[XutvJet]

I'd have to say the idle on my 2011 Cayman base is pretty smooth once the car is fully warm. It will be even smoother once the clutch and failing dual mass flywheel are replaced next week. I'm certain the damping springs in the flywheel are gone.

The tip-in 2.9 power is pretty tame below 4500rpms and there is an "on cam" sensation that is felt between 4000-4500rpms. The motor definitely needs to be revved out to the 7400rpm redline get all the power and I love that because I'm still not going crazy fast when I do it. My M235 happily pulls to the 7000rpm redline too, but it generates a lot more speed. The M235 kind of makes you drive lazy because of all the torque.

My biggest gripe about the Cayman and the M235 is the long gearing. Both cars do low 70s in 2nd and 3rd goes beyond 100mph. I do wish the gearing was a bit deeper, especially in the Cayman.

I am shocked by how smoothly (though slowly) and without fuss the Cayman will pull from 2200-2800rpm in 5th and 6th considering it's powerband and lack of torque.

[Alfisti]

I touched on the long gearing in another thread, i am well past illegal speeds in 3rd at 5K RPM and the engine is pulling hard and wants more but........ police.

[INTMD8]

Originally Posted by chris719

I don’t think this is science based, first of all. The mechanism you describe isn’t even correct.

What did I describe that is incorrect?

[INTMD8]

Originally Posted by INTMD8

What did I describe that is incorrect?

Still waiting

[Nonsensical]

I LOVED my Cayman! Then I got old and bought a Panamera

[chris719]

Originally Posted by INTMD8

Still waiting

Atomization is better with high pressure DFI. The distribution may not be. It's still not an idle issue. My S55 is smooth and rock solid at idle.

[INTMD8]

As mentioned, many people do not seem to notice a difference.

I do. There are also endless threads about S55 idle roughness so wouldn't say I'm alone.

Port injection results in smoother combustion at idle, low rpm/low load for reasons previously mentioned.

DI has it's advantages for efficiency and power under higher loads.

Any engines that have both port and direct injection use either 100% port injection for idle/low rpm or a very low blend of DI.

There are countless articles out there explaining this.

https://engineerine.com/port-vs-dire...ual-injection/

https://www.motorauthority.com/news/...port-injection

[chris719]

Originally Posted by INTMD8

As mentioned, many people do not seem to notice a difference.

I do. There are also endless threads about S55 idle roughness so wouldn't say I'm alone.

Port injection results in smoother combustion at idle, low rpm/low load for reasons previously mentioned.

DI has it's advantages for efficiency and power under higher loads.

Any engines that have both port and direct injection use either 100% port injection for idle/low rpm or a very low blend of DI.

There are countless articles out there explaining this.

https://engineerine.com/port-vs-dire...ual-injection/

https://www.motorauthority.com/news/...port-injection

All good info. All I can say is my S55 idles smoother than my S54 did. Smoother than my Mazda 2.5 MZR. Both are port injection. It's not really that close either, if I still had the Z4M I'd get an accelerometer data log from both cars. Most people complaining of rough idle with S55 have something going wrong. A lot of bad tunes, people running aftermarket plugs with the wrong gap, bad sensor, etc. You may well be correct in a world where every engine had an identical port injection version to compare with. I have a feeling the differences between port and high pressure DFI are swamped by other facets of the engine design and management in most cases.

You have come close to convincing me when you compare the two 9A1 variants, but my experiences with the Nissan VQ shows that engine NVH can change significantly simply with increased displacement.

[INTMD8]

The op asked

"Does anyone have any experience with these cars? Anything I should be aware of?"

So I shared my experience and observations as the 987.2 Cayman S and the base 997.2 Carrera both have a 3.4l direct injected 9A1 engine.


I'm fine with agreeing to disagree, just stating what I have observed.