4.10 or 4.56 gearing?
04-12-2008, 04:03 PM
#1
Thread Starter
Join Date: Sep 2007
Location: Conroe Tx
Posts: 14
4.10 or 4.56 gearing?
Hello there
My room mate just bought an 89 mustang 5.0 convertable. I am trying to guess
his gearing. At a gps indicated 70mph, the rpm gauge is at 2700rpm. This leads
me to believe the car is geared 4.56. Am I right? Thank you.
My room mate just bought an 89 mustang 5.0 convertable. I am trying to guess
his gearing. At a gps indicated 70mph, the rpm gauge is at 2700rpm. This leads
me to believe the car is geared 4.56. Am I right? Thank you.
04-12-2008, 04:35 PM
#2
6th Gear Member
Join Date: Jan 2008
Location: colorado
Posts: 6,395
RE: 4.10 or 4.56 gearing?
nope, sounds like 4.10s are pretty possible.
at 55mph im at 2krpm, i dont really hold a speed that fast, i normaly get up there, and back off, so im not sure.
but id be guessing there 4.10s
at 55mph im at 2krpm, i dont really hold a speed that fast, i normaly get up there, and back off, so im not sure.
but id be guessing there 4.10s
04-12-2008, 05:47 PM
#5
4th Gear Member
Join Date: Feb 2008
Location: Georgia
Posts: 1,761
RE: 4.10 or 4.56 gearing?
ORIGINAL: floodzilla
sounds like 4.10s, 4.56s ive seen at around 3gs at 70
sounds like 4.10s, 4.56s ive seen at around 3gs at 70
Tire circumfrence in inches x Tire rpm= in/min.....80.4"x930.2=74788.08in/min=6232.34ft/min=1.18m/min= 70.8mph
4.10's would put you at 74mph and 4.56's would put you at 66mph.
04-12-2008, 05:54 PM
#6
3rd Gear Member
Join Date: Feb 2008
Location: L.I. New York
Posts: 555
RE: 4.10 or 4.56 gearing?
ORIGINAL: TRexGAWD
It's definitely 4.30's. The T5 has a .675 gear ratio in 5th gear and the 89 vert has a stock tire diameter of 25.6" which creates a circumfrence of ~80.4". With 4.30's at 2700rpms in 5th gear the wheel would be spinning at ~930.2rpms.
Tire circumfrence in inches x Tire rpm= in/min.....80.4"x930.2=74788.08in/min=6232.34ft/min=1.18m/min= 70.8mph
4.10's would put you at 74mph and 4.56's would put you at 66mph.
ORIGINAL: floodzilla
sounds like 4.10s, 4.56s ive seen at around 3gs at 70
sounds like 4.10s, 4.56s ive seen at around 3gs at 70
Tire circumfrence in inches x Tire rpm= in/min.....80.4"x930.2=74788.08in/min=6232.34ft/min=1.18m/min= 70.8mph
4.10's would put you at 74mph and 4.56's would put you at 66mph.
04-12-2008, 06:18 PM
#7
1st Gear Member
Join Date: May 2007
Location:
Posts: 133
RE: 4.10 or 4.56 gearing?
LOLOLOL, I say they are 4.26 ratio due to the fact that you forgot to figure in the time zone they are in, and the moon phase of course!
Seriously, that formula would be great in a perfect world, why not just jack up the rear a count the rotation of drive shaft vs. tire? that would give you the REAL answer.
Seriously, that formula would be great in a perfect world, why not just jack up the rear a count the rotation of drive shaft vs. tire? that would give you the REAL answer.
04-12-2008, 07:53 PM
#8
Thread Starter
Join Date: Sep 2007
Location: Conroe Tx
Posts: 14
RE: 4.10 or 4.56 gearing?
Thanks for the help guys looks like 4.3s it is! I forgot to mention that he has
cobra rims onit. not sure if it is 16 or 17 in size. The guy that had it said he but a
new tranny in it. Never drove a manual 5.0 before but it seems to have a short shifter.
He also said the drive shaft was aluminum when he looked under the car. Thanka again
cobra rims onit. not sure if it is 16 or 17 in size. The guy that had it said he but a
new tranny in it. Never drove a manual 5.0 before but it seems to have a short shifter.
He also said the drive shaft was aluminum when he looked under the car. Thanka again
