Drag strip launch .... how?

[S4TAN]

Hello, can we have a discourse on drag strip launch technique for a total thicky like me...?

Sundays Pod session was the first time i've been to anything like that... it was great fun and i want to go again, and next time i'd like to see what my Panzer will do time-wise...

I went to the start line and watched the light sequence. From what i could make out it goes: staged (1st set of little amber lights), then staged again (2nd set of little amber lights), then a bunch of 4 big amber lights - and when they all go out you launch ... yes/no?

Question for the dudes that ran on Sunday: what were you doing rev-wise during the light sequence? And how were you launching (sidestep?) ... at what revs?

Ta!

[DavidT]

Thanks Julian.

I was trying to launch at 5k but its quite difficult to get that bit right.

I don't sidestep the clutch. I should do as I think its probably easier on the car but I just lift the pedal quickly from the bite point when the lights change.

I've only launched my car properly at Santa Pod, apart from on a muddy, wet 'B' road a few years back. I have found that you need revs to get the wheels spinning but not too many so the tyres grip with enough revs so the engine is still on boost . Too much wheelspin is bad because you get less traction and its very hard to work out when to change to second!

Graham has the link I was going to post, but here its again: www.rwyb.com

[Ads4]

I went to the start line and watched the light sequence. From what i could make out it goes: staged (1st set of little amber lights), then staged again (2nd set of little amber lights), then a bunch of 4 big amber lights - and when they all go out you launch ... yes/no?

There seemed to be quite a difference in the lights and the quickness of them while I was studying them from the line, almost as if the staging crew were getting impatient with those that took a little longer to stage than others. On quite a few instances the last car to stage slowly pulled up and got his second amber, still watching the crew for hand signals, when the four ambers instantly flashed and went to green, leaving this car to floor it from idle in a panic, while the other staged car was holding revs and on boost. In other instances when both cars staged quite quickly, the four lights lit slower and there was definately more time to rev and get ready.
On your run with Leon David, you rolled slightly passed the line and your staging lights went out, a crew member was walking down the side of your car as if to roll you back yet the lights still went green and as you both shot off he raised his arms in an irritated manner, as if he was pissed off that the lights had gone green while he was trying to bring you back!

[DavidT]

I went to the start line and watched the light sequence. From what i could make out it goes: staged (1st set of little amber lights), then staged again (2nd set of little amber lights), then a bunch of 4 big amber lights - and when they all go out you launch ... yes/no?

On your run with Leon David, you rolled slightly passed the line and your staging lights went out, a crew member was walking down the side of your car as if to roll you back yet the lights still went green and as you both shot off he raised his arms in an irritated manner, as if he was pissed off that the lights had gone green while he was trying to bring you back!

Thanks for that, I wondered what I'd done wrong

Here are a couple of vids:

My quickest run from inside the car (my best video editing ):

http://www.youtube.com/watch?v=HUkXrjoeDAM

And one someone else took of my last run (13.05 - forgot to switch the ESP off!)

http://www.youtube.com/watch?v=lGRmfzjH4sk

[ZeroK66]

Wow your gear changes are so quick. I must have a stuffed DV... I would have about 1/2 a second delay on each gear change

Best:

I believe the quickest way to launch is around 3.5k and slip the clutch getting max torque to the ground without getting wheel spin

Good:

A safer way is to get to around 4.5-5k and get the clutch out fairly quick to get wheel spin. Once the wheels break traction there is less chance of you damaging the car as all stress is gone then. I used this launch for my 12.42 - I must have lost a few tenths while spinning my wheels, but still a decent time.

I will practice 3.5k launches with clutch slip in time for my next pod visit. I WILL crack 11's next time

[DavidT]

I think you need more that 3.5k rpms. The wheelspin helps you, its not like a 2wd car with low traction. Read my post higher up for an explanation . Also, slipping the clutch puts a lot of heat through it.

Why do you think you have a duff DV?

[S4TAN]

Watched one of your launches Leon - and there was quite a gap between 1st and 2nd when you were changing gear - sounded like you were having a bit of trouble with the change (launch seemed spot on though to an onlooker) - could've had a good time had the 1st<->2nd transition happened quicker ...

Mind you I think the 1st<->2nd change is the hardest to get absolutely spot-on ...

[ChipHazzard]

I was told years ago, to launch as soon as you see the amber lights dropping, I practice daily at most sets of light on my daily commute on my bike as long as traffic conditions allow and when I get a chance in the car as well but only when it's safe to do so and I never continue thru the gears

[DavidT]

I was told years ago, to launch as soon as you see the amber lights dropping, I practice daily at most sets of light on my daily commute on my bike as long as traffic conditions allow and when I get a chance in the car as well but only when it's safe to do so and I never continue thru the gears

Yep, I forgot that bit. By the time the car is moving, the light will be green (on a drag strip anyway )

[ChipHazzard]

I also find that slipping the clutch helps me keep the front wheel firmly planted on the road, having had a huge moment years back where I dropped the clutch at approx 6k on the bike and almost flipped it

[ZeroK66]

I honestly believe that 3.4, maybe 4k is the sweet spot. If you get the clutch slip right without too much slip you will get a wallop of torque catapult you off the start line and you will be into second in no time. BRETT is the man to answer this question. He has broken enough car parts to know what works & gets best times...

Only had trouble once getting into 2nd... that case cause I lost traction in 1st and was not sure when to change. My changes are pretty quick.

DV's I reckon are shot because between each gear I had a large amount of time with NO PULL from the engine like major lag. Most noticed in 2nd -4rd and 3rd-4th. Watching your in car shot your car is on the power as soon as you change gear. They were replaced just over a year ago and Doug checked them last time the car was in. I have trouble with low speed driving too - bit jerky, which is why Doug checked them. I will have to check them again.

[quattrosteph]

I don't do it often but when i do it i just rev it at 3000/3500 and release the clutch quickly in 1 go, the launch is very neat and the second gear come quick very quick. If i make the clutch slip a little bit the clutch get too hot and slip like f.ck even after when i engage the second... wish is not good at all. But i do run a lot of torque that's why (520 fT)

[Ads4]

Figures for 997 GT3.....

Horsepower (hp @ rpm): 415 @ 7,600
Torque (ft-lbs @ rpm): 299 @ 5,500
0 - 30 (sec): 1.5
0 - 45 (sec): 2.4
0 - 60 (sec): 3.9
0 - 75 (sec): 5.3

1/4 Mile (sec @ mph): 12.2 @ 116.1

You're not far off Leon

http://www.edmunds.com/insideline/do/Dr ... eId=121383

[ZeroK66]

Awesome... with a novice driver and a bit of a wetish road I would take it then NICE!

[MarkB]

Awesome... with a novice driver and a bit of a wetish road I would take it then NICE!

And a dry road with a good driver... Not a hope!