anybody kno which rpms r best to shift at if you wanna launch w/ an automatic and manual shift? or is it jus betta to jus hit overdrive in D and floor it?

 

Please type in complete sentences.

Just leave it in D and go.

 

Is that what you did on your 15.2-second run? Overdrive on?
-Cyrus

 

Yes.

 

I made two runs, once manually shifting and once just flooring it, both with OD off.

I got slightly better times (like 0.050 difference) just flooring it.

 

Should have left it on
-Cyrus

 

Although I haven't taken my car out yet since the SC, I can speak of my experience before the SC. Regarding your first question, what RPMs to launch at, I don't have this down yet. I am still experimenting. I do find power braking to result in lower times so yes you should powerbrake. I just don't have the exact RPMs figured out yet. Probably around 2000 +/- 500. Your second question, is manually shifting better? Many people will argue this but I can with 100% assurety tell you yes. I did the test over and over and over, multiple times each night, multiple nights. I did all the math and I get exactly a .25 second average time reduction when manually shifting. Hope this helps.

 

Whats powerbreaking again?

 

Powerbreaking is holding down the break and revving the engine to a certain rpm and then hitting the gas as you lift off the break.

 

hold the brake pedal while keeping the revs up, when the light turns green, let go of the brake and floor it at the same time. instant power

 

If i hold down the break(not hand break im assuming but foot break) and hit the gas I will move.......

 

beat me to it

 

no you wont, either somethings wrong with your brakes or your revving it too high

 

You can't put the gas down all the way. Just hold it at about 1500rpm.

And it's spelled: b-r-a-k-e

 

The best you are going to get with stock brakes is about 2500 rpms before you start moving, you can't just floor it. You do have to get on the brake as hard asyou can with your left foot though, that might be your problem.

 

Power-braking too many times and you can go find a new tranny.

I wouldn't recommend doing power-braking until you have your tranny strengthened (VB, converter....)

I do, however, agree with all of you that manual shifting an automatic will give you a slightly faster time especially 0-60. With manual shifting it is easier to hold your 2nd gear till 6,000 rpm. I figured the 2nd gear allows you to go up to 70 mph b/4 you shift it to 3rd. Still, the gap between 2nd and 3rd is still too big.

In any case, you do not need your overdrive for a 1/4 mile race.

 

Why do you say that power-braking is bad for the trans? I don't see why it would be. Perhaps a little strain on the brakes but why the trans?

 

Ya your right at around 2k rpms its not gonna hurt anything, but in the long run, after repeatedly doing it, its not very good.. I mean the wheels should be spinning, but because you are holding the brake down they cannot. This is not natural for the drive train.

 

I fail to see why too. It shouldn't matter one way or another, you're just giving yourself a little more power from the start. Maybe if (somehow) you revved the engine up near redline and then let go...

But how does launching at 1500rpm damage the transmission?

 

I definately was on my way to a best run, until I slipped it into nuetral when going for 3rd and not looking at the shifter continued to rev, recovered and still got a 15.8 .

Now I am skeptical about abusing the tranny. I'll leave it in D and get faster in other ways so I still have a car to drive home

 

You are actually putting the strain on the transmission (the torque converter). Ever wonder why your engine does not die when you hold your car at a stop. It is the torque converter. Do a search. I believe people discussed that before.

 

Sure, but I still don't see the harm in holding the brake and revving to 2000 rpms. Now 'Neutral Drops', that's a whole other story...