Roush Speedo question!

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sk8mrw

New Member

Jan 11, 2004

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Sep 2, 2004

#1

• Sep 2, 2004

• #1

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.

 

00s281sc368

New Member

Dec 14, 2003

532

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Fremont, CA

Sep 3, 2004

#2

• Sep 3, 2004

• #2

Easiest and cheapest: send you computer back to saleen and they'll reprogram it in a day or two for 50 bucks.

 

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sk8mrw

New Member

Jan 11, 2004

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Sep 3, 2004

#3

• Sep 3, 2004

• #3

But, do the 99's come with Powerflash? Isn't that what is needed for it to be reflashed?

 

Saleen Mike

Founding Member

Oct 17, 2002

824

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Sep 3, 2004

#4

• Sep 3, 2004

• #4

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.

 

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2k2extreme

New Member

Sep 3, 2004

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Sep 3, 2004

#5

• Sep 3, 2004

• #5

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

Founding Member

Oct 17, 2002

824

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Sep 3, 2004

#6

• Sep 3, 2004

• #6

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.

 

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2k2extreme

New Member

Sep 3, 2004

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Sep 4, 2004

#7

• Sep 4, 2004

• #7

yep...done that. for every mile (marker to marker) the odometer reads 1.1 or 1/10 more. also checked car against speed gun 4 times at various speeds and as mentioned before, radar says (for example) 60 and speedo says 70. Saleen knows and says others have same problem and they don't know why.

 

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sk8mrw

New Member

Jan 11, 2004

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Sep 19, 2004

#8

• Sep 19, 2004

• #8

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.

 

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Apollo 13

New Member

Aug 9, 2004

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Tucson, Az. Its a dry heat

Sep 25, 2004

#9

• Sep 25, 2004

• #9

I changed my 3.08 gears in my 99 Saleen to 3.73s 2 days ago. The speedometer seems to read the same. I called the dealer to have them correct the computor for the gears.The service tech said my speedo sensor reads axle speed, on the ring gear, not the driveshaft. So no changes were required.