Quote:
Originally Posted by kyrix1st
Range Rover 5.0 SC would be the only transmission mechanically identical to XFR and XFR-S; ZF in Vogue is possibly the smoothest TC out there and is nowhere as sporty as a Jag (with ZF8HP) in general. I don't know which one Jag falls in, but I sure hope not it's in the same range as X6M.
How can a torque converter reproduce mechanical banging that is the result of engaging and disengaging pressure plates from dual clutches? If you are referring to exhaust "farts" apparently seen in F90 video, that is the same joke used in RS7.
I do recognize that use of higher thermal capacity materials/layouts to dissipate heat could be well engineered to produce good results, but it seems
rather than using higher thermal capacity materials ZF decided to direct oil flow so that higher thermal capacity is achieved. This is cost effective engineering, I'll give you that.
My question is, why not make it so that less heat is produced so it doesn't work the cooler so hard in the first place? That's less weight for less heat (Q=mCdT.) If most of the DCT bellhousing is empty as you say and ZF8HP weighs 91kg compared to DCT of 78kg, advantage of DCT is or MT is in lighter rotating mass.
Good info on ZF transmissions otherwise, efficient programming is always welcome regardless of its mechanical base; it's been a decade since Lexus focused on traction control programming rather than building a rigid chassis to cut down production cost and BMW seems to be following its predecessor albeit in different category.
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All Vogues from 9/13 on use the 8HPTU; the XFR and X5/6M also use the same transmission.
The "mechanical banging" isn't from the torque converter. It's from Transmission Brake Set B in gears 1-5 and only with the most aggressive settings active.
The torque converter design and functions in this application produces the least heat and least mechanical wear while providing the widest range of shift types and shift quality.
Might want to check the weight of 8DT75x vs 8HP75x (including the transfer box) WITH oil cooler and fluid included. The unit with the weight advantage isnt the one you suggest.