Grand Am GT

[Atle Gulbrandsen]

Can you drive FIA GT3-cars in Grand Am GT? (And what about Speed World GT Challenge)

Are the Porsches regular Cup-cars, or Cup S (GT3) or something else?

The BMWs are not as nice as the ones in FIA GT3 for sure, but I would like to see the Mazda RX8 in European racing as well.

[Atle Gulbrandsen]

I found my answer for the World Challenge. They seem to go in the direction of the FIA GT3 and GT4.

So let's hope for an Audi R8 in the World Challenge, then...

http://www.world-challenge.com/news/story.php?ID=1518

[Speed-King]

Grand Am GT is somewhat off a mess, since it is a "dual" ruleset, meaning that cars built to two different rulesets run in the same class against each other.

First of all you have the "normal" GT-cars, i.e. cars based on a production shell. Grand Am calls these "prep.1". Examples would be the Porsches, some Corvettes and the occassional Ferrari. Also the old PTG M3s were prep 1, but those haven't been raced for a while now.

The other group of cars are the "prep 2" cars, built on bespoke tubeframe chassis, mostly built by Pratt&Miller and Riley, but also some smaller American chassis builters. The prep2 rules give teams a lot of flexibility, e.g. they can swap engines as long as they are built by the same company and change from FWD to RWD.
Cars from that group are the Mazdas, the Pontiac GTOs and GXP.Rs, the BMW M6s, the new Camaros, some Corvettes, or the Mustang Blackforest raced a few years ago. Rumor has it that there will also be 1 or 2 Infinitis built to prep.2 rules this year.

The BMW M6 in your picture actually startet its life as a Pontiac GTO, then became a GXP.R, before the team turned it into a BMW, when it became clear that Pontiac would be killed off.

Both types of cars share a number of spec parts, among them a Bosch ECU and a spec rear wing built by Crawford composites.
Modifications on the bodywork of the cars are limited, FIA GT3 gives manufacturers a lot more freedom there.

As for the cars being interchangeable with Euro GT3: They aren't. The SRO would most probably never allow the silhouette cars from prep.2 and Grand Am demands different safety structures than FIA.
You can actually follow a team converting a Ferrari 430 Challenge car to Grand Am specs on this website.
Then, I supposse, that current generation Euro GT3 cars are a good deal faster than Grand Am GT cars. The Porsche raced in Grand Am for example is somewhere halfway between the regular Cup-car and the Cup-S, with which it shares the bodywork but not all the go fast parts underneath the skin.

I hope that answers most of your questions, if not, feel free to ask!

[Jonerz]

I must add the one funny change Grand-Am requires of the Porsche Cup car for instance to be legal in GA (amongst many other, less funny, more reasonable changes.) Grand-Am GT cars must use five-lug wheels as opposed to the center-locking hubs seen on most GT cars world-wide.

@Speed-King: With the advent of the Porsche GT3R will there be a Grand-Am version of the car, or is it already a spec above Grand-Am? Could GT3R body work find its way to a Grand-Am car at least? I'm stricken by that thing and I'd love to see it raced in North America.

Chris

[Speed-King]

@Speed-King: With the advent of the Porsche GT3R will there be a Grand-Am version of the car, or is it already a spec above Grand-Am? Could GT3R body work find its way to a Grand-Am car at least? I'm stricken by that thing and I'd love to see it raced in North America.

Never say never, but definitely not all that soon, as GT3 cars are a tad faster than GAGTs and the GT3R will be an especially fast GT3-car...

[cmk]

Indeed, given that the Cup S was already a spec too far for GARRA.

[Canada ALMS fan]

Originally Posted by Speed-King

You can actually follow a team converting a Ferrari 430 Challenge car to Grand Am specs on this website.

That is a great link! It would interesting to see how this build compares to the F430's that Tony Dowe is preparing for Grand Am. I would assume he is not starting with Challenge cars???

[Jonerz]

He's starting with GT3-spec cars if I recall correctly.

Chris

[old man]

I was asking one of the Porsche drivers with experience of all types and he said the Grand Am car was the worst to drive, not like any other because of set up rules, it was more "twitchy", "not nice" he said.

[FIRE]

@Speed-King: Thanks for the link. Always great to see such projects. Pratt & Miller, BMW and others should do the same.