Overreving engine with automatic transmition

[86TOYO2k17]

Originally Posted by mrg666

Even worse, if the rev limiter cuts the throttle at the same time when the engine is forced to rev at 10500rpm, there can be engine damage until engine brake slows the car down and rpm decrease below red line. I would imagine that is a big impact load on valvetrain and connecting rods. I have done accidental downshifts before and the AT allowed those. Since the shifting mechanism is sequential, one has to do a triple tap for such a severe case. I think the AT will not do that downshift, but I have no intention to find out.

I have tried money shifting numerous times. Won’t let me. If in manual mode it’ll even show up and down arrows indicating if you can up or downshift at your current RPM.

If i am cruising in 6th and want to do a pull in 3rd real quick ill hit the downshift paddle numerous times sometimes even 10times repeatedly it won’t go into 2nd above about 64mph. I’m sure this can all be changed in the tune if desired.

Maybe Pre 17s are different but i highly doubt it.

[mrg666]

^ that is a good safety feature. Thank you for confirming.

[Irace86.2.0]

Originally Posted by 86TOYO2k17

I have tried money shifting numerous times. Won’t let me. If in manual mode it’ll even show up and down arrows indicating if you can up or downshift at your current RPM.

If i am cruising in 6th and want to do a pull in 3rd real quick ill hit the downshift paddle numerous times sometimes even 10times repeatedly it won’t go into 2nd above about 64mph. I’m sure this can all be changed in the tune if desired.

Maybe Pre 17s are different but i highly doubt it.

And performance feature. You can just jam it into the lowest gear without concern. I don't have the auto; does it really move sequentially through the gears in manual mode like if you rapidly tried to change gears, would it really move sequentially, or would it jump gears? An automatic transmission in automatic mode will typically jump gears depending on accelerator position and gear, it may skip 3rd dropping from 4th and go to 2nd?

[86TOYO2k17]

Originally Posted by Irace86.2.0

And performance feature. You can just jam it into the lowest gear without concern. I don't have the auto; does it really move sequentially through the gears in manual mode like if you rapidly tried to change gears, would it really move sequentially, or would it jump gears? An automatic transmission in automatic mode will typically jump gears depending on accelerator position and gear, it may skip 3rd dropping from 4th and go to 2nd?

It’s sequential in manual. you can slap her between manual and auto mode whenever you like before during or after a pull, can still manually shift with paddles in auto mode and it’ll hold the gear basically turning to temporary manual mode for about 10seconds before going back to auto. But it’ll auto shift at redline still in “temporary” manual mode.

With my ssp stage 2 valve body the up shifts at WOT are almost instant and seem less. I believe the delay in acceleration from disengaging gear (stop acceleration) and re-engaging new gear(continue acceleration) was .3seconds and now I believe its .15sec. But it did sacrifice downshift speed a little and shifts daily driving are firmer/rougher.

I’ll either prep her in 4th if i want to pull in 3rd for 1 downshift away, or auto downshift then slap her to manual for upshifts.

[Irace86.2.0]

Originally Posted by 86TOYO2k17

It’s sequential in manual. you can slap her between manual and auto mode whenever you like before during or after a pull, can still manually shift with paddles in auto mode and it’ll hold the gear basically turning to temporary manual mode for about 10seconds before going back to auto. But it’ll auto shift at redline still in “temporary” manual mode.

With my ssp stage 2 valve body the up shifts at WOT are almost instant and seem less. I believe the delay in acceleration from disengaging gear (stop acceleration) and re-engaging new gear(continue acceleration) was .3seconds and now I believe its .15sec. But it did sacrifice downshift speed a little and shifts daily driving are firmer/rougher.

I’ll either prep her in 4th if i want to pull in 3rd for 1 downshift away, or auto downshift then slap her to manual for upshifts.

I was looking at these times for reference. I guess that is pretty fast. I suppose I was figuring 3-5 pulls/second max (333-200ms) would be faster than the transmission could keep up, so it would jump a gear, but I guess if yours is at 150ms then that answers that. Thanks.


https://en.wikipedia.org/wiki/Shift_time

[86TOYO2k17]

Originally Posted by Irace86.2.0

I was looking at these times for reference. I guess that is pretty fast. I suppose I was figuring 3-5 pulls/second max (333-200ms) would be faster than the transmission could keep up, so it would jump a gear, but I guess if yours is at 150ms then that answers that. Thanks.


https://en.wikipedia.org/wiki/Shift_time

I’m pretty sure it’s just programmed to not skip gears and intentionally be sequential in manual mode even if I could hit the paddles every 50ms it will go one by one although pretty quickly, it doesn’t even seem to wait long enough to fully engage the gear before downshifting again. But you’ll see the RPMs increase in pronounced “steps” based on gear/mph.
Also it up shifts now because of valve body at about 150ms (it’s hard to extrapolate exactly with ecutek refresh rate) But it’s easily twice as fast as before.
But downshifts are slower than before probably 350-400ms. I think it’s how they redesigned the valve body fluid passages and the solenoids it sacrifices some downshift speed for a lot of upshift speed. Same thing happens when you “tune” the auto shifts you got to choose one or the other.