Voddys drag launch tips (not mine, copy and pasted)

Well had so much fun yesterday, i might just end up having another go at this drag strip business, so thought id scour the web for launch tips.

I grabbed this off a beemer forum, but they grabbed it off another lol

These are not my work, but its helping me understand the best way to launch my car, good thing is ive already got the dyno out of the way, so i know where my peak power output is, and my highest torque is reached in relation to my RPM.

anyway, thought this might come in handy for others thinking about doing the 1/4 run.

"

I do think lowering the psi in your rear tires will make a difference. I don't know what size tires you have, but if you have the stock 245/40-17's in the rear, you want more tires on the road, not less when it comes to the 1/4 mile drag strip for launching.

Now the standard mfgr recommended psi for 245/40-17's is 32 psi. Here's the key, you gotta play with it some. If you go too low you could have cupping, and that doesn't help either.

I'm guessing at 245/40-17's for you, but that is my OEM size too for my car and I have run it at the track with those OEM Dunlops before (I usually run my drag radials at the track...). Anyhow, you're safe dropping them to 28 psi, no problem. You might even be able to go as low as 26 psi, maybe 25 psi, depends on the weather and the track surface temps.

Also, for less friction/rolling resistance, take the front tires up to 45-55 psi.

Also, for weight savings, take as much out of your car as you can. The spare tire and mounting apparatus can weigh as much as 30-40 lbs.

Back seat, passenger seat (my passenger seat weighs like 60 lbs), any excess weight. Take the gas tank down to 1/8th a tank of gas, 1 gallon of gas can weigh like 5 lbs, run a 13-16 gallon tank down to 1/8th a tank, another 50-70 lbs, etc...

You can shave 150-200 lbs with that kind of prep work.

Also, try launching higher. You need to find the sweet spot, between bogging and wheelspin, and that will takes lots of practice and change from day to day, track to track, etc...

The more traction you get from the tires, the higher you can launch your car, and you generally want to launch above torque peak so that when the tires grab, the tach drops, and if you can work the clutch right, avoid major wheelspin, you'll launch like a rocket.

With my DR's I launch at 5500 rpm. On my OEM Dunlops more like 4500-4800 rpm at 26 psi.

Gotta get the throttle steady when staging, an even rpm, clutch half in, half out, just about to grab, the tach dipping ever so slightly.

When the green hits, don't slam your foot down on the gas to the floor, quickly and steadily squeeze it to the floor, and gradually but quickly let out the clutch, sense too much throttle, keep it steadily continually going down and adjust the power to the wheels with the clutch, not the gas.

Now, if when you're shifting you're chirping your tires on every shift, you're losing maybe a tenth. In my car if I'm not careful I could get sideways on every shift, but this method can help anyone chirping on shifts too much:

Find the appropriate amount of throttle to stab back down, then squeeze it to the floor. For me, it's about halfway, then just like on the launch, I quickly squeeze the gas pedal down. I stab halfway (versus all the way back to the floor) and quickly squeeze the pedal back down to the floor. Makes for more uneventful shifts and buys me a couple tenths in the 1/4 mile (I have to shift 3 times, I finish in 4th gear).

Your car may work best with a 2/3rd stab then squeeze, or 3/4th throttle then the quick squeeze, all these techniques require practice and could change given the weather or the track. I take notes on all these items and then tape the timeslip next to it on a notebook page and save it for the future track visits.

Also, if you feel like you're destroying your clutch, you're launching properly if you feel like you preserved some of it, you're not launching right... "

I launch at 5500 rpm, pump my fronts up to 55 psi, rear drag radials down to 16-18 psi, plus all the weight shaving and cool downs in between runs...

Whatever it takes to eek out every last tenth in my car"

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Launch tip 2 slightly different.

"I'm not sure what to launch at with your car, depends on your power, where peak torque and hp occur, and what kind of tires you're running. Every car is different, and each car can be different on each different day, even at the same track.

Generally speaking, it's a very fine/delicate balance. With my car, I'll bring the revs up nice and steady, wait until I have them perfectly steady, on a warm day, say at 5500 rpm. I'll slowly let the clutch out, right on the brink of grabbing, the tach will dip- that's the grab point.

I'll modulate the clutch to where I can keep the revs steady again at 5500 rpm and wait for the green. Generally when the green hits, the gas pedal goes down- quickly, fast, but also gradual/fluidly. No slamming the gas down, no stabs of the pedal. Only smooth motions, no herky-jerky crap.

As the gas pedal goes down, you gotta use your left foot to regulate the power going to the wheels. Again, all motions must be fast and fluid and smooth, but also very quick

You gotta learn the feel of what it feels like just before your car is gonna break traction, and learn to kiss that edge without going over it, but to accomplish that you gotta push the envelope to learn and know where that edge is (and know that edge changes on each run, slightly).

As it hooks, you gotta "feel" the clutch pedal, you'll know when to let it out all the way, if you can. Some times, I barely get the clutch pedal all the way out before it has to go down again for the shift to 2nd gear.

