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trans brake tuning advice?

Posted By: duster408

trans brake tuning advice? - 12/06/13 02:09 AM

I am needing some help in calming my car down when leaving off the brake. If I footbrake my car pulls the wheels about 2 ft with a 1.27 60 ft. When I leave off the brake at 4300 it is almost on the bumper with a 1.22 60 ft. Other than wheelie bars, any ideas on what to do??
Posted By: rickraw

Re: trans brake tuning advice? - 12/06/13 03:33 AM

Did u try turning down ur launch rpm?
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/06/13 03:41 AM

Quote:

I am needing some help in calming my car down when leaving off the brake. If I footbrake my car pulls the wheels about 2 ft with a 1.27 60 ft. When I leave off the brake at 4300 it is almost on the bumper with a 1.22 60 ft. Other than wheelie bars, any ideas on what to do??



Whats the rear suspension
Posted By: duster408

Re: trans brake tuning advice? - 12/06/13 03:53 AM

I havent tried a lower launch, how much lower? It is ladder bar.
Posted By: rebel

Re: trans brake tuning advice? - 12/06/13 04:01 AM

i dunno about lowering the launch, i do bigger wheelstands when i launch at 3800 than i do set at 4800.
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/06/13 04:02 AM

Start a thousand rpm lower and work from there... add
some air pressure to the slicks.. strap the front down
Posted By: duster408

Re: trans brake tuning advice? - 12/06/13 04:04 AM

I thought a lower launch would make a greater gap for the converter to flash and would make it hit the tires harder.
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/06/13 04:09 AM

Quote:

I thought a lower launch would make a greater gap for the converter to flash and would make it hit the tires harder.



Try it... I dont have any issue with wheel stands at
lower rpm


Attached picture 7948705-5-108.JPG
Posted By: challenger451ci

Re: trans brake tuning advice? - 12/06/13 04:26 AM

Have you tried to slow things down with shocks at all? I know my car needs a fair amount more shock dampening between foot braking and using the TB.
Posted By: dizuster

Re: trans brake tuning advice? - 12/06/13 04:26 AM

Do you have adjustable front shocks? If so... try tightening up the extension.

Don't knock power out of it, figure out how to make the car go forward instead of up!
Posted By: challenger451ci

Re: trans brake tuning advice? - 12/06/13 04:29 AM

Quote:

Do you have adjustable front shocks? If so... try tightening up the extension.

Don't knock power out of it, figure out how to make the car go forward instead of up!



What he said^^^^^^^^^^
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/06/13 04:48 AM

Put the front of the ladder bars in the lowest hole...
you may need to add lower holes also if it cant angle
down enough... add more air to the slick to get a
controlled amount of spin... I do that also... dead
hooking isnt the quickest way
Posted By: Quicktree

Re: trans brake tuning advice? - 12/06/13 12:13 PM

start at 3000 rpm off the brake. every car I have ever driven was less violent with lower rpm. I have not lost anything in 60ft. if it's a heavier car reaction time may be a little slower.
Posted By: Quicktree

Re: trans brake tuning advice? - 12/06/13 12:15 PM

Quote:

I thought a lower launch would make a greater gap for the converter to flash and would make it hit the tires harder.

thats what they say but I am yet to experience that in a number of different cars and combo's
Posted By: Slingshot383

Re: trans brake tuning advice? - 12/06/13 06:08 PM

Pull the chip out and leave off the converter. All cars are different and will react differently to changes. Ladder bar cars tend to be harder to tame down, but you don't want a dead hook, nor do you want to blow the tires off, you DO need to know where the happy spot is with the most tire pressure, not the least pressure. I see a long TNT session in your future.
Posted By: gregsdart

Re: trans brake tuning advice? - 12/06/13 06:26 PM

Quote:

Quote:

I thought a lower launch would make a greater gap for the converter to flash and would make it hit the tires harder.



