Drum vs. Disc brakes on the salt

[Milwaukee Midget]

I removed my front brakes and will be running rear drums only this year. 

Chris, Are you going to make it to Wilmington before Speedweek and if so will this matter?

Gregg

 

I hadn't even given it a thought.  The spindles and hubs are cut, and there's no going back at this point.

I guess if the rear drums will haul it down from 105-110 before I wind up in the hangar, I might still be able to run Wilmington.

Gregg, seriously - I hadn't even given it a thought . . .  

[maguromic]

Bo and Sum, The springs are made of spring steel wire and there are two per caliper. Take a matching drill bit and spot face the pads to hook the end of the wire spring.  The wire hooks on both pads (one wire spring on the front part of the pads and the other on the back part of the pads).  It gives just enough force to knock the pads back of the rotor.  The spring in the picture came from one of my friends in NASCAR and is very common for qualifying in NASCAR. They are not that hard to make.  Tony

[jl222]

 
 Anyone who has ridden a dirt bike down a steep hill knows you can't stop or slow down without front brakes, You can't stop fast anywhere without front brakes. I learned this fast hill climbing on my 1st dirt bike. Going down the hill,appllied rear brake didn't slow much at all, steering and sliding like crazy out of control to bottom. Since learned to use front brake.

  You bike guys know this

  I've told this story before. Several years ago, before SCTA put a stop to it my cousins were doing a short test run away from course at El Mirage in there blown Chrysler Stude. Ed gave it a short blast and Sh.t NO BRAKES Well it had brakes
on the rears only, and they were working, but they were not stopping the car, they were just locked up and sliding as if on ice.

              JL222

[gkabbt]

I hadn't even given it a thought.  The spindles and hubs are cut, and there's no going back at this point.

I guess if the rear drums will haul it down from 105-110 before I wind up in the hangar, I might still be able to run Wilmington.

Gregg, seriously - I hadn't even given it a thought . . .  

No need to worry about a hangar but there are steel poles that have the approach landing lights on them.
If you run off the end of the track, just be sure to steer left or right to miss them!!!!!       

Gregg

[Milwaukee Midget]

No need to worry about a hangar but there are steel poles that have the approach landing lights on them.
If you run off the end of the track, just be sure to steer left or right to miss them!!!!!       

Gregg

Gregg, that's all fine and well - but the reason I removed the brakes was so I could lower the front end further - which required I choke off the steering so the wheels wouldn't rub in the fender wells. 

 

I guess I'll see how it works at Bonneville, and worry about Wilmington later in the season.

[Stan Back]

It ain't like you're goin' 122 MPH.

[Milwaukee Midget]

It ain't like you're goin' 122 MPH.

Something you've done backwards . . .   

[JimL]

On our roadster, I set it up with a double master cylinder using both ports, paired, to operate the rear drums.  This lets the master cylinder pushrod move enough fluid while leaving the brake shoe adjustment looser.  You may need to step down a size on the master cylinder bore diameter, or pedal pressure gets higher....probably not a big deal.

Two notes for this method:  one,  you need to ditch all the handbrake stuff in the rear drums (more stuff to rust), and two, it gets the shoes far enough back that you can still get the drums off after everything rusts on the way home!

I vote for rear drums because wheel cylinders are MUCH easier and cheaper to repair than calipers.  (really easy when you throw away all that emergency brake stuff)

JimL

[Dr Goggles]

It ain't like you're goin' 122 MPH.

Something you've done backwards . . .   

Nice play Gentlemen.

[Milwaukee Midget]

On our roadster, I set it up with a double master cylinder using both ports, paired, to operate the rear drums.  This lets the master cylinder pushrod move enough fluid while leaving the brake shoe adjustment looser.  You may need to step down a size on the master cylinder bore diameter, or pedal pressure gets higher....probably not a big deal.

Two notes for this method:  one,  you need to ditch all the handbrake stuff in the rear drums (more stuff to rust), and two, it gets the shoes far enough back that you can still get the drums off after everything rusts on the way home!

I vote for rear drums because wheel cylinders are MUCH easier and cheaper to repair than calipers.  (really easy when you throw away all that emergency brake stuff)

JimL

So you run two lines out back - one for each wheel cylinder?  Actually, that would be nice if you were to lose one side.

[floydjer]

Or...You could run a vacuum pump to the master cyl.  and retract the pads ala` Penske

[JimL]

I ran two into one right after the master cylinder, and then split again at the rear axle.  I used extra long flexible hose at the backing plates, in a U shape turn, to allow pulling the axles far enough to change punkins without opening the brake lines on the salt.  Poor mans quick-change.

This was a handbrake actuation, using a clutch pedal 'under-dash bracket' turned upside down for a pivot.

  I am not a big fan of foot operated brakes in a salt-flats car.  The fireboots are too big, the pedal is hard to reach during hand maneuvering in the pits, and its just one more obstacle to clean up the tracked in salt in the foot well. 

Handbrake is easier to modulate when loading and unloading, and you can reach it through a window/door on the trailer.  If you make it strong, (hence a clutch pedal bracket/pivot out of a pickup) you can have a side extension to get it even easier to reach during loading or pit maneuvering.  We had the handle curved over so a short extension could slip on, for "outside" braking.

And no master cylinder where its hard to reach or exposed to underhood salt.

JimL

[Stan Back]

"Something you've done backwards . . . "

Just rotating for panoramic camera shots.

[jimmy six]

Never used any thing but rear drum brakes on 2 different cars. 140-215 mph. All emergency brake stuff removed. Can back them off so they never drag. Use a 7/8" Wilwood master cylinder and hand brake for the roadster and stock 1940 Chevrolet master cylinder for my coupe. Both are 1957 Pontiacs and I feel they are more aerodynamic than disc's. Opinion no proof.

Never went out the back door at El Mirage even when chute failed. I like the KISS method.......JD

[wickedwagens]

Thanks for all of the replies.  It sounds like the disc brakes will not make it back on the car.  I will run 4 wheel drum brakes and set them up for 0 drag.

Thanks again for all the help.