Jump to content
The mkiv Supra Owners Club

The perfect 1/4 mile in an auto???


Jamesy

Recommended Posts

Right guys with all this chat about SP in a few weeks i just realised i have feck all idea about how to properly launch a TT Auto :taped:

 

 

* i'm wondering if you need to rev it like you do with a manual somehow while standing on the brake also?

 

* should you have the slip cont off yeah? must be?!!

 

* should you have OD off?

 

* should you floor it from the off or gradually floor it as you pick up a few seconds speed?

 

tar! :D

Link to comment
Share on other sites

Depends on the spec of the car.

You can hold it on the brake (power brake i think its called) and then release the brake and off you go, need to be carefull not to spin the wheels on the line though. Same for doing a burnout just let off the brake till the rear wheels spin and the front stay still.

Only problem with this is the tranny/dif might overheat if you do it too much. Not quite so dangerous if you have a uk spec with a cooler though.

 

Car should be in manu mode and just work your way up the box. OD shouldnt matter i dont think as your not going to need to use it.

 

http://www.modernracer.com/tips/dragracinglaunchtechniques.html

 

In general, automatic transmissions are known as being more useful for lazy commuters than for hardcore racers. But it may be surprising for some to know that many pro drag-racing cars have heavy-duty auto gearboxes. That's because the brake-torque launch is an automatic specialty. This launch involves keeping the car stationary by flooring the brakes with the left foot, while using the right foot to rev up the engine against the torque converter. In technical terms, this preloads the entire drivetrain with the stress of a launch, allowing the engine to rev closer to its power and torque peaks at the starting line. Brake-torquing is also beneficial for turbocharged engines as it allows boost to build up before the launch, reducing turbo lag. The only problem is that there is a lot of stress on the transmission, and the consequent heat build-up can destroy your automatic gearbox. Unless your car has too much power for the tires to handle, a brake-torque launch usually will not spin the wheels. This is because the automatic transmission absorbs the shock by design, and brake-torquing actually reduces stress on the rest of the drivetrain. Instead of a sudden massive load, the drivetrain has the torque applied slower instead of one huge jolt.

 

If your car has power brakes, you could apply the brake-torquing technique even better. At the starting line, shift your auto gearbox into neutral and floor the brake pedal with your left foot. Rev the engine once and quickly get off the throttle. You will feel the brake pedal sink further to the floor. This greatly increases the braking force. Now shift back into gear. You will now be able to rev up the engine even higher against the torque converter.

 

The downfall of standard automatics is their easy-going nature while shifting, so you lose power during the actual race, where a manual would have allowed for more aggressive upshifts. However, the shift points of an automatic can be professionally modified for drag racing, and some new automatics even allow for manual shifting or have a sport setting for quicker gear changes. In fact, you could shift up through the gears even on most conventional automatics for a little more oomph.

 

Drag Racing Launch Techniques

Edited by Guigsy (see edit history)
Link to comment
Share on other sites

Do a search on powerbraking it's a quick launch method for autos but does put a strain on your box and powertrain and if overused can fry your box.

 

just so im straight on this..

 

power braking is revving up to apporx 2k revs while also pressing on the brake with your other foot, then letting off the brake and flooring the accelerator?

Link to comment
Share on other sites

Depends on the spec of the car.

You can hold it on the brake (power brake i think its called) and then release the brake and off you go, need to be carefull not to spin the wheels on the line though. Same for doing a burnout just let off the brake till the rear wheels spin and the front stay still.

Only problem with this is the tranny/dif might overheat if you do it too much. Not quite so dangerous if you have a uk spec with a cooler though.

 

Car should be in manu mode and just work your way up the box. OD shouldnt matter i dont think as your not going to need to use it.

 

thanx...

 

mine is a bpu running just over 400 bhp mate...

 

i thought having OD off means the car "starts" in 1st gear rather than 2nd when its in auto mode?

Link to comment
Share on other sites

i wouldnt define 2k. it depends on various things like grip and things. The guys at the pod wont like you spinning the wheels on the start line while waiting for the green light. Its a bit of trial and error i think.

 

If its in manu mode and your useing the shifter you would be starting from 1st anyway regardless of if od is on or off.

OD comes into effect in manual mode once your into D (3rd) with it on it will shift up to 4th. with OD off it will stay in 3rd untill your about the dammage something then it will force its self into 4th (not a good way to go imo lol) turning OD on effectively just moves you into 4th.

 

With manu off and the car in D and not useing the shifter it will start in 2nd and you will be slow :p

With manu off and useing the shifter from L-2-D etc then it will still use the 1st gear regardless of ON on and OFF. The changes will be slower and smoother though.

