Ag951

It depends on the group. In the SCCA, it has to be a factory option, so the M030 is okay, but if they put the bigger rims on at the dealer, that would change the class.
But why would you want 17" rims? Unless you get a bigger brake kit, keep the stock rim size, smaller rims means less unsprung weight, which means better acceleration and braking.

Also (in SCCA at least) to add a factory option, you have to add every single piece from it. If I put M030 sways on my car, but didn't change the springs, torsion bars, even the bushings, to be the exact part shipped on an M030 951, then it's not stock. Some clubs might overlook this kind of thing locally, especially if you don't place high, (and you could always be dishonest and just not tell them), but if you start winning, people might start questioning.

hacker-pschorr

I was bascially wondering if 17" wheels were even an option on 944's at any time. The M030 fits with 16" wheels, right? I upgraded my car to 944 turbo spec brakes, not M030.

The 16" wheels on my car were a factory option. With SCCA rules, does that mean I have to run the original 16" wheels or any 16" wheel that is the same size?

iloveporsches

Lighter wheels, aside from less unsprung weight, is also less rotational weight. Just a few pounds of rotational mass can make a difference.

Z-man

17's were never an option on the 944 series. If you run with them, you are automatically put in Street Prepared or improved classes, depending on the sanctioning body.

Darth Coupe

You could get the 17's as a M030 option on the 968 however.

Ag951

The bigger brakes will change your class at SCCA, probably with other groups too. Make sure you have good pads and Motul or equivalent fluid to get the most out of your brakes.

Any rim from any company is considered "stock" as long as the diameter and width are the same as what the car left the factory (not the dealer lot) with.

hacker-pschorr

Do the bigger brakes change my class due to me upgrading or just the overall size. Because technically, they brakes on my car are smaller than what was optional on the 944S. How do they classify the size of brakes? By the number of pistons?

I'm running super blue brake fluid.

M758

Most rules don't care if you put bigger or smaller brakes. It is just if they are no longer stock (ie stock calipers, stock rotor size) Most groups allow any pads and many do not penalize for things like slotting or drilling again if they are stock sized (diamter & thickness) Then again some consider drilling and slotting not stock so you need to read the rules to be careful.

At our local PCA autocrosses we really don't care too much about rules. We compete and have rules, but is more friendly than rule oriented. With 30 to 50 cars most everyone knows each other and most of the mods. If some one does cheat in class we really don't car because what to you win? Nothing. Personally in 4 years of autocross I have not heard of any cheating complaints. I do know plenty of "mis-classified" cars, but usally these are errors of lack of rule knowledge vs an attempt to cheat.

I can't say it like this everywhere, but in the Az Region it is. To me this much more fun than the SCCA guys complaining about adding a complete M030 or just the shocks. To me that defeats the purpose of Autocross which is simple fun with a little competition rather than a hardcore beat the next guy attitude. If you want to compete that much go racing and keep AX at the level fun being #1.

Z-man

And the offset! The offset must be the same too! (Offset can create a wider track: that's why they have to remain stock)

-Z.

hacker-pschorr

Well said. To me AutoX is you against the clock and yourself. As long as each run you keep getting faster, your winning.

Stan944

M758 and Hacker-Pschorr:
I agree that autoX is mostly about competing against yourself.
On the other hand, I would rather compete with myself scoring 25th out of 52, instead of 52 out of 52, :-)
And I can't wait for my 2nd event!

hacker-pschorr

Me to!!!

iloveporsches

Hey, does anyone know what the stock-spring rates were for M474?

Ag951

Why not go for #1?
It's also about getting really fun G-forces going, and the adrenaline rush.

Hacker, if your car had a factory option of the same caliper model, then it's stock, even if they came from a 951. If your new brakes have more pistons, then it's street prepared.


My opinion of SCCA autocrossing has dropped dramatically recently.
First, they class my 951 with suspension mods in with a 996GT2 or a lightly modded Z06, '03 M3, etc. It's a good car, but it's not that good.
They have heats of 30 cars, so it's run, wait 20 minutes, run, wait 20 minutes, run, you're done. I like the lap style of the PCA or the six car heats of the defunct NASA autoX better.
Their events take eight hours or more for three to six runs (on Sunday they cancelled time onlys at the last minute, so I stayed five hours after my 2.5min of competition, waiting for time onlys, only to find out I could have left after running).
And now they just announced that their schedule posted since January is wrong, and their October, November, and December events will be on the same day as the PCA.

hacker-pschorr

But, the nice part about the "S" is nobody really know anything about this model. Most 944 people I know in the PCA though my car came with the 951 brakes stock. Granted, if I were to ever to go a real competative Auto X, there would most likely be a P-car person there that would know. I don't Auto X much. If I do I use my beetle. After I took my 928 around Road America, Auto X'ing the P-cars just wasn't the same. When my 944 is back on the road next year, I'll do a couple to get reacquainted with her. Then its off to Road America.