[Hendo741]

Anyone know what version of the zf8 is in the G42? Was reading something today that the G80/82 xdrive are running the zf76. Trying to figure out what the limit of the tyranny is.

[CDN-Driver]

Not sure if this helps:

[DSTR]

8HP51 (Gen 3) Gear Ratios:

1st gear 5.25
2nd gear 3.36
3rd gear 2.17
4th gear 1.72
5th gear 1.32
6th gear 1.00
7th gear 0.82
8th gear 0.64
Reverse 3.71

Fluid Capacity: Roughly 6 liters
Fluid Type: ZF LifeguardFluid 8 or equivalent
Torque Limit: 500 NM (369 lb-ft)

https://blog.fcpeuro.com/zf-8-speed-...cs-maintenance

ZF 8-Speed Transmission Upgrades

The 8HP45/50 may only be rated to just under 400 lb-ft of torque, but ZF’s other 8-speeds, like the 8HP70, can hold significantly more. Swapping from an 8HP45 to 8HP70 is possible and has been done before in BMW’s 3-series. It requires a new flywheel, recoded TCU, the 8HP70, and some other supporting bits but gives you an OE-spec transmission capable of holding twice the advertised power of the 8HP45. Any more torque than that, though, and you might want to consider other options.

The easiest way to beef up your 8HP45/50 is with an upgrade package, like those offered by Pure Drivetrain Solutions. They offer four different packages; the weakest rated at 750 lb-ft and the strongest capable of over 1200 lb-ft of torque. Each transmission is fully disassembled and features stronger clutches, stronger seals, and a few modified internal pieces. The strongest gearboxes also receive shafts, hubs, and baskets made from billet aluminum. The N55 or B58 engines mated to the 8HP are capable of some serious power; these transmission upgrades will ensure their reliability and longevity.

[G42M240]

^ so the m240i is the at the max torque limit of the transmission? That seems like a long term recipe for disaster.

[DSTR]

Originally Posted by G42M240

^ so the m240i is the at the max torque limit of the transmission? That seems like a long term recipe for disaster.

My thinking is the M240i has the 8HP70. I cannot find a definitive data showing this is gearbox chosen but given power of the M240i it would be the choice overall.

At ECS there is the page showing the application for it due to this pan being offered as a replacement

https://www.ecstuning.com/b-ppe-part...228053400~ppe/

[DSTR]

A nice more in-depth technical and engineering review of the ZF-8

https://www.thetruthaboutcars.com/20...eed-automatic/

[Hendo741]

Originally Posted by G42M240

^ so the m240i is the at the max torque limit of the transmission? That seems like a long term recipe for disaster.

This was my thought. I believe the Supra comes with the ZF8HP51 and it holds 500-600 wtq before it requires upgrading. Hence the question and see who had what data.

[Hendo741]

I also don't know how much the xdrive version compares to the RWD version at the limit.

[DSTR]

Originally Posted by Hendo741

This was my thought. I believe the Supra comes with the ZF8HP51 and it holds 500-600 wtq before it requires upgrading. Hence the question and see who had what data.

Per my contact Germany(my M-car mech who was the only person to service my cars) - 8HP51X is used along with similar models that utilize it.

510NM and he feels will easily take 600+ with the built in overcapacity
We chat today after he did the research. 51=510Nm per the catalogue.
BMW Z4 (G29)
Jaguar XE 20d RWD ,
Toyota Supra (A90),
2019-up

[Hendo741]

Originally Posted by DSTR

510NM and he feels will easily take 600+ with the built in overcapacity
We chat today after he did the research. 51=510Nm per the catalogue.

600 nm is less than 440 tq. These B58TUs are easily capable of well beyond that.

[DSTR]

Originally Posted by Hendo741

600 nm is less than 440 tq. These B58TUs are easily capable of well beyond that.

Certainly. With after-market modification. Thats not something in the design parameters BMW will account for. The correct application of gearbox corresponds with the power the motor installed makes.

Accounting for more is not something they design for in the factory. The higher power applications built in the factory gain the more capable ZF8 that is available for the designer to utilize.

Bottom line if you want the better or more capable gearbox you buy the more powerful model lol. This is rather normal overall.

That being stated there are aftermarket solutions to gain power in the gearbox.

For the average non -tracking driver they will be pleased with this package of motor and ZF8.

Overall the ZF8 configurations are durable. I am not worried at all with the stock configuration.

[Hendo741]

Originally Posted by DSTR

Certainly. With after-market modification. Thats not something in the design parameters BMW will account for. The correct application of gearbox corresponds with the power the motor installed makes.

Accounting for more is not something they design for in the factory. The higher power applications built in the factory gain the more capable ZF8 that is available for the designer to utilize.

Bottom line if you want the better or more capable gearbox you buy the more powerful model lol. This is rather normal overall.

That being stated there are aftermarket solutions to gain power in the gearbox.

For the average non -tracking driver they will be pleased with this package of motor and ZF8.

Overall the ZF8 configurations are durable. I am not worried at all with the stock configuration.

Who keeps cars stock?? 🤣🤣

The major appeal of the G42 is the B58TU and its capabilities with minor modifications.

[kumizi206]

It's probably similar to the Supra. Fine with bolt ons and tune. Once you go bigger turbos and E85, it will depend on how you drive it.

Most modified/tuner cars make quite a bit more than manufacturer rating before it becomes a problem.

[Ricochet48]

Originally Posted by Hendo741

Who keeps cars stock?? 🤣🤣

The major appeal of the G42 is the B58TU and its capabilities with minor modifications.

95% of people keep cars stock. This is an enthusiast forum, so it's not quite representative of the average auto owner.

That being I think BMW should give the transmission reasonable headroom for mods (without increasing costs too much).

[huzidada]

Originally Posted by Ricochet48

95% of people keep cars stock. This is an enthusiast forum, so it's not quite representative of the average auto owner.

That being I think BMW should give the transmission reasonable headroom for mods (without increasing costs too much).

Oh I'm not quite sure about this when certain cars are chosen, like the M240i or the Supra. I think a lot less than 95% keep these babies stock