3FE info

[jhanger]

3FE drivers: what is your RPM while driving 75mph? Also, please specify tire size, gear ratio, lift size and if you’re still rocking the a440f or converted to H55. Thanks.



I’ll start. 2800 rpm, 33” Coopers, 4.88, 2.5” OME, a440f with nomad extreme valve body and HD tc.

 

[Cruzerman]

This kind of data can be gotten simply by using a RPM calculator. Has nothing to do with what engine and lift, only transmission, gears, and tire size. I think the A440 has a .717:1 overdrive. while the H55 has an overdrive of ,845:1.

I think the calculator will be more accurate since your speedo is typically off if you've changed tires or gears. And if you're really interested in getting good results, measure the tires. The manufacturers lie about the size.

 

[jhanger]

I looked at those calculators online but did not have all the info to use them. My goal from this post is to find out what rpms other drivers with similarly set up rigs are seeing when cruising at 75mph. I want to know if cruising my 3FE at 75 mph pushing almost 3000 rpms is considered normal or being hard on my engine.

 

[Paul DiNapoli]

3FE at 75 mph pushing almost 3000 rpms

sounds about right for my rig. i've done the H55 swap + BFG 33's
speedo is reading low exactly 10% as measured by highway mile markers and a gps based speedo app on the smartphon.

truck will run 75 down the highway all day - but it's noticeably louder in the cabin and the gas needle moves a lot faster (and it's not like its ever slow to begin with)

H55F	A440F
1st....4.843:1	1st 2.950:1
2nd....2.619:1	2nd 1.530:1
3rd....1.516:1	3dr 1.000:1
4th....1.000:1	OD .717:1
5th....0.845:1

Gear Ratio Calculator

Gear Ratio Calculator

www.tremec.com

also - whatever tire height you use for your calculation - consider that they're wearing down as you drive on them...so brand new tires are going to have different dimensions a few years later at 50% of their life force having been spent.

take real measurements.

 

[bubfuji]

This Site has most of the Land Cruiser gear/tranny/transfer/tire size setups. It will also tell you the RPM's and MPH in the lower screens.

@75MPH With my 35" tires and 4.88 gears. I am at 2500rpm

 

[rrv333]

^ I have the same set up as bubfuji and I'm also at 2500rpm

 

[bubfuji]

Your RPM seems high for 33" tires and 4.88 gears. Are you sure you are in OD (4th Gear).

 

[jhanger]

Yes. The tranny is in 4th gear. I also have a roof basket with spare tire up top that acts like a sail. The motor was recently rebuilt. The tranny rebuilt 18 months ago with Nomad Extreme valve body and heavy duty torque converter. Around that time, I also changed gears from stock to 4.88s and rebuilt both axles and birfs. Also desmogged the rig 3 years ago.

 

[91FJ80Super44]

i don't know what mine runs at 75 mph but at 90 mph mine turns 2900, 31 in tires, 4.11s bone stock 91 fj80 with a 3fe, and obviously shes a a440f, i don't know if this is just for 62 guys with a 3fe or if its for all 3fe guys, but i mean 3000 sounds a little high a 75 mph for the 3fe, also have you gotten a GPS app on ur phone and checked and made sure the speedo is accurate?

 

[Alleycats]

Is your torque converter locking up in overdrive? (OP)