Infra

iTrader: (1)

These clutches aren't subject to nearly the same abuse as what's in a manual transmission, or even a DCT in normal conditions (meaning not using launch control). The clutch is engaging two parts that are already rotating at nearly the same angular velocity, in contrast to a transmission which must allow for slip between the rotating engine and non-rotating driveshaft.

They will need the fluid replaced. 60k is quite a long service interval. Many DCTs have a 35k interval. This tells me Lexus expects it to last beyond the life of the car. If I was buying an RC-F, I would not even worry myself with the TVD failing and needing replacement.

4TehNguyen

iTrader: (1)

diff fluid is really easy to change out, if you felt like it its not a big deal to do it

rjmalm

Back to the question re TVD measurement of the 3 modes.

Could one of you RC-F owners do a simple test and report the numbers.

Just put up the G display in advanced mode so the G values show from
some time period, then find a place you can drive in a circle, drive the max
speed that the diameter does not increase. Then change to another
TVD setting and increase or decrease your speed trying to feel the max G
using the constant circle diamater and throttle. Report the G value for all 3 settings.
The diameter of the circle is not critical.
Car and Driver reported .95g in a 200ft diameter circle but did not spec TVD setting, but
he does have a test note about TVD.
The author K.C Colwell calls this test Road Holding.

DrRick

will the TVD affect steady-state cornering (the G values you read in magazines)? in my understanding, absolute grip is determined by suspension and tires. the TVD is going to affect the ability to enter or exit a turn. obviously, it will affect maximum G's over an open diff. but im not sure it will show an improvement over a torsen or LSD in a constand radius turn. simply because there are no variables...

im sure someone will correct me if im wrong....

rjmalm

So if the G value is the same for each TVD mode then one would need
a slalom or figure 8 test to see the difference which it not as easy to replicate on each lap as the circle test might be. I guess I was hoping that the different modes of TVD might slightly change the
tire contact patch area and improve grip allow the lateral g force to be higher.

Ryanmcd

No way it could change the contact patch unless it changed camber and it does not. In fact it maybe slowing the the figure 8 because if the way it's going to have to change the weight so fast and I also feel that's why TG hated the car because the computer was trying to fight him as that's not a normal why to drive a car and the TVD was going back and forth "helping" keep the car in grip.

The only time I have seen anything like the TVD work well is in AWD cars and that's because it can really effect the traction of the car, with a 2WD car with a lot of weight transfer I just don't see it working well unless on a track.

Also if it was so good why did Lexus not publish anything about how much better the car is with it then w/o? Seems like a no brainier way to sell a 5500$ +75LB weight disadvantage.

ISF001

I found this chart, which should be of interest with regard to the G's being pulled by the RC F.

DrRick

He asked for steady state cornering. All cars will will spike the meter at certain points in a corner...

DrRick

The TVD should positively affect the TIMED figure 8 test in that it will impact the cars attitude getting into and out of the corner...

Ryanmcd

I would think some better wheels / tires and having -100LB would be better then the TVD, again if it's so good why do we not see any test data?

Also if it's pulls say .95G the TVD car will not pull anymore because that's a grip issue. Also I am new to the Lexus brand but it sure seems they have no clue on how to market it a car AT ALL, no data and if you call them up they don't have any idea either. But again I guess this is my 1st non real sports car so maybe it's different.

DrRick

I'm not going to speak on lexus' marketing of the TVD as it's obvious that they have somewhat dropped the ball. Even their more ardent defenders seem to be a bit confused as to what it does and the situations that it proved to be more beneficial over a standard LSD.

Or...perhaps the effects are so minimal as to not warrant any kind of distinctive marketing. The sad thing is that there will likely never be a standardized test of the TVD vs non-TVD cars. Leaving consumers to champion the money spent with no objective data.

However...in theory...the TVD equipped cars should show advancement in corner entry and exit. How much and whether it's worth the extra coin may never be known...

Ryanmcd

What if it's worse but they already made 3,000 of them and have to sell them

You would think adding $5500 +80LB they could say why it's better.

DrRick

i think we can surmise WHY its better. i would just like to know HOW MUCH better it is...

rjmalm

Same here!

Ryanmcd

It has to be faster it costs more $$$ right