Clasify my car

[Jnikic]

I'm trying to get a better grasp of PCA rules, but figured you guys might have some thoughts on what class I would want to race IF I decided I wanted to turn my DE car into a full fledge race car. Its very far from stock, but if there are certain mods I could reverse (going back to an SC flare, for example), that may well cost less than a whole new car.

This car is just so much fun to drive, but it may well not be a smart basis for a racing car (I won't be competitive in any car those first few years, granted).

1978 911 SC
73 RSR backdate w/Duck tail - 9x11x17 wheels
3.4L motor (98mm cylinder, 3.2 case; stock cam; Pauter rods; crank fire ignition)
46mm PMO's
Big Torsion bars, sways, Swing-A plates, solid bushings
Stock brakes, Pagid pads
Stock fuel tank
Bolt-in cage, 5 points, Recaros - RS Interior
Weight = 2,400 pounds

[Astroman]

First and foremost, the motor puts you in a GT class.

Minimum weight (with driver) for a 3.4 in GT4 is 2528
Minimum weight for a 3.4 in GT5 is 3089.

Plus the PCA GT motor "standard" is app 110 hp per liter... meaning your motor would need to produce about 350 hp to be competitive.

As much fun as your car may be, it's not an ideal PCA race car without putting a lot more $$$ into it. Converting it back to a "Stock" class 3.0 SC would also be costly.

[RichardNew]

If you really want to have fun build a care for the Chumpcar World Series. You can build one of those for less than the price of a Porsche engine. The most fun I've ever had racing was starting at Sebring with 128 cars on the grid. Woooo Hoooo.

Then the trick is to just keep driving for the next 11 hours.

Even better is that you can get your buddies to share the costs.

Richard Newton
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[Todd Simpson]

Jack is right on...PCA rules favor "stock"cars where the cars are highly developed but need to retain stock fenders, engines and transmissions, or GT classes where pretty much anything goes. Cars in between just wont work.

Take a look at the GT classification and go to the PCA website to get some lap times for the tracks you run on. You'll at least get some sense of the speed of the other cars you'd be running with. PCA groups a lot of different classes in the same group so while you might not win your class you might have some other cars around the same pace.

I got my PCA license a few years ago, and my car at the time was an RS clone with a 3.2. I actually fit into "Spec 911", where I was the only one in that class and ran at the back of my group. Oh well, I had fun. I recently put in a 2.7RS spec and I will likely go vintage racing.

You might want to check out NASA rules and see where you'd fit, or one of the vintage groups. A few of the vintage groups I've spoken with seem to have very strict rules, but they also want to keep the car counts high.

[175K911]

Your car is exactly the type that have people leaving Club Race for NASA. PCA favors either almost stock cars or fully prepped race cars. Depending on your HP and weight I bet you'd be solidly in NASA GTS3 with the 911's, 993's, E36 M3's and now a couple of Caymans. Though at 2400 for the car, and what is probably a 300+hp motor you could be in GTS4.

KTL on this forum has a really nicely set up 911 that has the capability of running up front in GTS3
Chris Streit has a 911 (for sale) that sounds a lot like yours and was the standard bearer here in the Midwest in GTS4.

NASA is simple- power to weight. Weight of the car with driver divided by the HP of the car at the rear wheels.

[kandhmfg]

FWIW - NASA GTS3 classing is max 11:1 wt/rwhp running DOT tires. (Hoosier R6/A6 are your best option for tires). It is a good class, that is competitive, I am right at the 11:1 mark with 200 rwhp and 2200 lbs (71 RS Clone race car). The M3's seem to be the dominant car where I am, but I can keep up with them and occasionally finish ahead of them. They are 240+ rwhp and 2650 lbs and up. GTS4 is 8.5:1. If you can keep it in GTS3, you will be better off, especially with your brake package and torsions.

Weight is with driver at end of race. If your car is 2400 with you in it and a little bit of fuel, then your max rwhp would be 218.

If that figure is before you get in and you weigh say 180 lbs, then comp wt would be 2580/11 = 234 rwhp max. (which would be roughly 275 f/w hp) I would think this could be around where you would fall hp wise depending on exhaust mods, compression, etc. But, only the dyno would confirm that.