So school me on manually shifting an Automatic

[joflaig]

I've played around a bit manually shifting my automatic, but frankly I don't know what I'm doing and want to be careful I don't break something or spin into a ditch or something. So, what I'm curious to know is how should I know when to shift from say 1st into 2nd and when eventually shifting into D, how does the tranny actually behave? Will it always put it into 3rd? How about down shifting?

What does it take to screw up and break the tranny or lose control of the car?

And finally, I assume when racing there would be advantages to manually shifting rather than just starting off in Drive, no? What would the procedures be?

Thanks!

[SFRT]

I say get a 4 speed...and go oldschool.....but then again, I like complicating things.

[1BAD68]

I do it all the time.
I have a Hurst V-Matic in my Charger and you can ratchet shift it or just use it normally. The first thing is make sure you have a tach installed so you dont ruin the engine, from a dead stop in 1st just floor it and enjoy, watch the tach, I always shift no later than 5500 rpm into 2nd and 3rd.
I dont think it hurts anything at least so far I haven't broke anything.

[joflaig]

I do it all the time.
I have a Hurst V-Matic in my Charger and you can ratchet shift it or just use it normally. The first thing is make sure you have a tach installed so you dont ruin the engine, from a dead stop in 1st just floor it and enjoy, watch the tach, I always shift no later than 5500 rpm into 2nd and 3rd.
I dont think it hurts anything at least so far I haven't broke anything.

I just have the crappy old stock column shifter and of course the tac in the dash. The rev limiter is set to 6000rpm. So how does the car behave and the tranny function differently when you put it in 1st and go to 5500 rpm vs having it in drive and stomping on the gas?

[The70RT]

As far as down shifting....a waste of fuel and bad for the trans. Brakes are cheaper than a trans.

[1BAD68]

The tranny will automatically shift even when you stomp on it, usually around 4000-4500 rpm. But when manually shifting at higher rpm's you'll be using more of the power curve of the engine. More power curve = more tire shredding or lower ET's at the track.

[joflaig]

The tranny will automatically shift even when you stomp on it, usually around 4000-4500 rpm. But when manually shifting at higher rpm's you'll be using more of the power curve of the engine. More power curve = more tire shredding or lower ET's at the track.

So in otherwords more potential for the rear end to sweep to the side when manually shifting at high rpms vs letting the tranny shift automatically.

[Ghoste]

Maybe slightly but I wouldn't worry too much about that.  I'd concentrate more on not shifting into neutral, that is a shortcut to breaking things.

[joflaig]

So you guys w/automatics who race or go to a test and tune once in a while, do you manual shift your cars?

[John_Kunkel]

Leaving the starting line in Drive puts all of the load on the overrunning clutch (sprag) in the transmission, placing the shifter in (1) applies the rear band and relieves some of the load on the sprag which is prone to failure if abused.

This makes leaving the line in (1) more desireable from a safety standpoint and also from the standpoint of controlling the shift points. I would always manually shift at the drags.

[joflaig]

Leaving the starting line in Drive puts all of the load on the overrunning clutch (sprag) in the transmission, placing the shifter in (1) applies the rear band and relieves some of the load on the sprag which is prone to failure if abused.

This makes leaving the line in (1) more desireable from a safety standpoint and also from the standpoint of controlling the shift points. I would always manually shift at the drags.

That's good technical info. So when you shift into 2nd at around 5500, and then eventually into D, doing so will the tranny always go into 3rd instantly?

[FJ571440B]

No expert,but launching in 1st is better to take the load off the sprague as mentioned(good info  ). If you are manually shifting with a stock trans,so it sounds,YOU will choose the shift points.But also as mentioned,for stock engines,I wouldn't(but have) rev past 55-5800 RPM's. You want to leave some room for the clutches to engage and not over rev the engine.Most stock bigblocks I've had will see 6000 RPM without problem.If its a tired motor,I would stay closer to 5500 or not wind it up much at all. Now if you leave it in D,the trans(stock) will aready have set shift points around 4500 RPM as said.I have never had a stock trans shift instantly into another gear. I have had some shift a little tighter (faster)than others,and some looser(sluggish). The whole point of shifting manually is to have full control of how the trans shifts and override how it is pre-set from the factory,and taking advantage of the engines power band. If you want instant shifts,get a manual valve body,but then you'll be shifting ALL the time,and some things will need to be tweaked for your trans to handle it. It can be done,but there is a little more than just putting in a manual valve body and having things be reliable. Your shifts will also be extremely harder than stock.   

[Runner]

every engine has a different disired shift point.  some motors dont wants to spin over 4000 and some spend  hours at 20,000 rpm (formula 1 cars)
 

[FLG]

Ghoste,

When you whack the slap stik shifters they lock until you back your hand off a hit it again. Also you cant go into neutral until you depress the lock on the shifter. Thats how it is on the 3rd gens, i assume the same for the 2nd.

