FiveOhNine

So it's a case of Lexus handicapping the engine so that it can't reach maximum thrust? Any idea, if over 7k, where the sweet spot would be?

Gernby

iTrader: (1)

The sweet spot (RPM) is different for each gear, and unfortunately is always higher than our ECU will allow us to go. The higher the gear, the lower the sweet spot would be since the gears get closer together.

Lexus picked the RPM they did for rev limit based on reliability, not performance.

FiveOhNine

Well sure, and the nannies are for safety. I'm not arguing the usefulness or purpose, just curious as to where it might be.

mikes rx

iTrader: (14)

Just because the pwr mode is "slower" in a 1/4 mi WOT run doesn't mean that it's slower in other cases.

For example, when in pwr mode and non-WOT driving, the transmission holds gears longer, downshifts quicker, and usually downshifts two gears instead of one under moderate acceleration.

Gernby

iTrader: (1)

It only holds gears longer at partial throttle. At WOT normal mode will always hold gears longer.

passnu2

iTrader: (33)

Is this true in all cars "or" just on the IS???

Thanks!

Gaugster

I my experience the answer is yes. I did four 1/4 mile passes with my car earlier in the spring.

16.042 @ 86.88mph
16.027 @ 86.03mph
16.132 @ 85.44mph
16.042 @ 85.90mph

Not too bad for a stock AWD car but the 16.1x was my slowest time as I tried the "sport" mode just out of curiosity. So, I lost about one tenth in the ET.

Regards,

Gernby

iTrader: (1)

My statement is just for the IS, but it might also be true for many other cars. It certainly would NOT be true for all cars.

mikes rx

iTrader: (14)

That's what I said :stickpoke:
Non-WOT = partial throttle

Gernby

iTrader: (1)

Damn ... I guess I need to open my eyes ...

juice14

paddles are good for downshifting, on the hwy specially, so u dont use ur brakes as hard.
also to hold a gear. or for those who go to mexico/canada and street race: u can hold a gear when racing from a roll.

Initial B

iTrader: (2)

bumping an old thread


I understand Gernby's chart (great chart, BTW), but I don't understand why Lexus would program PWR mode to shift at a lower rpm than NORMAL mode. Logically, this makes no sense to me and is actually kind of irritating, lol.

Aside from holding lower gears at partial throttle, quicker shifting, better throttle response...whatever else PWR mode does to aid performance - why would it not be programmed to provide the highest shift point as well?

Gernby

iTrader: (1)

I believe ECT-PWR is driven more by marketing than performance. I think they just want to make the power curve FEEL more powerfull, not actually perform better. Basically, I believe they set the shift point so that it would shift before power started dropping off too much, even though you would really want to take it ALL THE WAY to the rev limiter for the best 1/4 mile time.

sheltop225

PWR mode will be quicker at partial throttle than normal mode. Thats all it is for...it should really be called sport mode...the three modes are essentially transmission tunes, and don't change the engine tune any....snow mode locks the torque converter early to eliminate the torque flash of the converter...and pwr allows the converter to flash a little higher...all with different shift points as well...
That's what I seem to gather from my experience...

Gernby

iTrader: (1)

That's not true. It isn't quicker at partial throttle. It's just more sensitive and agressive. The DBW target throttle mapping is very different between the 3 ECT modes, and the up / down shifting points are different based on RPM and throttle position.