Diesel Engine Conversions Diesel Engine Swaps , 4bt Diesel and All Diesel Engine Conversion Related Discussions

SUPERDUTY CUMMINS NV4500 VERY LOW TOP SPEED

Thread Tools
 
Search this Thread
 
  #1  
Old 02-14-2013, 11:44 PM
motoxraca33's Avatar
Diesel Fan
Thread Starter
Join Date: Jan 2012
Location: Sacramento, CA
Posts: 31
Likes: 0
Received 1 Like on 1 Post
Default SUPERDUTY CUMMINS NV4500 VERY LOW TOP SPEED

hey guys, i put a 93 12v in my 2003 f350 with an NV4500 trans and i have very short gears and at about 65mph its just over 2k rpm's. first gear is super short, kind of like a granny low. not sure what i have for gears thinking 4:10 but i really need to lower them to get better speed but still need to haul my 44' enclosed trailer. do you think putting taller gears in the axles will be enough or will i have to re gear my tranny too... thanks in advance!!
 
  #2  
Old 02-15-2013, 01:30 AM
jdbigblue12v's Avatar
Diesel Wrench
Join Date: Mar 2011
Location: new york
Posts: 502
Received 12 Likes on 10 Posts
Default

I would personally run 3:54's you will have top end back and still have the torque to move the trailer
 
  #3  
Old 02-15-2013, 03:54 AM
wyoranch's Avatar
Diesel Wrench
Join Date: Mar 2007
Location: Stockdale, Tx.
Posts: 551
Received 10 Likes on 6 Posts
Default

Yeah, you have plenty of power potential in that motor to run higher gears. Being a 1st Gen motor it wont turn very high rpm. You can get a 3k governor spring kit which will allow you to turn more rpms. 2k at 65 isn't too bad. And I've never heard of anyone regearing the transmission, not sure if its possible. I'd just put 2" taller Tires on it, that'll drop your rpms.
 
  #4  
Old 02-15-2013, 07:06 PM
geddy's uncle's Avatar
Diesel Enthusiast
Join Date: Sep 2010
Location: Keller, TX
Posts: 415
Received 16 Likes on 15 Posts
Default

Put 3.55s in, maybe also get a taller tire, call it a day.
 
  #5  
Old 02-18-2013, 01:37 AM
motoxraca33's Avatar
Diesel Fan
Thread Starter
Join Date: Jan 2012
Location: Sacramento, CA
Posts: 31
Likes: 0
Received 1 Like on 1 Post
Default

Thanks guys ill put in 3.55's not too expensive!
 
  #6  
Old 02-18-2013, 07:44 PM
ID Shopteacher's Avatar
Diesel Fan
Join Date: Oct 2009
Location: Mtn Home
Posts: 77
Received 1 Like on 1 Post
Default

I'm running 285 75 16 tires with 3 73 gears with a first gen 12V and 3200 rpm gov spring and a NV4500 tranny! The tires are about 33 inches tall and I can bounce right up there to 90 in a heart beat, but it does like to cruse along at 65 mph! If I had 3 54 gears then 70-75 would be more of its comfort zone! My Super Duty had a V10 by the way !
It sounds like your pump might be limiting your top speed or else you have a fuel problem! filter or fuel lines???

good luck anyway.
 
  #7  
Old 02-18-2013, 07:54 PM
deck60's Avatar
Diesel Enthusiast
Join Date: Jan 2011
Location: South Dakota
Posts: 337
Likes: 0
Received 17 Likes on 16 Posts
Default

Originally Posted by ID Shopteacher
I'm running 285 75 16 tires with 3 73 gears with a first gen 12V and 3200 rpm gov spring and a NV4500 tranny! The tires are about 33 inches tall and I can bounce right up there to 90 in a heart beat, but it does like to cruse along at 65 mph! If I had 3 54 gears then 70-75 would be more of its comfort zone! My Super Duty had a V10 by the way !
It sounds like your pump might be limiting your top speed or else you have a fuel problem! filter or fuel lines???

good luck anyway.

what the shop teacher said
 
  #8  
Old 02-18-2013, 10:22 PM
geddy's uncle's Avatar
Diesel Enthusiast
Join Date: Sep 2010
Location: Keller, TX
Posts: 415
Received 16 Likes on 15 Posts
Default

Originally Posted by deck60
what the shop teacher said
It only counts if he was wearing his safety glasses.
 
  #9  
Old 02-18-2013, 10:26 PM
deck60's Avatar
Diesel Enthusiast
Join Date: Jan 2011
Location: South Dakota
Posts: 337
Likes: 0
Received 17 Likes on 16 Posts
Default

Actually I am wearing my safety glasses
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cjt8569
Chevy/GMC 6.2L and 6.5L
0
09-29-2015 06:39 PM
Dertyd
24 Valve 2nd Gen Dodge Cummins 98.5-02
24
06-07-2015 02:45 PM
Diesel Bombers
Latest Automotive Industry News
0
05-17-2015 12:10 PM
robbyS
5.9 Liter CR Dodge Cummins 03-07
3
04-16-2015 02:22 PM
stephenthinnes
24 Valve 2nd Gen Dodge Cummins 98.5-02
0
12-06-2014 11:54 AM



Quick Reply: SUPERDUTY CUMMINS NV4500 VERY LOW TOP SPEED



All times are GMT -5. The time now is 05:59 AM.