Datatek

Well-Known Member
Curiously the gearbox fault where the revs flare on 1st to 2nd and 2nd to 3rd has almost disappeared after hacking up the autoroute with 200 Kilo's of booze in the boot. It has slowly got better since I removed the Powerbox.
One thing I can confirm is that the fuel consumption is worse without the Powerbox with the car fully loaded on the autoroute. I put this down to the fact that it's so gutless it downshifts at even the hint of a hill:eek: I'll post the figures later when I've worked it out.:)

Overall MPG including sitting in UK traffic jams 24.69mpg brim to brim.
 
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Curiously the gearbox fault where the revs flare on 1st to 2nd and 2nd to 3rd has almost disappeared after hacking up the autoroute with 200 Kilo's of booze in the boot. It has slowly got better since I removed the Powerbox.
One thing I can confirm is that the fuel consumption is worse without the Powerbox with the car fully loaded on the autoroute. I put this down to the fact that it's so gutless it downshifts at even the hint of a hill:eek: I'll post the figures later when I've worked it out.:)
But i suppose that worse mpg is the lesser of two evils regarding the power box .
 
Hi Data -how come you have removed the powerbox, is it because you are worried about the gearbox?

Cheers

Jerry
 
Hi Data -how come you have removed the powerbox, is it because you are worried about the gearbox?

Cheers

Jerry

With the Powerbox the engine produces more torque than the autobox is made for. When the autobox started to give trouble I removed the powerbox.:)
 
With the Powerbox the engine produces more torque than the autobox is made for. When the autobox started to give trouble I removed the powerbox.:)

I thought the auto boxes were failry strong? It would seem strange that they developed a gearbox that could only cope with just the standard amount of torque - normally they over engineer gearboxes, particularly auto's on the diesels, to take more than the engine delivers!
 
Glad to hear you've got your RR back on the road and that it's running well. I bet it wont be Long before you get fed up and re-fit the power box...
 
I thought the auto boxes were failry strong? It would seem strange that they developed a gearbox that could only cope with just the standard amount of torque - normally they over engineer gearboxes, particularly auto's on the diesels, to take more than the engine delivers!

It's common practice for manufacturers these days to run boxes at or near the torque limit and in the case of some marques over the limit. The manufacturers get away with it because electronic control allows the engine torque to be reduced when a gear shift takes place. Fitting a power box takes the torque of the M51 engine considerably over the ZF4HP22's limit and of course the torque reduction commanded by the gearbox is effectively overruled by the power box to some extent.
 
Glad to hear you've got your RR back on the road and that it's running well. I bet it wont be Long before you get fed up and re-fit the power box...

It's never been off the road. I removed the Powerbox and the auto box has slowly recovered. I won't be re-fitting the Powerbox unless I can aquire a ZF4HP24 box to graft in that will take the additional torque. Reliability is more important than performance, it's still quick without the Powerbox compared to the Hyundai Galloper that preceded it:)
 
Curiously the gearbox fault where the revs flare on 1st to 2nd and 2nd to 3rd has almost disappeared after hacking up the autoroute with 200 Kilo's of booze in the boot. It has slowly got better since I removed the Powerbox.
One thing I can confirm is that the fuel consumption is worse without the Powerbox with the car fully loaded on the autoroute. I put this down to the fact that it's so gutless it downshifts at even the hint of a hill:eek: I'll post the figures later when I've worked it out.:)

Overall MPG including sitting in UK traffic jams 24.69mpg brim to brim.

That's interesting data because our V8 averaged over 22mpg when we took it to Southern Spain a few years back. Most of it was motorways but there was a lot of stop start stuff around Paris and southern France, as well as hilly country roads in Spain.

Lucky to get 14mpg in London traffic:eek:
 
That's interesting data because our V8 averaged over 22mpg when we took it to Southern Spain a few years back. Most of it was motorways but there was a lot of stop start stuff around Paris and southern France, as well as hilly country roads in Spain.

Lucky to get 14mpg in London traffic:eek:

Last time with the powerbox fitted it averaged 27mpg:)