Production vs Group 2? I have questions.

1982 Mazda Rx7 is the car in question.

Trying to decide if i want to mess with P rule restrictions or be less competitive and build for Group 2. I could easily go either way currently. I know the jist of Group 2 less one question.

What exactly is covered by "stock induction" in group 2? do they mean the intake manifolds must remain stock? Seems a tab off that a rotary could not run another intake manifold or change a carb style.


Production questions.

From what i understand, the car is going to be fundamentally as stock as possible. Everything has to remain within the generation of the car. In my case the body style is 81-85. So that means i can run the disc brake / lsd equipped axles that the cars came with correct? It was a factory installed option.

Can i modify the seat mounts to lower my seating a bit for head clearance?

also does anyone know where to find the California rally series or PW rally series rule book supplements i keep hearing about? I am referencing the Rally America book solely.

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

The Rx7 is Gp5 in the US, there is no reason to think a Rx7 is not competitive in Gp5 even in fairly stock form. I do not think it is even a legal car in Production, they use to be required to run in PGT where the car would be very slow vs AWD subarus today.

There is no PNW rule book only the NASA or Rally America book.

The stock induction means you can not turbo or supercharge the car.

So welcome to Gp5, where well driven RX7's have been competitive for at least 30 years and you do not need worry about rule restrictions.

As I recall the RX7 of that age can use larger brakes, longer trailing arms, faster steering and a good roll cage to stiffen it up.

Someone want to add to this, especially someone who has read the 2010 rule book?

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In the long run reality always wins.

Stock porting, stock induction required for Gp2. No carb swaps or different intakes. Beyond that you can head for street, bridge or P port and any carb in Gp5.

For production I believe you cannot update or backdate. I'm pretty sure the 1984 GSL was the only one with rear disc and LSD. So the car would have to be re-titled as a 1984 and everything be correct. It would really be tough to make and keep something that old within the strict limitations of P class.

Having had a Pport RX-7 I would open it up and go G5. There is something about 300+ hp in a light shell that is just plain fun.

well group 5 (was the original plan) it is then. the steering and braking issues i have resolved (been a rotary fanatic for better part of a decade) so i know the tricks. First engine will just be a stock port 13b with ITBs due to time and fiscal constraints. They and well, i dont have the skill at the moment to warrant 300hp.

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

Are you really asking this question? No one really "contests" production, anyhow.

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Welcome to the cult of JVL drink the koolaid or be banned.

but if i cant run production, its a bit of a moot point

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

Though with Rally America novices (less than 18 coefficiants) are restricted to group 2, production, and open light unless you can prove "significant previous automobile racing experience."

Historically speaking, Rally-America has been shown to be fairly lenient to beginners in mild-spec Group 5 cars. But you can always get the coefficients in NASA events first. Plus living in Mt Home, Alex will have some nice big coefficients available to him.
I'm sure you've seen this?
http://nocoastmotorsports.net/Manuals/rx7competitionmanual.pdf

The Old Escort one is also fairly good for RWD prep with solid rear axle.

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Grant Hughes

What does a P port 13B cost to build? What is typically used for fuel on a P port rally motors?

Build the car to G5. Where you have a lot more freedom. I would also talk with Andrew Havas about rallying a first gen rx-7. He was very very fast is his.

Of any "vintage" cars, I'd guess the early RX7 is one of the easier cars to find replacement parts for, and is nearly strong enough to survive in Production.

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Jason McDaniel

Andrew_Frick Wrote:
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> What does a P port 13B cost to build? What is
> typically used for fuel on a P port rally motors?
>
> Build the car to G5. Where you have a lot more
> freedom. I would also talk with Andrew Havas
> about rallying a first gen rx-7. He was very very
> fast is his.

The guy who used to do mine only charged about $500 to rebuild the motor and port it. Porting consisted of taking a 2 or 2 1/4 inch hole saw and drilling thru the rotor housings. MarineTex in a couple 90* elbows and seal the original intake holes. Runs on regular fuel with oil added directly to the gas. You must run dual exhaust to make it work. 300+ hp pulls from 6000 to 10K like there is no tomorrow. Basically it feels like the car has about 4 first gears...I could break the back tires loose on dry pavement shifting into 3rd (70mph or so).

jesus....have any of you read the rules? you can run an NA B13 in G2. and you can not modify the intake port no matter what.

DirkaDirkaJack Wrote:
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> jesus....have any of you read the rules? you can
> run an NA B13 in G2. and you can not modify the
> intake port no matter what.

Jesus yourself..have you not read the thread? We might be talking about G5...

yeah, i get that, just people were saying your only option was group 5 because of the B13.

heymagic Wrote:
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> Andrew_Frick Wrote:
> --------------------------------------------------
>
> The guy who used to do mine only charged about
> $500 to rebuild the motor and port it. >

Good old Doug Moe. Oh the stories we could all tell about that guy. Built the rollcage in my first Opel Manta rally car in 1987 for $350, tax included. Made out of water pipe and welded with a stick welder. Nice welds too, and all the tubes were welded all the way around.
Of course the cage wasn't exactly perfectly symmetrical but that car was rolled 3 or 4 times and it held up fine.