1/4 mile launch tips

[Durt]

Okay - dumb question(s) time, but I'd rather get bagged on for being a homer than wad my car up.
I've had my car for almost 10 years & have tracked it extensively, but never in the 1/4 mile. This month I'm going to an event & give it a shot. The few times I've done serious burn outs have been pretty dramatic & I'd kind of like to know what to expect if I drop the hammer for 1/4 mile.
I'll be running Blue Streaks - which are pretty sticky, but not drag slicks by any means. Any recommendations for revs at launch so I don't just melt the tires?
Any recommendations at all, for that matter?

Thanks - Durt

[CHANMADD]

practice and try,try and try again!!

[Excaliber]

I've found just a little wheel spin works best for me. The trick is to control it, and it's a fine line between a 'little' and 'going up in smoke'. I launch around 2500 rpm or so, but it really depends on your gears and tires what works best for you.

Surprisingly I worry more about the 2nd gear shift, THATS when I'm more likely to get serious wheel spin, at times accompanied by a serious 'pucker factor' as the car starts to dance around!

[Matt Kennedy]

Ahh, one of my passions....


Our cars do very well even on street tires. The hardest part of the drag racing thing, especially with our cars is that it takes quite a lot of self discpline to do it well. If you hammer it off the line and over rev it in every gear which is the most natural thing to do you'll have a horrible run. Keep this in mind as you follow the steps below.

1. Pre-staging: I'll assume you tires are going to behave a lot more like street tires than drag slicks. If so STAY OUT OF THE WATER BOX. Go around the water completely. You will most likely see other experienced drivers doing this. Go around the water and then if necessary back up slightly. Do a short dry burn out to clean off your tires. That's it. Roll up towards the line. (Water is for heating drag tires. It will only serve to hurt your traction on street tires.)

2. Staging: There are two staging beams and two corresponding staging lights on the top of the tree. As you break each beam one of the two yellow staging lights will light up. Once both staging lights are lit you are ready. When both cars are staged the race is started. Tip. Be ready. They do not waste time.

The self discipline here is to ignore everything going on around you and stare directly at *your* column of lights on the tree. In particular you want to watch for the last yellow light to comes on - just before the green. Leave when that last yellow comes on. Human reaction time will dictate that you won't actually leave until the green is on. If you wait to see the green light up you'll never get a good reaction time. If for some reason you have amazing reflexes and leave early and red light next run try to avoid staging quite so deep into the beams.

3. Launching: Our cars are very light thus traction is a BIG problem. Unless you are running true bias ply drag slicks you will need to do a roll away "street light" start. This means you will leave the line from idle and feather the accelerator. The goal is to work the gas pedal trying to maintain as much traction as you can until the car is accelerating down the track with full traction. (I can get a repeatable 1.8 60' times on lousy BF T/As doing this.) If you hammer the pedal you'll just spin. This is where the discipline comes in. Everything in your mind and body is going to be telling you to squash that gas pedal because the guy next to you is revving his engine to 4000 rpm and preparing for a hard launch. Don't do it. I tell Cobra guys this all the time. They almost always ignire this and hammer it the first couple of times out until they decide its emarrassing to run 14's and get slaughtered by the stock corvette, near stock mustang, or even the ricer lined up next to them. Note that you'll need to feather or manage the accelerator all the way through first and part way through 2nd. After that it should be pedal to the metal.

4. Driving the 1/4. Once you leave the line you should move your eyes immediately from the lights on the tree to your tach and don't take them off. For the rest of the quarter mile all you have to do is keep the car straight and shift every time your tach hits the correct rpm. You must watch where you are going (obviously) but you *must* also stare at your tach. Do not make the mistake of trying to shift by ear when drag racing. This too takes a lot of self dicipline. This too is something my Cobra buddies aren't always able to do the first time out. I almost always hear them bouncing off the rev limiter in every single gear. Not good for the car and just horrible for your ETs. WHEN YOU DO THIS IT WILL ABSOLUTELY KILL YOUR ET. If you are not sure where to shift then just plan on shifting a few hundred RPMS below your rev limit. Thats it. All there is too it.

In summary:

1. Avoid the water. Short dry burnout
2. Line up. Stare at the lights on the tree
3. Leave off idle when the last yellow lights up
4. Feather the gas - maintain traction
5. Shift your eyes to the tach.
6. Keep the car straight and shift at the correct rpm every time.

