Hey Guys, hope your holidays are going well. I have a 06 xlt 5.4 2wd prerunner setup and looking to install Gears, locker, and possibly torque converter. My truck has magnuson supercharger so she's got some horsepower and I have plans to hit 500-550rwhp. Im running 315/70r/17 Bfg's and want to lay some SERIOUS rubber down for some off road racing. Before i start asking what i should or should not get, let me caveat by stating that preruners ARE NOT 4WD!

I have done some research on ARB air lockers and eaton e-lockers but can not find an elocker for a 9" ford 06 differential. Is this not an option?

I already have an constant onboard air system with pump and tank so the ARB wont be a problem. I just want the most power to the ground as possible

For dessert racing (not rock crawling or highway use) what is your opinions with going up to a 4.88, 5.00, or 5.13 gear ratio? I know i have to get a dynotune to recalibrate my speedo and i know my top end will be sacrificed but im only looking at getting to 80hph as quick as possible. what are your guys thoughts? thanks for helping [IMG][/IMG]

 

just wanting to know what you guys suggest 4.88, 5.00, or 5.13 gear ratio?

 

Your diff is a 9.75", not a 9".

For that use, 5.13's, of course. It will be cranking about 4000 rpm at 80 in 3rd.

 

hey glc, thanks for the info. yeah i know its a 9.75 just got lazy in writing..haha

Did you find a graph or conversion sheet that factored the Rpms? if so can I have it? I assuming that this would be bad for long term high speed travel. In the races i am in, there are stretches of on road/off road sections. I might be going as fast as possible for about three-8 miles on road and then back on to rough back dessert country roads. thanks for the info. more insight is welcome

 

http://4lo.com/calc/gearratio.php

At 80 in overdrive, it will be cranking about 2800. Considering the redline is about 5400 rpm (tranny limited, not engine limited) that should be fine. That would still be a theoretical top speed around 150 mph.