Small helmets

[Superfast Matt McCoy]

With the recent DQ's for head position, and the helmet and padding rules that seem to be getting more attention, has anyone looked into helmets that are smaller?

Also, are helmets for smaller head sizes also smaller on the outside, or do they pop out all of them on the same mold and just compensate with foam on the inside?

Thought I'd as on here before I bust out the tape measure at the local motorcycle store.

[Superfast Matt McCoy]

With the recent DQ's for head position, and the helmet and padding rules that seem to be getting more attention, has anyone looked into helmets that are smaller?

Also, are helmets for smaller head sizes also smaller on the outside, or do they pop out all of them on the same mold and just compensate with foam on the inside?

Thought I'd as on here before I bust out the tape measure at the local motorcycle store.

[TMichaels]

What keeps you away from building rule compliant cars? I do not want to offend you, but is it really necessary to build cars that are so close to the rules minimum that you have to be afraid to pass scrutineering or be disqualified?

[D Collins Jr]

1. Racing demands to be right on the edge of rules minimums. Most notable are weight requirements, and as we can all relate to, ground clearance.

2. Yes Matt. I know that my helmet is bigger in outer diameter than Bobby's, and that our smallest team helmet. The other half is that the bigger helmet is racetrack rated, and the others are motorcycle rated. It is also important that the difference in this size is negligible. Put another way, the difference in size is not on the top of the head, where the measurements count.

[Wesley]

If you stay safely within the bounds of the rules and never try to push limits you're not going to beat anyone.

I believe we are responsible for at least one published rule clarification for pushing the envelope. Our most recent car had SEVERAL things that we thought "That's really close, I sure hope it passes"

It's our job to build TO the rules, not under them. It's the scrutineers job to catch if we break them.

Besides, we just have fat heads.

[TMichaels]

In my opinion passing scrutineering with no problems gains you more points than building a car to or over the edge of the rules. Especially with the events growing bigger and bigger and the scrutineering taking longer.

[mok]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
If you stay safely within the bounds of the rules and never try to push limits you're not going to beat anyone. </div></BLOCKQUOTE>

As Tobias said, in my opinion this is definitely not true for Formula SAE. You can build a perfectly rules compliant car and still beat all "not so rules compliant" cars.

My experience is, that most points on a FSAE car that are possibly in conflict with the rules, are simply there because the team members haven't paid enough attention to the rules and NOT because they are knowingly pushing the limits.

But: It is perfectly fine to look for example for smaller helmets if you got a tall driver. If you've got small drivers, than Percy is going to be the tallest anyway - and you can't change Percy's helemt size ;-)

[Thrainer]

BTW, we met Mr Percy personally when he wanted to take a seat in our car at Silverstone. He used an L size helmet, I think our smallest one.

http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Charlie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by D Collins Jr:
1. Racing demands to be right on the edge of rules minimums. Most notable are weight requirements, and as we can all relate to, ground clearance. </div></BLOCKQUOTE>

That may be true for performance-sensitive areas, but it's ridiculous to apply it to every rule.

In this case, adding the 1 lb or less to make your car meet the rules is all it takes. Just do it; that is not what is going to lose you the competition.

In motorsport there are minimum weight rules, however it is not uncommon to have a car 5 or 10 lb over the minimum weight. This is a safety factor to avoid being disqualified. It's not worth it to push areas that can ruin your entire event (yes even in 'racing').

[D Collins Jr]

Well put by all. A few last comments to the matter:
1. The original question of the post has been answered, without much contention or a link to Google. Applause to all.
2. We met a real-life Percy in California. I've accepted that it was proof that in beautiful Southern California, even Mr Royce will have some fun with scaring the bejesus out of the student teams.
3. Charlie, I completely agree with your safety factor point. The number of times I've seen a driver disqualified for not meeting min weight is absurd. That should never happen. On the other hand, it took three pounds of tubing to make our 2008 car rules compliant with the helmet clearances.

