that is true for the older auto transmissions that use a fluid coupling only drive mechanism, but the newer OD Ford trans' have the best of both worlds. While the converter slips, it multiplies the Torque output of the engine as much as 3 times over, but once the approximate stall speed is reached, the fluid coupling loses 3-10% in drive efficiency. Modern OD lockup trans' will lock up under full throttle, and after the stall speed is reached, therefore mechanically locking the flexplate to the input shaft in a 1:1 ratio. What you get then is some serious Torque multiplication of the high-stalling auto, and the drive efficiency of a manual gearbox. This only happens in the 4R70W, which has a direct clutch in the torque converter as its lockup mechanism, as opposed to the 2-piece input shaft method of the AOD.

 

My truck turns it's peak torque at about 3200 rpm. The torque converter specialists here told me to get a converter slightly lower than my peak torque, such as a 26 or 2800. This way, upon launching, at full throttle my truck will sit still until the tach hits 2600 and then take off, utilizing the launching during the higher torque peak. Right now it launches at 1800 rpm. At 1800 rpm my truck has no torque at all. I'm assuming it's much like popping the clutch with a manual trans. Rev your tach til' 2600 rpm then pop the clutch. This will either spin the tires or give you a better launch. At least a better launch than reving to 1800 and popping the clutch.

As far as the RWH vs. higher torque converters, I'm going to take your word for it on this one. Because even all the research I've done on torque converters, I really won't truly understand them until I actually install one.

Tom

 

John,

Where have you been. It's nice to have you visit us in the 4.2 forum.

Have you seen that I've got my times down to 16.73? Not to shabby for only owning the truck since July. The stock runs were in the 20's.

Also John, a bunch of us are planning a trip to the Houston drag strip in January. It would be great if you can come. I'm driving up from S. Florida.

See ya.

Tom Longo

 

Houston, Georgia? I've never heard of that strip, I always go to the Commerce, GA strip. Probably because every time I'm there I get flashbacks from the NHRA powerhouses that pound the asphalt every time I smell that tire smoke. I would really like that, I always enjoy a day at the track!

Congratulations on your 16 second timeslip, it's pretty awesome considering that you have a bohemoth truck, and still haul enough *** to seat 4 and all the luggage they can bring!

 

That is true TK. I am used to the old C6 trannys. Once the converter clutch is engaged slippage is not an issue.

 

John,

No silly.....Houston Texas.

In January.

If your interested in meeting up with a bunch of us in Louisianna, your more than welcome.

Tom

 

If it started right after they changed the gears and your truck only has 5000 miles on it then they didn't do something right.
Other possibilities are firestone tires . Ha Ha! seriously though a seperated or starting to seperate tire. Do you got mudders. If you want to feel vibration come take a ride in mine. My mudders are about shot with 80,000 miles on them. Oh man are they rough. They still work though off road.
I got 4.10 gears in my 91 4x4 and I run 3000 rpm at 60 mph. You are lucky yours is so low. I had an aod but got sick of rebuilding it every 80-100000 miles. I pitched it and put in a c-6. It is much more reliable but sure sucks the gas.