wyrick

Hey guys, Should I re-gear or keep doing engine mods?
I somewhat posted this on another mans thread tonight but then decided it'd be better to start from scratch. I done most bolt ons just shy of forced air, finally lifted with 32s. the engine still pushes the jeep well even with factory 3.07s.
My question is what am I missing in the equation? My first thought is put a cam kit in to re-coop lost power (because I've never done gears before and they are intimidating). I know I could get some of the power back by re-gearing, and could push it even further with a mild cam. Are there any true mechanical cons to not re-gearing and just putting a cam in?


Thanks for any and all feedback!

XJwonders

Regear it

wyrick

That's ideal, but am I screwing anything up if I don't?

XJwonders

your transmission

shooptube

X2. 3.07 is way to low for 32s. 4.10s or 4.56s should be used with 32s.

You will roast the transmission way before that power gets to the tires. Stop the engine mods till you regear.

andrewmp6

You can make all the power in the world but with the wrong gearing it will be a dog.And like said running the wrong gears for the tire size you have can hurt your trans over time from it having to work harder to run the same speed it use to with smaller tires.And bigger tires weight more so does put a little more strain on the drivetrain.

BsmittyXJSTL

x's 1000 on re-gearing it.

When dealing w/my Mustangs it always blew my mind the amount of $$$ ppl would blow on exhaust/intake/tune/tb bull crap/super coils/etc. Maybe cause they were smaller chunks of cash at a time but whatever.

The #1 SOP mod is gears all day long. It really is a smart move on our types of vehicles as we have effectively reduced our torque multiplication by putting bigger tires on our rigs. A good re gearing (kinda new to jeeps so I'm not 100% on what ratios for what application is recommended yet) makes your get up from a standing start much more snappy feeling, there's less bogging down. Just put your jeep in 4wheel lo and tap the gas (bit extreme comparison but same principle).

Had a 2000 GT w/ 3.73's and a 99 Cobra w/4.10's Both had 3.27's from the factory. Both were good but the Cobra with the higher revving motor and them 4.10's was just so much fun to stomp around!

You will cruise on the highway at a slightly higher RPM but that's really not an issue, gas mileage with these things should never even be a concern. If it is then this isn't the vehicle for them.

If you do end up doing a Cam later you will do well having lower (higher numerically) gears any way as pretty much any aftermarket cam grind for any car ever will yield higher HP #'s at slightly elevated RPM's vs and by doing so at the cost of low end torque Which is the whole reason you posted this thread and what you are ultimately in search of sir.

andrewmp6

Bsmitty this is a chart most of us use http://jeeptalk.org/gear_chart.php that chart is based on a auto xj and stock those are mostly 3.55.With a stick which the op has his is a 3.07 he can use the same chart but go up a gear size or two vs the auto trans.

Outlaw Star

3.07 was the gears used in 5spds so dont think he has an Auto.

For the cheapest regear, you can swap a set of axles from an Automatic XJ because they have 3.55 gearing. You will gain some of your "Umpfh" back but these are Jeeps, not sports cars. Dont hope for drag car performance.

wyrick

Thanks for the info guys, lol the writing is on the wall when everyone says re-gear with logic to back it up.
Originally I had my eyes on a set of salvage axle assemblies out of an auto (confirmed I have the AX15), and was planning on swapping them while doing the lift kit. I didn't on the idea that if I had any noise or vibration I might have trouble diagnosing.
lol no sports car, just want to make sure she'll take the hills of Arkansas fully loaded with gear.

shooptube

I am speaking as someone who daily drove on 32s for a few months. I have a 5 speed with 4.10 gears.

The manual trans has a slightly higher gearing than the auto. 4.10s are good for highway gas, 4.56 if its more street and city driving. I'm now running 35s on 4.10s and I have awful city gas, going to 4.56 soon.

Outlaw Star

Not arguing here but when it comes to helping out on these questions, please state whether you have 5spd or Automatic transmission as the gearing varies depending on which trans was in the vehicle.
IE: You drove 32's with 4.10's and a 5spd and it worked whereas someone with an Automatic might not be happy with that gear choice.

wyrick

Thanks this is good info, what RPM are you running at 70?

wyrick

My bad not giving all the info, I'll make sure to do so from here on out.

Outlaw Star

Lol. It's ok man. I meant it more twords everyone.
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