The real 100-300kph ultimate hp test thread
03-04-2007, 03:54 PM
#46
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Originally Posted by Stummel
The only solution besides ignoring all this shyt is to have the RT12 race against TBs RS 993tt.
03-04-2007, 06:40 PM
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Without wishing to enter into the battle about Ruf vs RS there is one part of Tobys post that interested me, which was the 200-300kph figures:
RS Tuning GT2 542hp 17.8s
RS Tuning 996tt 569hp 12.8s
That to me is a simply massive difference in performance, if correct. Given that both cars have the same frontal area and the same gear ratios (excluding the minor difference in rear tyre rolling radius). The first difference is in aerodynamics of course. This difference alone would account for a minor improvement in performance, as would the claimed extra 17bhp. However, there's simply no way that even to the untrained eye that these two minor changes could result in such a dramatic difference in performance. I say this because I've run at VMax a few times in various cars and the 996GT2 vs X50 TT is not massively different at high speeds, the aerodynamic impact is there, but not to the degree of these numbers.
On the quoted numbers the 569bhp RS TT is equal to the 750bhp Gemballa and slightly faster than the 650bhp RT12. I therefore flat out refuse to believe that the car tested had only 569bhp as quoted, given the comparables (and the comparable car claimed by RS itself).
Jean - can you please run your aerodynamic calculations on these two cars and see what your formulas puts the power figures at for the two times quoted, as frankly the 996TT figure just has to be wrong and I'd like to know with some science what you make of it.
Thanks
Guy
RS Tuning GT2 542hp 17.8s
RS Tuning 996tt 569hp 12.8s
That to me is a simply massive difference in performance, if correct. Given that both cars have the same frontal area and the same gear ratios (excluding the minor difference in rear tyre rolling radius). The first difference is in aerodynamics of course. This difference alone would account for a minor improvement in performance, as would the claimed extra 17bhp. However, there's simply no way that even to the untrained eye that these two minor changes could result in such a dramatic difference in performance. I say this because I've run at VMax a few times in various cars and the 996GT2 vs X50 TT is not massively different at high speeds, the aerodynamic impact is there, but not to the degree of these numbers.
On the quoted numbers the 569bhp RS TT is equal to the 750bhp Gemballa and slightly faster than the 650bhp RT12. I therefore flat out refuse to believe that the car tested had only 569bhp as quoted, given the comparables (and the comparable car claimed by RS itself).
Jean - can you please run your aerodynamic calculations on these two cars and see what your formulas puts the power figures at for the two times quoted, as frankly the 996TT figure just has to be wrong and I'd like to know with some science what you make of it.
Thanks
Guy
03-04-2007, 07:34 PM
#48
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Guy, Of course I agree re. theRS 542hp996GT2 versus RS 569hp996tt...... it looks wrong,the performance numbers are from the test on the first page (of this thread) from 911 & P world, I have no idea who took the numbers etc....
I do have another set of numbers for the 569hp RS 996tt which were done by the French mag "Flat Six" - they show it weighing 1536kg and do 80-150kph in 5.121s and 100-200kph in 7.978s so the 0-200kph looks about right...
As you have said before, tuners may be downplaying hp numbers (as they, RS, have done before IMO) to get headlines but currently I think that the majority of tuners are just taking the easy option and going with whatever their "dyno" tells them -which may or may not be Porsche hp.....I would like to wait until the ~520hp 997GT2 comes out and posts a ~30sec 0-300kph time before getting stuck into debating this further
I do have another set of numbers for the 569hp RS 996tt which were done by the French mag "Flat Six" - they show it weighing 1536kg and do 80-150kph in 5.121s and 100-200kph in 7.978s so the 0-200kph looks about right...
As you have said before, tuners may be downplaying hp numbers (as they, RS, have done before IMO) to get headlines but currently I think that the majority of tuners are just taking the easy option and going with whatever their "dyno" tells them -which may or may not be Porsche hp.....I would like to wait until the ~520hp 997GT2 comes out and posts a ~30sec 0-300kph time before getting stuck into debating this further
03-04-2007, 07:40 PM
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Guy, you kindly gave me your AX22 file for your storming 201mph vmax run - here is the 200-300kph portion: 17.6s......
which puts you 128metres ahead of my 19.2s run at 300kph -sort of puts into perspective how the seemingly small differences (eg 19.2 vs 17.6) actually are substantial on the ground, 128 metres is 420ft
which puts you 128metres ahead of my 19.2s run at 300kph -sort of puts into perspective how the seemingly small differences (eg 19.2 vs 17.6) actually are substantial on the ground, 128 metres is 420ft
Last edited by TB993tt; 03-04-2007 at 08:12 PM.
