Letting off the gas in-between shifts in AT transmission

[alexpham_]

I've had my AT FRS for over a year now. I love it but I would also love it to be manual if I could, but circumstances in life right now don't allow that.

For those that understand how the AT transmission works on this platform...Is it ok to let off the gas in between up shifts? I like to simulate driving stick when in manual mode. It could be a habit from driving stick before. (say im in 1st gear 60% throttle, let off gas, shift into 2nd, add gas again).

Sometimes I notice that the car hesitates to find the right RPM it should sit at when changing to the next gear when I do this.

So I went ahead and experimented with how the car likes to react. When driving regularly 40/50% or so throttle (2.5-4.5k RPMs), it doesn't affect it a whole lot. Letting off the gas, shifts the car slower I've noticed, but it sounds better in my opinion than a fast automatic shift. (Yea, i know its still an auto, it just sounds more pleasing to more my ears)

However, when in the higher RPMs and WOT, I've noticed that the car doesn't like it because the RPMs have to drop dramatically in order to sit at the correct RPM in the next gear (its more obvious in 1st, 2nd, 3rd and sometimes 4th gear. Gears 5th and 6th don't really make a difference since they're highway speeds.) Im guessing this has to do with the gas cutting off when depressing the gas pedal before shifting into the next gear.

Anyways, does anyone else do this? Try it for yourself if you own an auto, and let me know how your car reacts or if you understand what im trying to say.

Bottom line is, Is it ok for my engine and transmission? I don't to be hurting my car not knowing so.

Thanks

[FRSBRZGT86FAN]

Originally Posted by alexpham_

I've had my AT FRS for over a year now. I love it but I would also love it to be manual if I could, but circumstances in life right now don't allow that.

For those that understand how the AT transmission works on this platform...Is it ok to let off the gas in between up shifts? I like to simulate driving stick when in manual mode. It could be a habit from driving stick before. (say im in 1st gear 60% throttle, let off gas, shift into 2nd, add gas again).

Sometimes I notice that the car hesitates to find the right RPM it should sit at when changing to the next gear when I do this.

So I went ahead and experimented with how the car likes to react. When driving regularly 40/50% or so throttle (2.5-4.5k RPMs), it doesn't affect it a whole lot. Letting off the gas, shifts the car slower I've noticed, but it sounds better in my opinion than a fast automatic shift. (Yea, i know its still an auto, it just sounds more pleasing to more my ears)

However, when in the higher RPMs and WOT, I've noticed that the car doesn't like it because the RPMs have to drop dramatically in order to sit at the correct RPM in the next gear (its more obvious in 1st, 2nd, 3rd and sometimes 4th gear. Gears 5th and 6th don't really make a difference since they're highway speeds.) Im guessing this has to do with the gas cutting off when depressing the gas pedal before shifting into the next gear.

Anyways, does anyone else do this? Try it for yourself if you own an auto, and let me know how your car reacts or if you understand what im trying to say.

Bottom line is, Is it ok for my engine and transmission? I don't to be hurting my car not knowing so.

Thanks

There's no point in "letting off the gas" in between shifts on our autos, it's not a sequential dog box or anything like that it's a torque converter automatic that shifts quick on the downshifts. You're actually causing the TCM to slow your gear changes and heavily confusing the TCM logic when you do that.

I've only letting off the gas when hitting the paddle in odd circumstances, but never intentionally, and there is a noticeable delay. Also I let my friend drive my car and the car would jerk around alot with the latest TCM update and I realized he was being odd and letting off the gas between shifts.


If you want to pretend you have a manual, buy the manual

[leevanf]

My theory is that actually, i think the computer already “simulates” being off-throttle in between shifts even if your foot is on the gas. Probably cutting throttle during the actual shift and delivering it back accordingly with your foot on the gas. So, foot on the gas shifting would be the equivalent of a very efficient and accurate manual driver’s pedal control. Whereas trying to simulate a true manual by lifting off is pretty much like granny shifting and not giving it gas as you release the clutch.

My 2 cents!

[mkodama]

Leevanf is correct, just about every modern automated shift involves a throttle or ignition cut while shifting to reduce clutch wear and shift smoother.

Also, here’s a story for automatic people. I had a friend with an auto 2003 BMW 325i and he also wanted to pretend it was a manual. He would do exactly this, and also blip the throttle when downshifting because he liked the way it sounded. After a few years of this, his transmission catastrophically failed with no prior signs, stranding him on the side of the road. The oil that came out of it had chunks of metal. Never have I seen such a low horsepower engine destroy an automatic transmission so catastrophically. Said friend stopped doing these shenanigans and his new transmission never failed. End.

[humfrz]

Oh, I'll go along with the folks up above. It's an modern automatic transmission, just let it do it's thing.

It's not your grandfather's powerglide, that you could change when it shifted by letting up on the gas (to a certain degree).


humfrz

[humfrz]

Originally Posted by FRSBRZGT86FAN

If you want to pretend you have a manual, buy the manual

- that wasn't nice -

OH! - it's past ma med time -


humfrz

[FRSBRZGT86FAN]

Originally Posted by mkodama

Leevanf is correct, just about every modern automated shift involves a throttle or ignition cut while shifting to reduce clutch wear and shift smoother.

Also, here’s a story for automatic people. I had a friend with an auto 2003 BMW 325i and he also wanted to pretend it was a manual. He would do exactly this, and also blip the throttle when downshifting because he liked the way it sounded. After a few years of this, his transmission catastrophically failed with no prior signs, stranding him on the side of the road. The oil that came out of it had chunks of metal. Never have I seen such a low horsepower engine destroy an automatic transmission so catastrophically. Said friend stopped doing these shenanigans and his new transmission never failed. End.

Well, the downshifts on the twins auto is quite good and the rev matching is on point.

Also the 325i auto either had the 5L40e trans borrowed from GM or the ZF 5hp, neither were good transmissions for there class, the E46 m3 however had a dope SMG II transmission. All of them were finicky and required decent maintenance to fluid levels and filters. I think your friend may have neglected his car

[Stang70Fastback]

Letting off on the gas between shifts causes problems with the car finding the right gear because you are confusing the car.

"Oh, I thought we were accelerating, so I was going to grab 5th... but now you want to slow down a bit so, do you want me to stay in 4th?"

AT shift logic is just that. It is logic. It assumes that what you are doing with the gas pedal is what you want the car to do. Your fake lift isn't logical, and only confuses it. So... stop doing that.

Buy a manual if you're THAT into how a manual shifts, lol.

[Summerwolf]

You're supposed to let off the gas when you shift your manual...... wish I had known that!

[Gunman]

Flat foot shift, and let the computer handle it

[Leonardo]

Never Lift.






I have an AT

[mkodama]

Originally Posted by FRSBRZGT86FAN

Well, the downshifts on the twins auto is quite good and the rev matching is on point.

Also the 325i auto either had the 5L40e trans borrowed from GM or the ZF 5hp, neither were good transmissions for there class, the E46 m3 however had a dope SMG II transmission. All of them were finicky and required decent maintenance to fluid levels and filters. I think your friend may have neglected his car

While the SMG transmissions was strong because it was just a modified manual, the SMG actuator and controls were finicky. Also one of the roughest shifting automated manuals aside from the smart car.

Funny you say they needed maintenance; this person was the king of unneeded “preventative” maintenance and BMW sealed those transmissions and put a sticker on them saying “Lifetime fluid.”

[meadowz06]

The AISIN transmission is a very good unit. 200 millisecond shift times. Not bad for a single clutch box. Just let the transmission shift.