Yes. The MK60 unit has a pulse-based speedo output (on pin 26, if I remember correctly), so this would solve the problem. However, to change from the MK20 unit to the MK60 unit would involve entering a world of pain and expense. The electrical connector has a different pinout, so at the very least all the terminals would have to be swapped around. The electrical connector itself may also be physically different. The arrangement of the hydraulic lines is also different, so replacement pipework would be needed, at least as far back as a common union if not all the way to the wheel arches. You've then got further complications due the the G201 pressure sensor being external to the MK20 unit but integrated inside the MK60 unit. Basically, you'd have to update/modify the whole ABS system. As far as I know, it's never been done before, and it would almost certainly cost more than simply extending your existing 5-speed box to accommodate a 6th gear. Furthermore, the MK60 unit isn't as reliable as the earlier MK20 unit.So, does this mean if the ABS unit was changed to an MK60 variant that the speed output would be present?
Dug out this old post (#23) on a novel way of providing a speed signal - http://www.a2oc.net/forum/showthread.php?4241-6-Speed-Gearbox&p=95912#post95912I've just done some of the necessary research...
It seems to be that Option 2 from Vince's list above isn't an option. My new understanding (as of today) is that the software inside the instrument cluster is totally irrelevant when it comes to speedo signals. All instrument clusters pick up a pulse-based speedo signal; earlier clusters use the gearbox as the source, whilst later clusters use the ABS unit as the source.
If you fit a gearbox without a speedo drive (such as the 6-speed MYP gearbox), the cluster must then be able to pick up its speed signal from the ABS unit. However, if the ABS unit doesn't have a speed signal output, you've got serious problems!
My current belief is that the earlier MK20 ABS unit doesn't have a pulse-based speedo output, which would explain why it's fitted in conjunction with a gearbox speedo drive. Based on this new understanding, the 6-speed upgrade method suitable for a given car is therefore determined by the generation of ABS unit fitted, not the generation of instrument cluster. If you've got a MK20 ABS unit, you must upgrade via a gearbox extension (such as the one fitted to my car: http://www.a2oc.net/forum/showthread.php?21523). If you've got the later MK60 ABS unit, both upgrade methods are available to you (either MYP 'box or an extension of your existing 'box).
Option 1 from Vince's list above remains a possibility. If this is physically possible, then the MYP gearbox option becomes available to all.
Now that is truly 'thinking outside the box'. I like that, the idea is not unlike the ABS sensor. As it only picks up from one drive shaft it will be a little bit out when cornering due to one wheel rotating faster / slower than the other, but at speed when you are looking at the speedo the error is be very small.Dug out this old post (#23) on a novel way of providing a speed signal - http://www.a2oc.net/forum/showthread.php?4241-6-Speed-Gearbox&p=95912#post95912
PS. It would be worth checking the current 'plug-in' speedo drive ration and confirming this can be reproduced with the appropriate number of magnets