Rolex 24 Hour
01-29-2007, 12:18 AM
#1
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Thread Starter
Rolex 24 Hour
Porsche won the GT class by the skin of their teeth - the 2nd place Pontiac was within 1 mile of the class-winning GT3 when the checkered flag dropped.
The class-winning car of Jean-Francois Dumolin et al had been put backwards hard into a tire wall at least once early on, and was a ragged mess by the end of the race with duct tape flapping at many points, as well as having problems with overheating. But it soldiered on and got the job done.
The only GT3 engine failure I saw (read "blowup") was the # 85 car, which fell out of the class lead in a large cloud of smoke. The other GT3s to fall out succumbed, I think, to driver error or other mechanical maladies. Quite a testament to the robustness of our engine/tranny!
The TV coverage mentioned that the 997 GT3 Cup cars in the race were a special batch "built to Grand Am specs". I note they had red brakes and didn't have centerlock wheels(!). Anyone know what these cars are? 3.6L, 3.8L, HP, weight?
Thanks.
The class-winning car of Jean-Francois Dumolin et al had been put backwards hard into a tire wall at least once early on, and was a ragged mess by the end of the race with duct tape flapping at many points, as well as having problems with overheating. But it soldiered on and got the job done.
The only GT3 engine failure I saw (read "blowup") was the # 85 car, which fell out of the class lead in a large cloud of smoke. The other GT3s to fall out succumbed, I think, to driver error or other mechanical maladies. Quite a testament to the robustness of our engine/tranny!
The TV coverage mentioned that the 997 GT3 Cup cars in the race were a special batch "built to Grand Am specs". I note they had red brakes and didn't have centerlock wheels(!). Anyone know what these cars are? 3.6L, 3.8L, HP, weight?
Thanks.
01-29-2007, 01:09 AM
#2
Originally Posted by khaug
...The TV coverage mentioned that the 997 GT3 Cup cars in the race were a special batch "built to Grand Am specs". I note they had red brakes and didn't have centerlock wheels(!). Anyone know what these cars are? 3.6L, 3.8L, HP, weight?
Thanks.
Thanks.
In Fla on vacation, I took my wife & two daughters for the Rolex' final two hours today..... as Karl mentioned above, it was surreal to watch Dumolin's GT3 tattered rear body panels somehow resisting the turbulence, flapping away as they blasted past us at 170mph+... one unmistakable fact= the GT3 drivetrains are bulletproof!
I would recommend this race esp. to anyone with kids interested in cars-- I was impressed with the basic $30/ Unreserved Grandstand seats which allowed incredible views ($15/ea. available for w/military or college i.d.), young kids free (unlike Mid-Ohio lawn seats, the kids definitely need earplugs). Choice of seats- for every seat occupied there were one hundred empty seats. As usual, the parking lot outside had nearly as many interesting machines as inside... every 20th car in parking lot was a 911 variant from last 40 yrs, no kidding!
01-29-2007, 08:39 AM
#3
[QUOTE=khaug
The TV coverage mentioned that the 997 GT3 Cup cars in the race were a special batch "built to Grand Am specs". I note they had red brakes and didn't have centerlock wheels(!). Anyone know what these cars are? 3.6L, 3.8L, HP, weight?
Thanks.[/QUOTE]
Evidently there is a fair amount of modification to get a Cup Car to comform to Grand Am Specs and I understand that Porsche produced 11 (?) cars that meet the specs right out of the box.
As you mentioned they have the 5 bolt hubs and I'm sure the weight is correct. The motor is still the 3.6L motor but I'm not sure if the HP is the same but it 's probably the max allowed by rules.
It's amazing that the Pontiacs are basically tube frame race cars (like last years GTO's) and are allowed to compete with production Porsches.
Hope this helps.
The TV coverage mentioned that the 997 GT3 Cup cars in the race were a special batch "built to Grand Am specs". I note they had red brakes and didn't have centerlock wheels(!). Anyone know what these cars are? 3.6L, 3.8L, HP, weight?
Thanks.[/QUOTE]
Evidently there is a fair amount of modification to get a Cup Car to comform to Grand Am Specs and I understand that Porsche produced 11 (?) cars that meet the specs right out of the box.
As you mentioned they have the 5 bolt hubs and I'm sure the weight is correct. The motor is still the 3.6L motor but I'm not sure if the HP is the same but it 's probably the max allowed by rules.
It's amazing that the Pontiacs are basically tube frame race cars (like last years GTO's) and are allowed to compete with production Porsches.
Hope this helps.
