Cayman GT4: Where are we up 2 now? Déjà vu Edition

[snowy999]

its out

4.0 Liter. 420ps

https://newstv.porsche.com/en/

 

[ChrisW]

So it's actually quieter than a standard GT4.

At Donnington in the drive by it was 2.3dB quieter than the "average" GT4 ... and at the Snetterton static test it was 101dB at 4800rpm.

I then tested it again at 5250rpm ... 105.5dB.

Before the work was done at Oulton Park it was 104dB at 4800rpm.

 

[ChrisW]

And if you really want more power, DeMan Motorsport have a 4.5L engine for you.

https://www.instagram.com/p/ByadkI-nvop/?utm_source=ig_web_button_native_share

So how much over the rated torque figure will the Aisin gearbox comfortably run ?

 

[ralphmusic]

Chris,

There are a lot of USA tuned 981 cars running in race series and track days with 4.0L X51 engine with either manual and PDK gearboxes, no reports of failures.

The concern in the early days was around cooling in high ambient/ high altitude tracks but no real problems were reported.

I was told unofficially by a ZF person that the 420Nm rated PDK in 981 had been run up to 500Nm in extensive testing so I think in reality both boxes have greater capacity than the OEM rating and warrantied values.

Ralph

 

[Motorhead]

Ralph,

I'm sure the ratings for both the Getrag and ZF transmissions will be for max continuous torque, which undoubtedly will include a significant safety factor. With the well-publicised CGT4 manual gearbox failures, Getrag clearly got something wrong; although in fairness that was down to a manufacturing defect/limitation.

Jeff

 

[ChrisW]

Ralph, re cooling issues.

In the Clubsport race cars cooling is indeed an issue ... but for racing they disconnect the oil temperature sensor from the warning diagnostics and let the oil do the job it should.

Peak oil temperatures exceed 150C ... no failures so far. Oil is a consumable ...