How important are breaks

[Jonny Hotnuts]

Some might find this question a crazy thing to ask but I really have to wonder.

Take into consideration that my experience driving on the salt is limited to steering the team car being towed to pits or impound and driving to and from the pits to the hotel.

This is the first year that I and my pop will be driving a car at speed on the salt.
One reason I ask is because I pulled the RH side rotor off the rear (using a Mazda Rx7 rear end).
Because it has a solid drive system (no diff) one rotor will stop both wheels and because the rotor weighs something like 9 pounds and is about 11" I figure that it is good for at least 5 HP (and cost nothing).

Next year I would like to machine the other rotors down. I figure that I could remove 3-4 pounds off of each rotor conservatively and this could reduce unsprung weight by 12 pounds + @ 11".

My question is:

Is it a bad idea to lighten up the rotors, obviously I would not do this on a road car but given the nature of running at the salt flats (slip coefficient....long slow down area) I would think that there is really no situation that you would need to really get on the breaks......and if there is a situation like a spin would having more breaking potential really help anyway.

Any insight or experiences is appreciated.

[Glen]

In the last few years I have seen brake rotors break and come off the cars. Machining them down will make them lighter and weaker. Having a brake on one wheel can also cause the car to brake steer and spin or worse. I would run this by the tech people before you bring it up with only one rear brake.

[Stainless1]

I take as many breaks as possible, but we don't really ever use the brake on the race car or bike except at very low, low speeds, like when you don't want to roll another 30 feet.   
Weight placed in motion tends to stay in motion, (not Jack, but another guy as old I think)  Your brake disk is adding weight, that adds traction.  It isn't costing you HP. but you don't need it.  Our lakester has 1 disk on a solid axle.

[jimmy six]

Brakes need to be adequate to safely load and unload the vehicle from the trailer. ... Many vehicles have brakes only on one axle and can stop safely; be ready to prove your point.

Glen never takes a break. .   

[desotoman]

It is my opinion that you should not skimp when it comes to brakes. I know I won't.

I remember a streamliner running up at El Mirage back in the 90's, parachute did not open and he took the ride of his life out the back door of the coarse. Went air born when it hit the pucker bushes. Turns out he only had parking brakes on the rear and that is all they were good for.

Just remember it is your butt in the car and anything and everything can go wrong. Fires are no fun, and you would want to stop as fast as possible if you have one. Always prepare for the worst, and the chances are good you will be able to walk away when something catastrophic happens. Just my 2 cents.

Tom G.

[1212FBGS]

caught the brakes on fire once. gotta have good ones... ya don't have to use them but if ya do... there great to have
kent

[1212FBGS]

oh yeah... don't skimp on safety... unless ya like hospitals, wheel chairs, and feeding tubes! give up 5 hp and be safe. toss that stock crap away and get some real race brakes... try speedway they sell good ones for pretty cheep
kent

[JackD]

With no suspension on some vehicles, very limited on others , and added weight to the rear swing arm on the faster bikes, it would seem that unsprung weight is not the factor that it is in other forms of racing.
The weight to HP formula is used to measure acceleration over relatively short distances and does not apply equally to Bonneville.
Rotating mass, like unlightened cranks , and full weight brake rotating assemblies, are your friend when you resume power in the next gear because it helps to maintain what you already have.
Speed, time, and distances that are part of the Salt setup, are unique to it.
It even helps "Fraction Control" for those that depend on it so. 

.

[Bob Drury]

Jack, welcome  back.  How was the Kidney Pie and Bangers?

[JackD]

Jack, welcome  back.  How was the Kidney Pie and Bangers?

The local English food fare is safe from Me with them because I stayed away from it.

If you want to know some of the importance of a suitable stopping system, you might ask the 5050 entry from the EM Championship race that lost all the points for an event and with it his hopes for a season win.