So school me on manually shifting an Automatic

[Ghoste]

Technically, they both are.

[FLG]

Ive heard its not good to put the shifter in 1 with an auto for a burnout. From what i remember its really only a problem with wet ground then dry. When your burning out in the water if you keep the burnout going onto dry ground you put too much stress on the rear band when the tires start to catch.

[John_Kunkel]

Again, starting a burnout in 2nd gear is preferable but with an automatic VB there is no way to start out in 2nd; placing the shifter in (2) will still have the trans start in 1st (with no sprag protection) and shift to 2nd but no further.

In order for the rollers in the sprag to fully seat there must be a load on them, when the tires are spinning there is reduced load and, even though the tires might seem to be freely spinning, there can be momentary load/unload events that allow the rollers to slip their grip; when the rollers slip they develop flat spots which will eventually lead to failure.

Starting the burnout with the shifter in (1) applies the rear band to reduce the load on the sprag and prevent the slipping described above. After a little tire speed is achieved you can shift to 2nd and/or 3rd to complete the burnout; once the 2nd gear shift occurs the sprag is unused, it just goes along for the ride.

[FLG]

Gotcha, so burnout in 1st...then go from there 

[joflaig]

Awesome detailed info. Thanks!

[firefighter3931]

John, what type of valvebody do you have in your transmission ? Any shift reprogramming kit installed ?

One other thing to note when doing burnouts : once the tire spin has been initiated it's important to keep them spining....no off and back on throttle stabs. 


Ron

[joflaig]

John, what type of valvebody do you have in your transmission ? Any shift reprogramming kit installed ?

One other thing to note when doing burnouts : once the tire spin has been initiated it's important to keep them spining....no off and back on throttle stabs. 


Ron

It's just a plain jane 727 with some heavy duty components, but no shift kits or anything like that.

[firefighter3931]

John, what type of valvebody do you have in your transmission ? Any shift reprogramming kit installed ?

One other thing to note when doing burnouts : once the tire spin has been initiated it's important to keep them spining....no off and back on throttle stabs. 


Ron

It's just a plain jane 727 with some heavy duty components, but no shift kits or anything like that.

Based on that information the correct burnout procedure is the one that John K. outlined above. 

I would strongly recommend an aftermarket valvebody or at the very least a reprogramming kit like the B&M transpack or TransGo tf-2 behind that big Stroker. 

With high HP builds i prefer a full manual valvebody with low band apply. Turbo Action sells such a unit called their "pro-street" VB. I have one in my trans.



Ron

[471_Magnum]

There are differences in auto valve bodies. The Turbo Action Pro-Street auto valve body does give you full manual override. If you put it in first, it stays there until you shift or blow-up. Put it in second, it will start in second and stay in second. It will also manually downshift at any speed. It is also exquipped with part throttle kick down. (PTKD is a whole 'nother topic). I ran one of these in the Charger.

Anyway, I HAD to shift the old Charger manually due to limited traction. Mashing the throttle off the line in "D" resulted in massive tire spin while watching the competition drive away. Pedaling back resulted in a premature up-shift and a bog. The only way to get out of the hole at part throttle was to manually shift and not mat it until second gear.

I ultimately solved the problem by installing the five speed.

[joflaig]

Maybe one day I'll spend the money to switch to manual, but I think I have all the info now on getting the most out of the automatic tranny. I guess I'll play around with it on Saturday. Weather is supposed to be good.

[firefighter3931]

There are differences in auto valve bodies. The Turbo Action Pro-Street auto valve body does give you full manual override. If you put it in first, it stays there until you shift or blow-up. Put it in second, it will start in second and stay in second. It will also manually downshift at any speed. It is also exquipped with part throttle kick down. (PTKD is a whole 'nother topic). I ran one of these in the Charger.

Jim, just a FYI ;

Turbo action makes 2 different style "prostreet" valve bodies. The one you used maintains full automatic shift features and requires a kickdown assembly.

They also make a full manual VB with low band apply in both forward and reverse patterns....no kickdown linkage required. That is the one i have in my transmission....



Ron

[471_Magnum]

Yes, it maintains full automatic, but shifting manually fully overrides the automatic in 1 & 2. Put it in "1", it goes to first and stays there. Put it in "2", it goes to second and stays there. Put it in "D", it's an automatic.

From the Turbo Action website:

CHEETAH Pro Street Manual/Automatic  (p/n 17676)
Provide full manual control or permit automatic operation. Features positive shifts. Maintains stock shift pattern. Manual low gear anytime. Passing gear linkage hook-up required on Torqueflite.

[oldkimmer]

...........Ill try to straighten out the mass confusion..........If ur trans does not have a low band apply valve body u can still start ur burnout in in 1st gear, u MUST shift to 2nd or even 3rd BUT NEVER let it shift back to 1st cause u dont have any low band apply to stop the sprag which is free wheeling so when the wheels stop spinning the sprag is the only thing left to take the shock, that it explodes,....In ur factory auto trans u will have low band applied as long as u r in manual low on ur shifter when u do a burnout ALWAYS stay in manual low, cause as soon as u shift to 2nd u will have no band to stop the sprag when the wheels stop spinning and it shifts back to 1st and overloads the sprag..........factory trans= do burnout in manual low only.......hope this helps............kim.......

[John_Kunkel]

...........Ill try to straighten out the mass confusion..........If ur trans does not have a low band apply valve body u can still start ur burnout in in 1st gear, u MUST shift to 2nd or even 3rd BUT NEVER let it shift back to 1st cause u dont have any low band apply to stop the sprag which is free wheeling so when the wheels stop spinning the sprag is the only thing left to take the shock, that it explodes,

Totally wrong. As I stated earlier, the sprag rollers need a load to seat properly, spinning tires don't apply a sufficient load to the sprag to properly seat the rollers; if you start the burnout in first the sprag can slip because of the reduced load, it's the slipping that causes the damage not the throttle-back freewheeling. If there is no low band apply it has to be a manual VB and therefore the burnout should be started in 2nd. You don't have to worry about it shifting back to 1st by itself, it's a manual VB.

In ur factory auto trans u will have low band applied as long as u r in manual low on ur shifter when u do a burnout ALWAYS stay in manual low, cause as soon as u shift to 2nd u will have no band to stop the sprag when the wheels stop spinning and it shifts back to 1st and overloads the sprag..........factory trans= do burnout in manual low only.......hope this helps............kim.......

With a factory VB with low band apply you must start the burnout in (1) and then you can shift to 2nd and 3rd. With the rear band applied in low the sprag carries only part of the load so there's little chance of harming it with throttle misuse, when the shift to 2nd occurs the sprag no longer serves any function and just becomes a roller bearing. It's true that the trans will shift back to 1st when the throttle is released in 3rd and the wheels stop spinning but there is no load applied with the throttle at idle.