I've not put on a lot of mileage yet but since I was asked by an OP to compare my IS-F to the RC-F I'll run this by you.

I thought my '10 IS-F was extremely well balanced. Pretty neutral steering very good braking. It really was a joy to drive quickly. "Point and Push" was pretty much the rule.

The RC-F if giving me the impression that it is prone to oversteer. Has anyone else noticed this?

Feature-wise for safety features and creature comforts the RC-F wins hands down, but there is a 10yr gap between cars and Tech-wise that is an eternity.

 

i agree...1000%...my IS F is way more planted, maybe because it's four-door...IS F is easier to control and yes more balanced...RC F is easy to oversteer...

 

You can always run a square set up, should make steering more neutral.

 

Correct, RCF (especially TVD version) is easy to oversteer. With TVD in slalom mode, I can easily partial-throttle kick the tail out mid corner by applying a tiny bit of throttle in shorter gears and get the tail sideways. RCF track is wider in the rear with the same wheelbase as the ISF so the ratio of wheelbase/track width is a lot more tighter in the RCF. Cars with tight wheelbase/track width ratio have fast initial response, but can be twitchy once you get on the throttle. Also, the steering gear ratio in sport+ tightens up a lot on-center..

I made a thread of my experience here:

https://www.clublexus.com/forums/rc-...t-wagging.html

Although, my tires are less than 40% left and plan on going to Michelin Pilot Sport 4S next spring when the car comes out of hibernation.

Easy solution is put super sticky tires on it and it will give you a lot more mechanical grip in the rear or go with a square setup as recommended above.

 

So is it only the track version that has the Torque Vectoring?
I only see the Torsen LSD listed for mine, no mention of Torque Vectoring. I do not appear to have a Slalom option - just Sport and Sport+
And added the door courtesy light today

 

Yes, that is correct. The TVD came as part of the optional carbon performance package (carbon fiber pieces and TVD). It has three modes. Standard (splits torque equally at all times), slalom (gives short torque bursts on inputs from steering for quick maneuverability) and track mode (for long, fast and sweeping turns where it will adjust torque side to side to rotate the rear harder as long as the driver is feeding in the throttle to balance the chassis through the turn).

Check if there is this button on your center console (some early RCF had stand-alone TVD)

 

The Track Edition has the LSD.

 

There is no button and it is not the track edition

 

Do you track your car?

I owned an ISF for several years and now I have a non-TVD equipped RCF. The differences in the weight of the cars is apparent. Which car is more prone to oversteer is not readily apparent in a normal street-driven application. On a spirited drive (but still on public roads) the weight of the RCF actually makes it feel a little more prone to understeer to me, which is the opposite of what you've experienced. But I have not put my car in "expert" mode, and the traction control nannies keep the car from wanting to get loose on me. How a car behaves on the track is a different story entirely, and I never tracked my ISF nor do I plan to track my RCF.

The simplest comparison I can make is that the RCF feels like more of a highway cruiser GT car and the ISF felt like more of a hotted-up sport sedan. Generally when a car is more prone to oversteer it is more "tossable" and that is not what I'm feeling with the RCF.

 

I owned the IS-F for 8yrs. I never tracked my car but drove one at Limerock as part of the Skip Barber Driving school. I found the car nicely balanced and the steering to be pretty much neutral.
I found the IS-F to be a joy to drive on the road.
I have no plans to track the RC-F either but I have had the rear start to slide out, at least the recovery was uneventful. We'll see how it behaves as I adapt to it. So far I'm liking it.

 

Keep in mind, alignment is a big part of how the car behaves through turns. Depending on your how your camber and toe alignment is, you might get understeer or oversteer. Generally, more toe-in and closer to zero camber leads to less front end grip.

My RCF (probably because of the TVD) is very tail happy and I really love how it feels like a hooligan. It will slide its tail out by applying throttle mid-corner in lower gears through a turn. Also, tail wagging side to side some times. I have never checked my alignment so far.

What I experience is similar to the oversteer in this video at 4:55, 5:03 or 6:47.

 

My subjective experience; the RCF is prone to understeer. I believe the staggered fitment enhances this. I believe it is designed in as understeer is usually more easily corrected than oversteer. I have elevated much of the tendency toward understeer that I have experienced by running 275 square fitment. I can always fault myself when I experience oversteer. Wish I had tracked the ISF more while I owned it. The RCF is seeing 8-12 track days per year.

 

While you are right being an FR layout with staggered setup, slightly front bias weight balance (54/46 or 53/47), the inherent steady-state balance is towards understeer. With TVD unit, Lexus designed it to induce oversteer/rotate the car to get the front to hold the line tighter. I don't think Lexus was too worried about people crashing into walls as it sometimes turns either turn into a power oversteer or powerslide.

Since the revs die quickly and without tons of torque, I find it is super easy to correct the tail coming out even at higher speeds. I had the tail come around on me entering a high speed right hander on-throttle. All I had to do was counter it and let off the throttle a bit to get some engine braking and the tail quickly got in line. I find key is to not lift off entirely.

If I lift off the throttle entirely shifting the balance to the front mid corner in a tight turn then yes, I will get push/understeer. The key I find is to keep feeding in the power slightly tipping in the throttle through the turn and not to lift off entirely.

Also, my experiences might be different because of a little known fact that the LSD RCF and TVD/Carbon RCF fitted with different set of rear coil springs. Fronts are the same. I have really looked hard to find spring rates on each part number, but have not been able to find it. Since a stiffer rear end induces rotation/oversteer, the only possible explanation I think of is the spring rates are slightly higher to make the rear end more reactive in order to make it easier for the TVD to rotate the rear.

 

Yes, that's what I'm seeing as well...minus the track days. I can't speak to what a TVD equipped RCF feels like because I haven't driven one, but to hear someone say the non-TVD RCF is prone to OVERsteer is exactly the opposite of what I feel and what I'd expect given physics and the design of the car. Can I break the rear end loose? Sure. It's got enough power to overwhelm the rear if you apply throttle while turning. But that's a lot different to being prone to oversteer.

 

Yes that is my feeling. The car naturally wants to push the front end. Of course you can coax the rear end out with throttle and hard turn in.