When launching off a 2 step with a carbureted engine, which is better:

Mat the gas to bring the RPM up on to the rev limiter prior to launch and then launch with no accelerator pump shot?

Or apply just enough throttle to bring the RPM up on to the rev limiter prior to launch and then mat the gas upon launch, and get some pump shot- into the motor?

Thanks,
Joel

If I can't get the car to hook hard I leave on the floor mat becaise it doesnt seem to need the pump shot when it is black tracking. If I can make it stick reasonably well I have better luck setting the two step at say 5200, holding it at 5k and then matting the pedal on the bottom of the last yellow bulb. This technique seems to mitigate a bog especially when running (yawn) n/a.

This technique has also served me particularly well when using a nitrous kit activated by a WOT switch with a tine bit of delay programmed in (i.e. .1-.2 seconds)

Lots of variables at plat here especially driving style, clutch manners, power/weight ratio and traction. Many look at these variables as confusing and time consuming to dial in but I try to use them at my advantage the best I can wrap my head around what the car is doing. As we say "you will be the first one to know" lol

Push the trans brake button, foot to the floor, 2-step holds engine at set RPM, lights come down, let go of button....The engine will not care as the boosters take over while on the brake.

He has three pedals.

When I race pro tree I go to the floor. The car stays down and the reaction time is better. But it tends to hit the tires harder, When I race sportsman tree, I just touch the 2 step. Seems easier on the car

Push clutch in, hold the two step button on, foot to the floor on gas pedal, and I assume you have a way of keeping it in the beams.....

Always to the floor...

If you aren't going to leave with the gas pedal on the mat, why use a 2-step?

Bump in with the line loc on and the RPMs up some - 2000-2500. Top bulb comes on, pedal on the mat. Adjust the 2 step RPM to where you need it.

You can use a 2 step to have a 100% consistent launch RPM. It doesn't take wide open throttle to hold the unloaded motor at launch RPM. So you can mat the gas upon launch, so you get a pump shot. I'll just have to test.

Interesting topic for sure I always floor it on first yellow and don't let off until the stripe. One of the best stick drivers I know still doesn't use a 2-step at all. He just leaves like the old days, on the mat right before the launch and pulling gears on an old Nash box.
He races a 64 Galaxie wagon with an FE engine.

Gus

Quite a few of the SS/AH cars that are stick have the two step activated by the clutch pedal.

It is a common strategy now with drive by wire throttle bodies to limit throttle opening on the two step. Clutch cars will have an “arm” switch for the two step with either a clutch switch or clutch position sensor activating/ deactivating the two step. You can program the system to limit throttle opening to any angle you choose to get you close, but slightly beyond your launch rpm. The ignition then zeros in on the desired rpm. This is much smoother and easier on the engine. The driver arms the system, clutch pedal activates the two step, stomp the throttle pedal to the floor, and the engine floats at the desired rpm until the clutch pedal is released.

This is one of the Fueltech setup screens. you see that you can set the throttle angle on the two step.

Interesting stuff!

And we know you'll be out testing at LEAST 6 times before Drag Week, if not more...