I need to know if the automatic transmission in 4th gens shifts gears based on speed or RPMs. Who knows?

~THT

 

good question...i would think rpms....

 

I remember reading it's speed-based. But, I don't know for sure.

~THT

 

i would think its throttle ammount. i mean, it will shift up when you let off the gas, wether it be at 3k rpm or 6k rpm, same thing with what ever speed you are at.

 

i'm almost postive it's throttle controlled. i'm not sure if it goes through the TPS or not.

 

damn automatics

 

i notice when im crusing it shifts from 2500 -3k rpm, but when i floor it it shifts around 6k

 

I think its a combination of speed and throttle percentage. @ any % less than WOT, it shifts according to throttle %, because on my sister's car, for example, it will shift from lets say 2nd to 3rd put decreasing the throttle a tad bid. At WOT, it SHOULD always shift at redline, as gear ratios cannot be changed.

 

I don't know, but I think that throttle has more to do with it. At full, the auto will search for the lowest gear possible, and drop it there.
If it was speed based, wouldn't you shift at the same speed, no matter what throttle? We know that's not true...
If it was rpm based, wouldn't it shift at the same engine speed, no matter the throttle %? We know this too is not true.
Something to think about, or maybe I'm barking up the wrong tree...jus' throwing out some ideas.

 

It's only RPM based at WOT.

Ty, thinkin of a 5spd swap?:grin:

 

lol, wanna come down and help me? I'll buy you all the Wendy's you'll ever want.

 

you know they found a human finger in a bowl of chilli at wendy's right?

 

lol. I was paid with Wendy's food today as well..

 

In my mom's minivan when I floor it the car downshifts. It's throttle based among other factors.

 

I coudn't tell you exactly which one it is for sure, but i know speeds detirmine whether it will downshift or not. For example, in order for my dad's 5th gen to downshift into 1st geat @ WOT, it has to be below 30 mph, or it will not downshift. I would believe in that case it would be speed based because no matter if i were in OD or 3rd gear, it would downshift.

 

Trick question, its both speed and rpm sensitive lol

 

On older cars like the sub 2002 Maximas, it based off of rpms, throttle postion sensors, and an engine vacuum. When you floor it or give the car a little throttle, the engine vacuum changes (increases or goes to zero at WOT). The transmission TCM recognizes this and drops to the appropiate gear. On newer cars, the throttle-by-wire system is also involved.

In older cars without lockup torque converters, it was all vacuum based. Same with ignition.

 

and throttle position

Dave

 

im almost positive that the max tranny is vaccum controled, the less vaccum there is on the intake manifold the more open the throttle is, not positive though.

 

Okay, thanks guys. The reason why I asked this question was because before I put installed the 00 VI, my car would redline every gear. Now, she shifts at 6K and I wanted to know why.

~THT

 

all i know is under moderate acceleration, it ALWAYS goes ito 4th at 39mph.

 

Did you feel a really good increase on your butt dyno with the VI. I'm considering doing this mod in the future.

 

Screw the butt dyno this has been proven time and time again on a real dyno to gain back all the lost midrange hp/tq the MEVI lost.

 

We didn't hook up the RPM Switch yet, but compared to my old MEVI, the midrange on the 00VI would kick the MEVI's midrange's @$$