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Wachuko 04-07-2009 12:40 PM

America GS Consolidated Thread

The America GS 3.8 Hardtop Roadster, is a one of a kind car. It is a cabriolet (manually operated) with a Porsche factory built removable hardtop (with an electric sunroof and a heated rear windscreen). It has a special Porsche factory built roll bar covered in the America GS purple leather and embossed with the Porsche script. As of 2005 the car has approximately 350 miles on it.

I am pretty sure that most of you track and await all updates from Robert on the work he is doing in his car. From time to time I see questions on the car and the parts. We all know, from Robert comments, that there is not going to be a book about this car (there should be one)... I figured that the best we can do is try to consolidate all we know about it in one thread for everyone to enjoy.

Many of us here keep an eye for any of Robert’s posts to get a glimpse of the car. It was been in a few books as well but only with brief comments, never covered in full detail (specially after all the work he has done to it). The amount of people involved, the work with Porsche, some of the mystery, the use of the technology in racing, etc… We are really fortunate to have him share time, comments, and photos with this global community.

If I miss any photos, comments or details please chime in and update the thread with comments and photos I might have missed. There are old threads where the photos are missing (Rennlist crash or move to new servers :( )

And here is to the hope of seeing this beauty in person one day :cheers:. Anthony (Cobalt) had the opportunity to see it in person, as you can read in one of the threads.

I know Robert has made many post here in RL, and this is not a compilation of all his threads, just those specific to the America GS. But if you have the time, search on his threads, we are very lucky and honored to have him here sharing what he does and his insight or stories of timed shared with great legends in the automotive business.

And the company behind these parts? Cartridge Limited

Why is he calling it Humpty Dumpty? Humpty Dumpty because it was apart and put back together again... no falls, no walls, no crash involved.

Humpty Dumpty Is Coming Back Together
Humpty Dumpty On The Move
Carbon Fiber Oil Tubes
America GS Wheels
Pacem In Terris - We Have A Hood
Carbon Fiber Fan Shroud
Pieces Of The Last 6 Parts Of Humpty Dumpty Part I
Humpty Dumpty Wheels
Other Titanium Pieces
Which Finish Would You Prefer For Anti Roll Bars?
Let No Stone Go Unturned For Humpty Dumpty
Carbon Fiber Oil Cooler/AC Condenser Fan
Rear Hinges For Humpty Dumpty
Humpty Dumpty Titanium Hood Hinges
Another Potential Weight Saving. Can Anyone Answer The Question?
New Humpty Dumpty Parts
Weight Reduction In The Transmission Mount
Would Like Your Opinion As To What Part Goes Into Humpty Dumpty
The 5 HP Gadget
Transmission Goes Back Into Humpty Dumpty - Almost!
Humpty Dumpty Front Suspension Goes Together
Humpty Dumpty Interior Pictures
Humpty Dumpty Mirror
Humpty Dumpty Headlight
Humpty Dumpty Update - titanium license plate frame
Humpty Dumpty Rear Wing Blade
A Special Brake Part
Humpty Dumpty Exhaust
Every Detail Counts - ABS pump bracket
A Special Humpty Dumpty Part
Humpty Dumpty Update
Humpty Dumpty Rear Damper Mount
Humpty Dumpty Fuel Cell
A Few MORE Humpty Dumpty Pictures
My Engine Is Finally Coming Back Together -- And I Know It's Too Clean
Gold Plated Carbon Fiber Heat Shields
Torque Converter Housing
Brake and water reservoir bracket
Engine Testing Starts
Engine Success 445hp! :thumbup:

Threads with missing photos :( Very sad. The initial threads are missing the photos or linked to incorrect photos (anything that was uploaded later with the same file name is getting picked up by the threads...)

Carbon Fiber Firewall/Electric Circuit Control Box
Wiring Upgrade -- Incorrect Pictures Attached
New Wiring Update
Carbon Fiber Oil Tank
New Carbon Swing Arm
What Engine for the America GS?

Wachuko 04-07-2009 12:47 PM

Let the photos posting begin:

hawk911 04-07-2009 12:58 PM

Jaime, you have too much time on your hands. Come polish my wheels or something productive :icon107:

Wachuko 04-07-2009 01:05 PM

Originally Posted by hawk911 (Post 6459423)
Jaime, you have too much time on your hands. Come polish my wheels or something productive :icon107:

Actually, I don't... but working long hours in front of a computer... so I need a break from time to time. RL is it. Helps me keep my sanity.

