? about reaction-staging light-tree

**william SS** · 03-05-2008, 03:45 AM

OK when I go to the drag strip on fridays the tree goes yellow,yellow,yellow, then green. And on saturday nights its all three yellow at the same time then green. So my question is when exactly does the reaction timer start for each case and what would be considerd cuting a perfect tree. When am I supposed to leave the line. I originally thought that it started on the flash of the last amber light and when all three go yellow at the same time but im not sure. Maybe i sould just wait till i see green then go. Can someone please help me.

**Sleeper101** · 03-05-2008, 04:54 PM

Well the yellow yellow yellow-Green is a bracket tree, The 3yellow-green could be a .400 tree or .500 tree, most run .400 tree.

On the bracket tree.000 is perfect, Which is very rare to do. .001 to .050 is really good and takes LOTS of practice to do.

im not really sure on the pro tree of whats perfect. I have only ran it 1 time.

**RacerBob** · 03-13-2008, 08:14 AM

If you wait 'till you see green to leave, you'll be late. If you are new to this (and it sounds like you are) stick with the bracket tree.

Most tracks have switched to led lights, which in my opinion are trickier than traditional bulbs. I normally leave a the beginning of the 3rd yellow, but every person and every car are different. Remember, there is your reaction time, then there is the car's reaction time. Different set ups on the same car (like changing psi) can affect the car's reaction time also.

Another thing that you want to be aware of is how you stage the car. I have found that if I stage very shallow (bump the car forward untill the stage light just stops flickering and remains lit) every time, my reaction times are more consistant.

Hope that helps, good luck.

**98vettedave** · 03-13-2008, 10:56 AM

Originally Posted by william SS

OK when I go to the drag strip on fridays the tree goes yellow,yellow,yellow, then green. And on saturday nights its all three yellow at the same time then green. So my question is when exactly does the reaction timer start for each case and what would be considerd cuting a perfect tree. When am I supposed to leave the line. I originally thought that it started on the flash of the last amber light and when all three go yellow at the same time but im not sure. Maybe i sould just wait till i see green then go. Can someone please help me.

The reaction time starts when the light turns green. Obviously if you wait until you see the green light the RT will be very poor. Test and tune days at your local drag strip is where you can practice on the tree. All drivers and cars react differently...you need to find what is best for your set up...start by lauching on the last yellow light and adjust from there. Remember if you stag your car shallow then you must react a little sooner - this will improve your ET slightly. Just the opposite takes effect if you stag your car deep.

On the Pro Tree 0.4 or 0.5 is perfect depending on which system is being used.

**Fury_786** · 03-15-2008, 10:37 AM

'real' pro trees, (the ones NHRA uses on TV) are a .400 perfect.

ALWAYS leave on the last amber, whether its coming one at a time, or all at once.

if your still a little late you can deep stage, this is rolling into the lights farther and the top stage bulbs will go out. therefore you're closer to the line and your reaction time will be lower.

**tjw2** · 03-25-2008, 01:21 PM

On a pro tree .400 is perfect on a bracket tree .500 is perfect but it can be reprsented i two ways on your time slip it will either say .5xx such as .501 or it will say .xxx such as
.010 which is a .510 light. Most major tracks like Memphis Motorsports Park do it the .010 way. The key to good reaction times is consistancy in staging as others have said stage in the same place every time and the easiest way to do that is stage as shallow as possible. And when looking at a pro type tree dont look at the all 3 ambers when they come on at once focus on one and you will have a better reaction time.

**Kevin Garceau** · 03-29-2008, 03:21 AM

Its not the tracks that do away with the .5XX vs .0XX....its the timing system in use.

Most street/strip type cars will always be dead late on even a .500 pro tree. Same tree used in IHRA "Hot Rod" and NHRA "Super Street" which is the 10.90 index class.

How the car leaves the line also effects the R/T as well. I dont mean how fast but how it Physically launches when you take off. Many of the Stock and Super Stock cars their first move will be straight up, they will break the beam faster than if they were rolling out, even though their 60s may be slower. Once the beam is broken your R/T has been set. Even some cars that can pick the fronts kind of drive into the wheel lift so their vehicle stops the R/T timer slower than one that pops straight up.