Modern Autobox for Classic Cars?

[Markh]

tapkaJohnD said:

Since 2002, no Range rovers were made without an autobox!
And the latest Discovery can have the NINE speed ZF 9HP!
http://www.zf.com/corporate/en_de/products/innovat...
Is that the way you wnant to go?
John

I have a 2011 RRS too, the six speed is lovely, if i could make one of these work I would be happy.

[DonkeyApple]

mph said:

Looking at various classic saloons from the 60's and 70's I'm struck by the number of cars that are "hampered" by the old three-speed autoboxes of the period.

Not everyone wants to fit a manual gearbox and I think most Jags, Jensens, Rovers and the like somehow suit the autobox style of driving.

Question is - can a more modern five or six speed box be adapted to these old classics ? I realise all modern(ish) boxes rely on several electronic inputs, but surely these can be simulated or by-passed.

Has anyone carried out such a conversion ?

Surely there is a market for this - imagine an Interceptor, XJ12 or P5B Rover with a five speed autobox. I think it would be a revelation.

The relly short answer is no.

The problem is that all the modern 5+ speed auto boxes use TCUs that link in to the car's ECU. The efforts so far to create aftermarket TCUs have been dismal. There just isn't enough money demanding the solution to enable the proper investment to design aftermarket TCUs that will be genuinely mapped for the recipient vehicle etc. The efforts so far are very crude and just bang in gears for street or track racing. Unusable in normal road terms.

I just posted on a thread my experiences to date of trying to achieve this: http://www.pistonheads.com/gassing/topic.asp?h=0&a...

My core experience is that a lot of the aftermarket scene is dominated by US solutions and in that market they are fully geared up for mechanical solutions but just not for the very high tech world of TCUs etc.

So far, the best solution I have found is to use the latest 'dumb' 4 speed and if necessary alter the diff ratio to get overall gearing best suited to the application and it's use.

All my investigations have been around the Chevy and SUV market and the modders definitely prefer using hammers and torches than binary code.

MOPAR have an aftermarket TCU solution and maybe on Mopar forums there are some people who have mapped them up for general driving rather than for re enacting Fast and Furious scenes but I doubt it.

[300bhp/ton]

Markh said:

Any new info on this?, I am looking to install a more modern 6 speed auto into my classic Range Rover

The answer is almost certainly yes it is possible. But it becomes a matter of cost and how much you want to change.

I suppose other questions are, why? What do you want to achieve that you can't with a 4 speed auto?

How much are you prepared to change on the RRC? As one option would be to transplant the entire power train from a newer Range Rover into the Classic.

[DonkeyApple]

300bhp/ton said:

The answer is almost certainly yes it is possible. But it becomes a matter of cost and how much you want to change.

I suppose other questions are, why? What do you want to achieve that you can't with a 4 speed auto?

How much are you prepared to change on the RRC? As one option would be to transplant the entire power train from a newer Range Rover into the Classic.

You're problem there is that you have to keep replacing after the trans and do the TC, axles and everything out to the wheels. The actual easier solution is to instead replace all the running gear with either a Nissan Patrol or a Jeeps as it's an easier job, plus as its been done there are adaptors and more importantly alternate gearbox and TC solutions.

Another hurdle with using the later Rangie Trans is that it is a ZF unit and there is almost no aftermarket support for them. Any aftermarket support is for the U.S. solutions such as the 6L80 and the 5G Tronic.

[Caddyshack]

VetteG said:

My Corvette originally had a manual 4 speed Muncie gearbox, the revs needed on the motorway made long haul drives quite wearing. During the rebuild I took the opportunity to fit a 6 speed Tremec (5 close ratios and an overdrive 6th). Motorway cruising is now done at a very relaxed 1200 rpm, additionally I was able to fit a lower (4:11) diff which improved the acceleration, a real win/win mod.

G

I spoke to someone today who did the exact same thing to exact same car, his name was David.

