gearing and tires

thats why i run 31x11.50x16's on the rear of my truck, with 3.07 gears i need the shortest tire possible, as soon as i get the final say so about the rules, im looking for a good 4x4 trany/t-case combo to swap under my truck.....

with my 3.07 gears, 2.45 first gear, 31 inch tires, and turning 3200 against the governor spring i can run 39 mph......

with all that the same plus a 2:1 t-case (NP205) i can only get 19mph wheel speed......

if i put a manual valve body and higher torque converter in the truck i can leave in second and spin them 33 mph......

that is all based on IF i can turn 3200......of course 2600 pounds of weight against the tail gate helps with traction.....
 
LOGANSTANFORTH said:
to get 4000 rpms with a 33 inch tire, in direct drive, with 4.56's, 2.72 low gear, your going to need 32 mph.......with that all the same but 4.10 gears, your looking at just a shade over 35 mph......


with these "drag race" sleds we got out here now i would want as much ground speed as possible before they put the hammer on the truck......
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in my neck of the woods we dont have those fancy speed sleds, ours are heavy as hell from the get go, i can maintain 35-3600rpms down the track now with 33's and 3.73's. i am running bfg at's now but am switching to a 33" sts's this next season and i am expecting more bute which is going to hurt rpms. i am also going to swap chargers i can get it with a 1.10AR or 1.25AR but i think the 1.25 will be too much for my truck to light, i am wondering if swapping to a 4.10 would be worth the money since 4.56's might be too much for street driving
 
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BullfrogJohnson said:
in my neck of the woods we dont have those fancy speed sleds, ours are heavy as hell from the get go, i can maintain 35-3600rpms down the track now with 33's and 3.73's. i am running bfg at's now but am switching to a 33" sts's this next season and i am expecting more bute which is going to hurt rpms. i am also going to swap chargers i can get it with a 1.10AR or 1.25AR but i think the 1.25 will be too much for my truck to light, i am wondering if swapping to a 4.10 would be worth the money since 4.56's might be too much for street driving
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I say 1.10 A/R. Stick with the 3.73s and 33"s and stay in thrid gear wind it tight. Fourth gear is a huge jump for a 2.5" truck with a heavy sled. $.02
 
JOHNBOY said:
I say 1.10 A/R. Stick with the 3.73s and 33"s and stay in thrid gear wind it tight. Fourth gear is a huge jump for a 2.5" truck with a heavy sled. $.02
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big jump even with Johnboy tuning:evil
 
BullfrogJohnson said:
big jump even with Johnboy tuning:evil
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Darn Right.LOL But what would I know I only pull with one gear. :hehe:

Those tires and fourth gear are going to take BIG power.
I am hoping to pull in ZF 5th (1:1 like Allison 4th). But I have built engine, some pumps, and a 3" turbo. That is running 33" STS and 3.73s. I still aint sure I got enough.:doh:
 
A small charger can have the power in the lower end of the engine. I could hit drive with my 2.6 charger, but not even dream of leaving second with my 3.0 charger.
 
zstroken said:
A small charger can have the power in the lower end of the engine. I could hit drive with my 2.6 charger, but not even dream of leaving second with my 3.0 charger.
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Good Point.
 
Zstroken, i am going to run a s465, thought about a htt promax but i like the idea of a gt42 install kit so i can upgrade down the road, and i dont think anyone has runa s465 on a dmax so i would like to see what i can do
 
I would run the htt 66/16. It has an extended tip compressor wheel, the 65 doesn't.
 
can you get the 66/16 in a t4 foot with a 4" downpipe with above a 1.06AR and is it 2.6 class legal
 
Should be 2.6 legal. 66/25.4= 2.59. The 16 is a wastegated t3 mounting, but it is a 4" discharge.
 
Do I need 4:10's ?????????????
and what will it do to my mpg?

(right now with no load my tack is about 1,650 at 70 mph)


I have an 06 cummins with 37's and 3:73's. the truck is mostly stock accept ive got a bully dog pmt, 4'' exhaust (no cat), afe stage 2.

i never pull more than 8,000lbs. and the trany (auto) has the valve body and converter upgraded.

thanx for the help! !
 
also the mpg i'm getting now is about 13.3 with winterized fuel. 350 (to 400 in the summer) to a tank. 34gal tank - figure i burn 30 at a time.

thanx.
 
Tony R said:
theres not much choice a person has without a box i know that in my case hi sec with 4.88s is a lower gear than low 4 ive changed gears 3 timjes now trying to get it right just wanting help from others
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if you can't run 4th low with 4.88's you just plain need more motor so to be so upfront but it is the truth
 
i got the motor and yes 4.88s and 4 low is easy with a drag sled but its a little diffrent when you get the old sleds where the operator wont let you run with it i think alot of the problem is the pump but ill have one in april so no big deal alot of people want to give advice on what gear to run etc and they do it all the time low 4th its easy on the drivetrain etc watch my video etc i can do it you watch it and yell the smoke is falling out the stacks cause the engine is being pulled down all the way down the track because of to big of gear just my two cents not directed toward anybody
 
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