shifting into neutral after pass
 

http://yellowbullet.com/forum/showth...=172108&page=4

check out post #48

do you shift into N?

i do

i dont for several reasons

For those of you with automatics that go to neutral after the trap, count your blessings if you haven't blown anything up yet. It is true that certain transmission internals in certain transmissions turn at very high speed when the output shaft is doing the driving while coasting in neutral. In most transmissions, the planets will step up (overdrive) the low gear elements while coasting at high road speed. For instance, if your 3 speed transmission has a 2.48 first gear, and your driveshaft speed at the trap is 6000rpm, your low gear elements in your transmission would be turning 6000 x 2.48 = 14,880rpm!

If you leave your trans in high gear for a while after the trap, friction elements that make high gear will still be applied and will ensure that all the internals will turn no faster than your driveshaft speed.

If you ever have the luxury of looking at a partially built automatic transmission on the bench with the rotating assembly in it minus the front pump, grab the output shaft and turn it and note the speed of some of the internals in relation to the speed you turn the output shaft. The partially built transmission is in effect in neutral while you do this eye opening experiment.

Of course, if you have a stickshift or lenco, you don't have anything to worry about. Neutral at the trap is OK for these transmissions.

My old th400 would pretty much go into N when you left off the gas. I could let out at 7000rpm and it would go straight to idle. I know it wasnt really N but it acted like it.

I also thought the process was to put the trans in neutral to keep from loadind and unloading the crank. Learn something new everyday.

i usually go into neutral and sometimes have hit rev on accident

I am not positive, but i don't think this applies if you have a powerglide.

There is something I would need to know. Gerald?

after a nitrous pass i will throw the trans into neutral and shut her down. that way i can read the plugs and adjust nitrous pills. i guess i have done it wrong all these years

hal it only applies to fast cars you have no worries man

lol. that was messed up.

Ok phew

Thanks gearmesh never really thought about it.Good info.

Well I guess my transmission warranty is null and void, because I do it in the LTD and Mustang. I'll stop now though..:?

The engine would go to idle due to internal one way sprags freewheeling while coasting. By leaving your TH400 in gear after the trap, there was still a connection to the input shaft internally that prevented the high speed spin-up of other parts inside.

Since a powerglide typically has a 1.76 first gear, internal parts won't spin up near as much as a 3 speed or overdrive unit that typically has anywhere from a 3.06 to 2.48 first gear ratio.

With that being said, a powerglide is the least likely to centrifuge itself apart internally.