6 speed auto should be now possible

ghce

ghce

Well-Known Member
Have been doing a bit of googling on the net and it seems that there are now a number of after market stand alone auto box controllers which can be used on Toyota, GM, and Ford boxes.

Testing the Latest Transmission Controllers - Car Craft Magazine
Compushift Standalone Transmission Control Systems

A whole lot more info is about now on the net for those wishing to do these upgrades. I had been always a bit put off by doing the ZF-4HP conversion as to me it is old tech and only really gives advantage in out of city cruising over my existing BW65 but with the later 6,8 and now 10 speed boxes with better ratios , spreads and box efficiency I will be looking a lot harder at this.

Another nicety that appears in the ZF 8 speed is the ability to fit an electric motor instead of the torque converter which obviates the need for a starter motor and also can be used on demand for extra oomf if required, makes a nice party trick for a P6 as the motor is rated around 40KW making the car effectively a Hybrid.


Graeme
 
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ghce said:
Another nicety that appears in the ZF 8 speed is the ability to fit an electric motor instead of the torque converter which obviates the need for a starter motor and also can be used on demand for extra oomf if required, makes a nice party trick for a P6 as the motor is rated around 40KW making the car effectively a Hybrid.


Graeme
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How does that work, then? Is it similar to the modification of clutched automatic boxes?
A 4okw motor will need some beefy batteries and a suitable alternator, but it could be great fun.
 
Slight mistake 47 HP not 40 KW but still would make for silent takeoffs on electric alone.

The electric aspect could make a case for upgrading the lead acid to a Lithium ion battery, no more starting woes.....ever. lol
Here is a breif over veiw ZF’s 8-Speed Automatic Transmission - Tech Dept. but of course this is old tech now in the fast moving world of gearboxs and disruptive technologies such as electric motors and hybrid systems.

I originally started looking at the ZF6 speed back in 2005 or 6 and worked out all the gear ratio's and power to weight ratio's concluding it would transform the p6B with the standard engine torque curves but it would be even better with the 3.9 cam.
Probably the biggest concern after finding a box controller is the physical dimensions of the various gearboxes on offer, it would be nice to think that a more modern box might have shed a few pounds, I see that the AB60 toyota box weighs in at 95KG but I am struggling to find any info on the BW65 weight.
 
Some interesting stuff there.... A hybrid would be a huge project. I dont know how mercedes and bmw zf based hybrids do their control, but due to our prius misbehaving so much i can tell you there is a lot to it. There is an inverter, and a coolant system for the inverter. There is a battery pack, plus a cooling system for the battery pack as well as an exhaust system to remove excess gas from the batteries. There is then also a standard 12v gel battery (which is used to power the 12 v car electrics) and a dc-dc converter to charge the 12v battery. There is also the regeneration to take care of. In a prius this is in the transmission and the brakes only actually come on when you brake hard. Each of these things also has a separate ECU. I've counted 14 main ecus on the car so far. You may be able to simplify it, and it's certainly possible, but certainly not as easy as banging the motor and battery in.
 
I find actually the main advantage isn't necessary out of town. The ZF changes up and down the gears around town in a smooth, refined manner any BW will never get close to. Also it's nice to know it has more overhead for performance and its unlikely to need a rebuild in my lifetime. There's much more to 30 years of transmission technology than an extra cog. I suggest you try a converted car if you can. If I'm in the UK you are welcome to try mine.

I'd take any improvements available but none of this looks economically practical to me. Remember everything bolts directly onto the engine with no custom adaptor plates and bellhousings, the standard starter motor, the standard prop and shifter, there's no real re-engineering of the car. It seems a logical end point to the RV8.

I can easily see a more advanced project in the £5-10k bracket and it'd still be sub-optimal as modern transmissions work in conjunction with the engine ECU and not in isolation. At which point why not fit an engine and transmission from a more modern car complete?
 
I have tried the 4HP22 in Warrens car and yes it is quite nice but really not hugely better than my 65, a nice improvement but for me the biggest difference is the overdrive nature and a less busy V8.

On the other hand a bigger selection of gear ratios to choose from around town before overdrive kicks in would be a bigger advantage for drivability and the two overdrive ratios would certainly quiet down engine on the motorway.
2nd hand boxes should be readilly available at low prices, certainly here in NZ, the major difficulty would be an adaptor plate.
 
PeterZRH said:
Remember everything bolts directly onto the engine with no custom adaptor plates and bellhousings, the standard starter motor, the standard prop and shifter, there's no real re-engineering of the car. It seems a logical end point to the RV8.

I can easily see a more advanced project in the £5-10k bracket and it'd still be sub-optimal as modern transmissions work in conjunction with the engine ECU and not in isolation. At which point why not fit an engine and transmission from a more modern car complete?
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I know that there are bellhousing kits available for Toyota manual boxes ( and I guess Auto too) to adapt to RV8 for the Landrover crowd which would make a big difference in the hardness content of doing the conversion, as far as I can see just leaves tailshaft adapting and whether the box itself offers up readily to the P6B chassis with out and cut and shut or body bashing.


