OK last thread was getting kinda long so I decided to make a new one. Sorry if this has been answered before. OK, my Saleen has 3.55 gears in it, but the speedometer is off a bit (shows about 77-78 when going 70). I assume this happened when the engine was replaced, since the 3.55's were a factory installed option and I doubt Saleen didnt calibrate it correctly. But, this is putting miles on my car faster than it should, so I want it to stop! What do I need to do/buy to calibrate my speedo for 3.55's? I've read other posts that say send the Powerflash chip to Saleen to get it reburned, but (correct me if I'm wrong please) my '99 doesn't have a Powerflash chip as far as I know. Any help would be awesome, thanks everyone.
Roush Speedo question!
- Thread starter sk8mrw
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00s281sc368
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Easiest and cheapest: send you computer back to saleen and they'll reprogram it in a day or two for 50 bucks.
Saleen Mike
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- Oct 17, 2002
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The "Powerflash" is not a chip, but a reflash of the OE computer.
As said above, best bet is to send it back to Saleen and have them do it for $50.
As said above, best bet is to send it back to Saleen and have them do it for $50.
My 02 Extreme has this issue too...It reads 10 mph faster than actual speed. The "wonderful" (not really) folks at Saleen admitted this is a problem that they keep hearing about and they can't figure out (even on their VP's car). Flashing the comp. did nothing for me. So...until the cure is found, mine adds 1/10th more miles for every mile.
Saleen Mike
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Are you both sure that the odometer is also adding milage faster than it should?
If I am not mistaken, in the Mustang, like many other newer cars, the readings for the speedometer and odometer are independant of each other.
Try going for a 10 mile drive down the highway, staying in your lane, and check the odometer readings vs the mile markers on the side of the road.
10 miles is 10 miles regardless of how fast you drive, or how far off your speedometer is.
If I am not mistaken, in the Mustang, like many other newer cars, the readings for the speedometer and odometer are independant of each other.
Try going for a 10 mile drive down the highway, staying in your lane, and check the odometer readings vs the mile markers on the side of the road.
10 miles is 10 miles regardless of how fast you drive, or how far off your speedometer is.
OK, I came upon a revelation on my long drive to Cleveland this weekend. I think my car actually has 3.73 gears installed. I did all this math in my head, but let me see if it sounds right to anyone else. Alright, first I drove exactly 10 miles, marker to marker, to see how far off my odometer was. My odometer registered about 10 miles, 5 and a quarter tenths. So, in 10 miles it was 5.25 tenths overapplied, making my odometer approximately 5.25% off. Now, assuming my computer was set to 3.55 gears still, as it had from the factory (and hadn't changed since the new engine was installed), I had to apply this percentage to that number. I calculated that 5.25% of 3.55 was ~.18. Add .18 to 3.55 and you get 3.73. Does this sound right to anyone? If so, it appears that my college tuition in Miami's business school is a good investment. 
