Hello everyone:

My engine is bone stock right now, and MAYBE am looking modify. That brings me to my transmission. As far as what I have read, the 4r70w transmission I have is rated for 700 LB.FT.TQ.. As far as I researched, the torque converter multiplies that by 1.9. That means my transmission can sustain 369 LB.FT.TQ.. Not much over the 330 LB.FT.TQ. that the truck originally comes with.

What could I do to make my trany sustain more power? Would it just be less expensive to just swap in a 4r100w (I highly doubt it but throwing it out there)? Looking for the transmission to handle about 500 LB.FT.TQ..

Thanks!

 

First question is how much more you need, referring to power mods such as a super charging etc.
The r100 can be installed paying attention to the converter capability and all the sensor and plugup compatibilities needed.
The next choice is to have a known reputable trans shop rebuild the r70 to performance specs. That includes performance level clutches, bearings and other parts plus valve body changes. This setup can run a lot of $. Last, I had done was $4000 from LEVEL 10, Hamburg, N.J. a very high-level performance shop.
You may look them up, give a call to discuss what your application is and what they recommend, if you need a high torque application.
Another is Baumann Engineering that is also a high level source.
Both these sources have been in the biz a long time.
Good luck.

 

You numbers, as *I* have been made to understand them, are off. The 5.4 puts out 350 ft lbs of torque and the 70 multiplies this by 2, (or maybe 1.9) yielding 700 ft/lbs OUT. Some gurus say this is about right and the "70" does not mean 700 ft lbs, but is some Newton meaning, but yet is approximately as usually mis-stated in ft lbs.

I used BCA Transmissions. The shop is small and their site is basic, but after a view, talk to Darrin. He takes time to explain. He UpBuilt my 70. I thinks he's Ohio, I'm Calif. With shipping I still got an even deal or better. He's a Ford guy. You can do a 100, but it is a labor of love, not simple and straight forward. See those threads. My 265 HP and torque meet my needs so it was not worth the trans upgrade, though if simple, would have been nice.

 

I put a Greg Evans FTVB (factory Tech Valve Body) in mine when it had 30K miles on it...I just hit 270K. I have a deep pan and drain the pan & converter and fill every 50K with Shaeffers 204SAT transmission oil. the 4R70 is a pretty tough transmission, especially when maintained. https://www.schaefferoil.com/204-atf-supreme.html

 

Why thank you!

It's great to see some of my old stuff still come up.