Good luck and have fun!

HTH
-Matt

[Wayne Maybury]

Matt

Welcome to CC.

That is a GREAT FIRST POST.

You are 100% correct about the traction problem in first and second. Also, I have found that it is quite difficult to be able to look at the tach in first gear as everything is happening so quickly. I don't have a shift light yet but I plan on installing one soon. One final point, keep your foot in it until you pass through all the lights at the end so as to get a more accurate MPH.

Wayne

[RedBarchetta]

Originally Posted by Matt Kennedy

You must watch where you are going (obviously) but you *must* also stare at your tach...Do not make the mistake of trying to shift by ear when drag racing...I almost always hear them bouncing off the rev limiter in every single gear. Not good for the car and just horrible for your ETs. WHEN YOU DO THIS IT WILL ABSOLUTELY KILL YOUR ET. If you are not sure where to shift then just plan on shifting a few hundred RPMS below your rev limit.

Good advice. One easy mod is to loosen the mounting bracket on the tach and swivel it so that your shift rpm is pointing straight up at the 12 o-clock position. This way you don't have to figure out where 5,500 or 6,000 is...your peripheral vision will see the tach needle standing straight up and you can shift from there. Allow for a 200-300 rpm buffer to your rev limiter (i.e. if you are running a 6K chip, set the tach's 12 o-clock position at 5,500). Short shifting a couple hundred rpm will not hurt your ET as bad as an over rev.

-Dean

[Matt Kennedy]

Thanks guys. Just went live with a large project at work so I was working overnight - had plenty of time on my hands.

Don, Excellent point about the air pressure in the tires. I forgot to mention that I normally lower my rear tires to 15lbs at the track. Also, regarding straight axle vs. IRS - if you do have IRS that is another very good reason to NOT hammer it with a high-rpm launch off the line. Those half shafts cannot take the abuse. I personally know someone with a 500 hp car that broke 2 half shafts on his 1st and 2nd trups to the track trying to hard launch. He then had custom, over-size shafts made and then broke one of those before throwing in the towel (although all he really had to do an easy launch and he'd have been fine).

Lastly, I almost forgot one other tip that greatly improved my reaction time. This will seem silly but it makes a big difference. When staged and ready (assuming you have a std shift) let the clutch all the way out until it is just at the point where it catches. Leave your foot on the pedal right at that spot. You'd be amazed at how much faster your reaction will be vs. having to lift the pedal all the way from the floor. And remember reaction time can be key to winning a race but it has no reflection on your ET or your trap speed. Be sure to stop pick-up your slip after each race. Our track has a small shed like building in the return lanes where you stop and p/u your slips after each race. Check your reaction times. On a .500 tree you should be in the low .500s.

Have fun!!!

p.s. Here is a pic of launching using the roll away start technique. With some practice you really can hook pretty well. Notice how the rear is squatting and the front is lifted way up. And if you look really close you can see I am lined up with a late model Corvette. The crowds always love the cobra/corvette races.

[rblong]

Originally Posted by Excaliber

I've found just a little wheel spin works best for me. The trick is to control it, and it's a fine line between a 'little' and 'going up in smoke'. I launch around 2500 rpm or so, but it really depends on your gears and tires what works best for you.

Surprisingly I worry more about the 2nd gear shift, THATS when I'm more likely to get serious wheel spin, at times accompanied by a serious 'pucker factor' as the car starts to dance around!

Dito - be careful hitting 2nd! I have also had mine start to drift towards the top (sweet spot) of 3rd gear.

Make a few easy runs and get the feel.

It is a blast!!!!!!

[Durt]

Wow - great post indeed! Much appreciated.
The event I'm attending is actually a German car tuner challenge - my daily driver is a highly modified 2000 Audi S-4. With all-wheel traction & 480 HP, a lot of these cars get well into the 11's. But the organizers are begging me to bring the Cobra. I have no illusion that I'll put up world beating numbers (but you never know,) but I'm sure the violent launch of a Cobra is going to be a crowd pleaser.
As I've said, when I've done short burn-outs in the Beast, it can lurch all over the place & I lift for self-preservation. I didn't want to get up to the line, rev it to 3500 rpm & pirouette into a chain link fence. Sounds to me like a 1/4 mile launch is similar to the launch at my track events at the start - give it enough juice to keep hooked up and straight. Modulating the power will be tricky, but I have experience doing that - not just flooring it and holding on.
Thanks for the tips! I'll post results after the event on the 13th.

