Those without TVD
03-13-20, 12:16 PM
#1
Racer
Thread Starter
Those without TVD
So, I've had the car for a few weeks now and (15' non-TVD), and wanted some feedback on non-TVD owners on how they use the car. I don't mean to track this car but will occasionally make the nice morning canyon drive. Even then, my driving mannerisms are hardly what I consider spirited. How do you guys drive it? Meaning are you on throttle when you take a corner? Do you feather it? Do you brake then just accelerate out? Is there a way to minimize the nose-diving, plowing, undresteer-y effect of the car?
Just want some feedback at how non-TVD guys do it.
Just want some feedback at how non-TVD guys do it.
03-13-20, 12:20 PM
#2
Lexus Test Driver
What tire pressure are you running and the make/model of tires you have? Can you elaborate on those? Adjusting those can change things dramatically. I also find something odd about you getting plough even when you stated you are not driving in a very spirited fashion. Even with LSD, I believe you should not feel any plough until you get to 8/10ths or 9/10ths. I think you have the lowering springs on your car. Is that correct? Could also be an alignment issue or maybe, the springs are not working well with the dampers (like the RS-R, for example).
Last edited by 05RollaXRS; 03-13-20 at 12:35 PM.
03-13-20, 12:39 PM
#3
Racer
Thread Starter
It looks like they are 37 all around (warmed up). Also the tires are Lionhart LH-Five. They were on the car when I bought it. I don't think these are up to snuff with the MP4S I used on my ISF. Definitely one of the things to swap out. I looked these up and there is not enough info on these.
03-13-20, 12:47 PM
#4
Lexus Test Driver
It looks like they are 37 all around (warmed up). Also the tires are Lionhart LH-Five. They were on the car when I bought it. I don't think these are up to snuff with the MP4S I used on my ISF. Definitely one of the things to swap out. I looked these up and there is not enough info on these.
Definitely, your tire are a big issue here as they cannot resist dive under sudden braking overloading the front tires and suspension. Here is a list of things to check
- Your tires something like Michelin Pilot Sport 4S with XL reinforced sidewalls will help a ton. You can try going square setup as some owners do with 275s all around, but personally I would stick with staggered with super grippy and stiff sidewalls.
- Next review your aftermarket springs as they probably don't work well with dampers (especially, if they are RS-R). You can try getting the car alignment for a bit aggressive setup adding some camber (but, cannot adjust it much). Probably a high performance alignment was not done after the springs were installed.
- Tire pressure is another thing to check (go up to 38 psi front and 39 psi rear), but given the brand of tires I doubt that will help.
Last edited by 05RollaXRS; 03-13-20 at 12:51 PM.
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LRCSALES (03-13-20)
03-13-20, 12:58 PM
#5
Racer
Thread Starter
Yeah, I'll stick to the staggered. Been looking at MPSS, MP4S, and even the Continental Extremecontact sport (the MPSS clone...lol).
Working on trading up the existing springs for some OEM too.
https://www.tirerack.com/tires/tires...eContact+Sport
Working on trading up the existing springs for some OEM too.
https://www.tirerack.com/tires/tires...eContact+Sport
03-13-20, 02:14 PM
#6
Lexus Test Driver
Of the three you mentioned, the Pilot Sport 4S is head and shoulders above the other. MPSS are fine. Not bad tires, but the RCF version of MPSS were the softer version. They do a fine job, but the MPS4S in XL version would be the best option. I would recommend staying away from Continental. I had bad experience with Continental (Had ExtremeContact DWs on my C-XRS). Uneven wear, crazy levels of noise, harsh, only got 10K miles etc. Nothing beats Michelin quality and the MPS4S are the best high performance one's out there now this side of the Cup 2 tires.
Tires will also help brake better as some say, tires are even more important than brakes as far as stopping power goes. You can late brake with more confidence if you have great high performance tires on.
Regarding OEM springs, you will find the part numbers are different on rears for CF RCF vs standard RCF. You can go with either as ride height is the same. I believe only the spring rates might be different. When you get an alignment, you can get slightly dialed camber to enhance front end grip in turns. I think the RCF OEM suspension is very nicely dialed in for street use and high performance driving for us average drivers which is why I personally don't plan on changing anything.