Graeme
 
Don't think physically it'll be a problem, modern transmissions tend to be smaller and significantly lighter despite the extra gears. I just don't see this being a sub-£2k DIY project any time soon. I'd love to see it done. As I've stated before, the BMW E39 I had which had a 5HP was the first auto I'd owned where I genuinely didn't miss a manual gearbox. This wasn't the case with my earlier E34 which used a 4HP like my Rover it was obviously still a compromise.

I have rented a 7 speed Mercedes C class and it's very impressive. However much of the effective utilization of these gears is likely to be due to the integration of the engine and transmission as a unit - it wasn't always clear when driving as to why it would change as it did. More so now the latest model has 9 speeds! I'd guess as a "bolt-on" after 5 speeds you'd very rapidly be into diminishing returns in terms of what you'd practically achieve while still bolted to a 65 year old engine.
 
I am a confirmed manual man and this P6B is the only auto I have ever owned long term however the 65 is a very comfortable box though nowhere near as good as a manual, I have driven a few later autos with 5 and 6 and even 8 speed and yes they are a definite improvement over a 3 or a 4.
A lot of engine integration is possible even in a carburetted car by installing a TPS, vacuum points and electronic speed sensor (if the box doesn't already have one) I think with a modern well specked box controller you would see minor to no discernible driving experience loss.

Depending on how canny you are at sourcing 2nd hand bits and or finding cut price suppliers for new parts I think you might be in the $2000 to $3000 range in NZ but there are quite a few fixed price costs such as things like the Dakota speedo drive, gearbox controller and bell housing, the rest is pretty much an unknown.

The trouble with all my musings as to where to look for a box is that there is tooo much choice though this one would be a bit of a pipe dream Holy Shift! A Look inside GM’s new 10-Speed Automatic
 
Amazing. We're now in bicycle territory.

I agree with an old style box I'd still take a manual but its very clear that with so many gears and much better software control that in 99% of circumstance a modern auto will drive better than you, both in terms of performance and economy. Manual changes feel quite slow in comparison for a start. The only issue being converter losses for those that still use a converter. Even with a 4HP, top gear locked is significantly higher than an LT77. This is only possible as it'll lock and unlock itself to maintain forward progress in a way that'd simply be annoying in a manual car and indeed actually is annoying in some 6 speed manual cars. So that's potentially 1:0 to the auto in terms of cruising fuel economy even with something as old as a 4HP. Certainly on the motorway I've broken 30mpg with the ZF admittedly driving in a way I probably wouldn't normally.

One thing I do know is that the shifting is aided by some modulation of the throttle, so you'd likely need control over an EFi system and converting to some form of electronic "fly by wire" throttle. Not merely a reading of engine vacuum and RPM.

I remember coming down a mountain in my E39 for the first time and being impressed that it kept in low gear and did the engine braking for me. I have no idea how this algorithm is implemented in software.
 
Any one else have any dreams and desires regarding surpassing the tech of the ZF 4HP 22?
 
The following applies to the ZF6HP26, I've got one on my bench here and I can say it's quite a bit bulkier than the old 3 speed units. I forget the weight but I could just lift it on my own, dry without converter. The electronics (TCM) are inside the transmission, they form a complete unit with the valve block. I would say there is little to no chance of using ZF with an external controller. Its not a case of 1 solenoid per gear either - there are about 9 or 10 solenoid a some of which operate proportional valves, 2 speed sensors plus a position sensor on the rooster comb.

If it would run without the CAN bus messages to and from the ECM, then it would be quite complicated but possible to make it work as a standalone transmission. You would need to work out which CAN messages are used for driver demand, engine load etc and buy or make some electronic unit to send these messages out onto the bus. Where it would get complicated is if the gearbox controller won't work unless it's got communications with the ECM.

The late 90's and early 2000's rover cars retard the ignition for torque reductions when shifting gears, I do not know how much by but I remember was quite significant. I'm not sure if a drive by wire throttle would react quick enough for torque reductions anyway. But the interaction between ECM and TCM is complex, basically it's torque based powertrain control, i.e. driver pedal position is treated as a torque demand. Using an electronic throttle means that low torque demands can be met using a wide physical opening and high gear, thus allowing the engine to operate more efficiently.

You could do to get hold of a working car and basically disconnect the CAN connections between engine and transmission to see how it behaves. They are designed to be as fault tolerant as possible, although if the TCM goes into limp mode you know that decoding of the torque control messages is required. As someone else suggested transplanting a complete powetrain could be a more reasonable idea.

Interesting idea though, and anything is possible if you have enough time (and money)!
 
