Vaccum brakes...Launching under boost.

Orion231

Member
Joined
May 25, 2001
Ok guys, now I have the car running GREAT!...How do I build boost? I have vaccum assist, and stock brakes with new front pads and rotors. I went out and bought the S10 Wheel cyclinders today 85 S10 pickup. They are CHEAP! 7 bucks a piece! How do I install them, and what else can I do to hold boost? I hear some people lock the E-brake does that work or is that dumb.

Thanks!
 
IMOP I don't care for the e-brake launchs, the seat belts have to be to loose to reach it hehehe.

I have heard of people using one of the vaccume pump to help with those brakes but I have not tried them personaly.

Good Luck
 
I asked about E-brake launching a coupla weeks ago and the general concensus was that it will work, but you may end up damaging things (bending the backing plates) if you use it repeatedly.

Steve
 
You should be able to build boost with no problem with vacuum brakes assuming your idle vacuum, in gear, is 13-15" and everything is working.

If you ride the brake doing a burn out, you must lift off the gas and brake for a second or two before staging in order to recharge the booster...instead of being on and off the brake as you are staging...you can try bumbing into the second lite by using the gas to shove the car forward rather than modulating the brake pedal....

Be careful with those large rear cylinders..if the road is a little damp and everything is bled properly, the rear end will come around you before you know it at absolutely the wrong time. And, don't hammer the brakes when you cross the line, ease into them...so the weight transfer to the front under braking does not lighten up the rear too much and the big cylinders decide to act like the road is wet.

If you look at the cylinders you bought and the back side of the backing plate on the car at the mounting of the old cylinder, you will see there is a clip that holds them on..once you remove the brake hose and the shoes, etc, knock clip out and swap the cylinders...pull both wheels off but do only one at a time so you can look at the other side when you get confused putting the brakes and springs back on. A digital camera is a great help or a picture in a book.. A brake spring tool is a help but I always use a pair of adjustable pliers or vise grips to remove/install the springs...I do have the tool but by the time I figure it out, I general am finished using the muscle method... :)

Be sure the drums are round and the brake shoes are adjusted properly. Once you think they are well bled....come back and re do them a couple of days later.

I don't think you will have any trouble with a shortage of vacuum if everything is working correctly...have fun..you got off to a good start.

BTW, what's the elevation of the track at Wall? I was guessing about 2500".
 
Elevation at Wall?

I ran in Penwell, Texas, 4000 feet, I am going back to huntsville in a couple of months though...Thanks! So how do I actually build the boost to launch? Just mash the feck outta teh pedal till my face looks liek this.....:mad: then let go when I am ready to go?
 
LOL....I don't think you will have to push quite that hard, they are power brakes after all! (hopefully) :)

Just put your left foot on the brake firmly and bring the boost up to whatever level you can launch at without spinning the tires on the launch...maybe 4#? and hold it until the last yellow comes on and then floor the gas while taking your foot off the brake. (you will have to practice until you know when to let go of it...)

Remember you want to leave with all the possible boost without spinning the tires significantly...that will take trial and error practice and may change from day to day depending upon track conditions and weather.

Ask UNGN for some pointers...he is the king of drag radials as far as I am concerned...I think he can help get you focused.

Wall is the track on the east side of San Angelo...it's about 35 miles from my farm in Eden where I am going to move later this summer.
 
Although I can't really "recommend" it as I have heard of people breaking things, I used the E-brake to launch my T-Type several times at the track. I used the foot brake too, which may have helped distribute the load on the shoes more (don't know if some people were using JUST the E-brake?). Got pretty good at it, but always feared pulling the handle at the last amber and have my hood pop up! :eek:
 
handle

hahaahaaaaa....ooops, wrong handle !


John C.
LedSLED Motorsports
 
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