ace37

First time builder and getting into racing. I'm having kind of a fundamental question... even with a Spec Boxster - a well defined, well subscribed class and a good group of racers - there are some grey areas in the rules as far as what is and isn't legal. Nothing that matters too much, but building the car all of us should want to build it to the limits of the rules and no farther.

To me this question is fundamentally different from cheating or playing it safe. This is understanding and clarifying the limits and building to them so we all have a level playing field. A bright light eliminates the shadows. I figure with a national forum we can have a good discussion and hopefully learn a few things and get closer to the same page on some of the issues that show up. I also expect this discussion will show that what is cheating to some will be pushing the limits to others and still others will find it just plain common sense. And as an aero engineer I expect I'll see the same things a different way than a lawyer or a business executive, so discussion is a good thing.

So here are a few easy ones to start with... and while they're SPB specific, I think the question is bigger.

SPB and Rear Bumpers
It seems clear many SPB racers interpret that to allow complete removal of the rear bumper and then they elect to not install a steel reinforcement. Not everyone does this, so I think it's worth saying out loud in a public forum. If we want it illegal, let's make it that way, and if we want it accepted, let's make sure it's clear that's what we are doing.



But let's take it a step further - where does the "rear metal bumper" end? There is a metal beam with an attached heat shield as well as a black bumper frame mount that connects it to the chassis. While it's easy to interpret the metal beam alone as the bumper, the heat shield is integral and seems to be along for the ride. Furthermore, the black mount could reasonably be considered a key and integral part of the bumper assembly. I've seen one racer cut that black piece in half as that's where he drew the line. But taking a the most favorable interpretation of the rules is valid approach, it seems reasonable that a SPB legal car could unbolt and remove the full assembly from the car. Is this how it's interpreted by everyone? Should it be clarified in the rules? If it's interpreted in this way by only 10% of racers this will offer them a very slight advantage. And if nobody at all sees it that way, honestly, you guys need more creativity!


Open Brake Cooling - Using Wheel Well Vents to Cool Brakes
I'll be interested in venting the front side radiators to the front wheel wells and sealing the path below the radiators that goes under the car to ensure the air flows to the brakes. (Radiator air is very cool compared to rotors so the temperature of the air is not a good argument against this). Now in this case my interest in this change is far less about actually cooling the brakes and far more about reducing front axle lift by not having my radiator airflow exhausting underneath the car. However, it will genuinely cool the brakes, so I have a good argument supporting the vents. So is it legal? And why or why not? (And I don't think intent is ever a good argument to rest on.)

Example: http://986forum.com/forums/performan...er-liners.html




And just to use reductum ad absurdum and take it way too far, let's say I'd be interested in venting above the wheels to help keep my brakes cool. I could just cut the fenders and try to mimic the GT3RS wheel arch vents. Might also help aero a bit more... I'm sure that wouldn't pass scrutineering - it certainly shouldn't - but where is a line we all more or less agree on?

Frank 993 C4S

It's easy - rather then interpreting the rules by yourself and waste money on something you might have to un-do email Walt Fricke with the question.

bkovac

Per Walts confirmation a year ago,

"As far as holes in the liner this should be allowed as its the only way to get more air into the wheel/caliper area unless you do hoses and blowers. Half the cars out there have holes worn through the liners anyway so that should not create any performance benefit."

hf1

Interesting. Learn something new every day...

ace37

Asking the authority is a reasonable way to go. Maybe there just aren't a lot of questions asked on these builds.

I know some are more liberal in interpreting the rules than others and was hoping for some discussion on the matter, but I suppose those most likely to stretch the rules have a lot to lose and nothing to gain by disclosing and discussing it.

Personally if I want to get really creative I'll just run a series with open rules (like NASA GTS), but I was still expecting participants to try to maximize builds to the limits of the spec series rules. It sounds like a lot of the culture is awesome and everyone just wants to play fair and have fun, and any folks that don't aren't excited to discuss it.

I learned what I could from this thread. I'll email Walt with perhaps a longer list of questions when I get closer as I don't have the car nearly done yet. If I come up with more questions that can wait I may as well ask them all at once.

Lemming

Please put up the questions and Walts responses, because there seems to be differences. Inquiring minds need to know.