RS 4.0 vs 991 R
Discussion
martinday said:
This youtube video shows a 991R being launched :
https://www.youtube.com/watch?v=hA8eqCPgZe8
at 44 seconds into the video the car is at 6k revs and is doing about 51kph so 8.5k revs would give 72kph = 45mph so nowhere near cracking 100kph in first
. Just to play Devils advocate:https://www.youtube.com/watch?v=hA8eqCPgZe8
at 44 seconds into the video the car is at 6k revs and is doing about 51kph so 8.5k revs would give 72kph = 45mph so nowhere near cracking 100kph in first
• wheel spin in first gear
• second gear shows 98 kph @ 6000 rpm equates to 84.233 mph @ 8,300 rpm ( not including some wheelspin and digital speedo lag)
• car settles at103 kph in third gear (@49secs)@ 4200 rpm. Scales up to around 127 mph .(not allowing drag etc.)
Comparing those numbers to 911R's charts would make the 3.09 final drive about right and much longer geared than the 4.0 and GT3 991.
Edited by johnint on Thursday 17th November 16:20
Well I've geeked out a bit having some time on my hands. I believe the press brochure is in error with final drive 3.09 for the R and it's actually 3.89
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
[quote=isaldiri]Well I've geeked out a bit having some time on my hands. I believe the press brochure is in error with final drive 3.09 for the R and it's actually 3.89
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.[/
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.[/
Edited by johnint on Thursday 17th November 19:40
Magic919 said:
These are my calculated top speeds (mph) through the gears assuming a 3.89 diff. This assumes 8500 revs.
47
74
102
131
163
200
That's really useful. Would you be able to do the same maths for 3.09 final drive so we could correlate the video gearing of approx 24/25kph per 1000 rpm in third, finally solving the mystery!Thanks in advance47
74
102
131
163
200
Edited by johnint on Thursday 17th November 18:34
Magic919 said:
Sure. Here's the 3.09 version in mph.
59
93
129
166
206
253
That would mean top speed in fifth and sixth as a cruiser gear (which doesn't fit the reviews).
Thanks.just found a Sport Auto video "Colle del Nivolet" clearly shows 8400 rpm in third at 166 kph so Isildiri is right and it's consistent with your original figures. 59
93
129
166
206
253
That would mean top speed in fifth and sixth as a cruiser gear (which doesn't fit the reviews).
isaldiri said:
Well I've geeked out a bit having some time on my hands. I believe the press brochure is in error with final drive 3.09 for the R and it's actually 3.89
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
The line in the brochure says :Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
Final Drive Ratio 3.09 (constant 1.216)
What does the the "constant 1.216" part mean? 3.09 * 1.216 = 3.76 Is that the true final ratio?
Did a few laps of Silverstone a couple of weeks ago.
This was an early lap, and not ideal as you'll see, but it will show you how nicely spread the ratios are, and give some idea of the car.
NB Copse in normally 4th gear without the traffic. Also was usually quicker into first part of Maggots/Beckett's but didn't want to catch cars in front mid-corner. Same at Luffield,
Max speed was 152mph in 5th down Hangar Straight, never got into 6th, which is for Autobhan speeds or saving fuel!
https://youtu.be/Fo1bcg_wMrU
This was an early lap, and not ideal as you'll see, but it will show you how nicely spread the ratios are, and give some idea of the car.
NB Copse in normally 4th gear without the traffic. Also was usually quicker into first part of Maggots/Beckett's but didn't want to catch cars in front mid-corner. Same at Luffield,
Max speed was 152mph in 5th down Hangar Straight, never got into 6th, which is for Autobhan speeds or saving fuel!
https://youtu.be/Fo1bcg_wMrU
isaldiri said:
Well I've geeked out a bit having some time on my hands. I believe the press brochure is in error with final drive 3.09 for the R and it's actually 3.89
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
Porsche are very good at re-using the same parts as far as possible. the standard final drive for a lot of cars is 3.44 but there was a 3.89 used in the 7.2RS that reappeared in the gt4 that imo has likely been reused here. 3rd gear in the R at 7.5k rpm at 3rd gear per the video would be around 90mph ie 152kmh and 7k rpm in 4th gear would be around 110mph or 180kmh. Which kind of matches the video listed above give or take some speedo lag/inaccuracy. 3.09 final drive would give numbers way different to the speeds in the video.
Magic919 said:
These are my calculated top speeds (mph) through the gears assuming a 3.89 diff. This assumes 8500 revs.
47
74
102
131
163
200
That certainly makes more sense. It puts each ratio within +/- 3mph of the RS 4.0 (except for 6th being +7 in the R).47
74
102
131
163
200
Edited by turbofreeFLAT6 on Friday 18th November 01:08
APOLO1 said:
R has first 4 ratios same as 991GT3. It will hit red line at 74mph in 2nd, 91RS hits same at 64mph. The R seems to be geared just about perfect.
Apolo1 was 100% accurate and same for 91RS. Apologies but it was an interesting typo!Edited by johnint on Friday 18th November 04:46
I have the 991 RS in gear speeds people were asking about.
1: 48 mph
2: 75mph
3: 104 mph
4: 134 mph
5: 162
6: 187
7: 193
and a crazy tested time of 6.6 to 100mph, that's bloody 911 turbo fast !!!
and 0-140mph in 13.3 seconds, that one strong 4.0l NA motor !
1: 48 mph
2: 75mph
3: 104 mph
4: 134 mph
5: 162
6: 187
7: 193
and a crazy tested time of 6.6 to 100mph, that's bloody 911 turbo fast !!!
and 0-140mph in 13.3 seconds, that one strong 4.0l NA motor !
Edited by Porsche911R on Wednesday 7th December 21:42
Porsche911R said:
I have the 991 RS in gear speeds people were asking about.
1: 48 mph
2: 75mph
3: 104 mph
4: 134 mph
5: 162
6: 187
7: 193
and a crazy tested time of 6.6 to 100mph, that's bloody 911 turbo fast !!!
and 0-140mph in 13.3 seconds, that one strong 4.0l NA motor !
Where did you get these figures from, all independant figures i've read have the 991GT3 RS hitting the ton in around mid 7's eg Autocar 0-100 in 7.8secs.1: 48 mph
2: 75mph
3: 104 mph
4: 134 mph
5: 162
6: 187
7: 193
and a crazy tested time of 6.6 to 100mph, that's bloody 911 turbo fast !!!
and 0-140mph in 13.3 seconds, that one strong 4.0l NA motor !
Edited by Porsche911R on Wednesday 7th December 21:42
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