Went to the strip, too slow????

Adam... your reaction time will definately win or lose you a race, but it won't effect your ET one bit.

You can sit there for 30 seconds after the green light is on and still run a 12 second ET. It doesn't start timing your ET until you "trip the trigger" by passing through the 3rd photoeye at the starting line.
:TU:

The trick is getting your front tires to pop over the 3rd beam so your ET starts when your back tires trip the beam and ends when your front tires trip the finish line beam. Good for another .3 off your ET? :gt: LOL
(I don't know if you can do that... maybe it starts after you leave the 2nd photoeye, but I am positive your reaction time does NOT effect your ET)
:beer

 

Thanks for the info Rick!:beer Nothing like teaching a newbie cool tricks:grin: I couldn'r get enough of the track on Friday...I got bit by the race bug now...oh the bank account is going to hurt now:gt:

Maybe it was 60ft times that I was thniking about...my brain is not functioning all that well this week.

 

60 ft time makes all the difference. If you can drop from a 1.8 to a 1.6 you will easily be in the 12's.

 

Hey Brent,

Your mph gives an idea of what you'll be running. Your 60 foot time shows that you definitely have something to gain off the line.

If you do go to the taller tire (275 - 60's) expect to possibly lose some mph and some ET. Your 3.42's are a good gear for a 26" tall tire. With those tall ones, you're effectively bringing your rear ratio more like having a set of 3.08's.

The 98 mph should get you into the 13's if you get some traction on the bottom end. I would figure that you'd 60 foot a little better starting in low stall, since you're not quite into the meat of the torque band. Without sticky tires, those higher rpm's are going to put you into more torque, which will result in more tire spin.

To give you an idea of a pretty "efficient" run, I managed a 13.98 in my 71 GS455 in stock form (3.08 non posi) at only 96.8 mph. That was a pretty lucky pass with good traction.

I changed to TA headers/exhaust, 3.42's, and a Performer. On sticky tires I was consistently seeing 13.5's with a best of 13.43. I don't know if I ever saw over 101 mph. This was with a stock convertor (very tight too), launching just enough off idle for the car to load up on the suspension. I left it in drive, where it shifted about 5200 rpm. My 60 foot times were pretty consistent around 1.90.

Like was mentioned before, RT does not effect ET. The timers start when you break the staging beam (second one). So even if you came off the line wheels up, letting 'em hang for 100 feet... the clock starts. Of course your 60 foot time would be measured off the rear wheels if you did that!

I would recommend staying in the 26" height tire range. Some 275 - 50 - 15's would work although they're pushing the width of the stock rims.

I ran Hoosier Quick Time Pros that were only 8.5" wide and had no problem. They're DOT, but I didn't drive them on the street.

Hope this helps.

 

Drag race ET and RT

Is there a web page or something that explains what you and Rick wrote about ET and RT. Drag racing is new to me and I'm not sure of the significance of your RT.

 

Re: Drag race ET and RT

Not that I know of off-hand, but I'm sure they're out there.

I'll try to do this simply, but that's not one of my strong points.:Brow:

ET: Elapsed Time

That's how long it takes from the moments that you leave the beams on the starting line to the time you break them at the finish line.

RT: Reaction Time

This is a measurement of the time it takes from the green light to trip until your car leaves the beams. Often this is actually displayed based on the last amber which is usually .500 of a second prior to the green light being lit. Thus a perfect reaction time would be a .500 light, instead of a .000 light. It means the same thing though... you left right when the green came on.

This reaction has nothing to do with your ET because the timer doesn't start until you leave the beam. You could have a 20 second RT, but it only takes you 14 seconds from the time you (finally) leave the beams. Your time slip would display your ET and your RT as separate entities.

The importance of the RT is when you're in a race. If you and I line up together and we both run an identical ET (say 14.000 seconds), then it should be a tie, right??? Essentially it is, but if you reacted too slowly to the tree and left after I did, I would win the race because I got there first.

ME:
RT: .510

YOU:
RT: .520

IF we run an identical ET (down to the thousandth of a second), I will beat you by .010 (the difference between our RT's). But, that difference has nothing to do with how quick we went.

So your RT only matters during a race.

This gets more complicated when you're running a bracket race. Then you start getting into "packages". Your package is basically how far "off perfect" your run was. This is based on a dial-in system where you predict what your car will run.

Say I predict my car will run 14.000 seconds. You predict your car will run 15.000 seconds (usually you only write it out to the hundredth on your window). We race, you get a 1 second head start (difference between our predictions). Essentially it should be a tie race.

But, I have a .510 RT and run a 14.100 ET

You have a .520 RT and run a 15.095 ET

My package would be:
.510 (RT) - .500 (perfect RT)=.010
14.100 (ET) - 14.000 (dial in/prediction)=.100
.010 + .100 = .110

So my run was .110 off of a perfect run

Your package would be:
.520 - .500 = .020
15.095 - 15.000 = .095
.020 + .095 = .115

You were .115 off of a perfect run.

