Thread: Manually shifting automatic

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From time to time I get the call to race someone, and when I do, I down shift my automatic into 1st and go through the gears manually. Is this hurting my trans or anything else?

I will be installing a manual shift automatic valve body soon, but was curious in the mean time.

thanks.

Manually shifting will not hurt anything as long as you do not overrev the motor or accidently push it up into Nuetral, or worse yet, reverse (No! R is NOT for Race!).

Pat

No, it won't hurt a thing, but remember when you switch to a full manual valve body you will shift it like that ALL the time, no more putting it in D and forgetting about it.

Thanks guy's, that's good info to keep on hand.

As far as the car set up, Tech, this is what I've got going: the cam is not stock from my understanding (the guy before me installed it and it sounds and feels heavy), it has a 3.91 rearend, Edelbrock performer rpm intake and 750 cfm carb. As for the heads and valves, I have no idea. The trans is a 727 torqueflite and engine is a 440.

I have been shifting @ 5,200 rpm's, does that sound right? Another thing I notice is my rpm's at about 45 mph is around 2,500 cruising.

Also, the valve body I have been looking at is a Turbo Action "pro street" valve body which allows you to cruise in "D" but get better responsive manual shifts if/when needed.

Well keep us posted on how it turns out, and when your launches become boring check out a "clutchflite" tranny mod

No, i haven't gone to the strip and it doesn't look like I'll get to it this year but I'll try. Maybe next week if I can talk a friend into going.

I'll keep you posted.

I don't really understand what a torque converter does or how it will help. Please explain. And how do I know what rpm level I should get if I do?

In the simplest of terms, a torque converter is a fluid coupling between the motor and transmission. It takes the place of the clutch in a manual transmission set up. It has two sets of turbine vanes, the first set is bolted to the motor side, the second set is on the transmission side. When the motor side turns, the vanes push fluid against the transmission side. When enough fluid pressure is achieved, the fluid turns the transmission side and moves the car. This allows the car to idle in gear without the car moving or the engine dying.

Stall speed is the point where the Engine 'Stalls" when you put one foot on the brake and the other hard on the gas. Most stock converters stall between 1200-1500 rpm. A high Stall converter is looser and allows the motor to rev to a higher RPM before it hooks up and starts pushing the transmission side. There are numerous Stall settings that can be built into a converter depending on planned usage.

The down sides of higher stall speeds are higher heat and less efficiency at higher RPM. The slippage generates heat and also does not lock up as tightly. To deal with this last issue they now make "Lock-up" converters that actually mechanically lock up at a given RPm or condition giving near 100% efficiency. This is usually controlled electronically

Hope that helps you understand

Pat

Maybe we should work in shifts so we are not responding at the same time! :LOL You want days or nights?

Pat

Damn, that's a lot of info but it's making better sense and I've actually learned something useful. I'm going to print out your responses and reread them to lock in the info.

Thanks guys.