Yes, since very early on Lexus temporarily made TVD a stand-alone option while carbon fiber manufacturing issues were being resolved. Some of the '15 RCFs were ordered with moonroof and all options with TVD included. I personally would like to do the same and take it to a weight station and see what comes out with half a tank of gas.

I think a lot of your issues will be resolved once you get decent tires like Sport 4S (XL) and get the suspension/alignment sorted out. It will be night and day. The tires you have seem to be some cr*ppy unknown brand that are probably not even high performance tires. Tires make a huge difference on a high performance car.

 

You need to do some track days with an instructor. There are specific techniques to manage the understeer you can learn on a track that you would be foolish (at best) to learn on the street. The IS F understeers just like the RC F and it frustrated me until I did a few track days and got a clear education on how to manage understeer in a RWD car designed by the factory to understeer heavily. The thing I can tell you with great certainty, applying throttle through the turn is a really bad idea. It might feel OK at 6/10s, but it will put you off the road quickly as your speed increases. AMHIK. I came from motorcycles, and we wick the gas on entry to help the bike turn (they call it rear wheel steering), but cars don't do this, they just go straight when you do this (again, AMHIK). So there's a whole range of control you need to learn using throttle and steering to make the car agree with what you want it to do. Otherwise, you are bickering with the car, and the car always wins the argument by either scaring you to death or by going somewhere you didn't intend.

Your tires are the least of your concerns. Bad tires teach you a lot more than good tires do. They slide at lower speeds and help you learn technique at lower speeds where the consequences of a mistake are usually far less costly. If you really want to learn something, take your car on a wet, grassy field where it will slide easily but predictably at low speeds. The way it performs here is identical to the way it performs with more speed and traction, so you can learn what the car likes to do and how to deal with it at a much more relaxed pace. This is not unlike learning to lock the front wheel on a motorcycle and recover without road testing your leathers. We practice it at 20 mph because the timing and feel are identical at 20 mph and 120 mph (again AMHIK).

I guarantee you, the issues you are suffering are primarily caused by the nut behind the wheel, not the parts on the car. The more you learn about what the car likes and doesn't like, the sooner you'll be confident behind the wheel and you'll be able to drive more quickly with a whole lot more calm.

 

I usually follow this technique (slower-in, fast-out).

1- Approaching the turn, downshift to the lowest gear in the "braking zone" while applying brakes. Downshifts also help braking late and so do good tires. Also, fun to hear the engine machine gunning those downshifts
2 - With the steering loaded, enter the corner in what I perceive to the be "ideal cornering speed" given the type of turn that is (slow speed turn, high speed turn, sharp or sweeping etc.)
3 - Once the chassis front/rear balance is settled right after the entry, start feeding in the power while turning making sure the front tires are providing feedback on how much traction is available.
4 - Once reaching mid-corner, I go full throttle exiting out the turn on to the straight.

 

Thanks Lobux! Yeah, I really need some driving instruction. I’d like to schedule more track time since I live in SoCal and resources are a plenty. Thanks for jumping over the ISF forum to answer my question!

 

This is one of the good videos of RCF with an instructor sitting on the passenger side. Driver seems to be coordinating his braking and acceleration well in this video

 

Using downshifting to slow the car is not a good idea. Brakes are far more controllable than engine resistance. Sure, it's great to be in manual mode and have a downshift slam you against the belts with a slushbox, but it's not the best way to adjust speed.

Downshifting to the "lowest" gear is very questionable. You downshift to the gear you need to drive out of the turn. Very often in slow turns this is one gear higher than the lowest gear you can use because you can use the engine's power curve and avoid overwhelming the rear end with torque on track out which does two things really nicely - first, it frees up mental focus from rapidly shifting out of a low gear, second, it avoids power oversteer distracting you from a clean exit. If you plan to drift, knock yourself out with a low gear. If you want best drive out of the turn for lap time use the best gear for exiting the turn and preparing for what immediately follows the turn (straight, turn in another direction, etc,).

BOLD - This will make the car go straight if you are anywhere near using your tires properly. It is very bad and I would not advise anyone to try this. Never accelerate before the apex. Accelerate only on track out. There is a thing called string theory in driving. It basically says, there is a string between the throttle and the steering wheel. More steering, less throttle; less steering, more throttle. The first time you recognize this working you'll be giddy with laughter because it works so incredibly well and it allows you to balance front and rear traction with throttle and steering input.

When you accelerate you shift weight to the rear. The front needs all the traction it can muster to rotate the car. Accelerating before the apex only makes understeer worse. I found a slight lift just before the apex to be ideal to set the front of the car and keep from sliding off the track on exit (something no motorcycle racer would even consider). If the back comes around a little, so what, but if the front pushes all you can do is lift until you get rotation back again because the front is too light.

Roll on the throttle after the apex on track out. If you're in the right gear, you should be balancing front and rear traction with the throttle easily.

These are all thing you'll learn in your first few track events. They're worth their weight in gold, and when you start getting it right even in the tricky parts, you'll be 100% more confident driving at much less than your limit. Last but not least, the car is more than likely far more capable than you think, even with less than spectacular tires. It's just a matter of learning what it likes and doesn't like to do.

To be as fair as I know how - I advocated the exact same approach (based on racing motorcycles) until I went to the track and was shown first how dangerous it is, and second, how slow it is. I put four wheels off in turn 7 at CMP in my third session of the day doing exactly what Rolla says to do, and I got a "time out" for it.

 

It's really difficult to see what is really going on in this video. Seeing at least what the hands are doing makes a huge difference in understanding what the driver is doing to maintain control of the car. Seeing hands and feet is ideal.

 

Thanks. I think maybe, what I wrote did not come across as I intended to. Definitely, I don't go full throttle anywhere before apex as I came from the world of FWD cars with 62 - 63% of the weight over the front axle and I am hardwired to not trust my front tires. Once the chassis settles after the corner entry into the turn, I simply "gingerly" feed in the throttle feeling the balance front to back and not to let it shift back like you said. Once I get to the apex, only then I would go full throttle as it was my last point.

I also agree I have to be very careful being in the lowest gear (by that, I mean the gear that gets me close to the ~5500 rpm powerband) with the throttle especially with the throttle sensitivity of sport+ mode as being in the lowest gear can easily make the rear super twitchy especially with TVD adding more torque on the rear, it could get dangerous very quickly. Also RCF has gearing that stretches for days, which is why I think it generally maintains decent rear traction.

 

thanks for the info back on the hunt

 

Wait, so the 2015 model year had TVD as a standalone option... it wasn't included in the Performance Package? If it wasn't, what was the year when they started putting the TVD in the Performance Package?

 

Majority got it as part of the performance package in 2015 as well. I have a late build of a 2015 myself with performance package. There were a few months after the initial production start when RCFs were available with TVD as a stand-alone option and no carbon fiber version RCF were being built so there are a few '15 RCFs out there that have no carbon fiber, but have the TVD button in the center console.

 

So I would guess a majority of RC F's have the TVD with the performance package, even for the 2015 model year. I would guess only later versions of the 2015 RC F had the performance package with the TVD. And, does anyone know what the differences between 2015 and 2016 model years was for these cars?

 

2015 and 2016 were the same except a few minor cosmetic things like the exhaust tips, design of the pedals etc.

 

So it wasn't a major change, unlike the change from 2017-2018 models. Alright thanks!

 

The 2017+ did not have any major change either. Just AVS instead of the fixed suspension. The AVS in sport+ mode feels similar to the 2015/2016 except AVS has 30 levels of adjustment. 2018 got the larger screen for infotainment.