rijc99

I'm not bench racing anything. I just drove it back to back and the acceleration was the same in Sport S and S+.

Throttle response, shifts and all.

I even had my wife test it and a buddy. They all agreed. S. And S+ felt the same.

And you know what. Same thing with my X5. In sport or standard. If I floor it and activate the kick down... The transmission downshifts and to the same gear.

BTW. Did you activate kick down switch?

jjscsix

Nah, I only activated the power booster in the sport plus mode. I decided not to in the Sport mode just to screw with you guys......bwah ha ha ha .

I was pretty clear in my posts what I did and what I have experienced in the year we have had the car. I'll respond here for giggles and grins because I actually think the two of you are probably really good guys. But I'm done debating the issue.

rijc99

Videos...

WOT from 50 MPH

ECO

Sport S+ and ECO

Sport S

This is getting to 50 MPH, ALLOWING the RPM to settle, then hitting the kick down switch. Assuming the RPM has settled, (takes a little more time in Sport S and S+), upon WOT with activation of the kick down switch, the car drops down gears and goes to 3500-3600 RPM then accelerates the same from there in all modes.

bclexus

Thank you. These tests video results are excellent to confirm what you (and I) have been stating.

For those people that may be interested: In your tests (all) at 50 mph in each of the Drive Modes, the 8-Speed transmission automatically selected or engaged 3rd Gear each time at 3,500 RPM per the following stats:

2014 Lexus GS 350 F-Sport 8-Speed Transmission
Final Drive Gear Ratio: 2.937
3rd Gear Ratio: 1.863
Tire Circumference: 82.6" (265/35 x 19")
Engine RPM: 3,500
Speed: 50.03 MPH

The Engine and Transmission computer logic in the above test cases (all at 50 mph) chose 3rd gear to automatically engage at 3,500 RPM. Please note that the transmission did not automatically choose 2nd gear even though it would not have over-revved the engine - and the reason it did not automatically choose the lower 2nd gear is because engaging 2nd gear at 50 mph would have the engine speed at 5,120 RPM, which while 5,120 RPM is well under the engine's redline of 6,500 RPM it is too close to where the engine would be making peak torque performance for acceleration purposes. (Engine Torque for Acceleration & Engine Horsepower to Maintain Speed.) Additionally, in the computer's logic to choose the higher 3rd gear, there is consideration for the time (300+ milliseconds) that is lost for the next upshift that must take place so soon after the downshift just took place.

At what [lower] engine RPM point would the computer logic have chosen to automatically engage the lower 2nd gear instead of the higher 3rd gear? I do not know, but I suspect the computer logic would have chosen to engage the lower 2nd gear 'only' when the engine RPM speed at engagement of 2nd gear was well down in the 4,000 RPM range or even lower in order to use the engine's torque for acceleration. If the tests were conducted at such a speed in which it was borderline right on the threshold of [either] engaging 3rd gear or engaging 2nd gear, I suspect just 1 mph higher or lower would be all that is needed to have the computer's logic to engage one gear one time, and another gear the next time, which could be confusing for the person making the test ...which was my point that I was trying to convey in a previous post.

~~~~~~

One additional point - the computer logic would certainly be different when automatically up-shifting through the gears (e.g. drag race) going from a lower gear to a higher gear vs. already being in a higher gear and then automatically downshifting. For the former (automatically up-shifting through the gears going from a lower gear to a higher gear) the following is what can be expected when the GS 350 has a 8-Speed transmission. (Note the RPMs for Up-Shifts to engage the next higher gear.):

Below are ground speeds at 6,500 RPM engine redline for all 8 gears (2014 - 2015) RWD - AA81E 8-Speed Automatic:
(Speed limiter is electronically governed at 142 MPH preventing max speed of ~170 MPH • **Engine will not reach redline in 6th, 7th or 8th gear)

1st Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
1st Gear Ratio: 4.596
Engine RPM: 6500 Redline = 37.66565457305995 MPH (Up-Shift Engages 2nd Gear @ 3855 RPM)

2nd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
2nd Gear Ratio: 2.724
Engine RPM: 6500 Redline = 63.55042159243155 MPH (Up-Shift Engages 3rd Gear @ 4440 RPM)

3rd Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
3rd Gear Ratio: 1.863
Engine RPM: 6500 Redline = 92.92074525914309 MPH (Up-Shift Engages 4th Gear @ 5110 RPM)

4th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
4th Gear Ratio: 1.464
Engine RPM: 6500 Redline = 118.24545656952431 MPH (Up-Shift Engages 5th Gear @ 5465 RPM)

5th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
5th Gear Ratio: 1.231
Engine RPM: 6500 Redline = 140.62660310136764 MPH (Up-Shift Engages 6th Gear @ 5280 RPM)

**6th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
6th Gear Ratio: 1.00
Engine RPM: 6500 Redline = **173.11134841778357 MPH

**7th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
7th Gear Ratio: 0.824
Engine RPM: 6500 Redline = **210.0865878856597 MPH

**8th Gear:
Tire Size: 265/35 x 19" = 82.6" Circumference
Final Drive Gear: 2.937
8th Gear Ratio: 0.685
Engine RPM: 6500 Redline = **252.717296960268 MPH


8th Gear - 50% of Redline:
Engine RPM: 3250 = 126.35 MPH

Maximum Torque: 277 ft-lb @ 4,800 RPM
Maximum Horsepower: 306 SAE net @ 6,400 RPM

rijc99

Ok, upon looking closer, 3500 is about right. Revised. Thanks.

bclexus

It all happens so quickly, and there is a degree of analog needle bounce that cannot be prevented even with good instrument dampening - it is difficult to get an exact reading. The math and calculations confirms it...

rijc99

Normally, I would leave this alone... but since I was called a bench racer, forum nerd and liar... I'd like to see your videos at 50MPH...

I will concede you did say I probably am a really good guy. But, nonetheless, I was called out and I provided mine... Your turn to show me yours. At 50MPH similar to my tests please as bclexus already calculated 47ish is kind of the "on the fence" MPH for the trans shift logic. WOT at 50 pedal down as if you were trying to break it to ensure activation of kick down.

DaveGS4

iTrader: (2)

Guys, let's keep the conversation on the cars and not on the owners. No need for callouts, you all can discuss this topic without making it personal.