Drivers height

[Urvina]

When designing the cars frame and especially the cock pit, are you expected to fit them to the "95th percentile male" that the rule book refers to? Are these dementions what need to be done?
And if you don't reach between the "tallest driver's helmet and the helmet of the 95th percentile male", does that mean you can't drive? Unless you've got some kind of power seat that adjusts but I don't think that would be practical for this kind of thing.

Sec. 3.3.4.1

Erin

[Urvina]

When designing the cars frame and especially the cock pit, are you expected to fit them to the "95th percentile male" that the rule book refers to? Are these dementions what need to be done?
And if you don't reach between the "tallest driver's helmet and the helmet of the 95th percentile male", does that mean you can't drive? Unless you've got some kind of power seat that adjusts but I don't think that would be practical for this kind of thing.

Sec. 3.3.4.1

Erin

[Garlic]

Most popular and practical means is adjustable pedals. Easier said than done to make a strong stiff and easy to adjust design though. You don't have to fit any certain size person (Tokyo Denki is proof of that) but it's a good idea to build a car that will fit the intended drivers, with a little extra room for error.

[syoung]

3.3.4.1 says the roll hoop height and position must be sufficient to accommodate a 95th percentile male, and sets out an easy way to check that a 95th percentile male would be within the rules.

The only reason it mentions "the top of the tallest driver's helmet" is so that any team fielding a driver larger than 95th percentile will be providing enough protection to him as well.

The rules don't mention the 95th percentile anywhere else, so in theory you're free to make the cockpit very narrow and very short, but it's up to you really. You may think that in the presentation event it will be good to have a car you can sell to a reasonable proportion of the population. And of course design judges do often like to sit in the car themselves - see Dick Golembiewski's post in your "Design Event" thread, Erin (they "evaluate ergonomics"). I'm sure an averagely built judge would like to fit into a car you've supposedly designed to sell to average weekend autocross racers in their thousands.

Adjustable pedals are a good way to go: we've built adjustability in there but are hoping our custom seats (one for each driver) will provide enough adjustability on their own. It just means the smaller drivers will be more reclined in the cockpit, which lowers the centre of gravity too.

[UTA racer rikki]

syoung,

As I sit here, recalling the rules mind you, I think it's stated clearly in the tech inspection sheet that they will have two cardboard circles attached to the end of a stick that represents the 95th percentile male. The car's design must account for this, and this could mean your car doesn't pass tech!!! The roll hoop must be high enough so that the circle representing the helmet of the 95th percentile male has 2 inches clearance as stated in the rules.

Again, this comes from a recollection of the rules and being present at Formula SAE tech inspections. Read the rules on this carefully!

[syoung]

Yep, that's what I said. The only place where they check the car fits a 95th percentile male is (effectively) the height of the roll hoop 'clearance line' from the seat, i.e. a single dimension. They don't check the cockpit is long enough for a 95th percentile man's legs, nor wide enough to fit him. The design judges, though, will be able to check this by eye and may ask questions.

[BStoney]

It wouldn't be fun modifying your frame in Pontiac, nor do I think it would be possible to that extent....definitely leave a little room for forgiveness

Also, I would recommend not attempting to self-interpret the rules. You can submit questions, but I am not sure of the link...can anyone field that?

[Denny Trimble]

I know UTA had to raise the front of their footbox in '98 or '99 (cut and weld the frame) in Detroit. And, in '96 or so the UW team had its intake sticking up above the roll hoop / rear tire plane, and had to weld on a stupid looking extra roll-hoop.

The tech inspectors won't hesitate to make you cut and weld... http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Evan]

Denny;

Why did UTA have to increase the height of their foot box?

Thanks

-Evan Martin
Ryerson FSAE

[Denny Trimble]

The driver's toes were sticking above the "major structure".

[wrcRS]

Erin, I would think that we could make you some foam so you fit the car right. Just like they do for the endurance cars.

[Urvina]

Clinton? is that you?

get off the forum, no one wants you here!

haha

[mtg]

Foam inserts for short drivers definitely work well. UMR's current team leader is 4'11", and she has a thick foam insert for a few of the cars that works pretty well.

[Rob.C]

in response to dennys post, aston had to do exactly the same thing this year, purely becausee the guy that designed their intake didnt read the rules properly!

getting back on topic, it is always a struggle to get the roll hoop height right, sometimes you get a judge who is clearly over the 95th percentile trying to get in your car and then moans when he doesnt fit, and the responce that it was designed for 95th percentile doesnt seem to calm him, or provide a reasonable explanation!

what can we do!?

what about in the tech and design tents, having a 95th percentile dummy that they put in the car, and then measure roll hoop height legality from that??

[Deano]

With respect to the driver template that is specified in the rules, I've not seen this used in tech spec at Formula Student. All they do is run a stick from the rear to front hoop and measure the distance to the tallest driver's helmet.

We've not had any problems meeting this reg - and I guess neither should any team with a reasonably accurate CAD model of the actual driver.

Using the template specced in the rules would, I suppose, require a taller roll hoop than if it were designed around a more realistic driver model - i.e. one that accounts for the fact that the driver's back doesn't have to be straight.

If they're not going to bother using the template, then they might as well just scrap that rule and leave it as "50mm clearance to the tallest driver"�. I'd be interested to hear whether the other comps use the template.

Wrt scrutineering, at least in the UK, they don't actually check who the tallest driver is anyway, not to mention whether you have all the seat padding in etc. In fact the whole driver registration system this year seemed to be a bit haphazard. First off, they only seem to register drivers for insurance purposes. They have no idea which is your tallest driver for tech spec and, as far as I could tell, they had no way of knowing which driver had done which event. I'm pretty certain we could have used the same driver in every heat of every event (save one stint the endurance!).

There's too much room for teams to push the rules – you don't mind meeting the regs word for word if everyone has to do it, but it would be annoying having done this only to find others are getting away with their own interpretations...

Cheers,

[Bart Smith]

The rules are reasonably explicit in what they regard as to what the 95th percentile is. If you design around that size, you should be fine.

You will just have to use an adjustable pedalbox, seat inserts, or have all your drivers at roughly the same size!

On a side note, yes, I have seen cars that clearly do not meet the 95th percentile range, where their drivers are nothing over 5 6", and the scrutineers have not checked for compliance of such rules. Any driver that would be about 6ft tall would not even fit in the car...

I have heard whispers that there will be a dummy at the FSAE-A competition in December..

[BStoney]

As Michael Royce and the rules committee noted after FSAE East, "Perci", or the wooden 95th percentile male, will be used and his dimensions enforced at competition in 2007....Looks like some cars may be cut in half and a new roll hoop welded in. I guess we should bring our tube bender and some 1" .095 to help out others, if need be. http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Bart Smith]

We designed our car this year using the measurements provided in the rule book.

As this is one of the few parameters we can't change (dimension wise) we started here. Once we had our pseudo dummy in place, that set where our pedal box would be, and effectively the front bulkhead support.

Even our tallest drivers (and they are big hefty 100kg lads)fits inside this zone