951 Spec to be Competitive with 997 GT3 RS
06-16-2010, 10:31 AM
#46
Nordschleife Master
The thead is called 951 to be competitive with 997 GT3 RS if you expected anything different then I don't know what to say.
Your Pal
Fishey
06-16-2010, 10:44 AM
#48
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
06-16-2010, 11:02 AM
#50
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
Yes, it is entitled “951 spec to be competitive with 997 GT3 RS”. And you came up with a spec that is not what I would call a 944 and also fails to meet most of the other requirements made by the original poster –
Okay - so there are a lot of projects going on out there, all with different objectives. If I set as my objective the creation of 951 which could be competitive for performance with a 997 GT3 RS both on road & track (with the emphasis on track) what specification would be required, bearing in mind I'd be looking for the most cost-effective options. The car must retain a full interior, not be caged & retain its original bodywork. Tim
A couple other issues:
The V8 powered 944 will not be street legal (as a Porsche 944) in many states.
How much development time will you need to get all the custom one off parts to work in a real track environment? Very few highly modified 944s actually get sorted out due to this expense. Roy Chong had been sorting out his old 944 turbo for over a decade before it was totaled last year…most quit long before that!
The list of modifications / fabrication you listed, if done professionally and correctly, will get the price of the 944 up to the price of a good used GT3Rs….while the original poster did not mention any budget constraints I live in the real world and always consider the budget as part of the viability of a project. If there is no budget restrictions then yes, buy a F1 car and put a fiberglass 944 body on it….
BTW – have you ever driven a GT3 (regular or RS) on the track? How about ridden in one on the track? If not you don’t really know what you are up against…..
BTW – if I do make an exception and say that your proposed list is a 944 and qualifies the 911GT3RS will still kick its butt in anything longer than a short sprint race….2 hour race – GT3 wins, 6 hour race – 944 won’t even finish…
06-16-2010, 01:43 PM
#51
Drifting
Join Date: Dec 2002
Location: Phila.
Posts: 2,290
Likes: 0
Received 0 Likes
on
0 Posts
I disagree 100%
A few reasons I disagree is that the GT3 RS is a production car it has its limitations put in place.
Anyways, as far as setting up a 944 to compete I would do it something like this very generic
LS3 Head/Cam/Intake/Drysump
Multi Disk Clutch
Aluminum Torque Tube
951 Turbo Gearbox + larger cooler
Gearbox Mount Modified + Braced
Aluminum Shift Rod (Long black thing)
Shifter Linkage Change (Throw modification)
Large brake setup with 13-14" rotors front and rear. 2pc floating rotor setup
kokeln style Rear suspension setup
Fabricated front control arms + extended 19mm spindles
Aftermarket front hubs
kokeln swaybar or other adjustable sway setup.
Penske/Moton/Ohlin Coilover shocks front and rear
Seemwelded and braced Chassis
Aftermarket lighter sound proofing + thinner carpet
Aero changes (lights/Wing/Splitter)
Wheels/Tires
1. Lets just look at the specs of a 911 GT3 RS
SAE Net Horsepower @ RPM 450 @ 7900
SAE Net Torque 317 lb.-ft.
Front Tire 245/35 ZR19
Rear Tire Size 325/30 ZR19
Base Curb Weight 3020 lbs
Height, Overall 50.4 in
Track Width, Front 60.2 in
Track Width, Rear 61.4 in
Drag .33
2. Now lets look at a logical setup on a 944 chassis
LS3 Head/Cam/Intake
SAE Net Horsepower @ RPM 575 @ 6500
SAE Net Torque 522lb.-ft
Front Tire Size (without width added) 275/35/ZR18
Rear Tire Size (without width added) 295/30/ZR18
Base Curb Weight 2625lbs(Tony G) 2998(S2) I am guessing realistic 2800lbs for our Street/Race 944.
Height, Overall 50.20 in Stock / 48.20 in Lowered
Track Width, Front 58.20in +2 in for increased tire/rim width 60.20in
Track Width, Rear 57.10in + 2 in for increased tire/rim width 59.10in
Drag .33 (Added Tire Width and modifications to keep similar downforce as a 911 GT3 RS) .38-.40
So looking at the physical between a GT3RS and a properly setup 944 we know off the start 125hp advantage 944 and 320lbs advantage. The 944 is giving up advantages to the 911 GT3 RS in a few places. The very first and most obvious area is Aero Dynamics. The GT3 has years of racing development passed down from the GT3 Cup and GT3 RSR that allow it to achive better downforce with less drag. The second advantage for the 911 would be rear suspension. The front suspensions between the two cars are very similar in design but the rear are very different. Obviously the 944 rear shock setup is going to be modified significantly most likely with a Kokeln type setup. This suspension however does not allow for any kinematic toe or camber compression change.
I think it would be very hard for the GT3 RS to overcome the weight/power disadvantage. Also, its suspension disadvantage is reduced by having a production style shock vs a full racing coilover.