 

I think i got that all right :S click the manu link and it will explain :p

Edited by Guigsy (see edit history)
Link to comment
Share on other sites

 

If its in manu mode and your useing the shifter you would be starting from 1st anyway regardless of if od is on or off.

 

yeah mate sorry i was referring to in auto mode?

 

i think it feels faster in auto mode than manually changing the auto gears..... i am the only one?!!

Link to comment
Share on other sites

yeah mate sorry i was referring to in auto mode?

 

i think it feels faster in auto mode than manually changing the auto gears..... i am the only one?!!

 

Well. test it. I dont think it does. Pulls a lot better in manu mode. But its not as nice to drive.

Link to comment
Share on other sites

i think it feels faster in auto mode than manually changing the auto gears..... i am the only one?!!

 

I dunno... try both on the day and see what times you get! That's the great thing about days like SP, you'll get plenty of runs to try things out :)

Link to comment
Share on other sites

I dunno... try both on the day and see what times you get! That's the great thing about days like SP, you'll get plenty of runs to try things out :)

 

Absolutely :) Unlike RWYB days where there are very limited chances to get a run in, Suprapod will give you almost unlimited chance to try everything out. There will be plenty of experienced people around to offer 1st hand advice too.

Link to comment
Share on other sites

cool cheers.

 

so if in auto mode is the best method to turn OD off, apply some revs with foot on the brake to roughly 2k then on the green light just floor it??

 

erm. no.

Normal auto mode (in D) will still start you in 2nd gear (so not the best way to start). regardless of OD on or off.

 

As far as i know the only way to start the car in 1st gear is to move the stick to L.

 

But i could be all wrong. but this is my understanding

Link to comment
Share on other sites

cool cheers.

 

so if in auto mode is the best method to turn OD off, apply some revs with foot on the brake to roughly 2k then on the green light just floor it??

 

Maybe... since I didn't have an LSD in my Soarer, I had a little spin of one wheel on almost every run at about 3500rpm in 1st. Looking at the emanage logs, my reaction to that was to lift off to 90% throttle for 1/4 of a second, then back on full - I was really surprised at how consistently I was doing it!! :)

 

On the other hand, I did kill my gearbox that day :( so I think a little less than 2k would be safer.

Link to comment
Share on other sites

ok, bugger, just when i thought i had it!!!

 

so start it L then shift it onto D?

 

...the auto may be quicker but my old manual was so much more straight forward!! lol

 

no.

I give up. lol

Read this ---> manu (although on that link im not convinced normal driving with the car in D gives you 1st, my car doesnt feel like it)

 

press manu.

move stick to L.

Press brakes.

Build revs.

Release brakes when its time to go.

Shift from L to 2 and then into D as you go down the strip

Press brakes once you over the finish.

Return to pits.

Link to comment
Share on other sites

no.

I give up. lol

Read this ---> manu (although on that link im not convinced normal driving with the car in D gives you 1st, my car doesnt feel like it)

 

press manu.

move stick to L.

Press brakes.

Build revs.

Release brakes when its time to go.

Shift from L to 2 and then into D as you go down the strip

Press brakes once you over the finish.

Return to pits.

 

lol :blush:

 

thanx

Link to comment
Share on other sites

erm. no.

Normal auto mode (in D) will still start you in 2nd gear (so not the best way to start). regardless of OD on or off.

 

As far as i know the only way to start the car in 1st gear is to move the stick to L.

 

But i could be all wrong. but this is my understanding

 

Think you might be right and wrong :) - right if you're in manu mode, but in full auto mode and 'D' it would start off in 1st, wouldn't it? :search:

Link to comment
Share on other sites

LOL - pretend that there is some skill in launching an AUTO......

 

Strangely enough, there is probably more too it. Maybe why Autos own up the strip. ;)

 

*puts can of worms down*

 

I found it best to;

 

Manu mode on

OD off

Power brake just under 2k

Let off

push the loud pedal 3/4 way, maybe less, and tweek depending on grip

change up 1k before redline

 

hth

 

practice makes perfect :)

Link to comment
Share on other sites

OD is always off in MANU mode, so just pressing the MANU button means the box can't shift to OD.

 

I don't know about the D starting in 2nd thing though, I'm sure I've seen mine go through all 4 gears on a run (switching to OD when easing off past the finish line). Maybe it chooses based on how hard you hit the pedal? I'll have an experiment today if I can :)

 

To me, MANU mode 'feels' faster but I think my best time last year was in auto mode. My car was stock last year and will be BPU this year (fingers crossed) so I'll be interested to see if there's a difference.

 

I think the stock torque converter lets you rev up to 2.3k and I think that's the max no matter how hard you hit the pedal, but I could be wrong. I only tried it once last year and messed it up so will probably go from idle again. I might have a practice before SP and give it a go, but I certainly won't over use it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.