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#1
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footbrake help
I need to do something different or practice more as yesterday I only won one round. Sucks we only get one time trial on Sundays.
I use the stage rpm to adjust reaction times, around 2000 rpm. GTO 60 foots 1.64 If I bring up the rpm after I stage, sometimes there is not enough time to look down at the tach and back up before the lights start. Tach is mounted on the steering column ( street car ). I have tried to go by sound to gauge rpm and I do get close. I just turned all four brake drums and put on new pads, Yesterday I tried bringing the rpms up after pre-stage and move to the stage light, but the car seems to lunge forward. That is probably why I red light yesterday, too far into the stage light. I thought about a light for stage rpm. Anyone use these? https://www.raptorperformance.com/co...t-launch-light or a dual stage tach/light, not sure what the model number is https://www.autometer.com/pub/media/.../2650-1244.pdf Any other ideas? |
#2
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That stage light is an interesting idea, I haven't seen one of those before but it makes sense.
__________________
1972 Pontiac LeMans Thanks to Fuelab Digital Fuel Delivery Quarter-Max Chassis and Racing Components |
#3
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Not sure what ignition you have but you can also program a MSD 2-step ignition off the brake light switch to a specified RPM.
__________________
Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#4
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I race in a class where:
Delay boxes, Tran’s brakes, throttle stops, stutter boxes, and automated shifters prohibited. Two wheel line lock only permitted. Two-step rev limiter PROHIBITED. No three or four step allowed. So, no starting line rev limiter or fast idle carb/throttle switch, like used on a/c cars, is allowed. |
#5
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You can have 1 rev limiter? red line limiter?
A few of the street ET guys tried like Johnny406 said except they used the red line limiter at 2500 or whatever starting RPM wanted connected to the brake switch. Not sure if still legal or not, was 20 years ago.
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#6
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A rev limiter can be used when the car is in motion. No electronics during staging. Throttle has to be operated by your foot, no device can affect throttle operation or rpm. I'm not sure a rpm light can be used during staging, but I'd like to try that if no one has any tips for how to footbrake constantly with drum brakes.
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#7
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Id look into why the car lunges forward when trying to stage it 2000rpm.
Our technique for all our cars when foot braking is, prestage, bring to rpm, then creep in until stage bulb is just lit. We've never had an issue creeping in at rpm (we stage anywhere from 1600 to 2400 depending on the car) |
#8
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I used to do the same as slowbird, pretty consistent 9.60's once all the fluid temps had stabilised, 1.34 60fts.
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#9
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and for the snaeky bstard....you take the rpm activated switch and use it to POWER your tach....so your tach is DEAD ....UNTIL you reach your set point ...no lights...but you can surely see WHEN the tach needle JUMPS...."must be at or above my set mark:.
The 2 step light is great since you can't have a rev limiter. |
#10
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Quote:
Pedal effort, for easy creep, will change when drums and shoes get broke in. Clay |
#11
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If you can find a older brake shop they can turn your shoes to match the drums
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#12
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OK, I was thinking that maybe disc brakes were needed to creep up to the stage light.
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#13
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most just "adjust" the arc with a 2x4 and hammer.....doubt there is still somebody ALIVE that would even know how to cut a set of shoes..
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#14
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A place in Findlay still does them that’s why finding a older shop was said and yes they are alive.
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#15
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Never heard of that, but just watched a youtube video of a guy using a brake shoe arc grinder.
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#16
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It’s so shoes are matched to drum from the start not just on the ends.
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#17
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I use four wheel drums and foot brake. I pre-stage, bring it up to 2500 rpm and bump the brake to stage without lunging.
__________________
1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule. |
#18
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Quote:
Racing at Cedar Falls Continental 10", 3400 stall |
#19
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Try short shallow pump of brake pedal to get to second stage bulb. After you get a feel for it you can get real accurate with staging depth IMHO. It does take practice to get staged and bring rpm's right in the amount of time you have. No substitute for practice. Unless you're one of those unconscious people that were born with it lol.
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#20
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Quote:
That is why last week I wanted to try something different, bring rpm's up at pre-stage. |
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