USA enthusiast media test Carrera GT in Italy
03-19-2004, 09:29 AM
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USA enthusiast media test Carrera GT in Italy
I just had a delightful conversation with a writer for an American car magazine who had been testing the Carrera GT in Italy. This was apparently a USA media event held at a small, tight race track in Italy. The writer said that it was not conducive to high speeds and was "about as tight as a kart track" (maybe some hyperbole here).
At least one other writer with whom I am very familiar was in attendance from a competing magazine.
There were two test cars; a red one and a silver one. They were prototypes with sequence number "0000" on the dashboard. This sounds like the same two cars used in the European tests with which we are already familiar.
The following quick numbers were recited:
0-60 MPH = 3.5 seconds
0-100 MPH = 6.8 seconds
0-130 MPH = 10.8 seconds
1/4 mile = 12.2 seconds @ 132 MPH
70-0 MPH Braking = 145 feet - this result was the shortest braking distance that the editor could remember ever recording.
Max Lateral g = 1.1 g measured in average mode with VBOX GPS vehicle dynamics measurement system. (unknown averaging period)
The other writer measured 1.25 g using the instantaneous mode on the VBOX and looking for local data peaks.
The Enzo was tested some time ago using the average mode on the VBOX and came out at 1.03 g.
Tidbits:
As to fluid leak on Tim Allen's CGT; there are no external oil lines that connect the engine to the oil tank that is housed in the transmission casting. There are cast, or machined, oil passages in the two castings that are joined by gaskets at the mating surfaces where the engine and transmission castings are joined.
The carbon fiber body and chassis supplier is the same as for the Enzo (we already knew that). The CGT carbon fiber parts are produced at a rate of 2 per day until the Enzo production is completed. After that, the rate goes up to 2.7 per day. This starts in the Fall.
The 1/4 mile times are "conservative', and limited by available traction. All accelleration runs were conducted with the traction control "ON". Without TC engaged, the launches were described as "buck, smoke 'em, or stall". The difficulty comes from the very light rotating inertia of the engine. It is super quick to rev, but there is very little rotary inertia stored in the engine/flywheel/clutch to "dump" into the tires on launch. Makes it tough to perfect quick times.
The clutch doesn't really slip any appreciable amount. The take up distance in the clutch pedal is only about one inch. Motoring away from rest is easy on the flat by letting out the clutch pedal at idle, and then gently adding some gas. The editor said it was comfortable, but he might be nervous if he had to pull out of a parking spot going up-hill. He allowed that more practice time would certainly help.
The ceramic clutch seemed extraordiarily durable -- "took a sh** load of abuse". The writer for the competing magazine (known for abusing clutches to obtain stellar 0-60 times) asked the Porsche techs if they planned to replace the clutch after the testing. They replied, "No. ... Why?"
The lower control arms of the suspension on the CGT are made of steel because alloy isn't strong enough due to their unusual length. The "longness" contributes to better (lower) camber changes during jounce or rebound of the suspension. The control arms have been given an air-foil shape to help them intrude less on the aerodynamics of the rear under-body diffusers through which they pass.
The review is scheduled to print in May with a June, 2004 cover date.
That's about all I can remember from the conversation.
------------------------------------------------------------------------------
OK, I just remembered a bit more.
When the writer made some extemely superlative comments about the how the CGT was "pretty much the top sports car in the world" (re: my order, He kept saying how lucky I was, how fortunate I was, and how envious he was ), I was naturally curious if that judgment included the Enzo.
That is how the Enzo's 1.03 g in average mode on the VBOX came up.
I asked him to compare the CGT and Enzo. He said that he really couldn't do any fine comparisons of the differences in driving dynamics because it had been way too long since he drove the Enzo. He considered the dynamic performance of both cars to be roughly comparable.
He did say that he liked the manual gear change in the CGT better than the F1 shifter in the Enzo, but that was just his personal taste. The CGT shifter is not a cable shifter like the 996, but uses rods and he says feels terrific.
His overall feeling about the two cars came down to where each company had drawn the line between street car and race car. He thought Porsche had done the better job of finding the more perfect place to draw it. He said the fact that it was a convertible really pushed the CGT ahead.
