SanDiegoDavid

A few times I was able to go through 2 at 140-145. I believe that I could have easily dropped my time by 2-3 seconds. Saturday made me realize that l really need to get the suspension set up. Can't wait to go back with and see what I can do![/quote]

Maintaining that speed thru 1 and 2 you should be able to do 1:45-1:46 easily.

Laguna_Dude

IMO, those lap times are meaningless; as it represents a wide range of driver skill levels. Back in 2012; I did a 1:41 flat in a bone stock 2010 997 Cup on fairly worn Yokohama's. Having owned a 991 GT3 and now a 991 RS; i can tell you that with same driver; RS will be faster. The wider front tires and more aero are the major difference. I do feel GT3 revs way freer and faster; both are amazing cars; RS just has an edge with more of everything. Congrats; 1:48 is a very respectable time in a street car!

Laguna_Dude

for reference; in 2010 997.2 Cup was entering the banked turns above 160mph; would slightly lift to turn in; but then would stay floored through the entire banking; I would glance down and see 155-157 mph through the turn... was a puckering moment for sure. haha.

SanDiegoDavid

155, puckering for sure.

thusly

Personally, I would run for the hills if someone told me they can roll carbon fiber fenders......

dannyb

Dave,

Spoke with Joey from E Motion and he said the tire wear is a result of the suspension setup, not from making contact with the fender.

SanDiegoDavid

Dan,
Cool. Thanks, good to know. I'm going to just do the camber adjustment to -2.2 in the rear, have the RWS wiring rerouted and the spacers installed as well as toe in 1.5mm. Hopefully no rubbing after that.

Macca

I recently got to spend time with 991 GT3RS on the track.

I also got to spend time with a GT4 on a fast road drive. Ive already posted a review on that car vs the 991 GT3. The single biggest difference between the cars IMO is the engine. The GT3 is defined by its engine and the GT4 by its transmission. My review is alot more detailed than that but if I were asked for the largest single point of difference this would be it.

With regards to my experience between 991 GT3RS and 991 GT3 if I were asked to name the single largest point of difference it would be this:

Turn in and braking (front axle). IMO the RS brakes better and turns in sharper than the 991 GT3 and this its 80% of its performance advantage. These traits are a result of:

A). Large front tire real estate (footprint), especially under braking
B). Wider front axle
C). more front down-force


Yes the RS is more in many other ways (more tech, more aggressive looking, wider, more coveted etc) but in terms of out and out performance difference on the track the front end of the car is where its all at IMO.

For all intensive purposes the cars are otherwise only marginally different in performance. Obviously the large rear wing helps rear downforce on wide fast corners, but we dont have many of those on our tracks down here so the benefit is limited. On a track with long fast corners I believe the rear downforce will play a larger part but its still secondary IMO to whats happening at the front of the car - after all under-steer kills corner speed. The small power difference isnt really noticeable on the track IMO, especially now I have the DMS headers which Im yet to try on the track. The transmission and brake hardware are identical to the best of my knowledge. The weight is pretty much identical too with USA cars having the full fat glass.

The 991 GT3RS turns in much better than the GT3 and under brakes from a fast straight to a slow corner its on another level. Im sure you could put canyards on a GT3, a Cup lip and use a 265 x 19 front wheel/tire to try and replicate some of this but its besides the point, Im comparing the cars as they shipped out of the box.

The one mistake I believe Porsche made was going 21" and trying to squeeze that wheel under the rear fenders - this has led to lots of challenges for owners and less tire choice and geometry options.

Its my opinion Porsche should have stuck to a 20" rear, using a 325 profile tire and none of this would have been an issue and teh stance could alos have been optimized. The cost would have been 1s at the Ring and a few 10ths over a typical 2-3 mile track over what they ended up with at huge expense to convenience and cost of consumables to owners.

Just my 2c worth.

Id be very interested in your opinion David between the two, when you have the car set up and more seat time. You have done more track miles in your 991 GT3 than most on here and Im sure you will have an opinion on where the few seconds the GT3RS gains per lap on the GT3 are happening....

