Jimmy-D

Ditto

MEM82

is the benefit of the single mass to make the car rev more freely? Any other benefits?

CAlexio

Well, with engine having less rotating mass to move with each compression cycle, more of its power gets to the drivetrain than with a heavier flywheel setup. so a car with a lighter flywheel all else being equal should be faster accelerating

tonymission

So why is it even an option then? Seems like it would be standard.

MEM82

thanks!

bronson7

Exactly. Why would anyone order anything different and why would Porsche offer anything different?

997rs4.0

Only reason I can think of is if the customer doesn't like the rattling of single mass FW.

CAlexio

When a vehicle has lighter flywheels, the drivetrain is much less smooth, as there is less inertia to attenuate the engine's power. On the gas is very abrupt, and OFF the gas increase engine braking.. shifts become a more delicate affair to manage, where throttle control and smoothness with clutch becomes much more important. While it's not a perfect analogy, think of a race car, super light flywheels.. they shunt and stutter badly at low Rpm as each engine turn provides an impulse forward and then hits resistance, with no weighting effect.. but at high rpm they seem to fly through the tach which is desirable.

I made the mistake of putting a lighter flywheel on one of my road based ducati's, and it's now a complete mess in town, I'm always ok clutch trying to keep it smooth. But when I'm in mountains or at track, it's an absolute pleasure. As a non-related aside, on a motorcycle a lighter flywheel also has the incredibly awesome effect of actually changing the handling of the bike as you can make quicker left-right turns without the engine rotating inertia fighting you. On a car I don't believe this happens.

so aside from noise, a car with a SMFW takes on a VERY racey character, which may not suit the brand attributes that a company is going for. I think Porsche wants to charge MORE for a less refined "racey" car, which is why they normally reserve this for their RS cars. My best prediction (pure speculation) is that they don't want to make the "regular" GT3 so racey that people don't have a reason to move up to RS pricing? I think they might not offer it on 991.2 Gt3 purely to keep 911R that bit more special.. just like they'll add more sound deadening in, and put real door handles back in instead of straps.. pure branding segmentation.

Nizer

Was standard on 997 RS. Making it an option on 991R and I suspect on upcoming 991.2 GT3 allows Porsche to charge a $3,650 premium. Funny part is that it's likely cheaper to produce than the standard dual-mass flywheel.

BusDriver

More thoughts on the car:

On RWS…

The art of calibrating RWS seems to have been noticeably advanced on the 911R. Especially compared to other recent Porsches. For example, I find the RWS on the 918 overly aggressive and makes the car very oversteery on corner entry – I almost spun the car first time on the track. However on the 991 GT3 RS, RWS has the opposite feel as the car does not feel all that nimble and pointy, but very stable. Experiencing the 911R’s RWS was a goldilocks moment for me – it is just right. Not too aggressive on corner entry, but still very nicely pointy yet stable at high speed. In fact, RWS on the 911s highlights one of the few shortcomings of the Cayman GT4 – it is not just not as pointy as a small mid-engine sports car should be. Hopefully, the next GT4 also gets RWS.

Which brings me to some thoughts on the 911R vs the 997 GT3 RS 4.0…

RWS and Electric Steering are two features present only in the 911R. While the RWS is a very good thing as described above, the Electric Steering is more of a mixed bag. The 911R’s has excellent steering precision, but is completely missing the road feel and overall organic feeling present in the 997 4.0 RS’s hydraulic steering.

Ride quality is significantly better in the 911R as it is not as stiff as the older car – the R feels more organic and flows with the road compared to the slightly bouncy feel of the 4.0 RS. Engine performance is close, but the 911R has an advantage in acceleration over the 4.0 RS.

Despite the technical differences, the biggest difference for *me* is the look and spirit of the car. The R is a fun road going hot-rod, while the 997 4.0 RS is an aging track weapon that is a bit ridiculous on the road – giant wing, stiff ride, etc. While one cannot deny the 4.0 RS’s collectability for what it represents, the R is a better road car to drive, and a much better road car to enjoy because it has no giant wing or track pretense. The only thing I wish the R had - is hydraulic steering instead of electric.

turbofreeFLAT6

Thanks for the reviews, BusDriver. I'll declare my bias: I bought a GT4 new, recently sold it and bought a 997 RS 4.0; and my ignorance: I saw an R at Geneva but haven't driven one.

