Transmission Jolt And Left Foot Braking

[chimchim]

I couldn't stand the acceleration jolt on our 2004 RX330, so I had the dealer do the reflash. It helped... a little. But it's still there and ANNOYING, especially when I know it's wearing on the tranny.

So I was practicing left foot braking on the RX330 automatic, and I found that with left foot braking, you can trail brake into the turn and do a super smooth transition to gas... WITH NO JOLT.

So it looks like left foot braking is great for more than making Michael Shumacher fast.

[Rx330driver]

i always try to do left foot braking...one problem

my left foot cannot control pressure too well and it goes screaming into the brake pedal .lol

[wwest]

I firmly believe that the solution is a simple matter of "fooling" the engine/transaxle ECU control firmware. Each time you lift the accelerator pedal, even ever so slightly, the system is designed to upshift on the assumption you desire to enter cruise, constant speed, mode.

UNLESS you release the accelerator pedal VERY quickly and/or apply the brakes very soon after (or simultaneously for left foot brakers) lifting the accelerator pedal. This latter method TELLS the ECU that you wish to enter coastdown mode and as a result it will be much more likely to remain in the current gear ratio.

Additionally should it remain in the current gear ratio the transaxle will be "set" to recieve, instantly, a downshift command if your next depression of the accelerator pedal is aggressive.

In the recent past I have suggested that an aftermarket modification using the accelerator pedal sensor output might solve this problem. My idea was to send a signal to the ECU that the brakes were being applied each time the accelerator pedal goes to the fully released position.

[SW03ES]

I wouldn't reccomend left foot braking for people who aren't trained in precision driving...

[Rx330driver]

chimchim, i dont think that the jolt happens while your moving that quickly into a turn. It happens the most during stop sign traffic in between rolling stops and then gassing. just gotta go easy on the thing, after braking, give it a few seconds and then pedal.

i dont do left braking any more, my wife begins to :chairshot: and my head was beginning to hurt

[craig_dot_net]

I have the same problem. Took the car into the dealer and they re-flashed as well. No real difference. I have noticed, however, that if I know in advance that I will be in traffic that is stop and go, and may need to give it gas quickly but do not want the jolt, I can put the car temporarily in 4th. All of a sudden the car acts very differently. I only do this when traffic is very bad, and I know I may need to get into another lane quickly, or do not want the jolt. It also seems to significantly reduce the "hesitation" problem I had with the transmission. After the traffic and I can get up to speed, I put it back in "D". However, I was wondering if this was a bad thing to do, or if it reduced the life of the trans. Any thoughts?

[Rx330driver]

it shouldnt reduce hte life if the transmission. It just limits the car to only 4 gears, which means if yo uare going highway speeds, the only thing affected would be your gas mileage