SanDiegoDavid

Me too Macca! Unfortunately I'm waiting on parts from Germany to complete the "Wheel clearance track use" bulletin, so won't be getting the RS out on the track this weekend. It will have to be the GT3 at Buttonwillow this Saturday.
Nice summary of your experience and feelings about the RS. I agree with the 21 inch rears, just not sure its worth it. That being said, I'm eager to get it out on the track, specifically ACS, Thermal Club and Chuckwalla. The additional down force will be huge at Auto Club, so I expect to shave a couple of seconds off my GT3 time of 1:48.xx. The mechanical grip will come into play more at Thermal since its a relatively slippery surface. Maybe 1.5-2 seconds faster for the 3.1 mile full track?
Some of these improved times are attributable to my development as a driver and more comfort with individual tracks. The cool thing would be to track both cars the same day. Same driver, same day but different car. A true head to head comparison!

SanDiegoDavid

BTW Dan, cool avatar pic!

C.J. Ichiban

There is definitely a lot of time on the table for the 991GT3 at ACS. I would assume a ***** out lap to be in the 143 range. And I do mean *****- you can lose a second there because if you even lift a little bit too much, the drag at 140+mph slows you down a lot. The air is fighting HARD against your car at that speed.

Fwiw I did a 1:45 in my 997.1RS in 2009 and have gone 1:41 in my ACR with a passenger.

Downforce is a real factor in the ACR because you simply turn the wheel and keep the pedal planted for 1-2. That being said- since the aero is crude you are only doing 155 or so and then tire and drag scrub you into ~140mph range. It's not very slippery in a straight line and the best acceleration is from 50mph-125mph before drag slows your progress. Also the 5/4/3/2 downshift for the T3 tire barrier chicane is very challenging to max out your brakes and sequence for speed and depth in a 6spd car. The PDK takes this whole thing and chews it up with a smile.

The 997 and 991 cups have really pointy and low drag frontal areas so they should be in the 166-170mph range in that same straight, similar to what they do at Daytona...in our Cayman ClubSports we got to 171mph at Daytona for T1 and 160ish before the bus stop chicane. Granted that banking is higher but with real slicks on, the 997 cup is going to be Fast As F.

In my old RS, I could nick above 160mph on entry to T1-2 and then had to breathe and really be quiet on the wheel. A little too much steering? Lose 4-5mph. A little too much brake or too big of a lift? Out of the powerband, lose 1 second.

Laguna_Dude

i have yet to track my RS; but have been driving every night to break it in; a couple observations: 1.) the motor revs much slower vs. GT3 and 2.) the rear steering seems to be more dramatic and noticeable.. i actually do not like it. I felt in the GT3, the rear steering was noticeable, but not disruptive. I feel the RS' rear steer is so abrupt it distracts from being able to feel the car during the critical post-turn-in point at limit.. i hope this isn't the case at the track. GMG is taking her next week for some track goodies... and then plan to track for first time the week or so after at Thermal; should have more feedback then.

mdkim

While I can't say it's 100% the rear wheel steering, I also feel that the car turns in too abruptly at times requiring adjustment(s) mid-corner. I feel this even at freeway speeds just changing lanes sometimes. It could also be the track alignment but on my GT3 the aggressive camber just made the car wander with the grooves of the road...definitely a different sensation I'm getting in the RS.

More seat time may be the cure and perhaps all will be good at the track.

Laguna_Dude

I found a video on my mac with a couple practice laps at Fontana; you can see the speeds at entry of T1 and through T2. these are low 1:41 laps on fairly worn tires; car was sliding around a lot. Volume warning!

Laguna_Dude

I hope; also running factory alignment; let's see what GMG can do on the setup; they dialed in the GT3; felt so so good! I will get some footy at the track in the RS and post here. I do feel it is the rear steer; as it's the rear swinging around abruptly that is my issue; it's hard to feel what is going on back there as it's happening; easily can confuse for oversteer. Turn in is definitely sharper vs. GT3. the groove tracking is a common thing in theses cars.. it's part of the experience. haha.