[Superfast Matt McCoy]

I wasn't suggesting that teams should push the rules. Building close to the limit of the rules and buying a small helmet are two different things. If you design for a 2.25" clearance with a small helmet, and you would have designed for a 2.25" clearance with a large helmet, you're in the same boat at tech inspection. I was actually wondering if any teams had designed for adequate clearance and then looked for smaller helmets as an added buffer.

For the sake of the argument that has arisen...

If you have a driver that is taller than perci: a 0.1lb decrease in weight for designing around a smaller helmet, while maintaining the same adequate clearances, is an excellent design decision in my opinion. Especially since it is something you have to design around anyways.

In any case, make sure your CAD helmet is the same size as the helmet you're going to race with, lest you spend your labor day weekend cutting and re-welding.

[Yellow Ranger]

But if you can't make the rules fit Percy, there's a likely possiblity that you won't be able to fit a 'normal' sized helmet...

http://img167.imageshack.us/img167/7623/driverheadcp2.jpg

BTW Matt, no luck on that shock- how's the bike coming?

[Wesley]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by mok:
As Tobias said, in my opinion this is definitely not true for Formula SAE. You can build a perfectly rules compliant car and still beat all "not so rules compliant" cars.
</div></BLOCKQUOTE>

Show me one, and I'll retract the statement.

[TMichaels]

Our current car.

[Wesley]

Which competition did you win? I'm not up on the European ones.

And are you defining a "perfectly rules compliant car" as one that passes tech without modification?

[TMichaels]

We came in second at the FSG this year. If that is not enough, I would refer to Stuttgarts car. They won the FS UK this year.

I define a "perfectly rules compliant car" as a car that meets all rules including the intentions and clarifications of the rules.

[Wesley]

So, since tech inspection is the sole evaluation that establishes meeting this criteria, all cars that passed tech inspection are, as per the rules, rules compliant.

[Drew Price]

First:

The original original question of whether or not small helmets had the same outside dimensions as large ones is one I was hoping someone knew the answere to, and has not been answered yet. I would be willing to bet that some are smaller on the outside than others, but would probably require calling up MFG's or going to look at a motorcycle shop to check. Our big motorcycle dealer even carries some SA2005 rated helmets, along with the slurry of DOT ones, you I could probably get legit comparisons.

Not sure about your drivers but we had two very tall dudes drive the car this year - both around 6'3" - 6'4" - and one needed a large helmet, the other a small, so I think that is a reasonable valid observations. Some tall guys have small heads. Some short guys have big heads. Whether or not it's the same size head as Mr. Percy (a well documented big head) may or may not be important.

Second:

Certainly don't want to get caught too much into this, since it's waaaay off topic now, but we certainly didn't have anywhere NEAR everything on the tech sheet scrutinized by the inspectors during tech at Michigan this year.

I have heard the FS competitions the process is much more stringent, but there is simply not time to check compliance of every single rule in the rule book in the ~3-4 hour average time most teams spend in tech.

That changes the def a little bit.

Of course, we observed from the process that the adage that if you can gain an technical advantage by stretching a rule that either won't be checked, or is difficult to verify is part of the game. You have to weigh the tradeoffs.

We feel that since this is an educational experience, we are willing to sacrifice a percent here, and half a percent there to make sure that we get through tech the first time (which we did) and have extra time to be doing more useful things at comp, we will sacrifice the one percent.

Besides, it seems to me that impressing the design and presentation judges and finding a driver who know's what they're doing is a better way to ensure you will maximize your chances to get the points than it is to risk not fitting Mr. Percy by getting your CG 0.1" lower. But obviously the design judges like that sort of thing, so we're back to the beginning.

As always, my $0.02 (0.014 €).

Maybe I will change my sig line to Vonnegut's "And so it goes..."

Best,
Drew

[TMichaels]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
So, since tech inspection is the sole evaluation that establishes meeting this criteria, all cars that passed tech inspection are, as per the rules, rules compliant. </div></BLOCKQUOTE>
The disqualifications after or during the endurance at Formula SAE at MIS show that this may not be correct.

[Wesley]

As tech inspection is not a singular event, and occurs continually throughout the competition, (as per the rules) it follows that if you meet them to the committee's standard throughout the entire competition, you fulfill the rules, as declared by the rules.