01-29-2007, 10:02 AM
#4
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Specs:
Specs:
2007 Porsche 911 GT3 Cup - Grand Am Version
Vehicle Description (997 Type)
Concept:
- single-seated, near-standard race vehicle
in accordance with the 2006 Grand American Rolex Series Regulations
Engine:
- water cooled flat six-cylinder boxer engine
- 3,598 cc, stroke 76.4 mm, bore 99,98 mm diameter
- max. power: 309 kW (420 BHP)
- max. torque: 410 Nm
- max. rpm: 8,400 rpm
- four valves per cylinder
- dry-sump lubrication
- two-stage resonance intake manifold, central inlet air duct
- electronic engine management system MS 3.1
- sequential multi-point fuel injection
- required fuel quality: 98 octane ROZ, unleaded
- race exhaust system in accordance with Grand-Am Regulations
Power Train:
- six-speed sequential dog-type gearbox
gear ratios:
ring & pinion gear 8/32 i = 4.0
1st gear 12/38 i = 3.16
2nd gear 15/32 i = 2.13
3rd gear 18/31 i = 1.72
4th gear 20/28 i = 1.40
5th gear 26/30 i = 1.15
6th gear 28/27 i = 0.96
- pressure-oil lubrication
- oil-water heat exchanger
- single-mass flywheel
- hydraulic clutch center-release mechanism
- 5.5" triple-disc sintered-metal clutch
- limited slip differential 40/60 per cent
- rear-wheel drive
Bodywork:
- self-supporting body shell made out of galvanized sheet steel
- carbon fiber doors with window frame and plastic rear-view mirrors
- carbon fiber rear lid
- welded-in roll cage incl. shoulder- and door bar
- air jack system
- aerodynamically optimized front bumper and front spoiler edge
- carbon fiber rear bumper
- racing seat (driver side only) with fire retardant upholstery
- six-point seat belt
- removable steering wheel (with quick-release coupling)
- electric fire extinguishing system
- 100 liter FT3 fuel tank
Suspension:
Front axle:
- McPherson strut-type axle
- all struts supported by Unibal links
- Sachs gas pressure shock absorbers
- double coil springs (main spring and helper spring)
- two-piece lower control arms for camber adjustment
- blade-type anti-roll bar
- damper mounted to upright with twin-clamp system
- power steering with electro-hydraulic pressure feed
Rear axle:
- multilink rear suspension with solidly mounted sub frame
- all struts supported by Unibal links
- Sachs gas pressure shock absorbers
- double coil springs (main spring and helper spring)
- two-piece lower control arms for camber adjustment
- reinforced, continuously variable rear axle track rod
- blade-type anti-roll bar
- suspension continuously variable (height, camber, track)
Brake System:
- brake system with adjustable bias bar
Front axle:
- aluminum six-piston calipers, in accordance with the 2006 Grand
American Rolex Series Regulations
internally vented brake discs, 380 mm diameter, race brake pads
Rear axle:
- aluminum four-piston calipers, in accordance with the 2006 Grand
American Rolex Series Regulations
internally vented brake discs, 355 mm diameter, race brake pads
Rims/Tires:
Front axle:
- three-piece BBS aluminum rims (9J x 18)
- delivered with Michelin rain tires (24/64-18)
- final rim size and offset will be determined by Hoosier tire sizes
Rear axle:
- three-piece BBS aluminum rims (11,5J x 18)
- delivered with Michelin rain tires (27/68-18)
- final rim size and offset will be determined by Hoosier tire sizes
Electrics:
- Motec display with integrated data recording
- battery: 12 Volt, 50 Ah
- 90 Ah generator
Vehicle Weight:
- approx. 1140 kg
Colors:
(water-based paint)
Exterior: Carrera white B9A
Interior: white filler coat, no clear-coat finish
Vehicle Description (997 Type)
Concept:
- single-seated, near-standard race vehicle
in accordance with the 2006 Grand American Rolex Series Regulations
Engine:
- water cooled flat six-cylinder boxer engine
- 3,598 cc, stroke 76.4 mm, bore 99,98 mm diameter
- max. power: 309 kW (420 BHP)
- max. torque: 410 Nm
- max. rpm: 8,400 rpm
- four valves per cylinder
- dry-sump lubrication
- two-stage resonance intake manifold, central inlet air duct
- electronic engine management system MS 3.1
- sequential multi-point fuel injection
- required fuel quality: 98 octane ROZ, unleaded
- race exhaust system in accordance with Grand-Am Regulations
Power Train:
- six-speed sequential dog-type gearbox
gear ratios:
ring & pinion gear 8/32 i = 4.0
1st gear 12/38 i = 3.16
2nd gear 15/32 i = 2.13
3rd gear 18/31 i = 1.72
4th gear 20/28 i = 1.40
5th gear 26/30 i = 1.15
6th gear 28/27 i = 0.96
- pressure-oil lubrication
