TOMTOM wrote:Witch converter (non lock up)?
It's been my observation that it comes down to:
1 ~ Stock OEM replacement
2 ~ 89% modified
3 ~ 91% modified
2 & 3 amount to the same converter that has been modified so that the tolerances between the input components and output components are tighter so as to allow a much higher fluid coupling between the two (higher percentage of power transfer. 0% being no transfer and 100% being full lock-up).
As we know that energy is neither created nor destroyed, with an 89% converter ~ 100% power in and 89% power out equals
about 11% being turned into heat. That's where we see folks enjoying lower trans fluid temps and higher gas mileage when compared to OEM.
HOWEVER: not all that 11% is turned into heat. It's called a torque
converter for a reason. Pending the rpm, design, load, etc, a varying percentage of the apparent 11% power loss is actually changed from horse power to torque. It gives us an additional amount of bottom-end grunt.
So . . . .
It's my understanding the stock OEM converter is good for about a 65% or so connection. If one were to install a 91% converter in a work truck that must pull a heavy load out of deep muddy ruts, you might be disappointed as you may not pull the load (just can't get it moving) where as that same truck will flat out haul hiny down the road at no load/WOT.
A play truck, stop-light dragster exclusively might best benefit from a 91% converter.
An occasionally heavily loaded truck might do best with an 89% converter.
Most vendors will want your old unit as a core since they will open it up and do the mods. Some simply modify OEM components where others go to billet components and the like. I've seen prices range from $350 to close to $1000 for the 518 non lock-up conveter.
I've never seen a definitive comparison between the major players as with any torque converter, it's all down to the engine presenting the power. No two will be the same when looking at all the different levels of performance out there. We all have 5.9 CTD's and as I'm sure you've seen HP can be anywhere from 160HP to over 600HP.
This is all based on what I know and I don't build transmission nor have the power to destroy one coming off the line as it were. Those who know better will chime in I'm sure.
I hope this helps though. I'm in the cyphering stages of rebuilding my trans and I've got to figure out what I want converter wise. As dpuckett pointed out, one needs to consider what ultimately one's goal is so as to not buy the thing twice.
David