How wide is your chassis?

[Dash]

Just out of curiosity, how wide is the foot well of everyone's chassis?
I'm a suspension guy, so I'm asking out of pure curiosity. Our team is running with a "we'll make it just big enough for the template to fit" mentality. Now i'm not 100% against this, but I feel like adding in a decent amount of play ( maybe 1/2 - 1 inch clearance on each side ) won't hurt too bad.
Anyone else got opinions on this?

[Dash]

Just out of curiosity, how wide is the foot well of everyone's chassis?
I'm a suspension guy, so I'm asking out of pure curiosity. Our team is running with a "we'll make it just big enough for the template to fit" mentality. Now i'm not 100% against this, but I feel like adding in a decent amount of play ( maybe 1/2 - 1 inch clearance on each side ) won't hurt too bad.
Anyone else got opinions on this?

[EHog]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dash:
Our team is running with a "we'll make it just big enough for the template to fit" mentality. </div></BLOCKQUOTE>

In case you haven't noticed, the template is plenty HUGE. There is no reason to make it any larger. Now, if you need it wider or taller etc. to integrate nicely with your suspension pickup points, thats another story. Maybe make it 1/16" larger than template to ensure you pass? Whatever your comfort level is I suppose...

Remember, the larger you make it, the more inertia about every axis.

[Dash]

Ensuring we pass template is definitely #1 in my mind. In 09 when they first started putting the template rule together, our car was made to just barely fit it through. In the end, some weld bead is what caught the template from passing on both sides. The judges saw that we made a great attempt at it, and could be fixed with a file if we wanted and let us pass, seeing as it wasn't yet a pass or don't drive deal.

[Pico]

Knowing that the tolerances on a frame are in the order of +/- 1/16, usually leave about 0.25 all around the foot section. We almost didn't pass this year because the cockpit opening section was too tight because of a 1mm interference 5mm up from the top SIS height. An extra 1/4in insignificantly influences your inertia so better be safe than sorry.

[Dsenechal]

Agreed with Mcgill above... Even if you CNC cut all your frame tubes perfectly, and have a very nice jig setup (which we do both)... welding will tweak the frame more than 1/16 of an inch in one direction or another. I design around .25 inches on left and right sides.

Of course as already mentioned, suspension points will dictate front width more than anything.

[Kirby]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dsenechal:
Agreed with Mcgill above... Even if you CNC cut all your frame tubes perfectly, and have a very nice jig setup (which we do both)... welding will tweak the frame more than 1/16 of an inch in one direction or another. I design around .25 inches on left and right sides.

Of course as already mentioned, suspension points will dictate front width more than anything. </div></BLOCKQUOTE>

Or stupidly wide engine alternator covers, combined with engine removal requirement and rear triangulation for roll hoop bracing. http://fsae.com/groupee_common/emoticons/icon_frown.gif

[woodsy96]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Of course as already mentioned, suspension points will dictate front width more than anything. </div></BLOCKQUOTE>

Yeah, pullrod suspension and short FVSA lengths = behemoth chassis.