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Two-step on auto car?

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Old 05-16-2006, 01:56 PM
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Default Two-step on auto car?

Is it possible?

My buddy just got a two-step working on his M6 and took it to the track, and it was a sight to see. The car sounded awesome and while it wasn't launching to it's full potential it was still very impressive to me. I was wondering how you would work at two-step in an auto car? We figured it would be a good way to get more stall speed at the line (up to your stall speed we're assuming), and wiring the switch for it to let go to your brake lights so that you hold the brake, activate the two-step, floor the gas, and when you release the brake pedal it deactivates the two-step.

So if it is possible lets say you have a 4000 stall with a two-step. On the two-step you would theoretically be able to floor it with the two-step set to 4000 RPMs and with it wired to the brake lights when you release the brakes it would let go and you'd be off. Obviously harder on drivetrain parts, and who knows if it would even be worth it over just footbraking the car, but it might be a cool experiment.
Old 05-16-2006, 02:42 PM
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Yes it is possible. I have a brand new, never used, Harlan 2 Step sitting in my parts shed awaiting install in my A3 Daily Driver. Although I dont know about wiring it into the footbrake, I do plan on wiring it into the trans brake and nitrous.
Old 05-16-2006, 02:58 PM
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Seems like a transbrake and a two-step serve the same basic function unless I'm missing something. I could definitely see where a two-step would be beneficial in a 4L60E application as a transbrake for a 4L60E is pretty much a non-option.
Old 05-16-2006, 03:06 PM
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Originally Posted by josh99ta
Is it possible?

My buddy just got a two-step working on his M6 and took it to the track, and it was a sight to see. The car sounded awesome and while it wasn't launching to it's full potential it was still very impressive to me. I was wondering how you would work at two-step in an auto car? We figured it would be a good way to get more stall speed at the line (up to your stall speed we're assuming), and wiring the switch for it to let go to your brake lights so that you hold the brake, activate the two-step, floor the gas, and when you release the brake pedal it deactivates the two-step.

So if it is possible lets say you have a 4000 stall with a two-step. On the two-step you would theoretically be able to floor it with the two-step set to 4000 RPMs and with it wired to the brake lights when you release the brakes it would let go and you'd be off. Obviously harder on drivetrain parts, and who knows if it would even be worth it over just footbraking the car, but it might be a cool experiment.

It isnt my fault the tires coulndt keep up!
Old 05-16-2006, 10:30 PM
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With all the trans experts we have on here there has to be some answers on this.
Old 05-17-2006, 07:39 AM
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It would be great for consistency and helping you dial in your car.
Old 05-17-2006, 12:43 PM
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Originally Posted by josh99ta
Seems like a transbrake and a two-step serve the same basic function unless I'm missing something. I could definitely see where a two-step would be beneficial in a 4L60E application as a transbrake for a 4L60E is pretty much a non-option.
From what i know, a 2 step with transbrake would help getting a lower than stall launch RPM.. I think...

Curious to know how does a 2 step works in a Auto Tranny without transbrake...
Old 05-17-2006, 01:26 PM
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You will not be able to stall it up to the rated stall of the converter. A lot of factor play into keeping the vehicle stationary while stalling the converter up without a transbrake, some factors are condition of the tires, brakes and road/track surface. The two step will allow you to consistently stall your A4 to a predefined rpm, that your vehicle can achieve, without guessing if you are at the same rpm while at the starting line. It is a great tool for bracket racers or if your combination prefer being flashed over being stalled.
Old 05-17-2006, 01:34 PM
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Originally Posted by 12secSS
It is a great tool for bracket racers or if your combination prefer being flashed over being stalled.
How does the 2step help a "flashing" launch?

I have some BIG problems with consistency of launching, which has yield me SOME bracket racing early watching spots
Old 05-17-2006, 01:50 PM
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Flashing is when your starting/launch rpm is lower then the rated stall speed. This allows the converter to multiply the torque at an increasing rate for a short time until the stall is achieved. After which the multiplication starts to decrease. If you launch at the rated stall speed, you are pretty much launching at the max torque multiplication and as you launch you are "loosing" multiplication or you could also shock the tires too hard and spin them.
Old 05-17-2006, 02:06 PM
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Oh, I thought a Flash Launch off idle.. Now everything makes sense..

Thanks George
Old 05-17-2006, 03:16 PM
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I guess I'm not seeing how a 2 step would be all that advantageous in a non trans-braked auto.

Dan
Old 05-17-2006, 04:43 PM
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IMO, if you bracket race it is advantageous, since you can launch pretty much at the same rpm round after round. Also some converters work better when they are flashed, some from idle some from a higher rpm but lower then the stall speed.

Edit: Some Stock Eliminators use a 2-step when they foot brake to great success.
Old 05-17-2006, 05:43 PM
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I understand. You could do the same with a shift light and set it for your flash speed to I suppose, just rev till the light comes on and hold. I think there is a bit of confusion (maybe on my part) as to how a two-step works though, it's not really like a trans-brake, it's basically a settable momentary RPM limiter correct?

Dan
Old 05-17-2006, 10:30 PM
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Correct, it is a two-step rev limiter. I wasn't making that clear in the first post and thought that the way it works (as I understand it, it cuts off spark to half the cylinders when engaged) that you may be able to get more stall speed, but in a non transbraked auto application it seems like the only thing it would be good for would be consistency or exact RPM launches to get the most out of your setup. Even on the two setp you're not going to be able to stall much if any higher than you normally would, but it would make your launch RPMs dead consistent. My car seems to respond well to launches at fairly low RPMs (4000 stall, 1400-1600 launches) so I doubt one would benefit me very much. They do sound damn cool though.
Old 05-18-2006, 03:04 PM
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I got one put on my car recently, which is a dam fine unit from a sponser Synergy Motorsport (they have their own two-step box out now).

You have to be careful how long you stay on the two-step as well, it cut's spark, but not fuel so it can load up if you sit there on it to long.

My old A4 setup with a 4K stall also liked 1400-1600 launches.

I agree the two-step is useful for A4 and M6 cars that want consistant launches without looking down at the tach. and also works good for M6 turbo cars to spool up.

Dan
Old 07-29-2006, 05:36 PM
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bringing this back to the top....some n00b questions....

let me see if i have this right...there would be a switch to activate the two step correct? then i would put my pedal to the ground and it would keep the rpms at whatever i set the 2step at....how would the 2step be disengaged and the car be lauched?

maybe im lost somewhere...LOL
Old 07-30-2006, 09:31 AM
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There is a switch to activate it and a switch to deactivate it. When I had the M6, there was a switch in my ashtray to activate it. To deactivate it I used the clutch safety switch so when you let out the clutch, the 2-step de-activated. I'll now have the the the 2-step deactivate using the same switch as my transbrake which is located on the shifter for the TH400.

Dan



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