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Re: ways to boost torque
Posted: November 26th, 2009, 7:16 am
by kf_chris
I had thought that I wouldn't need to gear the jeep after the stroker install. I run 31BFG AT now but after the motor is in I'm going to change back to the 32 muds that I had until my CJ is built...then the 31's are going back on. I have an open open setup with 3.55 gears. I thought that the motor would have the power down low so that the small tires wouldn't be an issue. Maybe 4.10's in the future if I see the need. primarily a street rig because of work, I don't need to gear it just yet for trail use as I rarely hit the dirt with my schedule. Going to wait to see how it drives on the road and in traffic before considering gear swap...just chiming in my take on the situation
Re: ways to boost torque
Posted: November 26th, 2009, 8:02 am
by 1bolt
nothing will compensate for a poor gear/tire ratio like swaping to a numerically higher gear, speaking from years of experience myself and with friends rigs. Seems to be commonplace around where I live, people I've known always seem to try to upgrade their engines after a lift. One of my strokers ended up in just such a vehicle, an undergeared weekend warrior rig. The stroker by itself will just not compensate for the gears. And even if it could you'd lose mileage.
4.56 and 33's on my stroker XJ and I can chirp those 33's, with 31's you want AT LEAST 4.10's
Re: ways to boost torque
Posted: November 26th, 2009, 1:15 pm
by kf_chris
Thanks for that input. After all the money I'm putting in for the engine (I just dropped it off and am paying for a turnkey) I'm going to wait a while for the gear install. Maybe mid spring I'll get a set of gears put in. Anything will be better than the poor performance and milage I was getting before the bearings spun.
Re: ways to boost torque
Posted: November 26th, 2009, 2:07 pm
by IH 392
I don't have any issues with my 3.54 gears and 31" tires?, I can get one hell of a bark out of them when I want to and if the road is wet at all second gear is required for acceleration!, if I need more power I use low range.
Re: ways to boost torque
Posted: December 2nd, 2009, 12:16 pm
by MrShoeBoy
I remember reading that installing the pistons backwards would net some increase in torque. Not sure where I read this or how it works, anybody else heard of that or know the science behind it?
As for gearing run the lowest ration you can stuff in the axles. I have 35s and 5.13s in my MJ and it is SWEET with the 4.6L stroker and 5 speed. My old XJ had 4.10s and 35s and it was OK. Mileage didnt really change between the 4.10 and 5.13 but the seat of the pants feel felt better. If you are doing a lot of highway I would get 4.88s to keep the RPMs around 2300.
AARON
Re: ways to boost torque
Posted: December 2nd, 2009, 1:27 pm
by ilber
I am rolling on 35" with 4.56, i used to have 4.10 and 35". 4.10, at least in colorado going uphill with my 4.0 HO and 250k+ miles was BAD. I mean 5 gear was usless 99% of the time, 3rd essentially always required downshift in mid hill.
with 4.56 it is slightly better, I can sustain 65 most places, however mountain passes I will be in the right lane right behind 18 wheeler with 4 ways flashing away ( I would usually be in 3rd gear and doing 40-45 in the 75 zone)
My engine is lacking power, it is fairly heavy for a jeep, I believe last time I weighted I was close to 6k lbs ( granted I had a week worth of crap to survive in the wilderness).
look up
http://www.jeep4x4center.com/calculators/index.htm to see correlation for the gearing and tire height
ilber