Gear calculator accurate? - Mustang Evolution

Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 10-09-2014, 11:02 AM   #1
Registered Member
Regular
 
Nvrfastenough87's Avatar
 
Join Date: Oct 2014
Location: Clearwater
Region: Florida
Posts: 91
Gear calculator accurate?

Hi everyone,

I'm new to the forum and to mustangs. Just picked up a 13' gt with a bunch of mods, still have yet to get it to a shop to be figured out. I don't even know who tuned it...I've suspected its had 410 gears since the day I drove it. I found a thread where people recommended this site Rear-Axle Gear Calculator

I put it 40mph in 4th at 2100rpms, with 255/40-19 tires.. Might even be 2200prms, defintely just over 2k. Its saying I have 410 gears, is it accurate???

I'm not really crazy about the driveability, the super short gearing and the high rpms in 6th on the highway. I'm more of a start at 60-80 kind of guys so faster shifts and quarter mile times mean nothing to me.

What kind of $$$ would I be looking at the change to the 3.73s?? Its my daily driver so I think that would be better for me.


Thanks for any advice guys.
Nvrfastenough87 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-09-2014, 11:45 AM   #2
Registered Member
Regular
 
Grabber Blue5.0's Avatar
 
Join Date: Nov 2012
Location: East Haven
Region: Connecticut
Posts: 3,521
Give us some more info on your car? Auto? Manual? But that calculator should work.
__________________
2017 Dodge Challenger T/A Redline Tri-Coat
2015 Dodge Challenger Scat Pack Jazz Blue Pearl Sold
2015 GT Premium 401A Ingot Silver Sold
2011 GT Premium 401A Grabber Blue Sold
Grabber Blue5.0 is offline   Reply With Quote
Old 10-09-2014, 12:04 PM   #3
ME Bloodhound
Staff
 
Soccerluvr4's Avatar
 
Join Date: Feb 2012
Location: Sacramento/Bay Area
Region: California
Posts: 14,683
Easy way to check....

1. Jack the car up and support it on jack stands.
2. Remove the Ebrake
3. Mark starting point on both driveshaft and on wheel
4. Rotate the wheel 1 full revolution & count how many times the driveshaft turns.

If you have 4.10 gears then for that full revolution of the wheel your driveshaft will turn a hair over 4 times (4.1 specifically). Say you have 3.73 gears, that means the driveshaft will turn about 3 & 3/4 times for that revolution.
__________________

Bullitt build paused pending graduation

HID end all thread
Soccerluvr4 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-09-2014, 12:39 PM   #4
Registered Member
Regular
 
Nvrfastenough87's Avatar
 
Join Date: Oct 2014
Location: Clearwater
Region: Florida
Posts: 91
My current situation doesn't allow me to do anything like that... I just moved and I'm temporarily living in a place where I couldn't even do any oil change. I'm somewhat mechanically inclined but I'm not knowledgeable about tuning, just have a very basic idea. I did headers, full exhaust, and intake stuff on my previous car (c5) but thats as far as I've gone. I'm learning as I go.

Thats good to know, so a shop would be able to check very easily for me.

The car is an auto but I was using the select shift mode to check gear and rpms. Its nice if I drive it that way because I can stretch the gears out alittle but in auto or S mode its shifts so early, frequently and quickly its almost violent.. seems terrible for the car.

Its awesome unless I'm driving normally which is 90% of the time.
Nvrfastenough87 is offline   Reply With Quote
Old 10-09-2014, 01:15 PM   #5
Registered Member
Regular
 
Grabber Blue5.0's Avatar
 
Join Date: Nov 2012
Location: East Haven
Region: Connecticut
Posts: 3,521
Autos come with 3.15's so unfortunately it looks like someone put either 3.73's or 4.10's in. Not a good choice.
__________________
2017 Dodge Challenger T/A Redline Tri-Coat
2015 Dodge Challenger Scat Pack Jazz Blue Pearl Sold
2015 GT Premium 401A Ingot Silver Sold
2011 GT Premium 401A Grabber Blue Sold
Grabber Blue5.0 is offline   Reply With Quote
Old 10-09-2014, 01:20 PM   #6
ME Bloodhound
Staff
 
Soccerluvr4's Avatar
 
Join Date: Feb 2012
Location: Sacramento/Bay Area
Region: California
Posts: 14,683
Ok. Well easy way then to check. Get onto the highway, let it go into overdrive and see what your rpm is at 70mph. You have a 27" tall tire

with 4.10 = 2642
with 3.73 = 2239
with 3.55 = 2131

4.10... 4th gear at 40mph will put you at 2324 rpm
3.73... Same gear at same rpm puts you at 2114

That calculator you used they base the 4th gear off a 1:1, which yours is a 1.14, a 1.00 is a true 1:1, so that won't be too accurate.

This is the one i use, and its been dead accurate for me, it doesn't give you the axle ratio, so you have to work in reverse order kind of, but its easy to just plug in numbers to see where it should be.
http://www.crawlpedia.com/rpm_gear_calculator.htm

So it actually sounds like you have 3.73s based off of the rpms you were at in 4th when you tested.
__________________

Bullitt build paused pending graduation

HID end all thread
Soccerluvr4 is offline   Reply With Quote
Old 10-09-2014, 04:10 PM   #7
Registered Member
Regular
 
Nvrfastenough87's Avatar
 
Join Date: Oct 2014
Location: Clearwater
Region: Florida
Posts: 91
Quote:
Originally Posted by Soccerluvr4 View Post
Ok. Well easy way then to check. Get onto the highway, let it go into overdrive and see what your rpm is at 70mph. You have a 27" tall tire

with 4.10 = 2642
with 3.73 = 2239
with 3.55 = 2131

4.10... 4th gear at 40mph will put you at 2324 rpm
3.73... Same gear at same rpm puts you at 2114

That calculator you used they base the 4th gear off a 1:1, which yours is a 1.14, a 1.00 is a true 1:1, so that won't be too accurate.

This is the one i use, and its been dead accurate for me, it doesn't give you the axle ratio, so you have to work in reverse order kind of, but its easy to just plug in numbers to see where it should be.
Engine RPM / Engine Speed Calculator

So it actually sounds like you have 3.73s based off of the rpms you were at in 4th when you tested.
From what you're saying I have 3.73s. Another question I have.. since its an automatic the shift speeds can be changed with a tune right? thats really my main concern is that it seems to shift so hard and quickly.. Its only got 10k on the clock, runs very well, fast as hell, no other complaints what so ever.

is that a posibility? I plan on getting it retuned anyway, I want to make sure its set for 93 octane and want to see it puts down on a dyno.

Thanks for all the info
Nvrfastenough87 is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine speed calculator ( to help decide new rear gear set ) Spiney General Mustang Discussion 4 07-28-2013 11:24 PM
Are temperature guages accurate Blackedout Pre-2005 V6 Mustang 1 04-04-2012 04:54 PM
Where can I get an accurate value for a car? Hanan Classic Mustangs 3 12-20-2011 02:37 AM
Gear calculator Blackedout Pre-2005 V6 Mustang 1 05-25-2011 04:46 PM
UPDATE!! BUTT DYNO SHOWS HP GAINS and is accurate Danger Dude Pre-2005 V6 Mustang 46 01-05-2004 10:43 PM

» Like Us On Facebook



10:04 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.