I run in no-tranny-brake-allowed classes. Rules don't allow line lock on drive wheels, either. Last year I put the 2-step on a button, but that required three appendages to work together (foot off brake, other foot on accelerator, hand releasing button at the hit). Even then, when the Digital 6 got wet and fried toward the end of the season, it really threw me off; killed me at the Division V and end-of-season run in the classes I was toward the top in. This year in Sportsman classes (Stock Eliminator, etc.) that don't allow tranny brakes, NHRA is requiring the 2-step to be tied to the brake pedal. So, thought I'd try it this year. I was concerned the brake pressure release would lead the stop light switch by too much, probably an unrealistic concern. MSD fixed the box, got it installed last weekend (it's in the passenger compartment this time). First T&T is this weekend, we'll see how it goes. Works fine in the garage. . .

Using a brake light switch is common to activate a 2 step. You don't actually have to use a brake light switch. You just need some sort of pressure switch attached to the brake pedal.

When you step on the brake, the 2 step activates. It's no worse than letting the brake pedal and thumb switch go at the same time. Not a big deal at the end of the track. When you're stepping on the brake to slow down, you're off the throttle already.

You still won't be able to launch like a transbrake but it will allow you to launch at the same rpm every time.

My tach has a feature like that. The shift light on the tach can be set to a launch rpm. Below the rpm and the light is off. More than 200 rpm above the set point and the light flashes. Not exactly perfect but it can get you close enough to launching at the same rpm.

When the 2-step was on the button, I was never quite sure I was releasing the button and brake at the same time - a walking-while-chewing-bubblegum thing. This should be a lot easier, as I'll have the accelerator floored already anyway, and all I need to react with is the brake.

When the new NHRA rule was announced, I remember comments that the Sportsman racers would have to change their launch technique. So far, doesn't seem to have affected them that much.

i have been doing this for awhile now, but upon review of recent videos, its becoming apparant the brake pedal must be "slow" after taking my foot off. takes it awhile to come back up and release the switch. my car has been rolling out a foot or 2 before the nitrous hits. (launch rpm limiter is being held below nitrous activation rpm in other words)

for bracket racing i dont see there being a problem, though, since the car will still run the same # each pass.

You're also allowed to install a hydraulic pressure switch into a brake line. That way you don't need to wait for the pedal to travel back up to release the switch. As soon as the pressure drops, the 2 step turns off. This might be better as the pedal can move a slight amount, activating a pedal switch, before brake pressure is applied. Same goes in reverse. Pressure should be released before the pedal is all the way up.

hey stephen...that launch light on the sportcomp playback tach...yeah...my dad came up with that researching with autometer...just a cool snippit, lol!

The way the brake light switch is set up, the pedal is still down a ways when the switch opens on the way back up. So, it should be okay.

We'll find out Saturday.

Assuming we don't get too much snow tomorrow. . .

How does a manual trans car use a 2-step on the brake pedal? I dont have three feet!

It would seem to me that maybe is time to look into a delay box??????
You may need to pull up ready to POP but if you can figure out your skid length then letting off the button will be just a matter of watching the other guy roll in. Assuming the operator is treeing the same, class to class . Line up and Launch.

Put it on the clutch start safety switch.

MSD makes a selector module so you can use a relay to only activate the 2-step on the launch. http://www.msdignition.com/pdf/8739_8737_frm22502.pdf , see Figure 2. You can do the 2-step and line-lock together so you don't roll out of the beams while staged - if you're a couple of seconds faster than the other guy in a bracket race, that could make a big difference.

WHY???? he does not have near the car needed to commpete in electronics class, maybe if he stuck another $50K into he MIGHT have a chance with his door car, but even then it's not likely...by and large diggers rule that class, and anymore if your not on the dial with a .001-.003 with a .00? light...head stragiht to trailer, your fried...

5kid, you will like it, I've seen it done every way mentioed above:
2 step tied into brake light wire off the brake light switch
2 step tied into hydraulic sensor
bracket made to hold an actual button like we use for transbrakes and such so brake pedal arm depresses it while staged.


ALL of these set up's work fine...if you really want a quick release doing the brake light switch connection, just hook an auxliary spring to the brake pedal so it snaps it back that much faster.

You'll be fine and wonder why you made your life harder than it needed to be like last year...i agree, that's too much BS to think about..you need to set up it to "shut up and drive" so to speak..no thought process at all, just react.

Thinking like an inganeer instead of like a winning racer.