03-04-2007, 11:49 PM
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Guy,
Thanks for your interested post, I was starting to wonder if this is of any interest to Rennlisters.
I was surprised to see how important the impact of GT2 drag is on its performance at high speed. I posted below the findings. Remeber this is based on a 993TT with 450PS, I am simply doing changes to the aerodynamics. The CDA of the 996GT2 is 8% worse than the 996TT, again emphasizing that handling is more important than top speed depending on the objectives.
I can do the same simulations for your particular car if you have a dyno sheet or any other for that matter.
The difference is 3.1 seconds when reaching 300kph. In distance terms, it corresponds to 1,803 meters to the 996TT (5,915ft.) vs. 2,050 meters for the 996GT2 (6,725 ft.), a difference of 247 meters, 810 feet!. This is strictly the aerodynamic impact.
Hope this helps.
Edit: I have seen the Gemballa GTR750, the wing it has would stop an airplane from flying.
Thanks for your interested post, I was starting to wonder if this is of any interest to Rennlisters.
I was surprised to see how important the impact of GT2 drag is on its performance at high speed. I posted below the findings. Remeber this is based on a 993TT with 450PS, I am simply doing changes to the aerodynamics. The CDA of the 996GT2 is 8% worse than the 996TT, again emphasizing that handling is more important than top speed depending on the objectives.
I can do the same simulations for your particular car if you have a dyno sheet or any other for that matter.
Originally Posted by Jean
Let us talk in practical terms now. Base is a 993TT 450PS with 993TT drag.
Acceleration 200-300kph:
993TT with 996TT Body
CDA: 0.62
Time: 24.8 s.
Drag at 300kph: 1.56 m/s.sq.
993TT with 996GT2 Body
CDA: 0.67
Time: 27.9s.
Drag at 300kph: 1.68 m/s.sq.
All the above numbers were obtained through data at a multitude of points involving acceleration Gs, rolling resistence, aero drag, torque etc, etc..for every 0.05 seconds, they are not an average.
I can draw a graph of time vs speed and drag showing the acceleration lines and gear shifts etc, same as what a datalogger would, for the above simulations, it will take a while, but idf someone is genuinely interested I would not mind doing it.
Acceleration 200-300kph:
993TT with 996TT Body
CDA: 0.62
Time: 24.8 s.
Drag at 300kph: 1.56 m/s.sq.
993TT with 996GT2 Body
CDA: 0.67
Time: 27.9s.
Drag at 300kph: 1.68 m/s.sq.
All the above numbers were obtained through data at a multitude of points involving acceleration Gs, rolling resistence, aero drag, torque etc, etc..for every 0.05 seconds, they are not an average.
I can draw a graph of time vs speed and drag showing the acceleration lines and gear shifts etc, same as what a datalogger would, for the above simulations, it will take a while, but idf someone is genuinely interested I would not mind doing it.
Hope this helps.
Edit: I have seen the Gemballa GTR750, the wing it has would stop an airplane from flying.
Last edited by Jean; 03-05-2007 at 01:57 AM.
03-05-2007, 02:54 AM
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The Gemballa cars for the press are mainly build to beat Ring records and not to beat 0-300kph records.
RS "street" cars are more build for Autobahn performance and mostly have only minor aero mods.
RS "street" cars are more build for Autobahn performance and mostly have only minor aero mods.
03-05-2007, 04:50 AM
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Originally Posted by Stummel
I can somehow follow why Leon is rejecting all this theoretical estimates based on his believes and the money he put down for the Ruf cars.
The only thing that he has seen first hand is that his old Ruf has beaten TBs RS car. The thing here is that I am sure Leon does not believe TBs car was in limb mode back then.
As the RT12 outperforms the R Turbo for sure it makes no sense for him that TBs car should outperform the RT12... (Being faster in a straight line is at least a transitive function.)
The only solution besides ignoring all this shyt is to have the RT12 race against TBs RS 993tt.
The only thing that he has seen first hand is that his old Ruf has beaten TBs RS car. The thing here is that I am sure Leon does not believe TBs car was in limb mode back then.
As the RT12 outperforms the R Turbo for sure it makes no sense for him that TBs car should outperform the RT12... (Being faster in a straight line is at least a transitive function.)
