Posted By: tboomer
Launch RPMs.... - 07/06/11 03:18 PM
What are you guys launching of your tranny brake at? I have been letting go of the button at 4600..I have been thinking about going down a bit till I can get a handle on this thing...What do ya think? Ted
Very combination specific....
Sneak up on it to sort out any issues.
Posted By: MR_P_BODY
Re: Launch RPMs.... - 07/06/11 03:38 PM
That will change the reaction time Ted... so what
do you need to do with the RT... higher RPM and you
come off the line harder(unless you spin)... I dont
use a launch chip... I go right up on the stall of
the conv(5600 in my case).... keep playing with it
till you find the happy point
Posted By: MRMOPAR622
Re: Launch RPMs.... - 07/06/11 03:40 PM
I would go down as low as I could without killing the 60'.The lower you can leave at the easier it is on everything.If you only lose a .01 or .02 no problem leaving @ a lower RPM,but now a .10 that can be a problem.
Most important have "Fun" and "Enjoy" and then the Wins will follow.
Posted By: tboomer
Re: Launch RPMs.... - 07/06/11 03:50 PM
I think my biggest problem is when the car comes up into the air,is that I am jerking the steering wheel to the left...Jimmy says I should tape the steering wheel center...It makes a neat pic with the wheels up but tough to control!
Posted By: tboomer
Re: Launch RPMs.... - 07/06/11 03:54 PM
Posted By: MR_P_BODY
Re: Launch RPMs.... - 07/06/11 04:05 PM
Your turning the wheel... it didnt make a move till
it came back down... I assume you use your left hand
on the wheel and dont rest your arm/brace it and when
you launch your arm pulls the wheel some(to the left)...
I brace my left arm on the door/window sill
Posted By: tboomer
Re: Launch RPMs.... - 07/06/11 04:09 PM
Great idea,Mike! I may try that..Also when the front got aligned,it took some slop out of the steering..We are going into points #5 and#6 this weekend...And I really need some rounds! You don't get any points winning buy backs...
Posted By: gregsdart
Re: Launch RPMs.... - 07/06/11 04:10 PM
It looks to me like a chassis problem causing at least some of the move to the left. Focus if you can on your steering wheel on launch. If you see that you are not turning the wheel a lot, then something is unloading the left rear tire a couple of feet after the hit. Short shocks? Wrong preload?
As far as rpm, I would start at 3,000 rpm and see where things are. 3,000 should give you a consistent leave, and let you know what you need for proper chassis reaction time.
Posted By: tboomer
Re: Launch RPMs.... - 07/06/11 04:20 PM
Thanks,Greg! I need some different ideas...One thing I should say is that I have never scaled the car yet...
When I used the brake in my Challenger,I would set the limiter at 2500. Any higher than that and I was redlighting. When footbraking I was loading up against the convertor to 2000 to get the same r/t and 60'.
This was with a mild 440 that ran around 10.90's most of the time,for comparison.
Keith
Posted By: MRMOPAR622
Re: Launch RPMs.... - 07/06/11 04:50 PM
On launch if you are not lined up straight or if you are a little out of the groove it will do that. It looked like you were lined up right,that's just something to check next time at the track. If I were were you before going back to the track I would switch the rear tires and see if it starts pulling to the right.
Posted By: tboomer
Re: Launch RPMs.... - 07/06/11 05:03 PM
Some good thoughts here...Thanks! I never checked the rollout of the new tires,either..
Posted By: smokinwoody
Re: Launch RPMs.... - 07/06/11 05:10 PM
on the two step..5000rpm chip with a 5500 stall converter
thats when we had the Duster...
Posted By: topside
Re: Launch RPMs.... - 07/06/11 09:29 PM
You won't be inclined to turn the steering wheel if you hold it at the bottom, though some guys are reluctant to do that. Personally, I hold the wheel @ about 10:00. I don't like bracing my arm or locking it against anything solid; hard on the wrist if things go wrong. I don't keep a death-grip on the wheel either, something I learned on road courses; if the car goes where it's pointed, all you need to do is keep it pointed.
Posted By: Barnstorm
Re: Launch RPMs.... - 07/07/11 01:10 AM
3500 on the brake..if the track will hold it...2800 max on the footbrake or it will push the lites.
![Attached picture 6717206-998852905_4DmMz-O[640x480].jpg](https://board.moparts.org/ubbthreads/upload2/6717206-998852905_4DmMz-O[640x480].jpg "6717206-998852905_4DmMz-O[640x480].jpg")
Posted By: 540dust
Re: Launch RPMs.... - 07/07/11 01:50 AM
3600 9.5" 6000 converter and glide....
