Regearing questions? 3FE with 33's

[FearNoGrave]

I have had my 91 on stock tires, 33s, 35s and now 37s. 33s will not make a difference on stock gearing.

x2
I have a ‘91 on 33” tires, stock wheels, and a 2.5” EMU lift. I haven’t noticed much difference with stock gearing. Hills are still a b*tch, but that’s par with the 3FE in general. Highway and street have been just fine. I might go 35” the next time I need tires, but for now I like the 33”. I feel like they’re a good middle ground.

 

[Bludozer]

I have had my 91 on stock tires, 33s, 35s and now 37s. 33s will not make a difference on stock gearing.

Perception matters a great deal, the OP of this thread is about how 33s/3FE/stock gears felt like an absolute dog. IMO regearing is the most worth it mod with any tire size increase even on the 1FZ, with 3FE I'd probably regear it even with stock size tires.

 

[Marco Lau]

Perception matters a great deal, the OP of this thread is about how 33s/3FE/stock gears felt like an absolute dog. IMO regearing is the most worth it mod with any tire size increase even on the 1FZ, with 3FE I'd probably regear it even with stock size tires.

like i said..i have zero complaints even on 37s and 4.88. it pulls grade just fine even on my 3FE

 

[Bludozer]

like i said..i have zero complaints even on 37s and 4.88. it pulls grade just fine even on my 3FE

Have been seeing both sides of it since the beginning of time, nobody is necessarily "wrong". I am currently riding around on stock 4.10s with 35s and dying to get the 5.29s I have sitting on the shelf installed. Truck just feels so off.

 

[Bambusiero]

Here you go - by the numbers - Diff gear ratio, RPM's relative to stock

 

[Bambusiero]

But, in case you hadn't already heard this - to climb highway hills -
Downshift to 2nd gear and run up your RPM's into the 4000 range - 4400ish.
Not problem at all for this engine.
I have 285/33 tires on stock 4.10 diff gears - can easily hold 65mph.

 

[Marco Lau]

With 4.88 and 37s, I can hold 55-60mph on 2nd gear @ 4k, and 70-75mph on 3rd....

 

[Bambusiero]

With 4.88 and 37s, I can hold 55-60mph on 2nd gear @ 4k, and 70-75mph on 3rd....

Sounds about right.
Of course, that chart makes certain assumptions about the exact tire size, but gives a reasonable idea about how it works.
4.88 and 37s is revving a negligible 1.4% above stock - so, basically, 4.88 diff gears puts you back to stock engine performance on 37s.

Stock 4.10 diff gears on 33s is under-revving by 5.2%, which does make a noticeable reduction in torque, but can be made up for by downshifting. But - I would like better gearing.

 

[Bambusiero]

Have been seeing both sides of it since the beginning of time, nobody is necessarily "wrong". I am currently riding around on stock 4.10s with 35s and dying to get the 5.29s I have sitting on the shelf installed. Truck just feels so off.

Yeah, you're sucking wind right now with revs at 9.6% below stock.
5.29 on 35s would put your revs at 16.6% above stock.
Certainly - extra peppy on the road, but not great for highway travel.
Would be a very noticeable improvement for crawling in low range, I would think.

 

[Bambusiero]

My dream setup:

37's with 5.29 diff gears - which over revs by 10%
AND
Overdrive high range transfer case gears, which returns high range to stock revs
AND
3.12 Low range transfer case gears, which gives the maximum possible 3.325 low-range / hi-range gear ratio.

 

[Bludozer]

Yeah, you're sucking wind right now with revs at 9.6% below stock.
5.29 on 35s would put your revs at 16.6% above stock.
Certainly - extra peppy on the road, but not great for highway travel.
Would be a very noticeable improvement for crawling in low range, I would think.

Yeah, see people on here say all the time they are fine with 35s and stock gears. I can't stand it. I had 4.88s with 35s on my last truck and it was fine around town, on the highway and on the trail. Going with 5.29s this time for a little extra pep and better low range, I do very little highway driving (and when I do, usually stay in the 60-65mph range when I'm in a cruiser) so I'm thinking this set up is going to feel perfect. Worst case scenario I'm forced to go to 37s which wouldn't exactly break my heart lol.

 

[Bambusiero]

And just for fun - the totally modified transfer case gear chart.

 

[kw90surf]

With 4.88 and 37s, I can hold 55-60mph on 2nd gear @ 4k, and 70-75mph on 3rd....

I wonder if the difference in perception has to do with how we're used to driving our 80s. I was able to drive my 80 "gently" i.e. letting it upshift as soon as it was ready, using the minimum of throttle necessary to get to speed, avoiding downshifts on the highway etc a bit more "successfully" when it had 31's. With the 33's on it now it's more often that I have to hold gears longer and downshift on hills earlier.

But, I probably wouldn't notice this if my driving style was more, lets say, "pedal to the metal". Maybe the powertrain doesn't care that much, seems like a lot of people drive them that way. How does a sustained 4k RPM feel when you're running those hills?

