So, now that the GT4 specs are finally known....
Poll: So, now that the GT4 specs are finally known....
Total Members Polled: 158
Discussion
....and
1) Nordschleife times are essentially the same as the the 997.1 GT3
2) Power is "at least" 385hp so power to weight ratios are almost identical
3) 997.1 GT3 prices are going to be roughly comparable with new GT4 prices
...which would you have given the choice? A 997.1 GT3 or a Cayman GT4?
I don't have any LOI for a GT4 or anything, but in my head hypothetically, I think once I got over the "ooo new and shiny" moment of a GT4, I'd want to go back to my GT3 for 2 simnple reasons:
- rear-engined so more unusual in today's world where all other supercars etc which are mid- or front-engined
- a screaming 3.6 rather then a fairly generic 3.8
In the words of the Monkey: tell me I'm wrong.
1) Nordschleife times are essentially the same as the the 997.1 GT3
2) Power is "at least" 385hp so power to weight ratios are almost identical
3) 997.1 GT3 prices are going to be roughly comparable with new GT4 prices
...which would you have given the choice? A 997.1 GT3 or a Cayman GT4?
I don't have any LOI for a GT4 or anything, but in my head hypothetically, I think once I got over the "ooo new and shiny" moment of a GT4, I'd want to go back to my GT3 for 2 simnple reasons:
- rear-engined so more unusual in today's world where all other supercars etc which are mid- or front-engined
- a screaming 3.6 rather then a fairly generic 3.8
In the words of the Monkey: tell me I'm wrong.
PorscheGT4 said:
Steve Rance said:
So much more potetial in the 997 Gen 1. The engine alone would make it a no brainer or me
997.2 RS with sharkwerks 4.1 :-) would be my idealhow does a gen 1 have more potential then the gen 2, or you you mean more potential than a GT4
The issue I have with the GT3 and it's well know I dislike this issue is the low down torque you are left with on UK B roads at 90 mph as its ni on impossible to rev the thing out in 3rd gear to enjoy the car.
the GT4 has more torque and 1000 rpm lower than the 997 GT3 ? ie 310 lb/ft at 4700rpm vs 299lb/ft at 5500rpm
now while on track the GT3 sings, on B roads it's a pain in the arse to drive just because of that single issue.
while the GT4 will still do 86 mph in 2nd :-( at least when you pop in into 3rd you should have some shove there at 5k revs
While I loved owning my GT3 I never enjoyed driving it because of that single reason, I have no idea why other people don't have the issue !!!
The GT4 could also be annoying on B roads, but who knows till June/July ?
If it was a £1k change rather then a £3k change to make, I'd be all over it. As it is, since you can't rag the car properly on the road anyway, I'll leave as is for the moment as the gearing works fine on track where I intend to continue taking the car a lot.
As an aside, GTS manual gearing is unforgivably long in my book for the B/C GTSs, which is one of the main reasons why I'm going PDK for my BGTS
Steve Rance said:
The engine in the GT3 is probably one of the best engines that ever found it's way into a road registered road car. I believe it costs over £30K to replace. The chassis is derived from the 997 cup car and the 997 Cup car is a fast as the 991 cup car. Ergo as the 991 GT3 road car is quicker than the 997 GT3, the 997 road car has a lot more potential to be unlocked - which you can quite easily by fitting different dampers. You can take the 997 Gt3 all the way to propper GT racing spec without changing any of the running gear. I cannot think of any other water cooled car that you can do that to other thn a 996 Gt3.
I have a 997Gt3 gen 1 clubsport and there is absolutely no way that I would even consider selling it or swapping it for the GT4.
Interesting!I have a 997Gt3 gen 1 clubsport and there is absolutely no way that I would even consider selling it or swapping it for the GT4.
Steve Rance said:
Dont get me wrong, the GT4 looks a nice car but a GT3 it is not. It's unfair to the GT4 to make the comparison.
The phrase "knife to a gunfight" springs to mind 
PorscheGT4 said:
Mario149 said:
The phrase "knife to a gunfight" springs to mind
not if the GT4 posts a sub 7.40 ring timered997 said:
I think the GT4 looks great from what I've read;
I never found the relatively long gearing on the GT3 (996) an issue on the road - just use three gears ....
But you only really get to use 2 & 3/4 gears. IMO, in a sportcars meant to be driven on the road as well as track, you should be able to rev out the car in the first 3 gears without losing your licence instantly in extremis i.e. over 100mph. In a GT4 (and 997.1 GT3) you cannot. I had both my 993 and GT3 on track on Sunday. In terms of enjoyment purely considering the gear change, I would say I had more fun swapping cogs in the 993 at Brands than I did in the GT3 as there was more of it. Sure the GT3 change is sweeter, but in the 993 I could get 4th on the way up to Druids if I nailed Paddock (GT3 I could keep 3rd), I could snatch 3rd between Druids and Graham Hill (stayed in 2nd in the GT3) and could squeeze into 5th on Brabham straight if I nailed Clarke (only 4th in the GT3).I never found the relatively long gearing on the GT3 (996) an issue on the road - just use three gears ....
red997 said:
GT4 fills a different niche for me - 50/50 track to road, whereas the GT3 was always 90/10 track to road
or maybe that was just me
If the GT4 is 50/50 track road then it should *definitgely* have shorter gearing or maybe that was just me
J-P said:
I'm really struggling with this. On the one hand, I know that I should really love the way this thing drives and I'm OK with the power output. But I'd have liked a more high revving engine. I still think it's possible that a modded CR is a better option for me. I'll sleep on it and see how I feel in the morning.