Posted By: Leigh
Re: Launch RPMs.... - 07/07/11 02:12 AM
I hold the wheel with my left hand at 7:00, with my arm close to my body. This allows me to be relaxed, and not interfere with my button hand/arm. Also, line up in the burnout box, looking at the stripe. Burn to within' 6'-10' feet of prestage, and don't back up. Oh, forgot, 3,000. For a bracket car, any more is just parts $$$ down the drain. Let the converter flash take care of the rest. If it doesn't work, get another converter, or look for engine related issues.
In my cuda with a TF trans and tb running 9.80s i left at 3k with 20lbs in the front tires to stay green. In my camaro I left anywhere from 2850 with a trigger trans brake to 5200 at a alt factor track with a terminator trans brake. in my dart i was leaving at 4600 with a terminator button and a converter going away.
Posted By: moparmxz
Re: Launch RPMs.... - 07/07/11 03:38 AM
3600 most of the time if the track is greasy 3400.
Posted By: steeldust
Re: Launch RPMs.... - 07/07/11 04:00 AM
Some converters will flash and pull the car higher with lower stall if the converter is around 5,400 to 6,500 i started out with 3,600 and now i stall at 4,600 and it went up the same and my converter is a 5,000 stall and it could be the torque of the engine some times will pull the car or more air in slick or put more air in the slicks could help and it could just be the track
but you know your car better then any body
good luck
Posted By: cudabin
Re: Launch RPMs.... - 07/07/11 04:24 AM
Ted, the tape stripe at the top of the wheel is a good idea to ensure you are pointed straight ...
I always hold my left hand on the wheel between 7 - 8 oclock where my wrist is comfortable and my arm is resting on the roll cage door bar.
This makes sure i don't steer the car when the wheels come down. When i used to hold the top, i sometimes pulled off center when in the air...
Good luck,
Arnie
Posted By: Al_Alguire
Re: Launch RPMs.... - 07/07/11 05:21 AM
Like been said already very combination dependent. When I run S/ST I am at 3800, all out anywhere from 5800-6600 depending on tbhe track.
Posted By: tboomer
Re: Launch RPMs.... - 07/07/11 12:14 PM
LOts of good stuff here...Thanks everyone!
Now...a question for the guys leaving at 3000-3600. Are you using a chip in a two-step or leaving off the tach? The goal here is to be consistant!!
Posted By: MrSixpack
Re: Launch RPMs.... - 07/07/11 12:30 PM
I have always left on the brake at 5500 rpm and now I picked up some better 60 feet going down to 3500 rpm.
You should move forward and not up in the sky
And put an onboard camara in the car, I did and it was fun to see what I did in the heat of the battle.
And yes I use the 2 step.
Posted By: Just-a-dart
Re: Launch RPMs.... - 07/07/11 01:21 PM
3400 on a 2 step, full tree
Posted By: slippery440
Re: Launch RPMs.... - 07/07/11 02:36 PM
I talked to a old guy at Turbo Action Convertor years ago. I told him what the combo was and what I was doing with the car as in bracket style racing.Thats all we had for racing back then. I thought I needed a 5800 stall convertor (mostly for the wow factor). Well he asked me one question. How thick was my wallet? I had a very small budgit so from his recommendation I had a new 4800 converter. I been racing for awhile and the car is deadly and very little breakage. I leave at 3800 and the car will flash the converter at 4800. The 60' times are 1.42. Tested it couple times at 4600 and all the differance was .002 off the 60' time. Alot harder hit and I could see breaking things at that rpm.
What I see from the vidio is you turn the wheel at the launch. The car is not wheel standing its poping the wheels up mabe 6". If it was me I would launch at 800 below the converter stall and work on the car from there. I bet money you will end up faster.
Posted By: tboomer
Re: Launch RPMs.... - 07/08/11 01:03 PM
OK...Here is what we are going to do. The lowest rpm chip I could find is 3400. So that will be a start. I will also try to change my driving technique by resting my left arm on the bar with my hand in the 7:00 o'clock position. All of the years leaving off the footbrake I had one hand on the shifter and the other at the 10:00 o'clock position. Thanks for all of the suggestions,guys!!
Posted By: tboomer
Re: Launch RPMs.... - 07/09/11 12:36 AM
Says the guy who has an inch of dust on his car out in the garage!
How ya doin,Ray?
Posted By: Guitar Jones
Re: Launch RPMs.... - 07/09/11 01:45 AM
Depends for me too. 3000 when using the brake and no box. It will go .000 like that. If I'm slow that day I'll bump it up a little. I use a two step with chips. If it's a .4 pro tree then it's no chip and fully on the 4200 converter. It will go .012 like that but I have to be really on.
Are you allowed an air shifter? I love mine, I let go of the button and put both hands right back on the wheel, that way I don't turn it when it's in the air.
Posted By: tboomer
Re: Launch RPMs.... - 07/09/11 01:29 PM
Thanks...I can use an air shifter but the funds are quite low. Gonna hit the road here in a couple of hours for the weekend points races....I will report back Sunday night!!
