Re-gearing question.

[mattl600]

First off, happy New Years everyone. !


Think I may throw some 39” K02s for a bit.

Just had a new 3rd member put in with the linking so rather NOT re-gear until its rebuild time.

I’m currently running 37” KM3s which weigh in at 77.4 pounds.

39” K02s are weighing in at 79 pounds.

So there’s a 1.6 pound discrepancy.

Truck is currently goose tuned and is QUICK.

Just looking for some real world feedback.

Thanks!

 

[nikhsub1]

Was there a question in there? Seriously though, there aren't may running 39's so... it's all you bruh, tell us how it goes

 

[Nex]

Are you already running E85? Are you running factory gear ratio? If so remember the truck came with 35s. So a regear is not out of the question.

As Nik stated not many of us peasant Raptors are running 39s. You can try them out for a bit and see how they feel to you. Then make a decision on regearing from an informed position.

 

[BoostedToy]

I put on some 37” KO2’s six weeks ago. Absolutely no regrets on it and got them at a killer deal ($370/tire). Not sure about 39’s but I am sure that would have suspension (lift) work as a prerequisite. I have had some spirited driving with some suspension travel but haven’t jumped it. No rubbing so far. It’s been great. Goosetuned on E85. There is a significant weight penalty with the 39’s it appears. The 37” vs 315/70/17 is only 1lb heavier.

 

[thatJeepguy]

With the dawning of 8-9 and 10 speed trans now, re- gearing is less of a thing. Also the tq on the ecoboost is even more of an anomaly in regards with people feeling the need. That being said if you do some homework on a re-gear estimate calculator and go to say a 4.88 or 5.13 on 39’s , she’ll go from being decent to being spicy again. Now whether or not the rpm band will be livable on the highway and under 2500 will take some homework. Probably will be about 3500-5k.

Spicer Transmission Ratio RPM Calculator

Use the Spicer Transmission Ratio RPM Calculator to determine your engine’s RPM based on the transmission gear ratio, tire height, MPH, and ring and pinion gear ratio.

spicerparts.com

 

[ten_blade]

Currently running 39” KM3s with Currie geared to 5.13

Paired with 93 Goosetune she’s quick and nimble

 

[BaseModelRaptor]

Currently running 39” KM3s with Currie geared to 5.13

Paired with 93 Goosetune she’s quick and nimble

 

[Sunchild714]

Currently running 39” KM3s with Currie geared to 5.13

Paired with 93 Goosetune she’s quick and nimble

NICE!

 

[Booth9999]

NICE!

What the mileage on the freeway and cruising RPM at 80 mph? Also how do you like the KO3’S? I hated them on my gen 2. Crap traction in the snow/wet unless it was 12” of mud. Also they only lasted half of the ko2’s. How manny miles on them now?

 

[thatJeepguy]

What the mileage on the freeway and cruising RPM at 80 mph? Also how do you like the KO3’S? I hated them on my gen 2. Crap traction in the snow/wet unless it was 12” of mud. Also they only lasted half of the ko2’s. How manny miles on them now?

Agreed KO3’s were an ice skating rink in Montana snow for me.