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-   -   2015 Cayman GT4 (https://rennlist.com/forums/991-gt3-gt3rs-gt2rs-and-911r/822961-2015-cayman-gt4.html)

ExMB 07-13-2014 02:43 PM


Originally Posted by CAlexio (Post 11504046)
How does Panorama have inside info like this?.. Are they the official magazine? Or just healthy conjecture.. Interesting piece nonetheless.

Porsche Club of America (PCA) magazine - are you not a PCA member?


Originally Posted by CAlexio (Post 11504046)
Who is in, and who is out? ;-)

IN - if car is $10k above GTS (manual)
IN - if car is $15k above GTS (PDK-S)
OUT - if car has CLs
OUT - if magazine price prediction is true. Won't pay that for any Cayman - regardless of hype - way to close $ to GT3 for my taste.

Jimmy-D 07-13-2014 02:47 PM

Hence, it will be for any one in a 991 GT3 to step down to 400 HP. After tasting 475 HP with a 9000 rpm redline it will be tough to drive any thing slower. 430 HP would be a narrower gap to consider if it has a Manual. Any thing less I will not bother. Plus, the 991 GT3 will be far more exclusive as the years pass by.

otisdog 07-14-2014 12:33 AM


Originally Posted by ExMB (Post 11505133)
OUT - if magazine price prediction is true. Won't pay that for any Cayman - regardless of hype - way to close $ to GT3 for my taste.

Didn't see a mention of price in the quoted magazine article....

GrantG 07-14-2014 12:45 PM


Originally Posted by otisdog (Post 11506126)
Didn't see a mention of price in the quoted magazine article....

Some magazines came up with ludicrously high US price estimates, because they always make a straight currency convervsion of the German-market price that includes VAT tax. We get a very good deal in US (we actually pay fewer US Dollars than the Germans pay Euros, so if you make a currency conversion you will overprice the car ~ 40% - this is what they always do). Somehow the magazines still don't have a clue about relative pricing in the various international markets.

MKW 07-14-2014 01:20 PM


Originally Posted by Jimmy-D (Post 11505138)
Plus, the 991 GT3 will be far more exclusive as the years pass by.

not cogent except for the few collectors who will store and hold it for 20 yrs in almost new condition

most GT owners whom you are speaking to here seem to be the enthusiast type who are first in line for latest GT3 and flipping from base to RS to next base to next RS and so on and so forth, not stockpilers.

nh4 07-14-2014 02:37 PM


Originally Posted by MKW (Post 11506973)
not cogent except for the few collectors who will store and hold it for 20 yrs in almost new condition

most GT owners whom you are speaking to here seem to be the enthusiast type who are first in line for latest GT3 and flipping from base to RS to next base to next RS and so on and so forth, not stockpilers.

As someone on the GT4 list I can say I would much rather sell it to owner number two after 10 years and 150,000 miles of driving awesomeness versus 10 years of looking at it covered in dollar signs and only driving it to keep the engine from seizing.

I fully appreciate that there are collector cars out there, and that being a collector is a passion for some folks. I don't think I'm wired that way. I wouldn't be able to keep my foot off the gas long enough for anything to appreciate!

-nh4.

Tacet-Conundrum 07-14-2014 03:17 PM


Originally Posted by nh4 (Post 11507161)
versus 10 years of looking at it covered in dollar signs and only driving it to keep the engine from seizing.

The Epitome of Ferrari ownership. The more miles you put on it, the less it is worth. So it you want to make any money back on that Ferrari purchase, by-god don't drive it - just look at it.

Petevb 07-14-2014 03:24 PM

The July Panorama article notes 400 hp from 3.6 liters, and plans to homologate the car for GT racing, production in 2015. I assume that would mean GTE class?

The 3.6L displacement is a bit unusual, requiring either a new crank or new pistons, and only seems to make sense if the engine is used as the basis for homologation. If correct we can assume the new motor will share much in common with the race car. Current Le Mans rules require 2x 28.9 mm restrictor plates to be run for that displacement, which would limit race power to around 460 hp. Race weight is limited to >2739 lbs.

If one assumes a homologated race motor of 460 hp, a similar power level could be achieved in the street cars as well (the same specific power as the GT3 would yield 450 hp, and one suspects that if they de-stroke it then specific power would increase, yielding almost exactly 460 hp at 8500+). This suggests anything down in the 400 hp range would be considerably detuned. However if Porsche has changed their philosophy and finally sanctioned the Cayman as a race car, do they still feel the need to artificially limit it on the street as well? A de-stroked 991 GT3 engine would seem to make the basis for a very robust race car motor- piston speeds and stresses would be down, yielding more reliability as well as headroom. The question is, how much of that motor would we get?