Awesome truck by the way Marco.

 

[Marco Lau]

I wonder if the difference in perception has to do with how we're used to driving our 80s. I was able to drive my 80 "gently" i.e. letting it upshift as soon as it was ready, using the minimum of throttle necessary to get to speed, avoiding downshifts on the highway etc a bit more "successfully" when it had 31's. With the 33's on it now it's more often that I have to hold gears longer and downshift on hills earlier.

But, I probably wouldn't notice this if my driving style was more, lets say, "pedal to the metal". Maybe the powertrain doesn't care that much, seems like a lot of people drive them that way. How does a sustained 4k RPM feel when you're running those hills?

Awesome truck by the way Marco.

I just completed a 800 mile round trip from L.A. to Death Valley this past weekend in a caravan of 5 rigs include 3 JK on 37s and 1 JK w/ a 392 Hemi swap on 40s. I was able to keep up with the caravan for the most part throughout the NP on and off the highway doing within the speed limit, except when pulling steep grade up the pass, i had to downshift to 2nd manually and hold the rpm @ +/- 4000rpm to keep 50-55mph over a long duration of time.....the engine seems to be happy for the most part, my coolant temp was never above 195F. I also added dual pusher fan in front of the condenser and tranny cooler to keep things cool. Again, having healthy cooling system is key. Prior to my RD radiator upgrade, i was constantly having overheating issues with the CSF...

 

[Roastchestnuts]

like half the people have said its fine and I don't think I need re gearing immediately. I might in the future. it seems fine 0-55 mph. I notice it more at highway speed but not all that different. they actually feel better than my old 31s . I have a feeling those tires might have been more heavy. If I did re gear I would go 456 gear ratio and I would do the transfer case I think.I already posted this in the what did you do with your 80 this weekend thread. I should have put these tires on right after I purchased the cruiser. they make it drive and look sooo much better in my opinion. The added ground clearance with the 33x10.50 15s make a big difference for beach driving on the OBX of North Carolina. I might add some OME stock height springs this summer when I have more time. the cat likes the tires

 

[kw90surf]

Poverty pack? Cool! No sunroof either I'm guessing?

33's look great. The OME stock heights I have ride excellent, FYI.

 

[Roastchestnuts]

Poverty pack? Cool! No sunroof either I'm guessing?

33's look great. The OME stock heights I have ride excellent, FYI.

Yesss Poverty pack! you don't see very many of these. No rear 3rd row seats (not even mounting points), No flairs or running boards, no sliding cargo windows and no sunroof. I love its uniqueness. Looks kinda like an old UN vehicle. Its also a very early 1991 model. made in march of 1990. Thanks!!

 

[Retro LC]

Anyone with 33s who has either 4.56 or 4.88 re-gear please post their RPM at 75 mph. Preferably for 3FE FJ80s, or at least indicate if you are posting your RPMs for the 1FZFE or the 3FE so we can see apples to apples comparison. Bonus points for photos of the speedo and tachometer. The RPM calculators I’ve seen and used don’t appear to be accurate when all the variables are plugged in when I had 31s. Opinions on the optimal re-gear are wide ranging. I was pretty much set on re-gear to 4.56 on 33s for my 3FE, but now that it looks like an engine swap to Cummins R2.8, or 1HZ or GM 6.2 E-Rod swap is no longer in the cards, I am starting to come back around to the idea that 4.88 on 33s for the 3FE might not be so bad after all. At 2400 rpm the 3FE sounds like it’s in the sweet spot for flat highway cruising rpm. 2600 is on the high end of the flat highway sweet spot. 2800 is starting to get a bit on the high side for sustained flat highway RPM for the 3FE.

On a side note, shame on CARB for not allowing the 6.2 E-Rod swap in the 80 series anymore. Why would an agency tasked with supposedly being the champion of the environment not allow a more fuel efficient, less tailpipe emission, better performance motor to be swapped into the 80 series? This is a rhetorical question as there’s no explanation that makes any sense. Sounds like CARB has conflict of interests in that their policies care more about new car sales and the tax revenue associated with those sales rather than recycling and breathing new life into these older vehicles.

Anyhow, I digress. Anyone with 33s who has either 4.56 or 4.88 re-gear please post their RPM at 75 mph. Thank you!

 

[jonheld]

2800 is starting to get a bit on the high side for sustained flat highway RPM for the 3FE.

3800 rpm is high. The 3FE will happily sit for years at 2800 rpm as long as you keep feeding it.
33s and 4.88 is a good combination for a 3FE.

 

[Retro LC]

3800 rpm is high. The 3FE will happily sit for years at 2800 rpm as long as you keep feeding it.
33s and 4.88 is a good combination for a 3FE.

I’ve read before that you like the 33s with 4.88 on a 3FE combination. What rpm is your 3FE showing on the tach at 75? Also, just for the sake of clarity not sure where you got 3800 rpm—agreed that is way too high for sustained cruising highway rpm.