The GT4 had very slight understeer so I changed the rear ARB to stiff and found it impressively pointy. Unsurprisingly it sounds like it and the R have similar steering. The GT4's was accurate but heavy and artificial feeling, though the ARB change seemed to lighten it slightly and make it feel a little more closely connected to the road. But even then, although it gave decent feel of grip on dry roads it had none in the wet. Assuming you've had the R out in the wet by now, how is it?

I actually enjoy the 997 RS 4.0 the most when going hard on a bumpy road. I love the feeling of the suspension working hard but remaining composed and the car following the road surface. PASM rounds off the sharp edges much better than I remember my 996.1 GT3's passive dampers doing and I wouldn't want it any softer. However if it was a daily driver on slow rough roads it might be a different matter.

I know the R gets to 100km/h a 10th quicker than the RS 4.0 but I assumed that was down to either Cup 2 vs Cup+ tyres or better traction from the later suspension. The graphs show the RS 4.0 having more torque from 2,000-6,500 rpm and a similar power curve from there to the common peak at 8,250 at which point the RS 4.0 remains at 500 hp until the redline while the R (assuming it has the same curve as the 991 RS) drops off slightly.

I think an outrageous road racer is a necessary reminder to a politically correct world that speed thrills! I also have an old classic and it is a pleasure to see the enthusiasm that both cars create.

turbofreeFLAT6

What differences did you find?

BusDriver

turbofreeFLAT6 –great taste in cars. A 4.0 is a very special car!

Although the GT4 is a fabulous car, it does not have the pointy turn-in of the 911R. On the GT4, I have the anti-roll bars set full soft in the front and full hard in the rear. Even with those settings, the GT4 understeers significantly and is nowhere near as pointy as a 911R. The RWS really is black magic.

As far as handling in the wet, both the GT4 and the 911R are limited by their Michelin Cup 2 tires which are very slippery and slidey in the rain. I found the Bridgestone RE71R’s to work much better in the rain while providing similar dry grip as the Cup 2s. Main downside to the Bridgestone tires is that they generate a tremendous amount of road noise. Both cars have great steering precision but very little steering feedback, especially compared to a 911 4.0 RS. As an aside, the 911R’s steering and clutch are both a lot lighter than that of the other two cars. And the GT4 has the most flatulent exhaust of all 3 cars!

For me, there is nothing like the 911R - its RWS-enabled combination of pointiness and high speed stability, manic engine, stripped raw feel, wrapped in a subtle unassuming (wingless!) body. This car feels like an old-school hot rod Ducati and I love it.

Those are my opinions...but I enjoy reading yours and everybodys opinions on the GT4, 911R, 4.0, RWS, etc...so please write more.

turbofreeFLAT6

Thanks for further insightful comments, BusDriver. You've made me very keen to try RWS. I've not had a chance to take up my PEC Le Mans offer (from buying the GT4 in France) but will do so next year before it expires. I imagine the R is too rare to be on the fleet but hope to try RWS in a GT3.

It sounds like RWS with rear-engine could be the ultimate performance configuration (mid-engined agility with rear-engined traction) if only space could be found for a rear diffuser.

With so much front grip do you have any difficulty judging maximum corner speed or does it just make it easier to play with the tail?

I found the rear of the GT4 would snap quickly in the wet (but then snap back into line equally quickly after getting off the power). I assume the R is more progressive with the mass further back?

I agree with your comment on the GT4's exhaust. The engine note is almost non-existant at low revs and always less musical than a GT3's so I drove with the windows down and exhaust button on, which produced an emotive burble, crackle and pop at low revs and a remarkably loud and aggressive bark at higher revs.

Did you resist the temptation of stripes on the R to maintain full subtlety? I think my choice would be GT Silver sans decals. I loved my 996.1 GT3 in Arctic Silver, which from memory was similar to GT Silver and much more substantial than the current glitzy Rhodium.

Would you say the manicness and rawness of the R is similar to the 997 RS 4.0's? Out of curiosity do you/did you own a 4.0?

I wonder why Porsche didn't strip the same amount of sound deadening out of the 991 RS. As the most track oriented model you would expect it to be the most raw.

GrantG

Totally agree. Even the brand new RSR, GT3 R, and Cup have hydraulic steering (but hasn't been in a road going Porsche sports car for 5 years), so Porsche knows they haven't fully succeeded with EPS yet. All GT cars should have hydraulic steering.