Go-Kart deceleration

[cn1323]

The braking test for the competition we're entering requires the karts to go from a minimum speed of 40 kmph to a stop inside the braking zone of 5 metres. This would result in a deceleration of over 1 g, and many places I've seen calculate braking force without reverse calculations tend to consider 1 g as a theoretical maximum deceleration. I have considered a 50 kmph vehicle coming to a standstill in 4 metres for additional safety, which ends up with an even larger deceleration. Are there any limitations which will not let the vehicle achieve this sort of deceleration if the rest of the parameters like piston and mc bores and rotor radius are reverse-calculated considering these conditions?

 

[ezcome-ezgo]

I recommend less calculating and more doing.

 

[cn1323]

The thing is, we're a first-time team and need to get all our components, so calculating the force would help us pinpoint which calipers and cylinders to get; we couldn't afford to get them wrong as we're looking to source them right from sponsors. I just wanted to see if there was any other constraint that would not let the car decelerate that quickly? I could add some pictures of my calculations if that would be of any help.

 

[Denny]

Tire and surface friction are the biggest factors I can think of. You have to remember we are not engineers on here. Most of us still count using our fingers and toes! We just have some good old fashioned common sense and have learned what works for us and what absolutely does not.

 

[ezcome-ezgo]

Deploy a parachute.

 

[Whitetrashrocker]

Deploy a parachute.

Ground auger would do the trick too.

 

[madprofessor]

Lowered tire inflation is the best cure for offroad traction to not get stuck in the mud. I believe it's also a positive factor for increased tire/pavement friction on a gokart for shorter stops, and might possibly increase friction in sharp cornering on pavement.
Question: How important is a greater tire inflation on a gokart for speed and cornering on pavement that would make lowering the inflation a bad idea?

 

[Whitetrashrocker]

Higher inflation has less frictional drag and will probably go faster so to say. It also makes the tire a little taller and ever slightly increases gear ratio.
But for the most part it makes for a really rough ride.

 

[panchothedog]

cn1323 As Denny said, we are not engineers. Just folks who GO karting,
FIX karts, and BUILD karts on a somewhat regular basis. All your comments about G forces and reverse calculations. Who are you trying to impress.
It sounds like you are running in some form of organized competition. That is
absolutely great. If I were you I would go have a look at the braking system on some of the other karts I would be running against and then go buy the exact same parts. WHO cares about your deceleration formula. If you can stop as fast as the other guys it ought to be good enough.

 

[Denny]

I was talking this very thing over the other day with Wylie Coyote and he brought up a great suggestion a granite wall will stop you pretty fast.