[roscobbc]

The other alternative would be to keep the autobox and add a GearVendors overdrive ~ https://www.gearvendors.com - or for UK autobox, perhaps someone like this ~ http://www.nostalgiacars.co.uk/overdrive.html

[300bhp/ton]

roscobbc said:

The other alternative would be to keep the autobox and add a GearVendors overdrive ~ https://www.gearvendors.com - or for UK autobox, perhaps someone like this ~ http://www.nostalgiacars.co.uk/overdrive.html

This is good so long as the car is 2wd only on the road. No good if you have 2 props turning all the time though.

[DonkeyApple]

300bhp/ton said:

This is good so long as the car is 2wd only on the road. No good if you have 2 props turning all the time though.

Yup. Sadly won't solve my issue. Also, I wonder just how much torque the second system could handle?

[gareth_r]

It could probably be done, but it wouldn't be cheap, and you'd have to add the sensors to provide the data needed by the ECU (e.g. throttle position, RPM, road speed).

IS-F 8-speed in a Supra controlled by an aftermarket ECU: https://www.youtube.com/watch?v=9m0iRLW8pW4

Supra with a 4-speed A340 and a Suprastick controller. Doesn't seem to be too harsh.
https://www.youtube.com/watch?v=6Saa4DK3qjc
https://www.youtube.com/watch?v=BftaBwCDkDo

[C Lee Farquar]

300bhp/ton said:

roscobbc said:

The other alternative would be to keep the autobox and add a GearVendors overdrive ~ https://www.gearvendors.com - or for UK autobox, perhaps someone like this ~ http://www.nostalgiacars.co.uk/overdrive.html

This is good so long as the car is 2wd only on the road. No good if you have 2 props turning all the time though.

I run a Gear Vendors overdrive. The 'automatic' aspect of it was useless so I binned the electronics and just use a switch.

You need to put them before the transfer box for 4x4, which adds some length.

[0a]

The latest Harry's Garage video points out that the early XJS V12 is really hampered by the 3 speed auto box

https://www.youtube.com/watch?v=pIMQGk4xQqM

[anonymous-user]

There was a story on www.aronline.co.uk about a guy upgrading a Rover P6 V8 with a somewhat less ancient 4 speed mechanical ZF box. Even that is a bit step up from the old 3 speed slushers and as modern as you can get without electronics.

[Spidermann]

Hi Chaps, from research I have found what they call a "shortie O/D unit which will bolt straight on to my 383 Jensen. apparently, the only thing you have to do is get the prop shaft shortened by 7.5 inches when the O/D is in the car runs at 78% of standard RPM, ie 3200 down to 2340 at 60 MPH which will make a difference to my Jensen. Not that economy should even be mentioned when talking about Interceptors.

[Peter3442]

Graham Whitehouse does a ZF4HP (non-electronic) conversion for many classic cars

Motor Legends and KWE do a Ford 6R80 version of the ZF6HP in classic Jaguars.

And most of the Laycock overdrive restorers can add an overdrive to the drive train of any car subject to space availability.

Be aware that the more you ask for, the more it costs!

[lowdrag]

I have no knowledge of many boxes outside Tremec, but would there be a way of fitting the box in my Mercedes C-class 2014 into a classic? It is a most delightful 7-speed auto.

[DonkeyApple]

lowdrag said:

I have no knowledge of many boxes outside Tremec, but would there be a way of fitting the box in my Mercedes C-class 2014 into a classic? It is a most delightful 7-speed auto.

Short answer no. Longer answer yes or no.

There are two basic cut-off points. The first is when auto boxes went from being dumb, simple slush pumps to the addition of TCUs that rendered the auto emotionally needy objects that needed to be in constant contact with all other aspects of the car just to give it the emotional security that it had chosen the correct gear. Still thick as mince but now with the equivalent of a university degree so no longer is aware that it is just a stupid object for basic tasks only.

If an auto box talks to the engine, ie has a TCU then that is your first major hurdle.

Some now don't have a separate brain but are just controlled by the same brain that manages the engine etc.

The most common point where this occurred is when autos progressed from 4 to 5 speed. As far as I am aware all 5 speeds upwards are electronic and require a brain. 4 is the sort of transition era where most don't but some did by then.

The second hurdle is that you need to find someone who has built an aftermarket TCU/ECU for the gearbox that you want to use.

Third hurdle is the map for that gearbox.

