So, im in a delima. Im getting new tires on saturday, and going up in size. Well I need to re program the speedometer, and I know flashpaq's can do this. But im looking for more power and some decent mpg. Should I go with SCT because better settings and reviews, from what ive heard, SCT is the thing to have when it comes to these trucks. But I can't reprogram the speedometer with it. Truck is a 00' 1500 ORE w/ 5.9. Mods are Flowmaster 40, and soon K&N Cold air intake. Also was quoted 120$ from dodge to reprogram the speedometer.

So, what should I do here?

 

What size tires are putting on? You should only need to calibrate the speedo if your running 35"+

Superchips 3815 will calibrate your speedo and give you a bit better performance but not as much as you'll see with an SCT.

 

+1. I went with SCT and love it. I am running 285's and know that speedo is under by 10% and I just allow for it 0 such as driving what appears to be 65 in a 70 mph zone (actuall running about 72 mph.) I did not know that until the 2nd Trooper stopped me for going 77 in a 70....I was on cruise and needle set at 70.

 

285's Cooper ATP Discoverer's

 

That's odd.
I wonder if your truck was calibrated for 245's. I am currently running 3 mph slow.

As told by my ticket a while back...

 

Theory.

I dont know if this will work. Plus itll cost more.

Would it be possible to adjust for tire size with Superchips, then use SCT to program? I would think that the SCT would copy the Superchips tune as if it were factory, and upload its own. Therefore giving you a correct speedo and the better tune.

May be something to look into.

 

A dealer that knows what they are doing can adjust for tire size.

 

^Which most don't.


Call the dealer and ask for a tune up for a 98 Ram with a 360.

You will hear silence on the other end.

 

I think there is another module other than the PCM that works to calculate speed.

I found this last night....

 

The op has already spoken to a dealer as they want $120 so they do now how to do this.

C/P taken from my notes.

Chassis Diagnostic Manual. There, in section 29A, it explains the procedure needed to program the CAB for specific tire sizes. [The CAB sends a pulse stream to the PCM, which drives the speedo/odo; to change the calibration, the CAB needs to be told, among other things, the number of teeth on the RWAL sense ring and the rev/mi of the installed tires.]

So, if you change your tire size and your dealer hasn't a clue as to correcting the speed/odo, point him to the Chassis Diagnostic Manual, section 29A. It's all there.