As the season went on, I kept thinking I would move it to the brake light switch, didn't get to it, then the box fried.

New year, new season, repaired box, we're all tied for 1st place. . .

When I was foot braking a few years ago, I could never remember taking my foot off of the brake. We used to talk about it all the time. My son-in-law and me double hit the car, and he used to complain about not getting as good of a 60 ft as I did. All I could ever remember was stabing the throttle. Do you guys accually remember taking your foot off of the brake? My son-in-laws cousin raced the car we started with before his death and he had a micro switch hooked up on the carb linkage. He figuered out where his converter worked the best and installed a micro switch on it. He just staged pretty slowly, till the two step kicked in. When the lights came down, he just hit the gas and away he went. I never used a 2 step when footbraking, maybe we should have.

I never matted mine either with a 2 step, i just remember staging at a certain rpm and punching the loud pedal dont remember letting of the brake, so that musta just been instinct. We did alright like that, R/T's were nowhere near as consistant as they were when i went to the 4 wheel line lock/2 step/button....but i did alright footbraking. I always said if i were to continue in that class I'd get a shift light and an rpm window switch, that way when i was at my "staging rpm" i was still able to look at the tree as opposed to looking up/down, up/down to be sure i was where i was at rpm wise for a good 60'/and consistant R/T.


nother little trick, alot of guy footbraking use a A/C fast idle solenoid, they hook it to a toggle switch inside the car and activate it once they get ready to stage, that way car is already at set rpm thanks to the plunger pushig the carb open, it's easier bumping in with engine revs raised up, and it makes it that much more consistant....plus many street/sportsman classes dont allow 2 steps and guy pass this off as "factory" LOL!!

I guess both feet move with one brain command.

I started last year with the 2-step just running the throttle up above the rev limiter. I was concerned about my brakes holding. After about a month, I switched to just flooring it - the engine actually responded a little better to that (probably a carb tuning fine point), didn't put out any more power against the brakes (duh), and that takes one more motion out of the equation.

Tying the 2-step to the brake pedal will make launching a one-motion event.

I suppose I should stop calling it "2-step". Class rules only allow a single rev limiter, so I should call it "launch rev limiter". As long as the upper RPM rev limiter doesn't engage during a run, I will be okay.

LOL....play that ditty until somebody calls ya on it our track has it spelled out high end rev limiter only LOL!! but hey, that's what ya do, look at the rules and bend them to work in your favor...heck, even if you only get one event win before they call it/catch it...it's worth it...

If its on the clutch switch then it will activate when I press the clutch to change gears. A friend of mine tried that with bad results. I would still need some kind of push button or toggle switch to change between launch rpm and over-rev rpm.

We played it long & loud at the Div V Finals last year. The word was you can run a launch rev limiter as long as you don't have any other. Apparently they don't want people going down the track from, say 1000' on, popping a rev limiter. There's one racer in particular who has used a launch rev limiter for as long as I can remember in these same classes I run, and the track tech rep told me last year this was the interpretation and reasoning. Verified at Div V.

What was the problem with a rev limiter during a shift?

But, a switch you release after launch would work as well - just one more thing to think about.

The MSD relay set-up would deactivate the rev limiter after launch, but you'd have to release the button and clutch at the same time. And, the line-lock for burnout would be limited to your launch RPMs. Unless you rigged up another switch for burnout, with a diode or something to isolate the relay during burnout.

Shifting at 5500 rpms with a rev limiter of 3500 rpms = problem.

Speed shifting?

A lot of clutch racers shift on the rev limiter, albeit a high-speed. Not sure what the difference would be during that split second.

I'm putting together an LS1/T56 (in case you hadn't noticed), which I plan to race, so things like this have my attention. I've got the line lock for it, but haven't figured out details like 2-step and circuits.

put a digital 7 in the car. it will know which gear your in and can even setup a different limiter in each gear if you want it to.

Only got a couple of runs in while at the track for 4 hours. Green track surface, right lane was giving trouble all day, so they were only running from left lane a lot of the time. DA was good, but we had a head wind gusting from 10-20 MPH all day, really messed with getting any data.

2-step worked fine. Car ran so-so. Probably need a new fuel pump, maybe other tuning.

After the 2nd run, figured my time would be better spent getting the Camaro back together.

Will try again later.

But, looks like the 2-step on the brake will work fine.

I was going to get a Digital-6, as a Digital-7 is a race part and isnt "smog legal."

My friends car would backfire loudly when he shifted, and the rear end would get wicked loose. That isnt good with a 10 second blown LT1.