99-03 7.3L Performance Discussion of 99-03 7.3 Liter Ford Powerstroke Turbo Diesels Related To Performance And Longevity

Gear Ratio

Old Feb 22, 2010 | 11:20 PM
  #1  
Lange503's Avatar
Thread Starter
|
Diesel Bomber
Joined: Feb 2010
Posts: 1,058
Likes: 45
From: Vernal, Utah
Default Gear Ratio

What gear ratio will make it to where my rpm's are around 2000 or 2100 ish at 80 mph? and where can i find them?
 
Reply
Old Feb 23, 2010 | 03:43 AM
  #2  
9412Valve's Avatar
Diesel Enthusiast
Joined: Mar 2009
Posts: 240
Likes: 10
From: Okinawa, Japan
Default

355's maybe? Jeez, dunno really.
 
Reply
Old Feb 23, 2010 | 11:35 AM
  #3  
CSIPSD's Avatar
Diesel Bomber
Joined: Sep 2007
Posts: 7,638
Likes: 638
From: Bend OR
Default

Why do you want to be set up like that? It will make it laggy as hell around town and tow like crap...
 
Reply
Old Feb 23, 2010 | 11:43 AM
  #4  
Lange503's Avatar
Thread Starter
|
Diesel Bomber
Joined: Feb 2010
Posts: 1,058
Likes: 45
From: Vernal, Utah
Default

i am on the interstate alot and want better mileage, what gear ratio would be better? i tow very rarely anymore
 
Reply
Old Feb 23, 2010 | 12:35 PM
  #5  
CSIPSD's Avatar
Diesel Bomber
Joined: Sep 2007
Posts: 7,638
Likes: 638
From: Bend OR
Default

More then likely you have 3.73's and I would stick with that. Changing gears is expensive and your no going to recoup the costs in the long term.

Front and rear gear change will run you about 2k or so... Thats alot of MPG to have to save.
 
Reply
Old Feb 23, 2010 | 03:25 PM
  #6  
Lange503's Avatar
Thread Starter
|
Diesel Bomber
Joined: Feb 2010
Posts: 1,058
Likes: 45
From: Vernal, Utah
Default

oh wow, didn't know it was that expensive, i will just stick with the ones i have then, thanks for your help
 
Reply
Old Apr 6, 2010 | 09:20 PM
  #7  
the baptist's Avatar
Newbie
Joined: Apr 2010
Posts: 2
Likes: 0
From: newcomerstown ohio
Default

its a lot of money but has anyone run a gear vender? or electric fans
 
Reply
Old Apr 6, 2010 | 10:15 PM
  #8  
CSIPSD's Avatar
Diesel Bomber
Joined: Sep 2007
Posts: 7,638
Likes: 638
From: Bend OR
Default

Originally Posted by the baptist
its a lot of money but has anyone run a gear vender? or electric fans
Gear vendor is a nice unit, but... Its about 3k installed, which is a TON of fuel.


Electric fans make your truck all but worthless. They just dont move enough air when towing.
 
Reply
Old Apr 6, 2010 | 10:21 PM
  #9  
diesel pap's Avatar
Site Sponsor - Mighty Diesel
Joined: Dec 2008
Posts: 4,184
Likes: 213
From: West Virginia
Default

you might find somebody to trade gears with.
 
Reply
Old Apr 9, 2010 | 01:55 PM
  #10  
Karls03's Avatar
Diesel Wrench
Joined: Mar 2010
Posts: 996
Likes: 49
From: Fallon, NV
Default

Originally Posted by Lange503
What gear ratio will make it to where my rpm's are around 2000 or 2100 ish at 80 mph? and where can i find them?
You guys are killin me! It's a basic algebra equation: rpm = mph x gear ratio x 336 / tire diameter Simply rewrite the equation to solve for gear and you have (tire x rpm)/(mph x 336) = gear.
Since searching this out on Google never occurred to you, we'll do the math here. I'll have to assume that you're rolling 285/75R 16s.

(32.8 x 2000) / (80 x 336) = 2.44
Accounting for a 4R100's OD of 0.71: 3.55 X 0.71 = 2.52, close enough for this application.

If you're rolling 265/75s, you're going to need a 3.23 gear.

Gears and install aren't cheap, you're going to have to do A LOT of driving to get that money back. If you're that worried about mileage, get a small truck with a V-6 or a Prius! Gotta pay if you wanna play!
 

Last edited by Karls03; Apr 9, 2010 at 01:59 PM.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
corksil
Ford Powerstroke 99-03 7.3L
2
Aug 2, 2015 10:19 PM
Diesel Bombers
Latest Automotive Industry News
0
Jun 4, 2015 09:30 PM
bigdaddy0608
24 Valve 2nd Gen Dodge Cummins 98.5-02
3
Feb 26, 2015 04:52 AM
rtbcoop
1st Generation Dodge Cummins 89-93
0
Nov 29, 2014 11:33 PM
Diesel Bombers
General Diesel Related
1
Oct 18, 2014 10:52 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 02:20 AM.