what ratio is this?

82 GT · 02-28-2001, 08:03 PM

How do I find out what gear ratio I have if the RPM's are 2000 in 5th gear and the speed is 80mph? The tires are 222/60R15

------------------
'82 GT 351W,BBK shorties,
Comp Cam,edelbrock intake
625 cfm carter carb. c-4 tranny w/ pro stick shifter. 4 core radiator
Mallory distributor. 3:27
.........................

scott93gt · 02-28-2001, 08:36 PM

Sounds to me like they are 2.73's. I have 3.08 and run 70 mph at 2000 rpm in 5th. Your 15" tires come out to almost the exact same diameter as my 225/55R16 so I don't think the tires would be enough of a factor drop 10 mph. What is the code on your door tag? (driver side).

------------------
Scott93GT
1993 Mustang GT
Silver CC/Titanium Accent GT, Black Clothe interior.
5 speed, 3.08's, 3 chamber Flows, K&N, Hurst Competition Plus.

1991 F150 4x4 XLT Lariat
Six Stick Regular Cab LWB Tow Vehicle

82 GT · 02-28-2001, 11:01 PM

I just looked at the tag on the door. It looks like there is an "M" for the axle code.
Anyone know how to decode that?

------------------
'82 GT 351W,BBK shorties,
Comp Cam,edelbrock intake
625 cfm carter carb. c-4 tranny w/ pro stick shifter. 4 core radiator
Mallory distributor. 3:27
.........................

NOS_Notch · 02-28-2001, 11:17 PM

M is 2.73
Z is 3.08
E is 3.27

------------------
4.10's,long tubes & 75 shot...Goes 12.50's
Check it out at http://www.burnouts.webprovider.com

macx · 03-02-2001, 09:29 PM

You can get close a simple old fashioned way. Jack both rear tires just off the ground, chalkmark them at i.e. the exact bottom. Also mark the driveshaft. Spin both wheels exactly 1 revolution while somebody counts the rev's on the driveshaft. You'll get close.

86LX5liter · 03-03-2001, 12:28 PM

there is also that same tag on the rear end. There is a metal tag that hangs off of one of the bolts. Most of the time, it is worn, but you can still make out the ratio most of the time. I had 3.73's in my 86, from tha factory. But I had never heard of that before, so I checked with Ford. They had me come in, and they showed me the tag I told you about. They also did the test when you turn the tires and count the driveshaft revs.

------------------
12.54 @ 110.90
1.62 60'
best with old car, will let you know once i finish the transfer to the new to me car

click here to see my car!

02-28-2001, 08:03 PM	#1
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	what ratio is this? How do I find out what gear ratio I have if the RPM's are 2000 in 5th gear and the speed is 80mph? The tires are 222/60R15 ------------------ '82 GT 351W,BBK shorties, Comp Cam,edelbrock intake 625 cfm carter carb. c-4 tranny w/ pro stick shifter. 4 core radiator Mallory distributor. 3:27 .........................

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02-28-2001, 08:36 PM	#2
scott93gt Registered Member Join Date: Oct 1999 Location: Saltsburg, PA USA Posts: 468	Sounds to me like they are 2.73's. I have 3.08 and run 70 mph at 2000 rpm in 5th. Your 15" tires come out to almost the exact same diameter as my 225/55R16 so I don't think the tires would be enough of a factor drop 10 mph. What is the code on your door tag? (driver side). ------------------ Scott93GT 1993 Mustang GT Silver CC/Titanium Accent GT, Black Clothe interior. 5 speed, 3.08's, 3 chamber Flows, K&N, Hurst Competition Plus. 1991 F150 4x4 XLT Lariat Six Stick Regular Cab LWB Tow Vehicle

02-28-2001, 11:01 PM	#3
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	I just looked at the tag on the door. It looks like there is an "M" for the axle code. Anyone know how to decode that? ------------------ '82 GT 351W,BBK shorties, Comp Cam,edelbrock intake 625 cfm carter carb. c-4 tranny w/ pro stick shifter. 4 core radiator Mallory distributor. 3:27 .........................

02-28-2001, 11:17 PM	#4
NOS_Notch Registered Member Join Date: Sep 2000 Location: Fresno,CA. USA Posts: 384	M is 2.73 Z is 3.08 E is 3.27 ------------------ 4.10's,long tubes & 75 shot...Goes 12.50's Check it out at http://www.burnouts.webprovider.com

03-02-2001, 09:29 PM	#5
macx Registered Member Join Date: Oct 1999 Location: Gordonville MO USA Posts: 448	You can get close a simple old fashioned way. Jack both rear tires just off the ground, chalkmark them at i.e. the exact bottom. Also mark the driveshaft. Spin both wheels exactly 1 revolution while somebody counts the rev's on the driveshaft. You'll get close.

03-03-2001, 12:28 PM	#6
86LX5liter Registered Member Join Date: Dec 1999 Location: NY Posts: 524	there is also that same tag on the rear end. There is a metal tag that hangs off of one of the bolts. Most of the time, it is worn, but you can still make out the ratio most of the time. I had 3.73's in my 86, from tha factory. But I had never heard of that before, so I checked with Ford. They had me come in, and they showed me the tag I told you about. They also did the test when you turn the tires and count the driveshaft revs. ------------------ 12.54 @ 110.90 1.62 60' best with old car, will let you know once i finish the transfer to the new to me car click here to see my car!