I'm filling out my worksheets now, which shifting should I choose? I want the best performance possible but I don't want the shifts to be too hard or annoying. I'm thinking "Firm" but just wanted to see what others with more experience suggest.

 

HI Thayer,

This is something that, to get a really thorough explanation, you;d need to call us for, but I'll go over this briefly here now....

In short, circle "Firm." What that gets you is a nice progressive and linear set of shift characteristics that provide a nice smooth shift in "normal" driving but with less slippage, and then as you give it more and more throttle, the shifts get progressively firmer in response, just like they really should - so that by the time you are at wide-open throttle, it's a noticeably snappier shift but still without being overly harsh.

The idea is to properly protect the transmission properly as power levels go up, without spoiling the inherent smooth nature of the vehicle - this extends the service life of the transmission's friction materials, especially the clutches, as we greatly reduce the amount of slippage they are subjected to in the factory tuning.

Almost everyone goes with the "Firm" selection (as in 99%), so they get a nice linear progression in shift firmness levels based on throttle position, just like it should be - this way the wife usually doesn't even notice it in normal driving, yet you can enjoy the performance feel when you give it more throttle.

I think that's the best short explanation I can give - it really takes quite a bit of work to accomplish that with as complex as the many different control parameters that are in there for the 4R75E transmission, but this is something we have R&D'd to the nth degree, and have got a very nice calibration for, for each of the many different strategies these vehicles have each model year alone. We spend at least as much time on the transmission calibration as we do the engine tuning, and in some cases, even more.

So I'd recommend selecting "firm" - and remember, you will also still have the ability to adjust that to your own liking with the XCalibrator 2, if need be - though almost all of our customers do not do that, as there simply is no need, what we deliver works beautifully.

 

Thanks Mike. That is just the explanation I was looking for, any more thorough and I'd probably be confused. I would have called with this question but during my previous two calls this morning it sounded like your phones were ringing off the hook...wonder why...

 

You're very welcome, & I'm glad that did the trick.

Yes, our phones stay pretty busy - but never let that put you off from calling us if you need or want to, we're always happy to help if we can!

Things are nuts what with getting the new shop ready and now the Group Buy - 4 of us were wrestling part of the new chassis dyno into position for the better part of today, as well as going over some issues we found with the new 4-post lift that got installed yesterday that we had to deal with. We still have air lines to run, electric service to get run to numerous locations, telephones, and so many other things to get into place in the new shop - seems like it never ends!