---------------------
More remembering:
The writer really liked the view forward in the Carrera GT. In fact, he said the outward visibility, in general, was first rate. The door mirrors are quite large (maybe 11" wide X 5" tall) and made blind spots a thing of the past. The only caveat he had about the mirrors were that they somewhat obstructed his 10:00 and 14:00 vision. I asked if jay-walking pedestrians should fear the CGT and we shared a good laugh over it
Apparently, carbon fiber doesn't like to cooperate with making a beautiful painted surface. The body has something on the order of 30 kg of surface filler applied to cover up the "grain" or "mesh" effect that would otherwise result by painting the carbon panels directly.
Speaking of carbon fiber, when Porsche decided to make the engine cradle out of CF (instead of the already-been-done aluminum frame), some careful planning for engine cooling was part of the design. Since CFRP is plastic with carbon stiffeners, it doesn't have the same temperature-vs-strength performance as metals. It is stronger and lighter than metals at reasonable temperatures, but its mechanical properties fall off as temperature increases much more quickly than metals. As a result, there is quite a bit of exotic planning and engineering devoted to heat extraction from the major heat sources in the car. The writer marveled at the different coolers, radiators, and fans placed in just the right spots with careful attention to air flow that makes the heat management result so effective.
I mentioned the pictures on the web of Tim Allen's car, partially disassembled, that showed a front-mounted radiator that appeared to me to be the size of a small card table. He agreed that it was , in fact, a whopper of a radiator and might be as large as one square meter. I asked how the heated air was exhausted after passing through it, was it dumped underneath the car? He said, no, the airflow was split into two half-streams and directed into the wheel wells, where it could flow out the huge vents on the aft side of the front fenders -- just in front of the doors. I mentioned that when I had looked over the show car in Geneva, it looked to me like the front of the car was shaped like an F1 or Indy car with some fenders draped over the aerodynamics. He agreed that it appeared the same way to him.
At least one other writer with whom I am very familiar was in attendance from a competing magazine.
There were two test cars; a red one and a silver one. They were prototypes with sequence number "0000" on the dashboard. This sounds like the same two cars used in the European tests with which we are already familiar.
The following quick numbers were recited:
0-60 MPH = 3.5 seconds
0-100 MPH = 6.8 seconds
0-130 MPH = 10.8 seconds
1/4 mile = 12.2 seconds @ 132 MPH
70-0 MPH Braking = 145 feet - this result was the shortest braking distance that the editor could remember ever recording.
Max Lateral g = 1.1 g measured in average mode with VBOX GPS vehicle dynamics measurement system. (unknown averaging period)
The other writer measured 1.25 g using the instantaneous mode on the VBOX and looking for local data peaks.
The Enzo was tested some time ago using the average mode on the VBOX and came out at 1.03 g.
Tidbits:
As to fluid leak on Tim Allen's CGT; there are no external oil lines that connect the engine to the oil tank that is housed in the transmission casting. There are cast, or machined, oil passages in the two castings that are joined by gaskets at the mating surfaces where the engine and transmission castings are joined.
The carbon fiber body and chassis supplier is the same as for the Enzo (we already knew that). The CGT carbon fiber parts are produced at a rate of 2 per day until the Enzo production is completed. After that, the rate goes up to 2.7 per day. This starts in the Fall.
The 1/4 mile times are "conservative', and limited by available traction. All accelleration runs were conducted with the traction control "ON". Without TC engaged, the launches were described as "buck, smoke 'em, or stall". The difficulty comes from the very light rotating inertia of the engine. It is super quick to rev, but there is very little rotary inertia stored in the engine/flywheel/clutch to "dump" into the tires on launch. Makes it tough to perfect quick times.
The clutch doesn't really slip any appreciable amount. The take up distance in the clutch pedal is only about one inch. Motoring away from rest is easy on the flat by letting out the clutch pedal at idle, and then gently adding some gas. The editor said it was comfortable, but he might be nervous if he had to pull out of a parking spot going up-hill. He allowed that more practice time would certainly help.