To say that you have a to-the-letter, to-the-intent rule-meeting car is false. You have a to-the-rules-committee approved car. Whether or not you intentionally met every rule, you have no guarantee you met any rules other than the ones the committee checked.

I am confident in asserting that there is something on your vehicle that, if inspected closely enough, could be seen to violate the intent of a rule. It might be as minor as not meeting the "three exposed threads" rule on bolts.

In an extreme example, do you machine your restrictor 2mm undersize "just to be safe?" Not likely. While it seems that example would (correctly) have a greater performance impact than 2 inches of rollbar tubing, it has been learned from experience that in FSAE, every little bit helps. If you save an average of 50 grams on 50 components, thats 6 pounds. If you can average higher than that, so much the better.

I agree that it may make tech less stressful to provide margins of safety on highly scrutinized items, but if you don't try to push those boundaries, you might never gain those .001 seconds. That's all it takes to win.

[JVC]

I agree, it is a competition so it is not more than logical you try to get the most out of your car by interpreting the rules as much to your advantage as you can. However, there is one thing that cannot be compromised on a FSAE car, and that is safety (both Braunschweig and Muenchen had a crash this year, and our car flipped over last year).
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> If you stay safely within the bounds of the rules and never try to push limits you're not going to beat anyone. </div></BLOCKQUOTE> This is simply not true. To add another example to the list of fully rule compliant cars that beat the rest, it would be the Delft car. We came second at FS UK this year and we won FSG. And that with a car with a main-hoop line that easily accommodates drivers up to 6'4", and an impact structure that, despite the low sides, is way beyond the impact structure required by the rules, not to mention the protection against A-arm penetration by a carbon monocoque.

So instead of trying to dodge the rules running the risk of being, in the worst case, disqualified, be inventive incorporating the rules in your design instead. All you need to do is to think outside the box.

[J.R.]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
If you save an average of 50 grams on 50 components, thats 6 pounds. If you can average higher than that, so much the better. </div></BLOCKQUOTE>

I don't think that is how the team's from Finland feel. In an "extreme case" I think that they would rather have had the extra weight on their car, since that is an extremely disappointing way to Finnish a season.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I agree that it may make tech less stressful to provide margins of safety on highly scrutinized items, but if you don't try to push those boundaries, you might never gain those .001 seconds. That's all it takes to win. </div></BLOCKQUOTE>

Not to be an @ss, but you beat us by 30 seconds in the endurance, we finished 18th, you finished 21st. We had one of the most overbuilt cars at MIS. We have room to lose 1.5 - 2 slugs off of the car this year.

This may sound contradictory to what I just said but, there is an ENGINEERING competition, not just a racing competition. There are ways to lose weight safely from other parts of the car, it's not necessary to risk your whole season for a few ounces.

Perhaps try looking at fuel economy and design a little more seriously this year, since they are worth a whole lot more than your .001 seconds.

[Mike Cook]

Wes, I think our car is rule compliant and we certainly intentionally tried to not be on the ragged edge. I think a lot of people are really stressing the wrong things if they want to win a competition. Ultimate weight is of low importance if you screw up all the major things. We shouldn't be talking about gaining .001second or .01 or even .1's. Not when the top 10 cars lap times are vary by more than 3 seconds.


Also, in my opinion, getting through tech in a timely manner is really really important to being successful at a competition. So that should be a huge priority. I would even be willing to bet that the points I gain from being collected and relaxed after breezing through tech outweighs the points you would gain by pushing every rule to the extreme and being scrutinized in tech for 2 days.

When you look at other racing leagues (i.e. Nascar) there lap times are already very very close and making small improvements or pushing the rules envelope can really be the difference between 1st and 30th. But like I said before, lap times already vary so much at FSAE events; I think teams need to focus on other more important things.