So basically you'd have to fit mega-everything to the RV8 and do a decade or two of R&D. The safety implications of messing around with this alone are mind-boggling.

In the mean-time between now and the end of fossil fueled motoring, I'll enjoy my much improved 4-speed P6.

I quite like the idea of a P6 with PML Flightlink hub motors as an every day commuter. Much simpler. 640bhp and 4 wheel drive anyone?
 
robgee1964 said:
The following applies to the ZF6HP26, I've got one on my bench here and I can say it's quite a bit bulkier than the old 3 speed units. I forget the weight but I could just lift it on my own, dry without converter. The electronics (TCM) are inside the transmission, they form a complete unit with the valve block. I would say there is little to no chance of using ZF with an external controller. Its not a case of 1 solenoid per gear either - there are about 9 or 10 solenoid a some of which operate proportional valves, 2 speed sensors plus a position sensor on the rooster comb.

If it would run without the CAN bus messages to and from the ECM, then it would be quite complicated but possible to make it work as a standalone transmission. You would need to work out which CAN messages are used for driver demand, engine load etc and buy or make some electronic unit to send these messages out onto the bus. Where it would get complicated is if the gearbox controller won't work unless it's got communications with the ECM.

The late 90's and early 2000's rover cars retard the ignition for torque reductions when shifting gears, I do not know how much by but I remember was quite significant. I'm not sure if a drive by wire throttle would react quick enough for torque reductions anyway. But the interaction between ECM and TCM is complex, basically it's torque based powertrain control, i.e. driver pedal position is treated as a torque demand. Using an electronic throttle means that low torque demands can be met using a wide physical opening and high gear, thus allowing the engine to operate more efficiently.

You could do to get hold of a working car and basically disconnect the CAN connections between engine and transmission to see how it behaves. They are designed to be as fault tolerant as possible, although if the TCM goes into limp mode you know that decoding of the torque control messages is required. As someone else suggested transplanting a complete powetrain could be a more reasonable idea.

Interesting idea though, and anything is possible if you have enough time (and money)!
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Unfortunatly it looks like the ZF 6 speed maybe a bit of a no go, this was my reason for putting the idea aside as it just was too complicated and there was no info on the inner workings of the control system at that time and indeed still seems to be almost no info.
Luckily the Toyota 6 speed box looks a lot more promising with conversion kits already available and the box itself has even better ratios.
The Ford GM offerings also look very easy to control.


PeterZRH said:
So basically you'd have to fit mega-everything to the RV8 and do a decade or two of R&D. The safety implications of messing around with this alone are mind-boggling.

In the mean-time between now and the end of fossil fueled motoring, I'll enjoy my much improved 4-speed P6.

I quite like the idea of a P6 with PML Flightlink hub motors as an every day commuter. Much simpler. 640bhp and 4 wheel drive anyone?
Click to expand...

Been a dream of mine for a long long time, 4 hub motors, one on each wheel , lots of control, steering and regeneration issues to overcome to do it properly but what a car it would be!


Graeme
 
PeterZRH said:
So basically you'd have to fit mega-everything to the RV8 and do a decade or two of R&D.
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Indeed that was partly my point...however its by pushing the boundaries now and then that mankind moves forward.
For simplicity though I'm with you on the 4 speed upgrade - it gives you an overdrive and can be done mechanically.
In so far as safety goes that would be a good reason for sticking with the factory ECU's if possible, not to mention the thousands of man-hours that already gone into the control system calibration. Acheiving good road drivability in all conditions isn't a trivial job.


I quite like the idea of a P6 with PML Flightlink hub motors as an every day commuter. Much simpler. 640bhp and 4 wheel drive anyone?
Click to expand...
I went for a job once at FrazerNash and they were developing a wankel engined hybrid with hub motors, fascinating stuff.
 
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Fantasic. Interesting stuff. Were FrazerNash doing this with a particular application in mind?

The beauty of the Flightlink (now taken over I think) system is that it is very close to being a bolt-on solution as long as you can physically mount the hubs as these do the propulsion and all the braking. I'm lead to believe from what I read at the time the control software needed only to be calibrated for the regeneration and braking according to the weight distribution of the application (yes I'm sure it isn't quite as simple as that). At one end they had a mini and the other some huge American pick-up with it. The biggest drawback was the hubs were heavy and this is all unsprung weight. I wouldn't use them with Rostyles :)
 
PeterZRH said:
Fantasic. Interesting stuff. Were FrazerNash doing this with a particular application in mind
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I don't know what the application was but the development vehicle they had looked more like a small truck rather than a car. Its 10 years ago now so its hard to remember exactly. I do remember wondering about the unsprung weight and thought that would probably limit its use to offroad or utility type vehicles.
I visited an OEM car manufacturer who had a few prototype electric vehicles. The main gearbox was replaced with a brushless DC motor and the engine bay had a big bank of LiIon batteries. It could be charged from a 13A UK socket.
 
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