Sharky

Ok, I know to turn off T/C while at the track...
But, what about over drive?

I ran a 13.5 with overdrive off and a 13.3 with it on.

I have been told to turn off O/D when racing so why the better time with it on?

theedge67

I don't think it would matter much, probably just a variance on the temp/humidity/launch...etc. The car should run the same with O/D on or off.

Sharky

Can you elaborate on that? I am not challenging you, just trying to better understand my vehicle.

mvon919

It's and O/D... 5th gear. Disabling O/D doesn't change anything (pattern or pressure). Doesn't matter if it's on or off when racing.

Sharky

Ok... but when I am driving down the street and punch the O/D disable. The engine revs about 500 rpms higher. Almost like a downshift. So I am sure the O/D is not just a 5th gear.

theedge67

I hope I can explain this well enough. When you hit the O/D button, two things happen. The torque converter unlocks, and the car shifts out of 5th gear (if it was in 5th when you hit the button). If the car is in any gear but 5th, the converter will still unlock I think, then relock if it feels necessary. That could be the 500rpm raise you see. Or it just shifted out of 5th gear.

The O/D button just disables the overdrive, which is 5th gear.

Sharky

I got it.... That makes alot of sense.
Thanks

Obi Juan

what did you launch at during your 13.3 run?

Sharky

The Green Light?
I am not sure what you mean?
60' time????
I'll have to find my slip.

SixtySix

He means what RPM's did you brake torque to at the line.

Sharky

Oh, I preload the drive train to about 2000 RPM's any more and it breaks loose.
4:10 gears and all that.
I know you can put it in neutral and back into drive to allow the brake pressure to spike, I just seem too busy to do all that when I stage.

SixtySix

You know, I never thought of that. Might be good for a few hundred RPM's. I hear ya though, I've got 4.10's in my auto too, and I can't launch any higher than 2k either.

enitalp

Same here with 4.10. Best 60" 1.90 on nitto radial.
Just passed my command for a TCI 3000. Can't wait to see the result.

Sharky

Ohh that set-up with a line lock and you'd be set.

codeman94

if you never get going fast enough for the car to have a chance at shifting into 5th gear, it wount matter if the over drive is activated or not.

ren274u

when i launch at 1500 i get 1.9 on stockers.

ren274u

why does he need line locks?

Sharky

Because in an auto you have to brake torque to load the drive train.
With a torqu converter you can get your launch at a higher RPM.
And with a line lock you can ship the brake torque and use the line lock as a launch controller in union with the torque converter.

ren274u

i still dont get it, line locks go on the front, that has nothing to do with the torque converter.

enitalp

I have a linelock in front of course for burn my new slick, but i think he's thinking about using a linelock for the rear for staging.