6" Lift w/ 33's
07-12-2018, 12:50 PM
#21
Renaissance Honky
edit, actually broke out the calculator. 4.10's would get you just over 2,000rpm @70mph. I'm just under that with stock tires and 3.55:1's, so you'd be in the ballpark of 3.73's on a stock truck. If you want a little more 'jump', 4.30's would get you there. 4.56 might be a bit too loose, unless you tow a lot.
Last edited by Eric Kleven; 07-12-2018 at 01:01 PM.
07-12-2018, 12:53 PM
#22
Renaissance Honky
The geek math is calculating your piston speed to be between 5 and 6 meters/second. That's where efficient cruising happens. Since you're dealing with a lifted truck on big tires, I aimed on the high side. I
70mph on the 4.88's was just over 7, 2,370rpm, Right at 6 at 60mph, 2032rpm. Should feel pretty good.
Re-checked with 4.56 gears, 60mph @ 1900rpm, 5.7m/sec, 70mph @ 2,215rpm 6.6m/sec. Not a bad fit, either. This is pretty much spot-on where my '07 5.4 w/3.55:1 gears is sitting. Good commuting and highway gears, not real sporty. 2nd gear gets me up to 80mph, that's pretty fast. This is with the 3v engine, if yours is the 2v, it could feel a bit doggy.
Don't be afraid to spin that 4.6.
Last edited by Eric Kleven; 07-12-2018 at 01:13 PM.
07-12-2018, 12:56 PM
#23
Renaissance Honky
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Last edited by Eric Kleven; 07-12-2018 at 01:15 PM. Reason: things
07-12-2018, 07:49 PM
#24
Senior Member
With the 5.4, 4.56:1 gears will bring you back to about the same overall ratio (between gears and tire circumference) you had with stock tires and the 3.55's.
edit, actually broke out the calculator. 4.10's would get you just over 2,000rpm @70mph. I'm just under that with stock tires and 3.55:1's, so you'd be in the ballpark of 3.73's on a stock truck. If you want a little more 'jump', 4.30's would get you there. 4.56 might be a bit too loose, unless you tow a lot.
edit, actually broke out the calculator. 4.10's would get you just over 2,000rpm @70mph. I'm just under that with stock tires and 3.55:1's, so you'd be in the ballpark of 3.73's on a stock truck. If you want a little more 'jump', 4.30's would get you there. 4.56 might be a bit too loose, unless you tow a lot.
07-12-2018, 08:18 PM
#25
Member
Thread Starter
My .02:
Regearing is less about RPMs and more about transmission (though, they are related). Sure, your highway RPM will suffer if you regear but in gears 1-3 you'll get back a lot of power and grunt. AKA it will be more fun to drive.
The motor/tranny has to work a lot more during low end speed with stock gearing because it wasn't setup for the large tires (weight + width). Regearing improves efficiency but lowers efficiency at high speeds. If you've ever had a multi-gear bicycle, that is the best simple comparison.
Regearing is less about RPMs and more about transmission (though, they are related). Sure, your highway RPM will suffer if you regear but in gears 1-3 you'll get back a lot of power and grunt. AKA it will be more fun to drive.
The motor/tranny has to work a lot more during low end speed with stock gearing because it wasn't setup for the large tires (weight + width). Regearing improves efficiency but lowers efficiency at high speeds. If you've ever had a multi-gear bicycle, that is the best simple comparison.
07-12-2018, 08:55 PM
#26
Senior Member
My .02:
Regearing is less about RPMs and more about transmission (though, they are related). Sure, your highway RPM will suffer if you regear but in gears 1-3 you'll get back a lot of power and grunt. AKA it will be more fun to drive.
The motor/tranny has to work a lot more during low end speed with stock gearing because it wasn't setup for the large tires (weight + width). Regearing improves efficiency but lowers efficiency at high speeds. If you've ever had a multi-gear bicycle, that is the best simple comparison.
Regearing is less about RPMs and more about transmission (though, they are related). Sure, your highway RPM will suffer if you regear but in gears 1-3 you'll get back a lot of power and grunt. AKA it will be more fun to drive.
The motor/tranny has to work a lot more during low end speed with stock gearing because it wasn't setup for the large tires (weight + width). Regearing improves efficiency but lowers efficiency at high speeds. If you've ever had a multi-gear bicycle, that is the best simple comparison.
07-12-2018, 10:12 PM
#28
Sh!tllbuffout
Not regearing but you can change tranny shift points which would help a little.
What im wondering is isnt the 11th gen 4.6 as potent the 10th gen 5.4? Im running 35s on a 5.4 with 3.73s and i always turn OD off bc im in a hilly area. If i keep this truck i wanna get a tuner for a little extra pep.
What im wondering is isnt the 11th gen 4.6 as potent the 10th gen 5.4? Im running 35s on a 5.4 with 3.73s and i always turn OD off bc im in a hilly area. If i keep this truck i wanna get a tuner for a little extra pep.
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mmwest (07-13-2018)
07-12-2018, 10:20 PM
#29
Member
Thread Starter
A tuner is the icing on the cake, IMO. But it's just a bandaid if your engine can't power the weight of the vehicle. I wish lift kit companies would educate more on regearing.
My truck is a truck, not a sports car, but I want power and torque on highways, hills, and some stop lights too!
My truck is a truck, not a sports car, but I want power and torque on highways, hills, and some stop lights too!
The following users liked this post:
mmwest (07-13-2018)