There is a torque dip on the 981GT4 right where 2nd gear digs occur in the 40mph range. Shifting to first helps, but that is another shift in both directions.

While the 981 GT4 has adjustability it is very limited without toe links and camber plates. The 718GT4 has more adjustability since the chassis isn't prone to understeer like the 981. With shock allowances and possibly camber plates allowances and then the GTS cars lack of adjustment from the factory goes away. The only additional benefit then comes from double adjustable swaybars, which on a 981GT4 needs to be set at full soft full stiff anyways.

 

Camber plate and ride height adjustments are only applicable for non-street classes for 981/718 GTS, unless there's some other change I'm not aware of?

 

There is no camber plate allowances for the GTS but the GT4 can use shims on the LCA which is not the case on the GTS to get camber. The difference between -2.5~ versus -1.4 is very noticeable as the former is what I could get with plates. For the record, you can get a whole lot more than that with the GT4, it's just that it starts really causing excess castor.

 

I may be mixing TT sport additions vs street AutoX...

Regardless the Corvettes and Vipers can get more camber and they are AS and the C7GS is heading to AS. The 981 GT4s limited camber gain vs the other Porsches still should disqualify it when those cars are carrying better power and transmission.

Maybe I'm in the minority but I think the C7GS and PDK 718 GTS will be the cars to have in AS even if the 981 GT4 went there.

 

The manual 718 GT4 has the same gear box and therefore the same issue (PDK was only an option on 2021 and later models). The 4.0 certainly helps a bit, but it still faces the same challenges when compared to the Corvette. Let's face it, the SEB will ensure Porsches will never be the "car to have" in any class, other then maybe SS, but that's very course/driver dependent.

 

I've owned both 981 and 718 GT4 and I've seen no evidence to support what you're saying here. Yes, the chassis is supposed to be stiffer, but in reality, it's the same shocks, springs, bars, wheels, brakes, etc, and slightly heavier. I found the gearing in the 981 to be fine 98% of the time. And when it is too long, going to 1st was super easy with no anxiety over missing the shift with the rev match.

 

Why?

 

Because the C6Z is currently the car to have and the C7GS single handedly killed SSR which was healthy with C6Z and C5Z participation.

Why wouldn't it do the same in AS? Especially if the 335 Nankang is as good as advertised... Tire is the only thing holding that car back.

The 981GTS has shown some course dependant great results, now add power and significant torque while maintaining the best transmission in AS.

What car do you expect? The C6Z still? If tires stay small, and the Nankang sucks then maybe so. With 285 max width RE71s and unobtainable Yoks the C5Z could be the car, but I think the 718GTS can handle that car since it's not tire limited.

 

There are setup threads in both forums saying the opposite, along with Sam's FB group where the guys currently winning with 718GT4s(who are previous 981GT4 owners) are at. Both say the 718 is much more eager to rotate giving full use of the bars.

 

As I read the Fastrack proposal, under SS it appears to show the 718 4.0L GTS remaining in SS. Under AS, it appears to show all 718 GTS into AS. Any insight here as to which class the SEB really is proposing the 4L 718 GTS to run in? With its camber limitations, non-adjustable ARBs or ride height, it certainly is not competitive against 718 GT4 and Spyder in SS or the other SS cars.

 

Proposal shows GTS 4.0 staying in SS, GTS moving to AS.

Which is the better of the two cars for autocross and why?

 

I think you're correct to focus on tires. Oversized Hoosiers allowed the C7GS to take advantage of it's gearing coming off the corners and there was a wholesale switch from the Z06 to the GS.

But, the GS is nearly 300lbs heavier than a Z06. I don't think the Z06 is dead yet on street tires.

 

I dont think it will be dead necessarily. But I see a C5Z/C6Z transition. C5Z should still be just as competitive vs the C6Z as it used to be, but people would rather a C6Z and the Yoks tipped the balance. C5Z participation is dropping.



Either way, I think the C7GS and 718GTS to be good additions to an aging AStreet. I just also think the 981GT4 fits with these two. I expect the 981GT4 to be competitive but not "the car" to have. GT4 owners have shown good participation in the past and since availability and price is in line with other options I don't see it as a potentially crippling addition if it does show more potential than I expect. I fully expect a TYFYI but I find it worth the try. As a Corvette and Porsche fan/owner I'd love to see them all running together.



As a side note I think the 996GT3 belongs in AS too, but I can see difficulty in moving a 20 year old 6 figure Porsche to become a competitive option.


I think the 718GTS is severely underrated due to low fanfare of the Turbo 4.

 

Proposal says in the AS section "718 S & GTS (2017-22)". I believe the only GTS in 2022 was the 4.0L. If this is true, the proposal contradicts itself.

As to which is better for autocross, I have driven my 4.0L GTS in local events but have only passenger (instructing) time in the 4-cyl turbo GTS. Butt dyno says much more meat under the 4-cyl torque curve than the 6-cyl which, if driver and tires can handle it, would make the 4-cyl the quicker car. Big IF though. BTW, I see little if any difference in times between my current 4.0L 718 Cayman GTS and my previous 981 Cayman GTS (unicorn - X73, etc.). Chassis-wise, the previous could get -1.7 degrees camber on the front and 718 version can only get -1.4 degrees. Slight handling benefit to 981 offset by 718 torque and HP. On the street, 718 is superior. In an autocross course, it is close so why different classes?

As additional data, I did a track sprint on infield section of Daytona late last year with my 4.0L GTS. Although, I was braking gently due to a bad case of sciatica, I handily beat the C6Z that usually beat my 981 GTS in autocross. Well driven and prepped C7GS got me by 0.3 sec. though (~ same as did a 991.1 GTS). Net is my experience indicates it may be a coin flip between the three Cayman GTS versions in autocross, the sleeper 991.1 GTS and C7GS so why is the 718 4.0L GTS left to the lions in SS?

 

4.0L will command significant pricing over the 2.5L GTS, thus fitting more with the SS mix.