Wachuko 04-07-2009 01:24 PM

Light weight, Titanium, Carbon Fiber, Gold, aluminum lithium... words/phrases you will see used often when you start going over the threads... and no, forget about trying to buy any of this stuff... some of the people here have been lucky enough to receive something for their help testing a part... I hope those of you that have a piece of the GS in your cars to chime in and post a photo of the part.

hawk911 04-07-2009 01:38 PM

Those brake calipers are just kick ass sweet!!! It's almost criminal how clean all the parts are.

Wachuko 04-07-2009 01:44 PM

A few more:

Wachuko 04-07-2009 02:09 PM

And a few more:

Wachuko 04-07-2009 02:18 PM

I hope that in the process of uploading I don't repeat too many photos...

Wachuko 04-07-2009 02:41 PM

And a few more:

Wachuko 04-07-2009 03:06 PM

And a few more... swing arms

A few more of the front setup...

hawk911 04-07-2009 03:16 PM

are those ceramic rotors?

Wachuko 04-07-2009 03:54 PM

Originally Posted by hawk911 (Post 6459581)
Those brake calipers are just kick ass sweet!!! It's almost criminal how clean all the parts are.

From an entry Robert made in 2002:

Made out of aluminum lithium (aluminum lithium saves approximately 500 grams per caliper and is the material of which all F1 calipers are currently made).

Wachuko 04-07-2009 03:57 PM

Originally Posted by hawk911 (Post 6459937)
are those ceramic rotors?

From a 2002 post...

Originally Posted by Robert Linton (Post 159888)
...The rotors are not metal matrix composite (MMC), the surprise is that they are carbon ceramic. In fact, I believe that this is the first usage of carbon ceramics for a Type 964.

The weight of the rotor (in this instance, a 14 inch one) is barely a third of the metal equivalent. As to the bell, it weighs approximately one pound, i.e., about a third that of the stainless steel bells currently used by Porsche in connection with the PCCB. The reason Porsche uses a stainless steel version (other than durability) is that, particularly in racing, carbon ceramic disks could see temperatures in excess of 1000 degrees C and aluminum melts at 660 degrees C. Titanium, on the other hand, melts at 1660 degrees C. Hence, by using titanium as the mounting interface and by creating the air gap, lighweight aluminum bells are usable.

The "bobbin" terminology refers to the method of mounting, not the fact that certain of the components (i.e., the ones gold in color due to a protective coat of ti nitride) are titanium. This system, by the way, is similar to the mounting system generally used on F1 cars which use carbon carbon disks.

As to pads, the pads currently available with carbon ceramic brake systems tend to have shortcomings related to the heat that they are forced to absorb due to the nature of carbon ceramics as an insulator. This having been said, giving what is currently available, I would use the Pagid RS-19 compound until a better answer is available (in a few months).

Finally, please note that one cannot simply change metal rotors for carbon ceramics and expect the system to work properly or safely. It is, after all, a system, and, particularly given heat and dynamics issues, the calipers, fluid, hydraulics, ABS, wheel size, tire compound, etc., etc. all must be addressed. Additionally, when this unsprung and rotating much weight is eliminated from each corner, suspension components require alteration for optimal performance.

Lastly, the system pictured above includes a titanium certerlock system which is not required to be used with the carbon ceramics.

P.S. Although MMC rotors have been produced in the past, I know of no credible current application. Titanium rotors are, however, used in certain race applications, i.e., World of Outlaws. For weight and other considerations, I would favor carbon ceramics or carbon carbon if they were allowed in the particular racing class.

Wachuko 04-07-2009 04:48 PM

A few interesting info bits (these are take from posts from Robert... so any "I" you see is Robert... not me :D)

The America GS 3.8 Hardtop Roadster was built a few years after Dr. Porsche's 80th birthday present, the Panamericana. With that extra time, Herr Lagaay (H. Lagaay, retired Chief Stylist of Dr. Ing. h.c. F. Porsche AG) was able to devise a different exterior color, multi-color hand silk-screened primary leather, accent secondary leather, colored seat belts and zipper for the America GS -- which he (and I) thought more than successful than the Panamericana. Hence, while both cars have a type of green on the exterior, they are quite different and the interiors are also quite individual.