Just my opinion...
Mike



[/QUOTE]

Show me one, and I'll retract the statement.[/QUOTE]

[michaelwaltrip]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JVC:
I agree, it is a competition so it is not more than logical you try to get the most out of your car by interpreting the rules as much to your advantage as you can. However, there is one thing that cannot be compromised on a FSAE car, and that is safety (both Braunschweig and Muenchen had a crash this year, and our car flipped over last year).
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> If you stay safely within the bounds of the rules and never try to push limits you're not going to beat anyone. </div></BLOCKQUOTE> This is simply not true. To add another example to the list of fully rule compliant cars that beat the rest, it would be the Delft car. We came second at FS UK this year and we won FSG. And that with a car with a main-hoop line that easily accommodates drivers up to 6'4", and an impact structure that, despite the low sides, is way beyond the impact structure required by the rules, not to mention the protection against A-arm penetration by a carbon monocoque.

So instead of trying to dodge the rules running the risk of being, in the worst case, disqualified, be inventive incorporating the rules in your design instead. All you need to do is to think outside the box. </div></BLOCKQUOTE>

so how is pushing the limits of the rules or "bending" them any different than creatively interpereting them to your benefit? he isn't talking about intentionally breaking rules.... that's an entirely different matter.

yes there are 100% rules compliant cars that can win competitions, but none that haven't bent, or interepreted to thier advantage, a few rules here and there to gain an edge over the competition.

[JVC]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by michaelwaltrip:
so how is pushing the limits of the rules or "bending" them any different than creatively interpereting them to your benefit? he isn't talking about intentionally breaking rules.... that's an entirely different matter.

yes there are 100% rules compliant cars that can win competitions, but none that haven't bent, or interepreted to thier advantage, a few rules here and there to gain an edge over the competition. </div></BLOCKQUOTE>

Ok, I believe I should clarify what I wrote earlier. It is an engineering competition, and as for any engineering feat there is not one unique solution to the problem at hand, in fact there are an infinitely many, as can be seen at any FSAE event. Having that said you can only conclude there must also be an infinite set of designs that do not bend or push the limits of the rules. And in all likelihood there must be designs in this set that have a competitive edge over other designs in the feasible and near feasible region. It is all a matter of optimisation in the end. But as J.R. pointed out correctly,you should start from a feasible point, the first priority of any team should be to get the overall design right, especially concerning safety.

Or simply put: the rules offer more than enough space to build cars with a competitive edge. You must have a very good reason to start pushing or bending them.

[Wesley]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by J.R.:
Perhaps try looking at fuel economy and design a little more seriously this year, since they are worth a whole lot more than your .001 seconds. </div></BLOCKQUOTE>

Good advice, if a little late. We did a bit better in California in that department.

Mike, I agree, of course we built our car to be intentionally compliant. We welded on 9 pounds of tubing before going to competition because of a rule change that was made after we finished our rolling chassis.

We made it through tech in 2 hours, which seems to be the average for top teams, even after being given the "human percy special test" in California, with a debatably 95th percentile male.

But I do disagree that we shouldn't be looking for .001 seconds. You shouldn't stop looking for the big gains, but if you can see an economical small gain, why not?

Anyone who is in the sport of racing, and ENGINEERING falls under the sport of racing especially in this context, knows that it's the team that bends the rules a bit to suit them that generally does a bit better. After all, the rules are there to specifically limit design choices.

I'm also trying to point out that just because you designed to the rule doesn't mean you passed the rule. The techs are there as much to catch your foul-ups as they are to find the sneaky teams. There are certain rules you should and shouldn't push, and after this year we will most definitely make sure the roll hoop has a larger margin in case they change the rules again.

But I'm trying to impress a point upon you. Your ability to manipulate the properties of the things around you is what makes you a good engineer. You can see the yield stress of a material, the anisotropy of another and think, in this combination, we can push it up to the limits of its durability and save weight and increase performance.

How are rules any different than structural limits? As always, get close to them, apply an appropriate safety factor, and let it roll. Sometimes parts break. Sometimes rules break. It's all part of engineering something that is supposed to be at its peak performance. They aren't broken by intention, but by an attempt to gain that minute advantage. After all, it's a collection of minute advantages that makes the fast cars fast. They all have tires. They all have A-arms and engines and oil. But the win is in the combination of small design decisions.

[fade]

Sorry bobby, that helmet was modeled after one I had at the time and not one in the shop.