Need opinions on my sisters 4bt JK build.

Motostroker · Dec 2, 2014

Hey guys i just completed the swap roughly a year ago. 2011 JK wrangler 2 door. I sourced a VE pump 4bt and a 4l60 trans. Initially the motor was all stock, I completed the swap and work out all the kinks with it at stock power level. Time passed, and my sister started questioning the power. It needed roughly 40 more horsepower to have a respectable passing power, on ramp for interstates, etc.

I installed a HX 30 turbo, ARP head studs, a Fass lift pump, and a BAD to the bone Schied diesel VE lighting pump (rated to flow way more then i will ever need, i just left the stock fuel rack in the modded pump). The Jeep flat out hauls the mail now. It will bury a 35psi boost gauge almost instantly. I'm GUESSING around 200-250 horse. Neighborhood of 500ft torque.

here is my question, I HATE the trans i used. Its OK for stock power level, but with the new power, it still breaks the trans. I have had it fully built to the gills (Triple disk, shafts, drum, etc) and still breaks shafts, T/C all the time. Im using a COMPUSHIFT 2 controller, i have tuned it to perfection. along with the help of several trans builders that have looked over my tunes and gave me the thumbs up.

I have given up on the 4l60, but here is my dilemma. I cannot go much bigger and longer of a trans because of driveline angles. Manual is out of the question, she cannot bang gears.

What do you guys think i should turn too next? PCS controlled 47re? I'm pretty sure it's around the same length as a 4l80 though

Motostroker · Dec 2, 2014

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Powerstroke Man 6.4 · Dec 2, 2014

Motostroker said:
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That's one cool Jeep. Factory A/C?

6.0 p-stroke · Dec 2, 2014

I would think a 47rh/re would work well, assuming they're the same or similar length as the 4l60. Tuning an RH trans isn't bad as long as you have the kick down linkage, we used two pressure switches to control overdrive and lockup on my sisters fummins, it seems to work well and can be changed easily. They can be built to handle whatever that 4bt could throw at it too and I would think they have the same bell housings. That's a sweet project by the way!

Motostroker · Dec 3, 2014

Powerstroke Man 6.4 said:
That's one cool Jeep. Factory A/C?

Factory AC and alternator. No codes, all guages work!

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Motostroker · Dec 3, 2014

6.0 p-stroke said:
I would think a 47rh/re would work well, assuming they're the same or similar length as the 4l60. Tuning an RH trans isn't bad as long as you have the kick down linkage, we used two pressure switches to control overdrive and lockup on my sisters fummins, it seems to work well and can be changed easily. They can be built to handle whatever that 4bt could throw at it too and I would think they have the same bell housings. That's a sweet project by the way!

Thanks bud! I may do a 47re. Tuning would make it easier to tailor to her driving style. I'm OCD so I want it literally to shift perfect. Fool proof is the key to this build. A 19 year old girl drives it. She doesn't even know what a pyro gauge is. Looks like a 47 is 6 inches longer. I may just have to shove the rear axle back to make pinion angle happy

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6.0 p-stroke · Dec 3, 2014

I do like the idea of having better control over the RE but in our case we were working with what we had. How long is the rear driveshaft right now?

Motostroker · Dec 3, 2014

It's a double cardon shaft. Maybe 2ft?

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Skill_Kills · Dec 4, 2014

4bt in a JK, nice! 9 times out of 10 I see people move the rear axle back. About the only other option ive seen is angling the motor down with a tcase drop and motor mount lifts.

keeping my eyes open on this, I want one in my YJ after my rat rod

521turbo · Dec 8, 2014

Rossler Trans could build you a 4l60 that would hold. He builds some of the best GM trans on the planet.

http://www.rosslertrans.com/4l60e_or_th700 Options.htm

gwunter · Dec 9, 2014

I like the build. I bet that thing moves pretty good. I don't know what to tell you about the trans. Maybe its time she learns how to drive a manual. Once she gets the hang of it she may like it better, or hate it more. Lol