*Tree Variance System * Bob Frey

[FABMAN]

Is this new this year, has it already been talked about and I just missed it. I read a little about it on Drag Central on Bob Frey's article, just wonder if drivers had notice much difference.

FEATURE- Did You Know? by Bob Frey

 

[Bobby Bennett]

This is an in-depth story on why the NHRA implemented the variation.

Drag Racing Internet Magazine - Competition Plus.com - WHY THE NHRA NEEDED TO CHANGE THE CHRISTMAS TREE ROUTINE

 

[FABMAN]

This is an in-depth story on why the NHRA implemented the variation.

Drag Racing Internet Magazine - Competition Plus.com - WHY THE NHRA NEEDED TO CHANGE THE CHRISTMAS TREE ROUTINE

Bobby, thanks for the info.

If they have implemented this into the sportsman classes, it would interesting to see the effect it has on delays in the super classes.

I'll have to give NHRA the thumbs up for this one.

 

[Curt]

Bobby, thanks for the info.

If they have implemented this into the sportsman classes, it would interesting to see the effect it has on delays in the super classes.

I'll have to give NHRA the thumbs up for this one.

It wouldnt be a problem. We leave on the first yellow. this system is the time BEFORE the tree starts. At national events the time between stage and start is mostly the same. but it varys to much track to track at others races to trust.

 

[clwill]

It wouldnt be a problem. We leave on the first yellow. this system is the time BEFORE the tree starts. At national events the time between stage and start is mostly the same. but it varys to much track to track at others races to trust.

Exactly, there's a significant difference in the time delay caused by the car between most sportsman classes and the fuel classes. Most sportsman classes (and even Pro Stock) leave with the engine at a high RPM, meaning the car delay is just the time it takes the clutch/converter/tranny/whatever to engage. In the fuel classes, the engine has to rev, and THEN the clutch has to engage.

That's a key reason why the fuel RTs are so much slower than your typical sportsman RT, and why guessing in the fuel classes pays off. In most sportsman classes, the problem is WAITING for the light, and not being too fast. Hence the popularity of delay boxes. If you guess in a sportsman class, you red light a lot. And you don't need to guess to cut .002s and such.

 

[FABMAN]

Exactly, there's a significant difference in the time delay caused by the car between most sportsman classes and the fuel classes. Most sportsman classes (and even Pro Stock) leave with the engine at a high RPM, meaning the car delay is just the time it takes the clutch/converter/tranny/whatever to engage. In the fuel classes, the engine has to rev, and THEN the clutch has to engage.

That's a key reason why the fuel RTs are so much slower than your typical sportsman RT, and why guessing in the fuel classes pays off. In most sportsman classes, the problem is WAITING for the light, and not being too fast. Hence the popularity of delay boxes. If you guess in a sportsman class, you red light a lot. And you don't need to guess to cut .002s and such.

Chris, thanks for the explanation. I was checking stats on super classes at St Louis race and it seemed there were more red lights than normal that's why I questioned it. I never used timers when I raced but I question how you can red light when using timer.

 

[clwill]

I never used timers when I raced but I question how you can red light when using timer.

Works like this: you leave on the yellow (usually the top yellow). On a "full tree" (where you get the three separate yellows), you have .5 secs between each yellow and before the green. On a pro tree (all three yellows at once), you have .4 secs between the yellows and the green. With a delay box, you start with 1.1 secs in the box on a full tree and 0.0 in the box on a pro tree. You see what your average reaction time is. You then add (or subtract) from there.

With an S/C car, for example, it can often leave before .4 seconds is up, so a good driver with nothing in the box will red light (albeit consistently). You often see an S/C car put something like .020 in the box. The guys you see who seem to get .00x lights all the time would go -.015 (or something like that) without anything in the box.

Hope this helps,
Chris

 

[Randy]

With a delay box, you start with 1.1 secs in the box on a full tree and 0.0 in the box on a pro tree. You see what your average reaction time is. You then add (or subtract) from there.

And for that reason NHRA should not allow them on the cars. I bracket raced back before all this stuff when you actually had to drive the car and respond to the light, not have electronics make the call for you.

 

[my friends call me Zappy]

And for that reason NHRA should not allow them on the cars. I bracket raced back before all this stuff when you actually had to drive the car and respond to the light, not have electronics make the call for you.

Right on Randy. Let the driver, DRIVE. They keep talkin lower the cost, ban these gadgets.

 

[Crash]

And for that reason NHRA should not allow them on the cars. I bracket raced back before all this stuff when you actually had to drive the car and respond to the light, not have electronics make the call for you.

You are still responding to the light. Instead of "timing" the bottom bulb, you are reacting to the top. There are plenty of guys out there who stick a piece of tape on the windshield and leave on the bottom bulb....same idea.

 

[my friends call me Zappy]

Of course if they really wanted to cut the red lights, just go to an "instant green" system. Keep the variable delay they have now. After the third pre-stage is lit, the delay starts, then BAM green, no yellow flash.
Driver RT is just as important as now. Eliminate 90% of reds.

 

[Bill]

What they really need to vary on the Pro Tree is the length of time between the yellow lights come on and the green comes on. Set a window of say, .4-sec. to a full second. and make it automatic and constantly variable.

Nobody could second-guess (anticipate) the green. They'd have to wait until the saw a hint of green before they could start the car in motion.

It would put the"driving" back into driving.


While they were at it, they could fix the unfair advantage that the faster cars have in handicap racing by eliminating the "first red light" rule in handicapped racing.