The ceramic clutch seemed extraordiarily durable -- "took a sh** load of abuse". The writer for the competing magazine (known for abusing clutches to obtain stellar 0-60 times) asked the Porsche techs if they planned to replace the clutch after the testing. They replied, "No. ... Why?"
The lower control arms of the suspension on the CGT are made of steel because alloy isn't strong enough due to their unusual length. The "longness" contributes to better (lower) camber changes during jounce or rebound of the suspension. The control arms have been given an air-foil shape to help them intrude less on the aerodynamics of the rear under-body diffusers through which they pass.
The review is scheduled to print in May with a June, 2004 cover date.
That's about all I can remember from the conversation.
------------------------------------------------------------------------------
OK, I just remembered a bit more.
When the writer made some extemely superlative comments about the how the CGT was "pretty much the top sports car in the world" (re: my order, He kept saying how lucky I was, how fortunate I was, and how envious he was ), I was naturally curious if that judgment included the Enzo.
That is how the Enzo's 1.03 g in average mode on the VBOX came up.
I asked him to compare the CGT and Enzo. He said that he really couldn't do any fine comparisons of the differences in driving dynamics because it had been way too long since he drove the Enzo. He considered the dynamic performance of both cars to be roughly comparable.
He did say that he liked the manual gear change in the CGT better than the F1 shifter in the Enzo, but that was just his personal taste. The CGT shifter is not a cable shifter like the 996, but uses rods and he says feels terrific.
His overall feeling about the two cars came down to where each company had drawn the line between street car and race car. He thought Porsche had done the better job of finding the more perfect place to draw it. He said the fact that it was a convertible really pushed the CGT ahead.
---------------------
More remembering:
The writer really liked the view forward in the Carrera GT. In fact, he said the outward visibility, in general, was first rate. The door mirrors are quite large (maybe 11" wide X 5" tall) and made blind spots a thing of the past. The only caveat he had about the mirrors were that they somewhat obstructed his 10:00 and 14:00 vision. I asked if jay-walking pedestrians should fear the CGT and we shared a good laugh over it
Apparently, carbon fiber doesn't like to cooperate with making a beautiful painted surface. The body has something on the order of 30 kg of surface filler applied to cover up the "grain" or "mesh" effect that would otherwise result by painting the carbon panels directly.
Speaking of carbon fiber, when Porsche decided to make the engine cradle out of CF (instead of the already-been-done aluminum frame), some careful planning for engine cooling was part of the design. Since CFRP is plastic with carbon stiffeners, it doesn't have the same temperature-vs-strength performance as metals. It is stronger and lighter than metals at reasonable temperatures, but its mechanical properties fall off as temperature increases much more quickly than metals. As a result, there is quite a bit of exotic planning and engineering devoted to heat extraction from the major heat sources in the car. The writer marveled at the different coolers, radiators, and fans placed in just the right spots with careful attention to air flow that makes the heat management result so effective.
I mentioned the pictures on the web of Tim Allen's car, partially disassembled, that showed a front-mounted radiator that appeared to me to be the size of a small card table. He agreed that it was , in fact, a whopper of a radiator and might be as large as one square meter. I asked how the heated air was exhausted after passing through it, was it dumped underneath the car? He said, no, the airflow was split into two half-streams and directed into the wheel wells, where it could flow out the huge vents on the aft side of the front fenders -- just in front of the doors. I mentioned that when I had looked over the show car in Geneva, it looked to me like the front of the car was shaped like an F1 or Indy car with some fenders draped over the aerodynamics. He agreed that it appeared the same way to him.
03-19-2004, 10:50 AM
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Originally posted by Sloth
Thanks for passing on the info Mike.
Have you scheduled your CGT taxi ride yet???
Thanks for passing on the info Mike.
Have you scheduled your CGT taxi ride yet???
No, not yet. I'm working out some issues with PCNA about trying out a wide option seat. I might be able to do it in Atlanta.
Cheers,
03-19-2004, 10:36 PM
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Originally posted by ben in lj
they have both seats available for fitment in leipzig if you were to attend the taxi ride.
they have both seats available for fitment in leipzig if you were to attend the taxi ride.