The only solution besides ignoring all this shyt is to have the RT12 race against TBs RS 993tt.
The RT12 is much faster than the rturbo (beleive me) and since TB can't compete with the slower of my cars he wouldn't want to embarass himself again, time to
i think IMHO he should massage his ego more with optimistic speculative estimates..
03-05-2007, 06:01 AM
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Originally Posted by TB993tt
Guy, you kindly gave me your AX22 file for your storming 201mph vmax run - here is the 200-300kph portion: 17.6s......
03-05-2007, 07:44 AM
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Guy
As you know all the motors heat soak and it is the degree to which they do which I guess determines the max speed they can achieve....For example Leon's 993 on the run on the video managed 195mph against my 193mph across the beams which is surprising considering he is way ahead on the video -my guess is heat soak taking its toll ?
Your point about the performance looking similar approaching 180 made me think about my "handicap" on that day - the unplugged I/C sensor makes the ECU revert to a default 52.5 DegCintake temp -you may be able to make it out on the printout below -this retards timing by 4.5% (highlighted at the bottom) and backs the boost off a little (highlighted at the top) -My guess is that with the temp sensor plugged in the intake temp over 150mph after 10+ seconds at WOT must be approaching the 52.5DegC level anyway, so perhaps this IS the best performance my engine can put out (although I would hope the Secan would do its thing) ?
You can see when the intake temp hits 70.5DegC there is a further backing off timing and at 80.25 DegC the boost is pulled back by some 15%
As you know all the motors heat soak and it is the degree to which they do which I guess determines the max speed they can achieve....For example Leon's 993 on the run on the video managed 195mph against my 193mph across the beams which is surprising considering he is way ahead on the video -my guess is heat soak taking its toll ?
Your point about the performance looking similar approaching 180 made me think about my "handicap" on that day - the unplugged I/C sensor makes the ECU revert to a default 52.5 DegCintake temp -you may be able to make it out on the printout below -this retards timing by 4.5% (highlighted at the bottom) and backs the boost off a little (highlighted at the top) -My guess is that with the temp sensor plugged in the intake temp over 150mph after 10+ seconds at WOT must be approaching the 52.5DegC level anyway, so perhaps this IS the best performance my engine can put out (although I would hope the Secan would do its thing) ?
You can see when the intake temp hits 70.5DegC there is a further backing off timing and at 80.25 DegC the boost is pulled back by some 15%
03-05-2007, 05:11 PM
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In our German forum a guy wrote something very interesting about the 997tt.
There is a "rumor" about the 997tt reducing boost when the exhaust temps reach 860 degree celsius at the sensor near the 1st lambda probe. This is kind of hidden as it is not shown on the boost gauge.
This would perfectly explain the crappy 100-200kph times of even the tuned 997tt.
The 0-100kph figures are fantastic though.
There is a "rumor" about the 997tt reducing boost when the exhaust temps reach 860 degree celsius at the sensor near the 1st lambda probe. This is kind of hidden as it is not shown on the boost gauge.
This would perfectly explain the crappy 100-200kph times of even the tuned 997tt.
The 0-100kph figures are fantastic though.
03-05-2007, 10:30 PM
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Dear Leon,
My 911 is not, nor will not, be turboed. Even so, I come to this forum to gain understanding. It has profited me well. Someone as Jean, with whom I've had disagreement, has been most patient, kind, and always a gentleman. I put trust in his experience; I place honor in his integity. It is the fiber that holds any society together.
I would respectfully request that you, while you may strongly disagree with his summations, would maintain the same higher ground that he seeks. It can only serve all of us well.
You've a fabulous car and should be rightfully proud. I only ask for a gentleman's consideration.
I thoroughly enjoy the technical dialogue on this forum and hold out hope that everyone will continue to enlarge my understanding of the cars we all enjoy.
My best,
Noah
My 911 is not, nor will not, be turboed. Even so, I come to this forum to gain understanding. It has profited me well. Someone as Jean, with whom I've had disagreement, has been most patient, kind, and always a gentleman. I put trust in his experience; I place honor in his integity. It is the fiber that holds any society together.
I would respectfully request that you, while you may strongly disagree with his summations, would maintain the same higher ground that he seeks. It can only serve all of us well.
You've a fabulous car and should be rightfully proud. I only ask for a gentleman's consideration.
I thoroughly enjoy the technical dialogue on this forum and hold out hope that everyone will continue to enlarge my understanding of the cars we all enjoy.