Thus, my car would have beaten yours by .115 - .110 = .005

Essentially, my package was .005 better than yours. Now you see why my tagline is "best package wins". :laugh:

Of course had you run a 14.995 you would have lost because you went quicker than your predicted ET, which is called "breaking out". Had we both went quicker, then whoever was closest to their dial (irregardless of the RT) would be the winner. Had I ran 13.999, I was closer to my dial than you were.

...yes, I always win in my scenarios. :bglasses:

 

Thanks

I got it. It's not that hard once you explained it.
Thanks again

 

Reaction time means nothing.....unless you are racing someone else.

Brent - what you really have to work on, with these tires ir new stickies....is whittling away your 60' times and the only way to do this is practice. Luckily......you dont necessarily have to go to the track to do so (more in a bit....:Brow: )

Your car seems to run very consistantly which is a good thing - It means one (or more) less things to figure out. Your goal should be to drop your 60' times to 2.0 or under....which is VERY Do-able.

If you do that....you're cutting .3-.4 of the 60' times.....which should nearly double to .6-.8 off your ET !!

So, your 14.5-14.7 becomes 13.9 :TU: Now add a better carb and MMMmmmm

The Pure Stock and F.A.S.T. guys do it (60 ' in 2.0 or better) with ALOT more power than you're making and ALOT less tire than you even have now.

The trick is.....not overpowering the tires and knowing, by experience, how much the tires will take.

The best way to practice ?? Find a nice CEMENT parking lot....Long off the beaten path and Practice !!

All you are going to do is

1) Stage the car, as if at the track, left foot on brake, right foot on gas, bringing it up to "X" RPMs
2) Say in your head or outloud...."!,2,3....GO"
3) Launch the car and take it up to about 4K then brake
4) Return and repeat often

Two things you are going to vary - your launch RPM, and how hard you hit the gGas pedal when you say "Go"

Instead of Mashing the gas pedal as fast as footingly possible try squeezing the pedal to the mat in, say a 1 second interval

So.....in High Stall, Say you bring the RPMs up to 1900......on GO!, side slip the brake and S Q U E E Z E the pedal, but not to slowly.

Do it again.....and again....and again

Try and make the pedal time consistant.....and vary your launch RPM. Until the tires break loose.

Try Increasing the pedal speed a bit once you find a good launch RPM.

Play Launch RPM and pedal speed back and forth....you're learning to flirt with that fine line of barely holding traction.....and going up in smoke. It takes time....and practice....

Lastly......now that you've found a Sweet RPM and Pedal speed combo - Forget about it:grin: Why ?? Track conditions and weather change with the minutes and what worked today might but probably wont work tomorrow. What will work, is developing this feel for what the tires will take and "Dialing Yourself In". You can use this benchmark as a starting point, but more important is to feel how the car responds, TODAY, and you respond accordingly. If it didn't break loose, try another 100 - 200 RPM at launch.....or Stay at that RPM and Pedal alittle quicker


Ohh !!! When you change Carbs.....be ready to go out and practice again 'cause the car is going to react differently. With practice, you'll only have to make a few test launches to dial it in

Have FUN !!

 

My RT's were all under .364 except for one. I had a .196, .211 and a .215, Am I in the wrong business?? John Force, look outp

I did not have a 98 mph run, that was my mistake in the first post. I was running ~95mph. I am hoping that I will run a little cooler with the new t-stat and improve the power with a bigger carb. I also checked my Q-jet, it is an 800cfm so I will get it all fixed up. Has anybody ever seen an elec choke version, or know if it can be converted?

Then I will run some better tires in an attempt to take advantage of the high stall launch. Sure would be nice to see some 13's:grin:

I think that Olds was a '72, my mistake. It is a pretty sweet car, it has the W-30 rear end cover, VERY cool looking. The top is a little ratty but not a bad machine. He typically runs mid 14's with it on street tires, only mod he admits to is headers.

 

launch techniques....

Launch technique is the key to your 60' times.

With my '69 350 if I leave from an idle I won't spin the tires, 95% of the time. If I bring the RPMs up to 1000 and hold it there I'll spin the tires about 75% of the time. If I bring the RPMs up to 1200 and hold it there it'll spin every time.

Now that's just my car, your car may or may not react the same. Depends upon how your's is set up suspension-wise. Every car will react a little different.

I agree that with some practice and minor tuning you should be able to get your times down into the 13s.

 

I know that every set-up is different but, just how much wheel spin do I want off the start? I always assumed that I needed a little to get it up into the power band, you know, between lugging it and frying the tires. The more I think about it though, if I leave in high stall ~3000 rpm, I would probably want minimal spin as I am already where the power is right? It will be interesting to see what happens with more traction.

I was also shifting about 5000-5200. With the 750 carb it probably didn't matter, it sure felt a little flat once I hit third gear.