Engine modifications to automatic cars - Why?

[XavierMace]

There are DCT's which are alright, but even most autos with manual select have inconsistent shifts, don't hold gear, etc. I've test many of them, and they rarely seem to work right for whatever reason, which I suspect is fundamental to the converter/planetary-clutch design.

It sounds like you haven't driven a good modern auto.

 

[mindless1]

Retarded people that can't drive cars without inventing problems.

 

[AdamK47]

This thread is hilarious on so many levels.

 

[Raizinman]

This thread is hilarious on so many levels.

Yes it is hilarious because you can't argue with stupid.

 

[agent00f]

It sounds like you haven't driven a good modern auto.

Which autos shift without lag?

I've pondered the idea that switch-shifters of that sort in performance oriented cars should be two stage. First a hint to the transmission of an intent to shift so it can prepare whatever it needs, then the shift itself.

 

[fralexandr]

modern CVTs generally are pretty good with shifting. I don't know if you'd lump them in with autos.

https://youtu.be/h7_LE05dfgU?t=603
engineering explained 2014 Corolla S on its paddle shifters

http://www.roadandtrack.com/car-cul...s-an-automatic-and-it-isnt-even-the-best-one/

 

[agent00f]

modern CVTs generally are pretty good with shifting. I don't know if you'd lump them in with autos.

https://youtu.be/h7_LE05dfgU?t=603
engineering explained 2014 Corolla S on its paddle shifters

http://www.roadandtrack.com/car-cul...s-an-automatic-and-it-isnt-even-the-best-one/

I believe the whole idea of CVTs is lack of need for shifting. A smart CVT can in theory (like a "sport/race" mode) always keep the engine in the max power band.

The problem with autos will always be that the nature of their "automation" requires decision-making from incomplete info. The shift button are in an abstract sense a hint to to the car of your intentions, whether it's to be more aggressive (downshift) or less. So with a cvt, you can directly dial in that info of what ~rpm you want to be in, and the transmission will do the rest.

 

[rancherlee]

Which autos shift without lag?

I've pondered the idea that switch-shifters of that sort in performance oriented cars should be two stage. First a hint to the transmission of an intent to shift so it can prepare whatever it needs, then the shift itself.

Many autos can be built to shift without noticeable lag. The problem is a "fast" shifting auto is usually pretty harsh and most people wouldn't accept that. Another issue is the majority of cars/trucks built today have electronic throttle bodies and also induces "lag". I've had many Sticks and Autos over the years and my favorite transmission has been the 4R70W in my Thunderbird. I fully modified the valve body and run a 3500rpm triple disk converter in it and it shifts just about instantly between gears under hard throttle along with getting rubber due to how harsh it shifts. Automatic with a stall converter really lets you load up a turbo too 😉