My best,
Noah
03-06-2007, 06:33 AM
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Originally Posted by N51
Dear Leon,
My 911 is not, nor will not, be turboed. Even so, I come to this forum to gain understanding. It has profited me well. Someone as Jean, with whom I've had disagreement, has been most patient, kind, and always a gentleman. I put trust in his experience; I place honor in his integity. It is the fiber that holds any society together.
I would respectfully request that you, while you may strongly disagree with his summations, would maintain the same higher ground that he seeks. It can only serve all of us well.
You've a fabulous car and should be rightfully proud. I only ask for a gentleman's consideration.
I thoroughly enjoy the technical dialogue on this forum and hold out hope that everyone will continue to enlarge my understanding of the cars we all enjoy.
My best,
Noah
My 911 is not, nor will not, be turboed. Even so, I come to this forum to gain understanding. It has profited me well. Someone as Jean, with whom I've had disagreement, has been most patient, kind, and always a gentleman. I put trust in his experience; I place honor in his integity. It is the fiber that holds any society together.
I would respectfully request that you, while you may strongly disagree with his summations, would maintain the same higher ground that he seeks. It can only serve all of us well.
You've a fabulous car and should be rightfully proud. I only ask for a gentleman's consideration.
I thoroughly enjoy the technical dialogue on this forum and hold out hope that everyone will continue to enlarge my understanding of the cars we all enjoy.
My best,
Noah
03-06-2007, 06:42 AM
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Originally Posted by TB993tt
Guy
As you know all the motors heat soak and it is the degree to which they do which I guess determines the max speed they can achieve....For example Leon's 993 on the run on the video managed 195mph against my 193mph across the beams which is surprising considering he is way ahead on the video -my guess is heat soak taking its toll ?
Your point about the performance looking similar approaching 180 made me think about my "handicap" on that day - the unplugged I/C sensor makes the ECU revert to a default 52.5 DegCintake temp -you may be able to make it out on the printout below -this retards timing by 4.5% (highlighted at the bottom) and backs the boost off a little (highlighted at the top) -My guess is that with the temp sensor plugged in the intake temp over 150mph after 10+ seconds at WOT must be approaching the 52.5DegC level anyway, so perhaps this IS the best performance my engine can put out (although I would hope the Secan would do its thing) ?
You can see when the intake temp hits 70.5DegC there is a further backing off timing and at 80.25 DegC the boost is pulled back by some 15%
As you know all the motors heat soak and it is the degree to which they do which I guess determines the max speed they can achieve....For example Leon's 993 on the run on the video managed 195mph against my 193mph across the beams which is surprising considering he is way ahead on the video -my guess is heat soak taking its toll ?
Your point about the performance looking similar approaching 180 made me think about my "handicap" on that day - the unplugged I/C sensor makes the ECU revert to a default 52.5 DegCintake temp -you may be able to make it out on the printout below -this retards timing by 4.5% (highlighted at the bottom) and backs the boost off a little (highlighted at the top) -My guess is that with the temp sensor plugged in the intake temp over 150mph after 10+ seconds at WOT must be approaching the 52.5DegC level anyway, so perhaps this IS the best performance my engine can put out (although I would hope the Secan would do its thing) ?
You can see when the intake temp hits 70.5DegC there is a further backing off timing and at 80.25 DegC the boost is pulled back by some 15%
03-06-2007, 09:55 AM
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Noah,
Thank you for your kind words, mature discussions we had indeed despite our disagreements. Thanks for that.
Leon,
There is enough data posted here and on other threads to show that he was indeed "handicapped"..
If I was the one having run against him, I would have certainly admitted that at least. No one is saying you did not win that day, these are 2 very different things.
Would it be possible for you to get an AX22 and do some 100-200kph runs for us or 100-300kph next time you are at the track, it would be very interesting to have an RT12 in the database.
Geoff , Guy, I provided the data you asked for, any comments, questions, more info?
Thank you for your kind words, mature discussions we had indeed despite our disagreements. Thanks for that.
Leon,
There is enough data posted here and on other threads to show that he was indeed "handicapped"..
If I was the one having run against him, I would have certainly admitted that at least. No one is saying you did not win that day, these are 2 very different things.
Would it be possible for you to get an AX22 and do some 100-200kph runs for us or 100-300kph next time you are at the track, it would be very interesting to have an RT12 in the database.
Geoff , Guy, I provided the data you asked for, any comments, questions, more info?