Try it... I dont have any issue with wheel stands at
lower rpm


I agree. Start with the rpm lower, adjust as needed. You can also try a more aggressive setting with the shocks and ladderbars in the back, but the launch rpm will need to be high enough to bridge the gap between the weight transfer of the suspension and the hit of the converter. If it isn't balanced, the result will be spin after the initial move. The last place to work is the front, starting with shock settings, then limiting travel.
Its, a balance, and if the car is set up with too much launch torque and too high of a CG, wheelie bars may be needed to fix the issue. The last place to work is the front, starting with shock settings, then limiting travel.
Posted By: Dragula

Re: trans brake tuning advice? - 12/06/13 06:32 PM

1-I would not try more than one change at a time
2-I would not go for more air in the tire and less traction
3-scaling the car will really help you set it up where you want it
4-I would lower your launch rpm


We could launch off our TB at stall but if we use it, I launch anywhere between 1900-2500...Foot brake the same way. When we want to hold the front end down, we shorten the front travel limiters...Us bracket racers don't generally try to run the car on kill mode every pass down the track...We look for consistency...
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/06/13 06:48 PM

I would NOT pull the launch chip out.. in my sig pic
thats a 5600rpm launch with no chip... if it werent
for the wheelie bars my car WOULD fill over... the pic
with 6" or so wheels up is a lesser launch rpm... in
the sig pic that is a 1.19 60' the lower wheelie is
a 1.22 60'... I control with spin with a 1/8 psi to
1/4 psi adjustment in the tire pressure(once you find
the happy pressure)... depending on the weight bias
and CG of the car you will/might end up with different
numbers for your launch rpm and tire pressure... once
you get a decent launch then you can fine tune the
shocks to the rpm...... but lower the front of the
bars so it pushes forward and not as much up... start
out with a SAFE launch before you bust up the car
Posted By: Al_Alguire

Re: trans brake tuning advice? - 12/06/13 09:05 PM

You need to focus o the suspension. Shock settings etc. You are dead hooking the car causing it to wheelie. Assume with those 60's it is a fairly quick car so what ya want is wheelspeed that will tame down the wheelies as well. Ladder bars are inherently violent so you will likely need to at the very least make some shock changes if not moving the bar to a different hole.
Posted By: JACK1440

Re: trans brake tuning advice? - 12/07/13 03:23 PM

I was just having a conversation similar to this. The Cuda is running the best et's ever (9.95) but, it seems the '60 has fallen off a bit. Now a 1.39 used to be 1.36. Question is... how much under your converter flash should your brake chip be?
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/07/13 03:36 PM

Quote:

I was just having a conversation similar to this. The Cuda is running the best et's ever (9.95) but, it seems the '60 has fallen off a bit. Now a 1.39 used to be 1.36. Question is... how much under your converter flash should your brake chip be?



There is no set amount.. all cars and chassis set ups
are different... if the chassis was set up right you
could be right on the conv
Posted By: JACK1440

Re: trans brake tuning advice? - 12/07/13 04:42 PM

thanks Raff. I'm gonna try bumping her up a bit....
Posted By: Slingshot383

Re: trans brake tuning advice? - 12/07/13 06:05 PM

No chip is set on kill, but it is also the limit of what the car can do. 400 - 600 rpm under working stall (high gear, foot on the brake , wing the throttle and make note of highest rpm). Yes you don't want the slicks to spin, but to slip just a bit. Once again you need to know that spot at which it knocks the tires off and then drop in 1/4 lb. increments.
Posted By: JACK1440

Re: trans brake tuning advice? - 12/07/13 06:31 PM

Well I found out about the no chip by accident. I blew a alt. belt in the water box and when I staged the car and brought it up on the brake the 2 step didn't fire. It went straight to "kill". Man she left like a monster. I just wasn't sure if that would "kill" the drive line if I made that a habit. Sure did love it though... The chip is set at 4200 on a 5000 stall currently although I haven't done the 3rd gear test to find out true stall.
Posted By: MR_P_BODY

Re: trans brake tuning advice? - 12/07/13 09:34 PM

Quote:

Well I found out about the no chip by accident. I blew a alt. belt in the water box and when I staged the car and brought it up on the brake the 2 step didn't fire. It went straight to "kill". Man she left like a monster. I just wasn't sure if that would "kill" the drive line if I made that a habit. Sure did love it though... The chip is set at 4200 on a 5000 stall currently although I haven't done the 3rd gear test to find out true stall.



A high percentage of the time I dont run a chip on
the launch... only on the 10.0 stuff.. been doing
that for years... no problems.. the trans hasnt been
apart in 6 years(didnt need to)
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