John H

Can some one briefly give me the differences between a 996 Cup (GT3) and a Grand Am cup car? My monikers may be all wrong but I think there are three "classes" of Cup car in the 996 line. RSR, GT# and Grand AM (GS).

My understanding is the RSR is that is really what it is called is more powerful, has no abs and is the top of the food chain and according to a previous thread does not justify the price difference for most HWFM Racing drivers.

The GT3 Cup car has abs, is not quite as powerful and is more common.

The GS or Grand Am cup car is the less quick of the three, is heavier and is more of a glorified GT3 street car? Is the GS car more long legged when it comes to significant maintenace intervals?

I am trying to sort this out in my mind as the prices seem confusing in that a good GT3 Cup is not that much more than its GS cousin but seems to be much more of a car. What are the strengths and weaknesses of the GT3 Cup and the Grand Am cup? I am not really looking to get into the RSR.

TIA

M758

996 GT3RS or RSR are factory build AMLS/Le Mans GT cars. Fastest 996 NA bodied cars out there. Many elements designed for speed and for pro race team maintence.

a 996 GT3 Cup is a factory prepped race car based on the GT3 and more of a worked over GT3. These cars have proven to be acceptale for full pro/semi-pro to well funded amature maintinence/teams

There are ATLEAST 3 versions of these Grand Am GT, Speed World Challenge, and Carrera Cup/supercup etc

Grand Am Cup GS uses a 996 street car (non X51) (not a GT3 at all) that is modded for racing.

John H

Thanks Joe. Now I understand the pricing differences and relative competitiveness.

Mark in Baltimore

John,

Are you moving up in class?

4 Kurves

Can someone elaborate a bit more that within the 996/997 GT3 Cup car group the specific difference between Cups prepared for the different series?

For example I know a few obvious ones:

Grand-Am GT: 5 lug nut hubs required (throw back to NASCAR I assume)

Speed GT: Higher wing mounts allowed raising the rear wing to the roof level (but not exceeding).

Carrera/Supercup: I always assume these were stock Cups but maybe not?

All 3 series require fuel cells?

M758

I don't know all the details, but

Carrera/Supercup/GTC3/IMSA GT3Cup = stock cup cars

Grand Am GT = 5 lug hubs, I believe stock GT3 Cup motors, Window net vs lexan door window and probably host of detail changes

Speed GT = Cup body with "speedvision Motorsports motor" I think this may be a GT3RS motor or one very close to in hp. Again additional detail changes as allowed by series rules.

Beyond this are the SCCA GT2 class GT3 cups. Not sure what allowances they have vs the standard GT3 cup.

John H

Mark,

I'd like to but am limited with a small ...uh.. wallet. With GS cup cars floating around at $50,000, it is very tempting but not sure I will be satisfied. Can't really afford the GT3 based cup cars. So I think I am in a holding pattern for now.

John

JW in Texas

Take a look here for some info

Mark in Baltimore

Cool, John. We need more D class cars.

John H

Ahh, you know Joe wouldn't let the car leave D. I just thought we might grow into a two car team. I am tired of RoShamBoing for the right to drive it in the sprint races.

analogmike

> Carrera/Supercup/GTC3/IMSA GT3Cup = stock cup cars

Yes, and factory sealed motors and trannies are required in IMSA and probably Supercup too.

>Grand Am GT = 5 lug hubs, I believe stock GT3 Cup motors, Window net vs lexan door window and probably host of detail changes

These and the Speed GT can use RSR suspension pieces. These are solid bushings, some of the GT3 cup parts are closer to stock bushing types.

> Speed GT = Cup body with "speedvision Motorsports motor" I think this may be a GT3RS motor or one very close to in hp. Again additional detail changes as allowed by series rules.

I have been told the Speed GT engine has the plenum cut out and a rewelded plate for more air flow at higher RPMS. The stock GT3 cup engine runs out of torque at high RPMS. It also has high compression pistons, Cams, and can rev to about 8500-8800 (GT3 cup is about 8200).

RSR has even higher comp with even more radical cams and higher RPMs.

> Beyond this are the SCCA GT2 class GT3 cups. Not sure what allowances they have vs the standard GT3 cup.

SCCA piggybacks on Cup rules but I had to add windshield clips and rear window straps. I also had to remove my windows and install a net for SCCA.
On the GT3 cup, SCCA allows alternate wheels of the stock size while other series require stock BBS (Cup, IMSA GT3 cup) or aftermarket BBS (PCA GTC3). Speedvision allows any wheel of the legal size (they are bigger than stock size).

Hope that helps!

John H

Mark, Manny and Mac

Found these pics on a Grand Am site from VIR last fall.