Thats just my $.02
A few reasons I disagree is that the GT3 RS is a production car it has its limitations put in place.
Anyways, as far as setting up a 944 to compete I would do it something like this very generic
LS3 Head/Cam/Intake/Drysump
Multi Disk Clutch
Aluminum Torque Tube
951 Turbo Gearbox + larger cooler
Gearbox Mount Modified + Braced
Aluminum Shift Rod (Long black thing)
Shifter Linkage Change (Throw modification)
Large brake setup with 13-14" rotors front and rear. 2pc floating rotor setup
kokeln style Rear suspension setup
Fabricated front control arms + extended 19mm spindles
Aftermarket front hubs
kokeln swaybar or other adjustable sway setup.
Penske/Moton/Ohlin Coilover shocks front and rear
Seemwelded and braced Chassis
Aftermarket lighter sound proofing + thinner carpet
Aero changes (lights/Wing/Splitter)
Wheels/Tires
1. Lets just look at the specs of a 911 GT3 RS
SAE Net Horsepower @ RPM 450 @ 7900
SAE Net Torque 317 lb.-ft.
Front Tire 245/35 ZR19
Rear Tire Size 325/30 ZR19
Base Curb Weight 3020 lbs
Height, Overall 50.4 in
Track Width, Front 60.2 in
Track Width, Rear 61.4 in
Drag .33
2. Now lets look at a logical setup on a 944 chassis
LS3 Head/Cam/Intake
SAE Net Horsepower @ RPM 575 @ 6500
SAE Net Torque 522lb.-ft
Front Tire Size (without width added) 275/35/ZR18
Rear Tire Size (without width added) 295/30/ZR18
Base Curb Weight 2625lbs(Tony G) 2998(S2) I am guessing realistic 2800lbs for our Street/Race 944.
Height, Overall 50.20 in Stock / 48.20 in Lowered
Track Width, Front 58.20in +2 in for increased tire/rim width 60.20in
Track Width, Rear 57.10in + 2 in for increased tire/rim width 59.10in
Drag .33 (Added Tire Width and modifications to keep similar downforce as a 911 GT3 RS) .38-.40
So looking at the physical between a GT3RS and a properly setup 944 we know off the start 125hp advantage 944 and 320lbs advantage. The 944 is giving up advantages to the 911 GT3 RS in a few places. The very first and most obvious area is Aero Dynamics. The GT3 has years of racing development passed down from the GT3 Cup and GT3 RSR that allow it to achive better downforce with less drag. The second advantage for the 911 would be rear suspension. The front suspensions between the two cars are very similar in design but the rear are very different. Obviously the 944 rear shock setup is going to be modified significantly most likely with a Kokeln type setup. This suspension however does not allow for any kinematic toe or camber compression change.
I think it would be very hard for the GT3 RS to overcome the weight/power disadvantage. Also, its suspension disadvantage is reduced by having a production style shock vs a full racing coilover.
Thats just my $.02
Also this production car ran in the 24 hr of nurburgring and finished 13th overall.
06-16-2010, 02:26 PM
#52
Nordschleife Master
Dear Fishey,
Yes, it is entitled “951 spec to be competitive with 997 GT3 RS”. And you came up with a spec that is not what I would call a 944 and also fails to meet most of the other requirements made by the original poster –
As I said I don’t consider a V8 powered 944 a 944 anymore – I am not saying that V8 powered 944 are ‘bad’, they are just not 944s anymore.
A couple other issues:
The V8 powered 944 will not be street legal (as a Porsche 944) in many states.
How much development time will you need to get all the custom one off parts to work in a real track environment? Very few highly modified 944s actually get sorted out due to this expense. Roy Chong had been sorting out his old 944 turbo for over a decade before it was totaled last year…most quit long before that!
The list of modifications / fabrication you listed, if done professionally and correctly, will get the price of the 944 up to the price of a good used GT3Rs….while the original poster did not mention any budget constraints I live in the real world and always consider the budget as part of the viability of a project. If there is no budget restrictions then yes, buy a F1 car and put a fiberglass 944 body on it….
BTW – have you ever driven a GT3 (regular or RS) on the track? How about ridden in one on the track? If not you don’t really know what you are up against…..
BTW – if I do make an exception and say that your proposed list is a 944 and qualifies the 911GT3RS will still kick its butt in anything longer than a short sprint race….2 hour race – GT3 wins, 6 hour race – 944 won’t even finish…
Yes, it is entitled “951 spec to be competitive with 997 GT3 RS”. And you came up with a spec that is not what I would call a 944 and also fails to meet most of the other requirements made by the original poster –
As I said I don’t consider a V8 powered 944 a 944 anymore – I am not saying that V8 powered 944 are ‘bad’, they are just not 944s anymore.
A couple other issues:
The V8 powered 944 will not be street legal (as a Porsche 944) in many states.
