+10ps

 

991.2 Speedster engine had ITBs and particulate filters, unlike 991.2 GT3 engine.

 

I’m wondering if the engine configuration would fit without too much trouble. Although, they have had a few years to do it.

 

Nope. The Speedster has the 992 GT3 engine with individual throttle bodies and integrated PF/catalytic converter exhaust and a whole bunch of other changes.

 

I know I'm late to the game here... but the Speedster wasn't just about being a GT3 for the road. It's also the only way to get a naturally aspirated convertible 911. They could have thrown out all the fancy Speedster and GT3 stuff and just stuck that motor in a standard 992 chassis and they'll sell every last one at whatever they want to charge for it.

 

Do you know what other changes? Do have driven 991.2 GT3 engine vs. 991 Speedster or EU 991.3 RS engine in comparison...what your experiences?

 

I had a 991.2 GT3 and have driven a speedster. In my limited comparison I felt like the throttle was more immediate on the speedster. It also had an Akra aftermarket titanium exhaust so can't compare the sound... it was sublime compared to stock. Flywheel effect was very light and fast revving, sort of like the SM 911R feels when you rev it.

Other who owned both cars are probably better judges of this.

 

Anyone considering going from 991.2 GT3RS to the 718 GT4RS?

Im looking into it.

 

No, the rear suspension in the Cayman line is not up to it. I would go after a Mclaren 600LT - far more advanced than anything being proposed for the GT4RS.

I doubt the GT3 engine will be in the 4RS and even if it is that won’t make up for the rear suspension. Moreover, the Cayman as good as it is needs a ground up makeover.

Consider this - cars like the Miata and the Alpine have better suspension setup and geometry than the Cayman. Struts all round no longer cut it and on high speed rough payment are skittish.

 

 

LOL - Of the brands in discussion, I own a 991.2 GT3 RS, a 720S and a Cayman GTS - so am speaking from a position of ownership. The problems with the rear suspension set up in the Cayman including the GT4 are well understood by those that use them on the track and in other forms of motorsport. Dropping in the noise box from the GT3 doesn't solve the suspension problems. On flat smooth tracks it will be fine but will be limited by the track and wheel tire choices - but on rough roads it won't be particularly good, moreso at high speed - it will simply become unsettled. None of this is a mystery to those that have pushed these cars in environments beyond the most benign tracks.

 

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^Spot-On @groundhog

 

The 4.0 GT3 engines and the 4.0 GTS/GT4 engines share the exact same bore and stroke, despite being different engine families. So sharing some internals is certainly plausible.

 

Don't even need to push it to track speeds to discover this. It becomes evident hustling the car rapidly down a bumpy curvy road. The rear suspension of the GT4 is not exceptional.