Launching an automatic

Russ

Russ

Club Member
Hey,

Thinking when I come to the pod this Summer to watch and learn, seeing as theres nothing better to do I might give the green machine a run :devil: LOL it's going to be rubbish and slow but might give everyone a laugh and I might even beat some rude piece of rubbish.

How do you launch an automatic. I was thinking about a break lock kit, however it has ABS that I can't turn off so that's no good.

Or is it just pull away as normal, there's no hope?:( :D
 
I would do what I always do for road driving, use both feet:rolleyes:

Brake on with left then you can rev a little with right, lights go green and you are off. It just saves a little time moving your right foot from one pedal to another, you are straight on the gas that way.
I have never done a drag race (hoping to this year) so I don't really know what I'm talking about here, someone else might have actually experience of an auto on the drag strip.
 
The torque converter in any auto has a stall speed which governs the rpm that can be built against the brake when stationary - usually between 2000 and 2500 rpm. This gets you somewhere near the max torque point and will improve the overall time achieved (as long as you have the traction capability to hold on!).

In a race auto, the torque converter would be replaced with one at a higher stall speed to match the peak engine torque - maybe as high as 4000 - 4500 rpm in a serious car. The trade off is that road drivability is compromised and the car "slurs" away from a standstill with normal acceleration. Ideally a high stall speed would be coupled with valve body mods to sharpen up the shift points and raise the rpm of the shift. Z32s can buy external electronic devices to achieve this, e.g. HKS ELC (Electronic Line Controller).

In RatZ with the BBC and TH400 auto, I had an Art Carr reverse shift pattern box with manual shift only, 4500 rpm stall, a device which locked the car into first and reverse simultaneously and selected step 1 of a two step rev limiter. This was actuated by a thumb switch on the shift lever so you would sit in stage with foot to the floor, engine at 4500 rpm and launch the car by taking your thumb off the switch. The rev limiter was released to step 2 (about 8500 rpm) and the auto box let go of reverse and launched the car!

Don't try this at home. No animals were hurt in the course of this procedure....
 
LOL Rob! :D

Thanks for the info Mike, interesting way to launch! Have to get some practice in. Can I cook the torque inverter if I sit higher in the revs for too long?

Car is 1710kg with 170bhp/170lbft, I think we'll be on for about a 3 minute quarter :D Everyone will have gone home by the time I finish!
 
Sorry, forgot to mention that holding an auto at stall speed for any length of time generates heat which may ultimately cause failure of parts in the box....:eek:
 
Hi,
Best way to launch an auto is....change the gearbox to a manual!!...Then you'll only fry the clutch! :eek: :p
Cheerz,
JEZ
 
LOL Suzy, I'll wait for you don't worry.

So potentially this could end up an expensive operation, I might just take the extra 0.5 it takes to do a 1/4 and save the repair bill :D

I look forward to it Chunk, cheers
 
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