With regard to the seats, they were available in several versions of Type 964, are fixed back and, to at least me, are very comfortable while being simultaneously supportive. As to the backs, you are correct -- unlike any of the other versions which were either painted in a color or left black, those of the America GS are completely leather clad (with the racing harness eyelets trimmed in the purple leather). Finally, in this regard, special thanks is due to 3M Corporation which assisted in this effort by sending a 10 gallon drum of a special glue to Porsche AG for use in making the covering of the backs of the seats a permanent affair.

Front Suspension:
- one piece cast titanium uprights with carbon fiber cooling ducts
- ceramic ball wheel bearings
- titanium adjustable ball joints
- carbon fiber a arms
- titanium/aluminum drop links
- titanium/aluminum track rods
- integrated 300M ion impregnated axle/center screws
- titanium centerlock hubs with integrated titanium driving pegs
- 350 mm x 34 mm carbon ceramic brake disks with floating 2618 aluminum bells mounted with titanium bobbin systems with air gaps
- carbon fiber/titanium venturi-effect integrated left and right suspension links, cross-member and under-tray with access door
- titanium fasteners

to this will be attached:

- carbon fiber struts with integrated angle adjustment
- true 4-way adjustable titanium/aluminum dampers with blow off pistons --electron beam welded hard chromed titanium outer shafts and titanium hard chromed inner shafts -- connected by stainless steel braided Raychem covered hoses with machined fittings with –4 titanium quick disconnects to reservoirs with integral adjusters
- aluminum integrated front spring caps/spacer sleeves/nut sleeves
- beta c titanium main and helper springs with ultra high molecular weight plastic transition pieces
- aluminum 4-way spring rate adjusters with integrated titanium locking mechanism
- aluminum lithium monobloc 8 titanium piston calipers with air gaps, two pads per side, quick release pad pins, titanium quick disconnects in place of bleed screws and titanium quick disconnects in the lightweight stainless steel braided Raychem covered hoses with machined titanium fittings between the calipers and the chassis hard lines
- 4130 zinc passivate coated anti roll bar with 5-way adjustable 4130 machined ends with Orkot® bushings, titanium bushing stops, titanium mounting brackets and titanium fasteners
- titanium/steel center lock nuts
- one-piece forged magnesium center lock wheels with titanium pressure shims

1. Blueprinted And Dynamometer Tested
2. America GS Engine Management System Programmed For Use With America GS Tiptronic® Transmission
3. America GS High Flow Hot Wire Induction System
4. Reduced Weight Cam Deck
5. America GS Drilled Camshafts
6. Reduced Weight Adjustable Rocker Arms
7. America GS Cylinder Heads With Copper/Beryllium Valve Seats
8. America GS Cylinders
9. America GS Lightweight Pistons
10. America GS Metal Matrix Composite Wrist Pins
11. America GS Titanium Connecting Rods
12. America GS Aluminum Gears
13. America GS Aluminum Sprockets
14. America GS Titanium Intake Valves
15. America GS Titanium Exhaust Valves
16. Uprated High Pressure Fuel Pump
17. Uprated Fuel Rail
18. Adjustable Fuel Pressure Regulator
19. America GS Engine Oil System
a. America GS Carbon Fiber/Titanium/Aluminum Engine Oil Tank With Uprated Anti-Aeration Cone
b. Increased Pressure And Scavenge Engine Oil Pump
c. America GS Aluminum High Efficiency Triple Engine Oil Cooler System
d. America GS Aluminum Engine Oil Cooler Distribution Manifold
e. America GS Aluminum Engine Oil Lines With Machined Aluminum Fittings
f. America GS Machined Aluminum Engine Oil Line Fitting
g. America GS Machined Aluminum Oil Filter Console Fittings
h. America GS Machined Aluminum Thermostat Fittings
i. Goodridge G-Line XF Engine Oil Hoses With Goodridge Machined Aluminum AN Fittings
20. Uprated Gaskets
21. America GS Increased Flow Air Filter Box With Induction Snorkel And Increased Air Flow Lid
22. BMC America GS Increased Flow Air Filter
23. Plastic Valve Covers
24. Crankshaft, Flywheel, Pressure Plate, Connecting Rods, Connecting Rod Ends And Pistons Balanced
25. Engine Cleaned, Ported And Polished
26. Engine Case Windage Adjusted
27. Engine Case Dovetailed
28. Goodridge G-Line XF Fuel Hoses With Goodridge Machined Aluminum AN Fittings
29. America GS Lightweight Alternator With Titanium Shaft
30. America GS Titanium Pulleys
31. America GS Titanium Cam Deck Fasteners
32. America GS Titanium Chain Housing Covers Fasteners
33. America GS Titanium Fasteners
34. America GS Titanium Washers
35. America GS Titanium Engine Casing Studs
36. America GS Titanium Engine Exhaust Studs
37. America GS Titanium Engine Support Mounting Studs
38. Silver Plated Jet Nuts
39. America GS Carbon Fiber/Aluminum Engine Support/Engine Shroud/Air Conditioning Compressor Mounting Platform
40. America GS Titanium Air Conditioning Compressor Support Bracket And Fasteners
41. America GS Carbon Fiber/Titanium Engine Mounting
42. America GS Carbon Fiber/Titanium Solid Engine Mounts
43. America GS Titanium Engine Mounting Fasteners
44. Castrol RS Synthetic 10W60 Racing Engine Oil