To be fair, both drivers should have an equal chance to red light.

As it stands, if the slower car (ALWAYS the first to leave the line), red lights, the faster car never has HIS chance to red light, a decided (and, unnecessary) advantage. Software to fix this problem has been around for years but NHRA has more inertia than Mount Everest and since it won't make them a red cent, they probably will never correct this inequity.

 

[clwill]

And for that reason NHRA should not allow them on the cars. I bracket raced back before all this stuff when you actually had to drive the car and respond to the light, not have electronics make the call for you.

OK, but the electronics aren't "making the call". You are. You still have to decide what to put in the box. If you are inconsistent, the box doesn't help.

All the box does is change the number on the time slip. Without the box, the consistent driver would still have a window of +/- .010 (perhaps) and they could tune the car to it. The inconsistent driver with their +/- .200 window would win a couple of rounds, never a race. Just like it is today, and like it should be.

And "back in the day" didn't you have funky buttons with mechanical delays, and tricks in the throttle linkage, and...? It's all the same, only different

If they really wanted to get rid of it, Paul/Bill are right: get rid of yellow. Who needs "ready, set, go" when "ready, go" is just fine

 

[Randy]

Chris:

A couple of years ago I was bored and had nothing to do at the shop so I went to Irwindale Raceway's 1/8th mile on a Thursday night with some friends to watch. Since I'm not much of a watcher the first thing I did was take my car to the tech area. Ooops!

My daily driver/throw away car is a PT GT Turbo. It actually ran a 9.71 in the 1/8th which sorta surprised me, I guess.

Anyway, I made a half dozen runs. The first two runs I red lit. Both were in the .460-.470 range. I was leaving off the end of the second bulb (it was a 5 tenths 3 amber count down tree). I tried waiting, watching the third bulb light up and ended up with a .560 light. So, I tried going in a little deeper leaving off the third bulb, then I tried pushing on the brake harder (automatic) to slow my reaction time and leaving off the end of the second bulb, I tried cross staging (slightly, but it worked for me back in the OCIR bracket racing days). Bottom line was, I was making "driver" adjustments to maximize my efforts.

Trying to leave between events on the tree makes you work for it (events meaning specific hard events on the tree like bulb on or bulb off every time). Today, you leave off your favorite bulb when it comes on, dial the numbers in you box, go grab a burger and head for the staging lanes. I know it's not that easy, but when you know you are racing or watching the cars launch off a chip, hitting the delay, then the car dies at 10 feet for two seconds and then runs right on the 11.50 dial in at 227.65 miles per hour it's a joke. It's like the whole thing has been dumbed down, to me.

Take all the junk off the cars and race. Then you'll see who really can drive.

 

[yoda]

Of course if they really wanted to cut the red lights, just go to an "instant green" system. Keep the variable delay they have now. After the third pre-stage is lit, the delay starts, then BAM green, no yellow flash.
Driver RT is just as important as now. Eliminate 90% of reds.

The Friday Street Drags at SIR are done on that kind of tree, and it completely sucks... All the regular racers are lost and all the street guys are clueless. NOBODY has a decent light, and most races are lost in a big way off the line.

If you think there are issues now with competition being one sided, slip the "instant green" into the equasion and watch how many teams start looking for a new place to race...

 

[clwill]

Today, you leave off your favorite bulb when it comes on, dial the numbers in you box, go grab a burger and head for the staging lanes. I know it's not that easy, but when you know you are racing or watching the cars launch off a chip, hitting the delay, then the car dies at 10 feet for two seconds and then runs right on the 11.50 dial in at 227.65 miles per hour it's a joke. It's like the whole thing has been dumbed down, to me.

All I've ever suggested to people is: try it. It's really frigging hard. Looks easy, computer handles all the problems, any idiot could do it, yadda, yadda. It's really not. No it's not "old school", but it sure isn't easy either.

Gotta be a reason that a huge number of pros cut their teeth in S/C, and why great leavers like Dave Connolly go there when they need practice.

Each to their own. You like ketchup, I like mustard. Whatever.

Chris

 

[FABMAN]

All I've ever suggested to people is: try it. It's really frigging hard. Looks easy, computer handles all the problems, any idiot could do it, yadda, yadda. It's really not. No it's not "old school", but it sure isn't easy either.

Gotta be a reason that a huge number of pros cut their teeth in S/C, and why great leavers like Dave Connolly go there when they need practice.

Each to their own. You like ketchup, I like mustard. Whatever.

Chris

I went to the strip with my daughter, first time on drag strip 01 Mustang GT and I had her leaving on last yellow, lights were in the 70's so after a few passes I figured the reaction of the car and had her leave on the third yellow and it made a big difference so I figure that's what going on with the timed systems. As she gets better she may go to electronics but I want her to learn her own abilities first. I prefer the pro tree I think it shows the true reaction of a driver.

 

[Curt]

All I've ever suggested to people is: try it. It's really frigging hard. Looks easy, computer handles all the problems, any idiot could do it, yadda, yadda. It's really not. No it's not "old school", but it sure isn't easy either.

Gotta be a reason that a huge number of pros cut their teeth in S/C, and why great leavers like Dave Connolly go there when they need practice.

Each to their own. You like ketchup, I like mustard. Whatever.

Chris

Tell it brother. Very few s/g s/c cars run "on the number" out the back. Go watch the wheel racing at the top. most cars are set up fast so they can race. Thats why some very good drivers never win a national event. BTW we dont get 8-10 passes at each race to "get the cat right".