You gotta do this time and time again, over and over again, to learn your car's nuances. Here's where it gets tricky- you can complete a run, cut a 1.85 60' time, come back study your notes, take 1 psi out of each rear tire and do the same thing but be able to launch higher and all of a sudden, BOOM, 1.72 60' time on the next run and shave 3 tenths off your 1/4 mile ET as a result, given you don't mess up your shifts as you go down the track.

Was it the 1 psi less in the rear tires? Was it being able to launch at 100 rpms higher at launch? Did you shift too early on the previous runs? Or did it all simply come together on that run?

The other key is consistency. The more consistent you can get with your runs, the better the results on the next run. Cuz you can begin to play detective and find the little things you need to tweak/correct on the next run to make it better, etc.

It takes tons of practice. I have almost 17 yrs of practice now, and I'm no master of the technique- I'm a good drag racer, sure, but I ain't "great"

It's part science, part art, and lots of concentration, hard work, dedication, perspiration, determination, patience, and practice-- if you find those things fun, you'll "get it" eventually.

If you're just starting out drag racing, you'll make mistakes, don't waste a run, if you blow the launch, haul ass down the track and work on your shift points from gear to gear, etc. Take notes on everything, launch rpms, shift rpms, tire psi, front and back, try to weigh your car, if you can, get out your dyno sheet and study shift points, and adapt at the track when your calculation prove to be close but not quite right, etc...

Most people discount drag racing as not requiring a whole lot of skill- the people who feel that way are the ones who have either never tried it, or have and aren't that good at it, and aren't willing to work at it, to become better at it, etc. It's a world of nuances and subtleties, and a couple hundred factors to consider that are often beyond your control.

And it can be frustrating at times, you can do everything right and get crappy results- it just takes some severe stubborness and stick-to-it-iveness."

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A Quick Q and A from a different forum

-"Should I launch at my peak torque?"

Not neccesarily, you should launch at the highest rpm that you can without wheelspin. That's gonna vary car to car, day to day in any given car. Try to find the sweet spot for launch rpm. Try launching at 2500 rpm. If wheelspin occurs, try lower. If not, try 3000, then 3500 rpm, etc, until wheelspin occurs, then dial it in, find the best spot.

"Also I have tried but there is no "spot" on the gas that holds it at 3500, it will just keep gaining rpm's. Should I blip the throttle on and off lightly to keep it "around"3500?"

Hmmmm, that should not be the case. You should be able to have the clutch half in and half out at the very edge of grabbing, and be able to maintain a steady rpm with the gas. The key is to use the clutch pedal to regulate/modulate the tach to keep a steady rpm, essentially you're riding the clutch at launch to maintain a steady rpm, the gas pedal does not move, and blipping it is the worst way to launch.

"Also when I launch it is my understanding that I should not move the gas, only the clutch and then once the clutch is fully engaged, and not spinning out, start pressing the gas down more?"

Not exactly. The gas pedal won't move during staging if you're riding the clutch just before launch. But when the lights go green, in one fluid/smooth motion you press/squeeze the gas pedal down to the floor, gradually but quickly (don't slam it down), and use the clutch pedal to modulate/regulate any wheelspin, not the gas. The gas has to go down quickly but smoothly, use the clutch to avoid wheelspin.

"Also should I make the pressure on my rear wheels lower than recommended, and higher on the fronts? About how much?"

Yes, generally drop the rear tires about 4-5 psi from the tire mfgr recommended specs, and raise the fronts about 10 psi above the tire mfgr recommended specs. This will give the rears a larger contact patch, more rubber on the road, and allow you to launch a little higher (rpms) cuz you'll have slightly more traction, and increase the chance of sidewall flex, which is good for launching. You can adjust the pressures and play with them, try to find the best psi for that given day (road surface and temps will dictate the best amount, etc). If you go too low cupping with occur, and defeat the purpose of getting more rubber on the road. The reason for upping the fronts is for less rolling resistance/friction.

- - - Updated - - -

For Autos, not sure how well this will go with the zed auto, but it might help with some parts

Auto's- similar principle. Get the revs up as high as you can (you can't regulate power to the ground with a 3rd pedal) but you have to use the brake with your left foot, find the place where the wheels just start to break traction.

Line lock it to find that place. Then start over, find that rpm again. The light goes green remove your left foot from the brake pedal. Again, like with stick cars, quickly but gradually push the gas pedal to the floor. Don't slam it down. If you do you'll likely spin 'em. If you do slam it down and the car takes off without any wheelspin- you weren't revving high enough when you let the brake off.

You want to be at the absolute limit where you are about to break traction, but not inducing wheelspin.

From there, it depend on your automatic. Some tranny's- you're better off shifting it yourself from gear to gear, others, you're better off just holding the gas down all the way down the 1320. Watch where your tranny upshifts under full throttle. If it shifts early, or over revs for any reason- take the matter into your own hands and practice upshifting it yourself.

I don't know if anyone makes stall convertors and shift kits for auto tranny BMWs, like they do for Fords and Chevys, but that might be something to look into too....

tubbedF100- the purpose of this thread was launch techniques I have used over the years to achieve the best possible times at the Track- hence, wht it's in the Track Forum. I'm a believer in finding a way to eeek out every last tenth in my car at the track.

Again, the purpose of this thread is Launch Tips & Techniques for Drag Racing at the 1/4 mile TRACK, not street...