- oil-water heat exchanger
- single-mass flywheel
- hydraulic clutch center-release mechanism
- 5.5" triple-disc sintered-metal clutch
- limited slip differential 40/60 per cent
- rear-wheel drive
Bodywork:
- self-supporting body shell made out of galvanized sheet steel
- carbon fiber doors with window frame and plastic rear-view mirrors
- carbon fiber rear lid
- welded-in roll cage incl. shoulder- and door bar
- air jack system
- aerodynamically optimized front bumper and front spoiler edge
- carbon fiber rear bumper
- racing seat (driver side only) with fire retardant upholstery
- six-point seat belt
- removable steering wheel (with quick-release coupling)
- electric fire extinguishing system
- 100 liter FT3 fuel tank
Suspension:
Front axle:
- McPherson strut-type axle
- all struts supported by Unibal links
- Sachs gas pressure shock absorbers
- double coil springs (main spring and helper spring)
- two-piece lower control arms for camber adjustment
- blade-type anti-roll bar
- damper mounted to upright with twin-clamp system
- power steering with electro-hydraulic pressure feed
Rear axle:
- multilink rear suspension with solidly mounted sub frame
- all struts supported by Unibal links
- Sachs gas pressure shock absorbers
- double coil springs (main spring and helper spring)
- two-piece lower control arms for camber adjustment
- reinforced, continuously variable rear axle track rod
- blade-type anti-roll bar
- suspension continuously variable (height, camber, track)
Brake System:
- brake system with adjustable bias bar
Front axle:
- aluminum six-piston calipers, in accordance with the 2006 Grand
American Rolex Series Regulations
internally vented brake discs, 380 mm diameter, race brake pads
Rear axle:
- aluminum four-piston calipers, in accordance with the 2006 Grand
American Rolex Series Regulations
internally vented brake discs, 355 mm diameter, race brake pads
Rims/Tires:
Front axle:
- three-piece BBS aluminum rims (9J x 18)
- delivered with Michelin rain tires (24/64-18)
- final rim size and offset will be determined by Hoosier tire sizes
Rear axle:
- three-piece BBS aluminum rims (11,5J x 18)
- delivered with Michelin rain tires (27/68-18)
- final rim size and offset will be determined by Hoosier tire sizes
Electrics:
- Motec display with integrated data recording
- battery: 12 Volt, 50 Ah
- 90 Ah generator
Vehicle Weight:
- approx. 1140 kg
Colors:
(water-based paint)
Exterior: Carrera white B9A
Interior: white filler coat, no clear-coat finish
01-29-2007, 03:26 PM
#6
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Member
I saw a few more engine failures before the event started. I even took a quick photo of the one from the Synergy Racing pole sitting GT3.
I also saw this Koni Challenge car in the garage area while I was there:
I also saw this Koni Challenge car in the garage area while I was there:
01-29-2007, 05:43 PM
#7
Originally Posted by Michael B.
I saw a few more engine failures before the event started. I even took a quick photo of the one from the Synergy Racing pole sitting GT3.
I also saw this Koni Challenge car in the garage area while I was there:
I also saw this Koni Challenge car in the garage area while I was there:
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01-30-2007, 02:15 AM
#10
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As I recall the Grand Am GT rules were changed to require 5 bolt wheel attachment (as opposed to a center lock) for the GT cars after the TRG outright victory in a GT3RS a few years ago. Grand Am didn't want to see the Daytona prototypes beat by a GT car. Five bolt wheels mean longer pit stops. So, five bolt wheels are one aspect of a "Grand Am" spec car.
01-30-2007, 03:15 AM
#11
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It's amazing that the Pontiacs are basically tube frame race cars (like last years GT
Are you sure they are tube frame cars the comontater said they were 480 pounds heavier than the porsches.
02-20-2007, 01:08 AM
#13
I figure Daytona is still 'on topic' since this weekend.
Came across this article from a few yrs ago..... thought it's a quick, interesting read/pics-- at least for relative novices like myself!
http://info.detnews.com/joyrides/story/index.cfm?id=148
Came across this article from a few yrs ago..... thought it's a quick, interesting read/pics-- at least for relative novices like myself!
http://info.detnews.com/joyrides/story/index.cfm?id=148