The 7G tronic unit in Mercs is absolutely lovely, as you say. It would be a wonderful unit to use if it fit in a trans tunnel. But you need an aftermarket TCU and you'd then need to map it for your bespoke application.

As far as I am aware there is no product. The problem with Mercedes is that the entire aftermarket scene for the brand is based around wrapping, fart noises and chip changes. It's completely base bling. It's even close to impossible to find someone who rebuilds AMG units and you soon lose the will to live after the twentieth hard to comprehend conversation with someone who didn't even realise there were moving parts inside the metal case because they sell wonder chips that make the car move. The world of post 90s Mercedes aftermarket products and services is a deeply, deeply depressing window into a part of society best swerved.

That said, the 5G tronic box is just as good and more importantly it is from the Chrysler era of Mercedes so the box found its way into other US brands which have a strong tradition of after market kit. It was in Jeeps and other things. So that era of Mercedes AMG engines (NA and SC) and gearboxes are interesting and usable.

The issue is the map. You can get a TCU for the 5G but as you can imagine, like the Compushift system for the ZF4 box it is fundamentally designed for Big Dave to bang in nasty changes while racing for pink slips.

The reason why the Merc 5 and 7G boxes were so great wasn't because of the box itself but the hours of endless mapping of the changes and defining how the box would work with a particular engine, in a particular car and for a particular user average. It's where Merc succeeded and BMW failed with their programming of the exceptional ZF6 and 8 boxes.

The 5G TCU was relatively simple and no one selling it knew if it could be mapped for pleasant road use which requires hours and hours of you driving around with a laptop logging data in a vast array of situations to try and create a bespoke map. Most TCUs are simple boxes just designed to up the line pressures for quicker changes and pass control to the human brain, basically making the box a manual.

The absolute key for modern autos is just to use what everyone else is using and where there is the most aftermarket options and support. That really means heading to America for the range of expertise and options and narrowing it down to MOPAR.

Unlike the European manufacturers, Chevy have embraced the aftermarket and now you can get factory TCUs for their auto boxes along with numerous adaptor plates etc from quality, long term partners. And lots of online support for getting your mechanical connection done and then all your mapping needs.

It is however, still much simpler to just select an engine that bolts straight o to your preferred gearbox. Luckily most cars are better with a Chevy V8.

If someone were looking to auto an old Jag then to be honest, not a lot beats the 3 speed torqueflite. It's cheap, bulletproof, no electronics, fits in the trans tunnels, adaptor plates exist and as seen with old three speed boxes in the XJ12 and Porsche 928, they produce some of the fastest accelerating vehicles between 50-70 which is actually really where you want great performance most of the time. And most importantly it is reversible with spanners.

[aeropilot]

DonkeyApple said:

If someone were looking to auto an old Jag then to be honest, not a lot beats the 3 speed torqueflite. It's cheap, bulletproof, no electronics, fits in the trans tunnels, adaptor plates exist and as seen with old three speed boxes in the XJ12 and Porsche 928

A lot of V12 Jag's in the mid-late 70's had the GM TH400 gearbox fitted anyway, so much easier to replace that with the GM 700R4 overdrive 4-speed auto......plenty of aftermarket support for that swap.

If space is limited, and there's adaptor plate options available from US speed shops, then the earlier TH2004R overdrive auto is an option as this is size wise, close the the early TH350 3-speed and Powerglide 2-speed auto's.

The 727 Torqueflite though was by far the best old style auto from the 1960's US era, whether it was smooth shifting behind a Chysler Imperial wafting down the highway or sitting behind a 426 Hemi running down the 1/4 mile in 13 secs.

[DonkeyApple]

I keep forgetting Jag didn't use the Torqueflite but the TH400. It was the Rangie that did. They both get slagged but were and are brilliant boxes and it's always cheaper and easier to not be reinventing the wheel.

[aeropilot]

DonkeyApple said:

I keep forgetting Jag didn't use the Torqueflite but the TH400. It was the Rangie that did. They both get slagged but were and are brilliant boxes

Not forgetting that all but the earliest RHD versions of the RR Silver Shadow and Bentley T Series were fitted with the GM TH400 as well.

Edited by aeropilot on Saturday 18th November 11:56