Durt

[greg schroeder]

Originally Posted by Durt

Thanks for the tips! I'll post results after the event on the 13th.

Durt

How did you do? Any video or time slips?

[496fe]

Hey Durt,

I'm still holding my breath waiting for your results.

Durt? Durt? Anyone? Anyone?

[Yetiman]

I bought a GTech Pro, and it helped immensly, especially with my 60' times.

As Matt said, do a roll away "street light" start. This means you will leave the line from idle and feather the accelerator. The goal is to work the gas pedal trying to maintain as much traction as you can until the car is accelerating down the track with full traction. (I can get a repeatable 1.8 60' times on lousy BF T/As doing this.) This is pretty much what I do both with the Hoosier TD's and Yokohama's (neither of which are good drag tires). I found I am the fastest when I let them spin just a small bit, right on the edge.

I am a huge fan of the S4. I talked my sister (who used to have no interest in cars at all) into buying an A4 several years ago. She turned into a much better driver, even doing two autocross instruction days in it. After the A4 got hit while parked she replaced it with an S4 Avant which she LOVES.

[Archrms]

Matt,

Great insight on 1/4 mile technique. I have yet do do some official track time, and your tips will help when the time does come. Thanks.

[Don McCain]

Durt
There are several things you need to be aware of when you go to the drag strip.
1. What type rear end do you have? This basically dependent on the make car you have. The FFR car is based on a mustang straight axle on the rear. This type axle typically leaves the line better than an IRS car. The
IRS car takes some getting used to. Make several 1/8th
mile passes to get used to your starting line proceedure.
Shift @ 5000
2. When shifting to 2nd and 4th gear watch out for letting your left or steering hand, jerk to the left. I have seen this cause a lot of trouble and cost valuable ET.
3. Drop your rear tire air pressure down 2-3 Lbs. This will aid in your off the line bite.
4.RELAX on the starting line.
5. Use your emergency brake as your line lock. Hold the button in while on the line and keep it in until it is all the way in the down position. This will take some practice.
There are a couple of other things but hopefully this will get you headed in the right direction.
Have fun and be carefull.
Don

[Durt]

Originally Posted by Don McCain

Durt
1. What type rear end do you have? This basically dependent on the make car you have. The FFR car is based on a mustang straight axle on the rear. This type axle typically leaves the line better than an IRS car. The
IRS car takes some getting used to. Make several 1/8th
mile passes to get used to your starting line proceedure.

My year Superformance has an 8.8 Ford IRS as I recall. Most of my hard acceleration results in a pretty hard pull to the left. I don't know if this is just the torque demons twisting the car - but it could be the car isn't set up properly. All I know is, the "pucker factor" has definitely been present during rocket sled launches - hence the reason for my initial post.

[BossCER]

good stuff...............thanks Matt

[Durt]

I've always regretted that Superformance comes with a stock IRS. In a car this small, I can't imagine the "improved" handling characteristics are worth the constant demolition of half shafts (I rip at least one CV boot every time I track the car.) They don't appear to be any more durable in the twisties than they are under hard acceleration. I'd love to retrofit a solid axle sometime in the future.

[Naumoff]

Originally Posted by Durt

I've always regretted that Superformance comes with a stock IRS. In a car this small, I can't imagine the "improved" handling characteristics are worth the constant demolition of half shafts (I rip at least one CV boot every time I track the car.) They don't appear to be any more durable in the twisties than they are under hard acceleration. I'd love to retrofit a solid axle sometime in the future.

Get some custom halfshalfs made.

[Excaliber]

Following up on Matts tip about letting the clutch out till you JUST feel it starting to engage. This also tightens up the drive line, taking slack out of all the gears (trans, rear, drive shaft). This avoids the shock of the drive train getting hammered when all that slop is suddenly taken up. THAT is what typically is to blame for broken axles and such.

As for air pressure, thats a tricky one. I tried 15 to 18 lbs without success and it felt very squirely at speed. Less is not always better. For my tires 20 plus seems about right.

IRS, I've found, is offers a much better ride on the street than a solid axle. IRS for me, always!

[Matt Kennedy]

Excaliber I never knew that about tightening up the driveline but it makes total sense. I just learned something. Thanks. Excellent point.