1. Tiptronic® Transmission – Blueprinted, Polished, Reinforced And Dynamometer Tested Race Version
2. High Performance Software For Tiptronic® Transmission Including:
a. Specially Programmed For Use With 3.8 Liter Engine
b. Permits Driver To Hold Transmission In Gear In "Tip" Mode – Transmission Will Not Override Driver
c. Higher Performance In Automatic Mode
d. Transmission "Learning" More Rapid In Automatic Mode
3. Torque Sensing Differential Mounted To Ring Gear With Specifically Made Stainless Steel Bolts
4. Carbon Fiber/Titanium Side Transmission/Differential Housing
5. Wire Electro-Discharge Machined 300M Transmission Output Flanges
6. Lightweight Flywheel
7. Titanium Transmission Linkage Brackets
8. Aluminum High Efficiency, Lightweight Transmission Oil Cooler
9. Goodridge G-Line XF –8 Hoses With Machined Aluminum AN Fittings From Transmission To Transmission Oil Cooler
10. 8 Aluminum Quick Disconnects Between Transmission And Transmission Oil Cooler
11. Titanium Transmission Fluid Fill Plug
12. Carbon Fiber Transmission Fluid Pan Including:
a. Titanium Banjo Level Indicator Fitting
b. Titanium Drain Plug
c. Aluminum Fasteners
13. Titanium Transmission Fasteners Throughout
14. Titanium Transmission Mounting Fasteners
15. Titanium Differential Fluid Fill Plug
16. Magnetized Aluminum Differential Fluid Drain Plug

But as this was being done, the assembled group had three more "simple ideas" -- which, together, will save over a 500 grams of weight:

1. Replace the black steel mounting arms with titanium equivalents.
2. Modify the carrier so as to reduce weight.
3. Remake the mounting bracket to reduce its size and the size of the Delrin® mount.

Some quotes from posts from Robert:

Originally Posted by Robert Linton (Post 6403531)
Yes, the America GS has a Tiptronic. But, then again, it is a unique Tiptronic in that, when put into the "Tip" mode, it has no brain, i.e., it only shifts if the driver shifts. In other words, you can hold it in any gear as long as you want -- and its is a Tiptronic with a limited slip differential. As to America GS vs. Turbo S, that is a personal preference -- and I have always thought that Rolf Sprenger's Turbo S was among the best cars Porsche ever built. Having said that, with, in its final form, approximately 450 HP and 450 Nm of Torque and weighing less than 2200 lbs (1000 kg), not to mention unsprung and rotating weight significantly less than the Turbo S, a far better braking system than the Turbo S, 4-way adjustable dampers and other adjustable suspension components, etc., etc, I suspect that the America GS is at least worth of consideration.

P.S. The Type 964 3.8 RSR was a great car and the Turbo LeMans GT even greater.

P.P.S. Looking to see if the LSD can be a bit weight reduced through the use of titanium.

Originally Posted by Robert Linton (Post 6407196)
You are correct, the power to weight ratio would be better than the CGT. As to how to get to the weight, engineering, engineering and engineering. As to the engine, it has been a 3.8 and now it is going to 4 liters. And with engineering (on both sides of the Atlantic -- full story to be told after success), we should get to approximately 450 HP. Finally, if we took easy weight out and, for example, did the doors, fenders and roof out of carbon (ala CGT), not to mention the seats, we could easily get below 2000 lbs (910 kg).

On the question of why not go with more CF parts (Doors, Roof, etc.)

Originally Posted by Robert Linton (Post 6407253)
Because the project was to learn about a variety of things (e.g., designers, engineers, materials [composites, metals, coatings, adhesives], production sources) and doing these parts in carbon would have accomplished very little other than additional pure weight reduction after all else that was done.

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