Also what the hell did they do to the engine? It's around 20g/km worse than a C2S and is supposedly de-tuned version of the same engine - bizarre!
Is the C2S emissions value for the PDK? The manual in the GT4 will be less efficient. Actually, the manual in the C2S would be 7 speed so there's probably more economy there than the 6 speed GT4 manual as wellAlso what the hell did they do to the engine? It's around 20g/km worse than a C2S and is supposedly de-tuned version of the same engine - bizarre!
I think what'd be quite interesting in this discussion is if 997.1 GT3 values and GT4 values stay at similar parity for the next few years. That means that in a couple of years time once everyone has had a good go in their respective cars, we can each move onto the other for little or no cost Bets of both worlds! Then we can all revisit this thread and swap our answers to the opposite side 
Bets of both worlds! Then we can all revisit this thread and swap our answers to the opposite side braddo said:
hondansx said:
braddo said:
J-P said:
Also what the hell did they do to the engine? It's around 20g/km worse than a C2S and is supposedly de-tuned version of the same engine - bizarre!
I wonder if it is a clue that they shortened the gearing?O/T....or rather back to the original topic briefly!
The poll is showing virtually exact 1:2 split at the mo 2 out of 3 people would take the GT4 over a 997.1 GT3. Thought more would plump for the GT3 tbh.
I might start a new poll in say a year's time and see how desirability may have changed
The poll is showing virtually exact 1:2 split at the mo
2 out of 3 people would take the GT4 over a 997.1 GT3. Thought more would plump for the GT3 tbh.I might start a new poll in say a year's time and see how desirability may have changed
fioran0 said:
Now that the factory dyno plot appears to be out for the GT4. Here is an updated thrust curve plot showing the GT4 versus the 997.1 GT3 (3.6L) and the 991 GT3. All vehicles stock.
The GT4 is the blue line, the 997.1 GT3 is the red line, the 991 GT3 is the purple line.
The higher the line, the more force you have for acceleration at the given velocity. This sort of chart is useful for gauging how much acceleration a car will have as it goes through the gears.
Does this account for differences in weight?The GT4 is the blue line, the 997.1 GT3 is the red line, the 991 GT3 is the purple line.
The higher the line, the more force you have for acceleration at the given velocity. This sort of chart is useful for gauging how much acceleration a car will have as it goes through the gears.
NewExigeS said:
Thanks for providing this data, very interesting.
How did you get it btw?
You can match the dyno charts, in gear speed curves and gear ratios from the Porsche car handbooks i.e. choose the speed you're considering, match it to a gear on the in gear chart, look up the gear ratios to find find the rpm, use the rpm to get the torque, use the gear ratios to get a multiplier for the torque to get thrust. then plot the thrust (force accelerating the car) against speed. Then repeat many times for different speeds (say every 5 mph) on a spreadsheet. If you're comparing different cars you can bring their weights (masses technically) into it to account for any differences in how much they weigh e.g. for a given thrust, a car weighing 10% more will accelerate 10% less since Acceleration = Force / MassHow did you get it btw?
At least that's how I'd do it!
Mario149 said:
NewExigeS said:
Thanks for providing this data, very interesting.
How did you get it btw?
You can match the dyno charts, in gear speed curves and gear ratios from the Porsche car handbooks i.e. choose the speed you're considering, match it to a gear on the in gear chart, look up the gear ratios to find find the rpm, use the rpm to get the torque, use the gear ratios to get a multiplier for the torque to get thrust. then plot the thrust (force accelerating the car) against speed. Then repeat many times for different speeds (say every 5 mph) on a spreadsheet. If you're comparing different cars you can bring their weights (masses technically) into it to account for any differences in how much they weigh e.g. for a given thrust, a car weighing 10% more will accelerate 10% less since Acceleration = Force / MassHow did you get it btw?
At least that's how I'd do it!
Here's my effort for a version of fioran0's acceleration chart. Points to note:
1) It accounts for weight of the cars as per the other graph does
2) It uses the gear ratio figures to calculate km/h per 1k rpm, referenced on speed in 2nd gear for each car at redline (6.5k in the 993, 7.8k in the GT4, 8.4k in the GT3). I do not have gearing info for the GT4, but AP seemed to say it was the same as the GTS, so I have assumed it will do the same speed speed in 2nd gear as the GTS, just at alightly higher revs as it goes to 7.8k rather than 7.4k i.e. it has a slightly shorter final drive. If it doesn't and the gearing is *exactly* the same as the GTS, it has a very negative impact on performance so this is the "best" case
3) It doesn't account for drag, but I'm working on a rough calc to include it, not sure it'll bring much to the party though
4) Acceleration on y-axis is plotted as a percentage of the max acceleration achieved in 2nd gear in the 993 NVR - I figured that 2nd gear shove is where we subconsciously "butt dyno" a car on the road so it seemed a useful normlizing figure.
5) Torque figures used in the calcs were read off factory dyno charts from the owners manuals every 500rpm on each rev range with the 250rpm intervals extrapolated as a mid value between the 2 points either side
Any questions, fire away.
Enjoy....
It's not beyond the realms of possibility I might find calc errors, but will update the chart if I do.
If anyone has exact gearing data for the GT4 let me know and I'll update the chart if it's diff to what I used
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