All of the above is speculation, I certainly have no inside sources. However it certainly makes for a nice story. Detune that motor less and it sounds like a pretty epic car.

GrantG 07-14-2014 04:12 PM


Originally Posted by Petevb (Post 11507276)
A de-stroked 991 GT3 engine would seem to make the basis for a very robust race car motor- piston speeds and stresses would be down, yielding more reliability as well as headroom. The question is, how much of that motor would we get?

Agree - always thought a destroked true dry sump version of 991 GT3 motor would be the best case scenario, but not sure how likely that is. 9k rpm would certainly be more reliable with lower piston speeds and motor would rev more responsively (feel like a lighter flywheel).

The lower cost and higher torque of an X51 motor might make the better business case for Porsche (and is in line with rumors I've heard). If they do that, I still hope they spring for the separate oil tank.

If they do surprise me and give a >425hp destroked GT3 motor with 9k rpm and dry sump, I personally am prepared to pay a little extra (assuming manual gearbox option).

TRAKCAR 07-14-2014 04:15 PM

^^ now we're talking. And make it rev to only 8000 to make it last forever with same torque in lighter car.

GrantG 07-14-2014 04:22 PM


Originally Posted by TRAKCAR (Post 11507382)
^^ now we're talking. And make it rev to only 8000 to make it last forever with same torque in lighter car.

Not sure if you were replying to Pete or me, but a destroked GT3 motor would result in less torque (displacement), so you'd want to keep the high redline there (9k would be much less stressful on a destroked version).

If you were replying to my suggestion that we might get the 3.8L X51 motor, then torque would be same as GT3 but redline is only 7,800 (with power peak at 7,500).

The first choice would be killer and very aggressive feeling - the second would be torquier and better around town. I vote for #1.

Petevb 07-14-2014 04:43 PM


Originally Posted by GrantG (Post 11507396)
Not sure if you were replying to Pete or me, but a destroked GT3 motor would result in less torque (displacement), so you'd want to keep the high redline there (9k would be much less stressful on a destroked version).

If you were replying to my suggestion that we might get the 3.8L X51 motor, then torque would be same as GT3 but redline is only 7,800 (with power peak at 7,500).

The first choice would be killer and very aggressive feeling - the second would be torquier and better around town. I vote for #1.

The trouble is #1 makes more sense with a PDK reather than manual to walk around the torque hole, and de-stroking would only make that hole bigger... I'd still want the manual.

I don't know that an X-51 version makes an ideal basis for homologation- it seems you'd need to change quite a lot of parts between street and race versions to get the reliability and power they need. Simply sharing street and track parts worked well for previous GT3 motors, why not again? Of course they don't need to share much- the Cayenne V8 that won Daytona shared very little with the street motor.

Same question on the chassis- they have been using double wishbones on the front of the RSRs for a while now, but the street cars haven't seen them yet. It'll be very tempting to go the same route to improve the kinematics and compliances for the Cayman race car, question is will the street cars get the good stuff or not? The car might get pricey if they do...

GrantG 07-14-2014 05:08 PM


Originally Posted by Petevb (Post 11507452)
The trouble is #1 makes more sense with a PDK reather than manual to walk around the torque hole, and de-stroking would only make that hole bigger... I'd still want the manual.

A 3.6L would still have a similar torque to weight ratio as the 3.8L GT3, given the lighter chassis. I know PDK would suit this engine well, but so would a 7 speed close-ratio manual, imo (I don't mind lots of shifting). But a 6spd is more likely and I could still make due there. PDK-S is certainly faster, but I just want to have fun.

Petevb 07-14-2014 06:00 PM


Originally Posted by GrantG (Post 11507516)
A 3.6L would still have a similar torque to weight ratio as the 3.8L GT3, given the lighter chassis.

Depends on the state of tune. At 400 hp it'd be no problem, but if they're chasing the 460 hp level the air restrictors allow it'd be worse. And the 991 GT3 already has a big torque hole that makes a manual look dicey... Still, there is something to be said for needing to wind a motor out.

Dan39 07-15-2014 08:56 AM


Originally Posted by Petevb (Post 11507452)
Same question on the chassis- they have been using double wishbones on the front of the RSRs for a while now, but the street cars haven't seen them yet. It'll be very tempting to go the same route to improve the kinematics and compliances for the Cayman race car, question is will the street cars get the good stuff or not? The car might get pricey if they do...

Very interesting comment, Pete - can you expand on it, perhaps?

We saw that both the 650S and 458 Speciale have double wishbones in the front and the GT3 has Macpherson struts.

The McLaren also has them in the rear while both the Porsche and Ferrari have multi-links.

Is Porsche trying to save us a few pennies here with a non-ideal solution or is it simply the expression of a different philosophy?

Thx in advance.


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