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03-21-2004, 12:08 AM
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Those quarter mile times and 0 to 60 times are a total joke for a half million dollar car. When those times hit the American Mags that car will be a laughing stock. The car can't get off the line because it lacks the torque to do it. You guys can tell me all day long about how this car is more than just a performance number car and is a track car. But the fact of the matter is when you come out of a hairpin or any corner where you need to downshift to first gear and leave that corner to go down a long straight the performance numbers of 0 to 60 and quarter mile times are very relevant. I am really disappointed.
03-21-2004, 10:18 AM
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Wow,... it's time to calm down, Les.
"when you come out of a hairpin or any corner where you need to downshift to first gear and leave that corner to go down a long straight the performance numbers of 0 to 60 and quarter mile times are very relevant."
What is needed in these cases is great power-to-weight ratio. Zero to sixty times and quarter mile times are an indicator of power-to-weight ratio. But if the launch is compromised by limited traction, their indicating power is seriously compromised. If you read the notes I took from the conversation with the tester, you will notice that the launch was still a work in progress for him. He got a 0-130 MPH time of 10.8 seconds, while European testers measured numbers varying between 10.2 and 10.9 seconds for 0-124 MPH. The quarter mile times I quoted may have been a listening error on my part, or a transcription error on his part, because they don't square with the 132 MPH trap speed.
Porsche's official advertised time for 0-124 MPH is 9.9 seconds. Perhaps their test drivers are more accomplished at leaving the line optimally, or the production cars are somewhat lighter that the prototypes which are available to the media for testing.
"The car can't get off the line because it lacks the torque to do it."
I don't see how you can make this assumption. It has enough torque to smoke the back wheels if the traction control is turned off for the launch. I'd say it doesn't have enough rear-wheel grip to get all the torque to the ground in a controlled way. Most drag-race launches require some slippage in one or more drive-train components to maximise power transfer at the beginning of the run. If the clutch won't slip, all that's left is the tires. If the tires slip too much, power transfer ends up melting a puddle of rubber and causing little forward motion. It's a bit more complicated than it looks, perhaps
"when you come out of a hairpin or any corner where you need to downshift to first gear and leave that corner to go down a long straight the performance numbers of 0 to 60 and quarter mile times are very relevant."
What is needed in these cases is great power-to-weight ratio. Zero to sixty times and quarter mile times are an indicator of power-to-weight ratio. But if the launch is compromised by limited traction, their indicating power is seriously compromised. If you read the notes I took from the conversation with the tester, you will notice that the launch was still a work in progress for him. He got a 0-130 MPH time of 10.8 seconds, while European testers measured numbers varying between 10.2 and 10.9 seconds for 0-124 MPH. The quarter mile times I quoted may have been a listening error on my part, or a transcription error on his part, because they don't square with the 132 MPH trap speed.
Porsche's official advertised time for 0-124 MPH is 9.9 seconds. Perhaps their test drivers are more accomplished at leaving the line optimally, or the production cars are somewhat lighter that the prototypes which are available to the media for testing.
"The car can't get off the line because it lacks the torque to do it."
I don't see how you can make this assumption. It has enough torque to smoke the back wheels if the traction control is turned off for the launch. I'd say it doesn't have enough rear-wheel grip to get all the torque to the ground in a controlled way. Most drag-race launches require some slippage in one or more drive-train components to maximise power transfer at the beginning of the run. If the clutch won't slip, all that's left is the tires. If the tires slip too much, power transfer ends up melting a puddle of rubber and causing little forward motion. It's a bit more complicated than it looks, perhaps
03-21-2004, 12:54 PM
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The poor launch times have more to do with the short clutch takeup, lightweight flywheel, and low reciprocating mass of the engine. From my ride in the CGT... it is certainly not lacking in torque. IMHO... 0-60 time is a poor benchmark for any of these performance cars.
03-21-2004, 11:05 PM
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Wow... my jaw has officially hit the floor.
1) Sloth, how did you get a ride, and how can I get a ride?!
