Dragstrip Question

[jking]

Hello, this is my first time here. I finally went to the drag strip and can only get a 14.2. (first time at drag strip). I have a t56, and am trying to figure out the best way to run it. I can get a 2.3 60 foot, and 100 mph. All stock. Car weighs 3735. Do you think it can do better than 14.2? Do you guys (with the six speed) take it to 5900 rpms like i do or shift at diffrent points?
thanks

The launch is by far the most important part of the run.

As a rule of thumb, every .1 you knock off of your 60' comes out to about .15 off of your ET. I suspect this has something to do with momentum, but I really don't know the physics behind it. Time slips don't lie though..

You should be able to hit mid 13's. Your trap speed is low for some reason, maybe it was your driving, or maybe it needs a tune up or has some mechanical problem.


Different model cars have different launch characteristics such as optimal RPM, available traction, ect..

But the method of launching a manual tranny car is the same across the board.

If you are running street tires, do not drive through the water, and do not smoke them down. Just drive around the water (if possible) and do a practice launch or two before you get to the light.

You need to figure out what RPM your car launches best at. I don't recall the RPM on my LS1 C5, but my Z06 sweet spot seems to be 3600-4000.

The key to launching is to eliminate the two factors that kill time. Spinning and bogging. If you launch too low, you will bog, and if you launch too high or apply too much gas, you spin. I would prefer to spin as opposed to bog because you can control the amount of wheel spin by backing off of the gas. Once you bog, you are screwed, and you have to wait for the RPMs to come back up, all the while losing valuable time.

The best launch method is to find your best RPM range, and slip the clutch on your launch, allowing as much power as possible to the back wheels without spinning, while keeping your RPMs up to prevent a bog. Basically the clutch asorbs all of the extra power that would be causing your wheels to spin.

It takes a lot of practice at first, and it's not the best way to go if you are worried about clutch longevity, but it will get you your best times.

When you get to the line and staged, let your clutch out to the point right before it starts to engage, and hold your RPMs in the sweet spot. Probably around 3500.

When you are ready, let out on the clutch to the point where it is nearly engaged, but not all the way, and try to use the throttle to keep the RPMs in the sweet spot. This usually all takes place in the first few feet. As you feel the car start to hook let the clutch out all the way, and apply as much gas as you can without spinning. With decent tires, you should be fully engaged and on your way in the first 15' or so.

It sounds like a lot, but it happens fast, and with practice, you will be able to pull it off smoothly without thinking about it.

With an LS1 car, I would suggest that you shift as close to the redline as possible without hitting the limiter.

[jking]

That is for straight up street tires.

DR's are a little different and a lot depends on the car.

My Mach 1 I could dump the clutch at 5k and it would launch really hard with 1.6x 60's. There really wasn't anything to it..

I have to apply some clutch slip to the Z06 on DR's. I've gotten some 1.7x's out of it.