anyone ever used a two step to launch under 3000 rpm, if you have how did it work as far as consistency and how the motor reacted

any opinions or advive would be great thanks

 

When i first started racing years ago they allowed our street class to use a button, so i had 4 wheel loine lock set up, 2 step off the button. convertor would'nt allow anything over 3200rpm to hold on the 4 wheel brakes and i used an adjustible MSD pill (the red one with a tiny screw in it) set at 2800. It was good 98% of the time but once in awhile it'd load the motor up and bog/chug when i let go of the button. Going below 3000 is touch and go, so take that for what it's worth.

 

i wouldnt recommend using it at 2500 or under.. i have the 3step with the adjustable *****.. set her at 2k for $hits and giggles because my tires would never hold anything anyway and it backfired.. sounded like a shotgun coming out of my carb.. and i will agree with IHI.. it is a touch and go thing..

i have a stick so its a bit different.. my launch rpm is about 5k and i bring her up to 3k-4k just on pedal and when the lights come down, i floor it.. let go the button and dump the clutch at the same time..

 

Just don't sit of the 2-step for a long time. Push the button then come up on the throttle just enough to hold the rpm. When you see the last yellow light come on, let go of the 2-step button and push the throttle to the floor at the same time. Running a 2-step and cast pistons isn't good. I don't know how well hypereutectic pistons will do but forged pistons are preferred.

The advantage of using the 2-step will be to launch at the exact same rpm every time.

You could also hook it up through a brake light switch. As soon as you let go of the brake pedal, the 2-step turns off.

 

so if i were to leave at 2400 on a 2 step it would work most of the time right.

one other thing i talked to my uncle and he said i could use his spare 2 step and he also thought may be i should only give enough go pedal to activate the 2 step or may be half throttle to make it lauch better and not have to go so far to the floor when i cut her loose. i think this idea is similar to stephens if i understood you right.

so what do you think try it or not i got hyperutectic slugs?

 

Just going to part throttle on the 2-step will allow you to launch at the same rpm every time and not going to WOT on the 2-step won't load up the engine with fuel however loading up with fuel may be a good thing.

You need to understand that when using a 2-step and launching at a part throttle higher rpm, the carb has gone through it's accelerator pump shot. If you're not at WOT and you go from part throttle to WOT, there may be a lean stumble.

Hypereutectics will probably survive banging off the 2-step.

 

cool man thanks for the info i think i will give it a shot and see what happens

 

If having doubts call holley, they will tell you how their carbs will react to..
They wer able to help me with my car loading up at 4500 rpm, intermediate air bleeds were way to small allowing to much mid range fuel, and they were actually 4 smaller than holley said it should have came with... I launch at 3000 sometimes with no issues on the bbc with dominator, the guy I bought chassis off of told me he used to leave at 2800 in that car, he also used bbc with dominator. I would say if the dominators can do it, whatever you are using should be able to...

 

Up through last season I had the 2-step set at 2800 (new torque converter this season, not sure where I'll set it yet).

I found putting the throttle wide open worked best. The carb is happy, the soft rev limiter keeps the engine from loading up with fuel. I have the 2-step tied to the brake light switch, so all I have to do when I see the last yellow is let go of the brake pedal. On the occasions that I run nitrous (switched on WOT), I also have a normally-closed relay tied to the brake light switch so the nitrous doesn't hit until the brake pedal is released, and therefore the rev limiter is released. Works great, my RT's were the same whether NA or nitrous.

FWIW, I'm running E85 & forged pistons.

 

ok guys i think that i get what your saying and i'm just gonna put it on.
and i think i will call holley like 87TA suggested cause i do have a4150 800cfm on my motor and i would like to see what they have to say

i really appreciate all the help guys this forum is by far the best as far as people and info

 

hmmmmm.......you mean I shouldn't be using my 2 step on my cast pistons????? Actually I rarely even bounce of the low side, I use it just enough to control my launch RPM's since consistency is king for bracket racing.

 

what rpm do you lauch at?

 

2800.... I give the car enough throttle to bring the rev's to ~ 2K then when the second amber lights I jump on the throttle and release on the third amber. The engine just starts to hit the limiter when I release. Although I need to change my launch technique becuase this method is starting to release the red beast. I am going to try a single bump into the stage beams instead of the 2 bumps I was doing.

Also to eliminate the "pump shot lag" I loosened my pump arms so that they were slowed down and didn't "shoot" as quickly.

 

thanks for the info

another thing i would like to know is what kind of trannys you guys might be running, because mine is a TH350 with the lock up system in it and i was just trying to figure out if the lock up is better or worse for drag

alot of my buddys say that i should junk it and put in a non-lock up TH350 and get a trans brake just so i don't have to deal with all this other $hit