How much development time will you need to get all the custom one off parts to work in a real track environment? Very few highly modified 944s actually get sorted out due to this expense. Roy Chong had been sorting out his old 944 turbo for over a decade before it was totaled last year…most quit long before that!
The list of modifications / fabrication you listed, if done professionally and correctly, will get the price of the 944 up to the price of a good used GT3Rs….while the original poster did not mention any budget constraints I live in the real world and always consider the budget as part of the viability of a project. If there is no budget restrictions then yes, buy a F1 car and put a fiberglass 944 body on it….
BTW – have you ever driven a GT3 (regular or RS) on the track? How about ridden in one on the track? If not you don’t really know what you are up against…..
BTW – if I do make an exception and say that your proposed list is a 944 and qualifies the 911GT3RS will still kick its butt in anything longer than a short sprint race….2 hour race – GT3 wins, 6 hour race – 944 won’t even finish…
Second, Regardless of how you feel about the V8 option the fact remains that VIN numbers follow Chassis not Engines and as such are totally street legal so long as they meet emission laws in your state. Also, your insurance usually wants to have this information so they can jack your rates. Think about all hot rod owners that don't have matching engines are there cars not street legal? Seriously?
Third, 944 Chassis with proper modification has proven to be a reliable setup in endurance racing over the last 20+ Years. If you are talking about the LS3 Chevy Engine, Palm Face.
Fourth, Car setup really? Now, I will admit that it can be hard to get the perfect setup takes knowledge and Experience. Also, conditions will always be a factor. That being said getting a base setup and general feeling of the car is not very difficult if you use your brain. The same can be said for a 911 GT3 RS if you want to set it up perfectly its going to take time so I fail to see your point.
Fifth, Why do I have to drive any certain car? A simple look at lap times will give an idea of there speed.
06-16-2010, 03:11 PM
#53
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
Second, Regardless of how you feel about the V8 option the fact remains that VIN numbers follow Chassis not Engines and as such are totally street legal so long as they meet emission laws in your state. Also, your insurance usually wants to have this information so they can jack your rates. Think about all hot rod owners that don't have matching engines are there cars not street legal? Seriously?
I suppose you can always just lie about it and hope not to get caught….
Actually I would love to see what you would do to make a 951 gear box last behind a well-built V8 in an endurance setting….
Palm Face? All I saw was a Lilly white hand waving around that doesn’t look like it has ever seen the business end of a wrench!
Fourth, Car setup really? Now, I will admit that it can be hard to get the perfect setup takes knowledge and Experience. Also, conditions will always be a factor. That being said getting a base setup and general feeling of the car is not very difficult if you use your brain. The same can be said for a 911 GT3 RS if you want to set it up perfectly its going to take time so I fail to see your point.
In the end it’s a pointless debate – you are not going to build the car of your spec so you can feel free to imagine what it could do, hell it might even break the speed of light….
06-16-2010, 03:50 PM
#54
Pro
Join Date: Aug 2002
Location: Netherlands
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
06-16-2010, 03:53 PM
#55
Pro
Join Date: Aug 2002
Location: Netherlands
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
The Kokeln setup was for me one of the cheapest ways to lower the car and loose weight. A custom setup would have been more expensive.
06-16-2010, 04:03 PM
#56
Rennlist Member
Hans, pm sent. 
06-16-2010, 04:21 PM
#57
Nordschleife Master
What is your reasoning and/or experience as to why a 944 won't work in an endurance race.
I know a few people have tried it, and it didn't work...but has it been the cars fault?
06-16-2010, 07:28 PM
#58
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
Its not our cars fault, its just lack of development of true racing parts. Our cars were never really raced with factory support and the cost to develop those parts is a lot higher than most folks can afford.
A good example is how many dry sump 944s have most people seen? Not many…and that is pretty much a mandatory part to go GT class racing (If you want it to last!)
The other problem is that most of us are running with a lot more power than stock. I believe you could make a 944 NA into a successful endurance racer a lot easier than a 944 turbo. If you were to take a GT3 and double the horsepower you would have similar problems getting it to last.
06-16-2010, 11:51 PM
#60
Drifting
Join Date: Dec 2002
Location: Phila.
Posts: 2,290
Likes: 0
Received 0 Likes
on
0 Posts
That's the development that chris is talking about. Say you get the engine to be reliable for 24 hours of all out running. You have to think about the heat that builds up in all components after a short amount of time and is then constant for hours. Wear and tear take on a new meaning. Things off the top of my head that could fail after hours of racing on a stock type car;
wheel bearings/hubs - stock front's won't last long
spindles - probable fatigue failure in an endurance race
CV axles
trans - won't last long unless you are babying it, in which case you won't be keeping up with a GT3RS
oil temps ok?
coolant temps ok?
ball joints
Control arms
rear trailing arm shock mounts - single shear lower won't fly
clutch fork
brake cooling sufficient?
shifter/anything in the linkage