Also, i dont think im beating up the tranny by doing this but someone correct me if i am. I know where my RPMs are in 1st so if im cruizing in drive and want to stomp on it (i only do this at about 20mph or under) instead of letting the kickdown drop the tranny in first ill manually slide the shifter into first and whomp on it...makes for a MUCH quicker downshift then letting the kickdown linkage do the work.

[firefighter3931]

Leaving the starting line in Drive puts all of the load on the overrunning clutch (sprag) in the transmission, placing the shifter in (1) applies the rear band and relieves some of the load on the sprag which is prone to failure if abused.

This makes leaving the line in (1) more desireable from a safety standpoint and also from the standpoint of controlling the shift points. I would always manually shift at the drags.

Good advice ! 

One thing i will add : do not burnout in first gear....start in second then third and roll out of the box. 

A good starting point for yours would be 5500 rpm shiftpoints.   



Ron

[joflaig]

Leaving the starting line in Drive puts all of the load on the overrunning clutch (sprag) in the transmission, placing the shifter in (1) applies the rear band and relieves some of the load on the sprag which is prone to failure if abused.

This makes leaving the line in (1) more desireable from a safety standpoint and also from the standpoint of controlling the shift points. I would always manually shift at the drags.

Good advice ! 

One thing i will add : do not burnout in first gear....start in second then third and roll out of the box. 

A good starting point for yours would be 5500 rpm shiftpoints.   



Ron

Why always do burn outs in 2nd?

But just recap, burnout in 2nd... then when leaving the line start in 1st and shift at 5500rpm into 2nd and then again into D when hitting 5500 again.

When is it safe to downshift from D into 2nd or 1st?

[firefighter3931]

Why always do burn outs in 2nd?

This protects the overrunning clutch from failure. If the sprag rolls over the trans will spin up to 2X engine speed and you can explode the front drum....not something you want to do. The last trans i saw (that exploded) fit in a 5 gallon pail....most of the pieces fit in the palm of your hand. 

But just recap, burnout in 2nd... then when leaving the line start in 1st and shift at 5500rpm into 2nd and then again into D when hitting 5500 again.

Exactly ! 

When is it safe to downshift from D into 2nd or 1st?

I would say 4000rpm is safe....the shift recovery rpm is ~1500 with a 727. Shifting at 4000 in D to second will bump the engine speed to ~ 5500 or so. Be careful when doing this because you have a real torque monster there.....things can get a little squirrely ! 

Maybe find a deserted road with lots of room and "experiment" a little with your downshifts to see how it reacts. 


Ron


Ps. How is the Knee rehab coming along ?

[joflaig]

That's great info Ron, especially about downshifting. I know you can get into trouble with that and hadn't found real specific advice to follow.

I'm still with crutches for another week. I will probably get one more drive in my car this year. There were light flurries yesterday.

Incidently, the shop that rebuilt my transmission used that Ultimate Sprag. From what I understood it might have been slight overkill since the engine was a "mild" build, but I wonder within the scope of what we've been talking about in this thread, having that will it give me any extra leeway in terms of not breaking something as fast if I screw up?

AND on another note, it seems like it would be much easier to read the face of a big aftermarket tac mounted to the steering column than the one in the dash. How would that work with the shift light on these things since this is an automatic? I'm probably less interested in the shift light (depending on how it works) than just better being able to see the RPMs to know when to manually shift.

[six-tee-nine]

You set the most of these shift lights yourself at the desired rpm.

And by all means be carefull when shifting down especially on wet or slippery roads because at that point you will brake real hard on your engine wich can cause the rear wheels to slightly block, so you'll end up in the ditch sooner than you can blink your eyes...

go ahead and practice on an abandoned airstrip or another place with lots of room so you can atleast smile after you went sideways

[joflaig]

You set the most of these shift lights yourself at the desired rpm.

So people who have automatics, is it a common sight to see big tac and shift light -- and don't tell me to get convert to a 4 speed ?

[1BAD68]

dont worry about your speed, the shift light is set according to rpm's. Once it hits the set rpm then the light comes on.
But for an automatic, just shift when you get to the desired rpm's. You really don't need a light.

[Ghoste]

Ghoste,
When you whack the slap stik shifters they lock until you back your hand off a hit it again. Also you cant go into neutral until you depress the lock on the shifter. Thats how it is on the 3rd gens, i assume the same for the 2nd.

Quite familiar with the Slapsticks but they don't appear in the Chargers until 71.  The 2nd gens (and 1sts) can be shoved from first all the way into neutral in one shot if you want.

[FLG]

Thanks for the correction 

[John_Kunkel]

One thing i will add : do not burnout in first gear....start in second then third and roll out of the box. 

That's good advice with a full manual valve body but with an automatic VB it's impossible to start off in 2nd gear.

Once again, with an automatic VB,  it's important to pull the shifter into (1) to apply the rear band before doing a burnout or launching.

[joflaig]

One thing i will add : do not burnout in first gear....start in second then third and roll out of the box. 

That's good advice with a full manual valve body but with an automatic VB it's impossible to start off in 2nd gear.

Once again, with an automatic VB,  it's important to pull the shifter into (1) to apply the rear band before doing a burnout or launching.

Who's right on this one?