Different sized wheels compared to what the PCM is configured to, affects transmission output/ wheel speed sensor, only slightly but if you were hiking it over 200, then you would notice it. Only Ford technicians can adjust this with there WDS (portable computer unit).

Rusty · 05-08-2003, 20:33

Most Fords are like this now with there PCM's.
The larger the diameter of the wheel the slower the speedometer reads in relation to the vehicles actual speed (unless PCM is reconfigured) because there is more surface around the tyre to contact the road.

Kypez · 05-08-2003, 22:25

will have to get the speedo recalibrated then... cause its a 1cms - 1.5 cms difference overall... Ford said it wouldnt do it and that i have to go to someone private to get it done... will let you know how the second round of testing goes once I get the speedo recalibrated....

Thanks for the resposes, Muchily appreciated.

Aussie Pete · 05-08-2003, 23:17

Quote:

Originally posted by Kypez
will have to get the speedo recalibrated then... cause its a 1cms - 1.5 cms difference overall... Ford said it wouldnt do it and that i have to go to someone private to get it done... will let you know how the second round of testing goes once I get the speedo recalibrated....

Thanks for the resposes, Muchily appreciated.

Did you read what I said? The speedo is irrelevant because what you're seeing on the speedo is supposed to be what the PCM is seeing. So if you put on larger wheels you'll get over 230km/h but still seeing 230 on the speedo.

If you want the speedo recalibrated go to that place at Silverwater. I think it's called General Instruments - they used to (still?) do the cop cars.

Kypez · 05-08-2003, 23:57

I didnt mean any disrespect Pete... I'm just trying to figure out whats wrong... the thing is that I cant get over 210 - 215... so are you saying that there is a problem with my PCM??!! I'm trying to follow here....