Speedo correction help please - TKO500

[GRGT1994]

Hey guys, I just got a Tremec TKO500 from Steeda installed. Anyone know how best to correct the speedo. I'm running 3.73 gears.

Thanks.

 

[Beasty306GT]

Mustang Speedometer Gear Guide
Ring & Pinion Speedo Gear Part Number
1983-89 Mustang Manual 5-Speed
3.08 18 Tooth
3.27 19 Tooth
3.55 20 Tooth
3.73 21 Tooth
4.10 23 Tooth
1990-93 Mustang Manual 5-Speed
3.08 20 Tooth
3.27 21 Tooth
3.55 23 Tooth
1984-89 Mustang Automatic AOD
3.27 19 Tooth
3.55 20 Tooth
3.73 21 Tooth
4.10 23 Tooth
1990-93 Mustang Automatic AOD
2.73 19 Tooth
3.08 20 Tooth
3.27 21 Tooth
3.55 23 Tooth
1996-98 Mustang Cobra Manual 5-Speed
3.27 19 Tooth
3.55 20 Tooth
3.73 21 Tooth
4.10 Speed Cal
1994-98 Mustang Manual 5-Speed
Except 1996-98 Cobra
3.08 20 Tooth
3.27 21 Tooth
3.55 23 Tooth
1994-98 Mustang Automatic AOD
2.73 19 Tooth
3.08 20 Tooth
3.27 21 Tooth
3.55 23 Tooth

 

[ScratchinFerTra]

You can change the gear on the vehicle speed sensor (VSS), but they tend to get chewed up over time depending on the ratio/gear needed to correct your speedo.
You can buy a Speed Cal Speed Calibrator - SpeedCal at AmericanMuscle.com - Free Shipping! takes about an hour to install/set-up but worth it, you can change tire heights, gears, etc and flip a few switches to correct your speedo forever. Downside is $100 vs $10 gear.
Stan

 

[GRGT1994]

I have the SpeedCal already installed. Used it well for my T5 and 3.73 gears. Problem is, it's not even in the ballpark with the TKO500. I hit 150 mph in 1st gear. So obviously the SpeedCal will not correct down that much. It's generally designed to increase the MPH reading when shifting from stock to a 3.73 or 4.10 gear set, and I need to go the other way.

 

[str8stang036]

I have a TKO-600 and 3.73 gears. The TKO's use a different speedo gear than T-5 tranny. I got mine from pro motion powertrain. I believe it is a red 23 tooth speedo gear for you.

 

[toyman]

I have the SpeedCal already installed. Used it well for my T5 and 3.73 gears. Problem is, it's not even in the ballpark with the TKO500. I hit 150 mph in 1st gear. So obviously the SpeedCal will not correct down that much. It's generally designed to increase the MPH reading when shifting from stock to a 3.73 or 4.10 gear set, and I need to go the other way.

I've got a unit similar to the speed cal for sale. It will adjust 100% up and down in 1% increments. PM me if you are interested.

 

[ScratchinFerTra]

If you have the Speed Cal, you are set, start flipping dip switches, this will correct what you have.

I went from a T5 with standard 25" 245/45/17 tires and 2:73 gears to a TKO600 with 28" tall 275/60/15 tires and 4:11 gears, so it will work.

The chart is found:
http://lib.store.yahoo.net/lib/mustangtuning/speedcal.pdf

I have proven this is not 100% correct, I calculated my RPM for a few MPH at
Gear Ratio Calc

And changed settings until I was on the money.

Stan