2) Mike, you've owned more Porsches then I've owned boxers I think... are you planning on getting a CGT? If so, when you get it, can I drive up there and get a ride in it?...or a parking lot drive??
3) The Enzo posted lateral acceleration figures in upward of 1.36g... can I get a ride in one of them?!
4) The FSAE Auto-X beast not only matched the CGT's 0-60 time with me driving, we also beat both cars peak cornering g's! ...even though it's not as amazing and technologically advanced, I got a ride AND was asked to get it on video
...now I don't feel so bad about never getting a drive in a CGT, lol
... does anyone know how many RL'ers have a CGT on order?
1) Sloth, how did you get a ride, and how can I get a ride?!
2) Mike, you've owned more Porsches then I've owned boxers I think... are you planning on getting a CGT? If so, when you get it, can I drive up there and get a ride in it?...or a parking lot drive??
3) The Enzo posted lateral acceleration figures in upward of 1.36g... can I get a ride in one of them?!
4) The FSAE Auto-X beast not only matched the CGT's 0-60 time with me driving, we also beat both cars peak cornering g's! ...even though it's not as amazing and technologically advanced, I got a ride AND was asked to get it on video
...now I don't feel so bad about never getting a drive in a CGT, lol... does anyone know how many RL'ers have a CGT on order?
03-22-2004, 02:16 AM
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Mike,
You are right I need to calm down about this car. And I agree in general with your post.
What drives me crazy about this car. Is I am really trying to like it. As a matter of fact after looking at Toby's slideshow on the gallery. I called my dealer and got myself back on the list to get a CGT. Then I read your post about this clutch from hell that no one except the Porsche test drivers seem to be able to comfortably drive. And those poor performance numbers and I am back in CGT 446,000 hell!
You guys may think these quarter mile and 0 to 60 times are inconsequential but Porsche thinks they are important enough to insert in the CGT product information guide and sales brochures.
The other thing about these performance numbers that gets me is that the 11.4 quarter mile time Porsche states the car will do has not yet been duplicated by anyone else who drives the car. Can anyone remember the last time a Porsche did not err on the side of being conservative? My experience has been that Porsche's numbers were always on the low side. Not with this car. OK I am calm now.
You are right I need to calm down about this car. And I agree in general with your post.
What drives me crazy about this car. Is I am really trying to like it. As a matter of fact after looking at Toby's slideshow on the gallery. I called my dealer and got myself back on the list to get a CGT. Then I read your post about this clutch from hell that no one except the Porsche test drivers seem to be able to comfortably drive. And those poor performance numbers and I am back in CGT 446,000 hell!
You guys may think these quarter mile and 0 to 60 times are inconsequential but Porsche thinks they are important enough to insert in the CGT product information guide and sales brochures.
The other thing about these performance numbers that gets me is that the 11.4 quarter mile time Porsche states the car will do has not yet been duplicated by anyone else who drives the car. Can anyone remember the last time a Porsche did not err on the side of being conservative? My experience has been that Porsche's numbers were always on the low side. Not with this car. OK I am calm now.
03-22-2004, 05:16 AM
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The "FSAE Auto-X beast" I refer to is my school's Formula SAE racecar.
To watch Kevin do 0-60mph in 3.5 second, click here
To watch pure abuse (I was asked to do this for the camera, I swear!) and to get a decent laugh, click here
Sorry for the confusion, I lose all coherence when excited past a certain point
hehe
To watch Kevin do 0-60mph in 3.5 second, click here
To watch pure abuse (I was asked to do this for the camera, I swear!) and to get a decent laugh, click here
Sorry for the confusion, I lose all coherence when excited past a certain point
hehe
03-22-2004, 11:13 AM
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Originally posted by FSAEracer03
Wow... my jaw has officially hit the floor.
1) Sloth, how did you get a ride, and how can I get a ride?!
Wow... my jaw has officially hit the floor.
1) Sloth, how did you get a ride, and how can I get a ride?!
Originally posted by Les Quam
Then I read your post about this clutch from hell that no one except the Porsche test drivers seem to be able to comfortably drive.
Then I read your post about this clutch from hell that no one except the Porsche test drivers seem to be able to comfortably drive.