Tires will also help brake better as some say, tires are even more important than brakes as far as stopping power goes. You can late brake with more confidence if you have great high performance tires on.
Regarding OEM springs, you will find the part numbers are different on rears for CF RCF vs standard RCF. You can go with either as ride height is the same. I believe only the spring rates might be different. When you get an alignment, you can get slightly dialed camber to enhance front end grip in turns. I think the RCF OEM suspension is very nicely dialed in for street use and high performance driving for us average drivers which is why I personally don't plan on changing anything.
Last edited by 05RollaXRS; 03-13-20 at 02:32 PM.
03-13-20, 04:08 PM
#7
Racer
Thread Starter
Of the three you mentioned, the Pilot Sport 4S is head and shoulders above the other. MPSS are fine. Not bad tires, but the RCF version of MPSS were the softer version. They do a fine job, but the MPS4S in XL version would be the best option. I would recommend staying away from Continental. I had bad experience with Continental (Had ExtremeContact DWs on my C-XRS). Uneven wear, crazy levels of noise, harsh, only got 10K miles etc. Nothing beats Michelin quality and the MPS4S are the best high performance one's out there now this side of the Cup 2 tires.
Tires will also help brake better as some say, tires are even more important than brakes as far as stopping power goes. You can late brake with more confidence if you have great high performance tires on.
Regarding OEM springs, you will find the part numbers are different on rears for CF RCF vs standard RCF. You can go with either as ride height is the same. I believe only the spring rates might be different. When you get an alignment, you can get slightly dialed camber to enhance front end grip in turns. I think the RCF OEM suspension is very nicely dialed in for street use and high performance driving for us average drivers which is why I personally don't plan on changing anything.
Tires will also help brake better as some say, tires are even more important than brakes as far as stopping power goes. You can late brake with more confidence if you have great high performance tires on.
Regarding OEM springs, you will find the part numbers are different on rears for CF RCF vs standard RCF. You can go with either as ride height is the same. I believe only the spring rates might be different. When you get an alignment, you can get slightly dialed camber to enhance front end grip in turns. I think the RCF OEM suspension is very nicely dialed in for street use and high performance driving for us average drivers which is why I personally don't plan on changing anything.
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03-13-20, 05:31 PM
#8
Lexus Test Driver
Yes, the MP4S is my first choice. I've had gripper tires like the Nitto NT05s but the 4S has been the best all around tire I've had. I'm looking to trade up my springs in the next 2 weeks...once I get that done and the tires I can make a better assessment of the car's capabilities. But even with those shortcomings I'm liking the car more and more everyday. It's too bad I couldn't keep both my ISF and RCF. Similar DNA but totally different personalities.
Last edited by 05RollaXRS; 03-13-20 at 05:38 PM.
03-13-20, 11:36 PM
#10
Lexus Test Driver
Torque Vectoring Differential
It would be no surprise that a car of the RC F’s track capability would offer torque vectoring to sharpen handling response. The news here is that the RC F uses the electronically controlled Lexus Torque Vectoring Differential (TVD). The TVD uses precisely controlled multi-plate clutches, rather than the vehicle’s brakes, to optimally distribute torque to each rear wheel whether or not the accelerator is pressed.
The design aim with a TVD-equipped RC F was to make full use of the vehicle’s yaw moment for turning posture so good that it would feel as if the steering angle and direction of the vehicle travel were solidly joined.
Electronic control and precision electric actuator motors that are adjusted in units of 1/1,000-second ensure the appropriate amount of torque is distributed to each rear wheel. TVD can generate torque transfer regardless of how large or small the engine torque is, creating a yaw moment around the center of gravity and realizing movement similar to the LFA with its 48:52 front/rear weight distribution.
The driver won’t notice the TVD’s seamless operation but rather will simply enjoy the feeling of using the accelerator pedal to help steer the car through corners.
Lexus meticulously tested the TVD at the Nürburgring and circuits in Japan to fine-tune its operation and cooperation with the new coupe’s Vehicle Dynamics Integration Management (VDIM) system.
The TVD distributes torque to match the conditions of the moment, ensuring dynamic response when negotiating S-bends, for example. It improves vehicle attitude in low-to-mid speed corners, providing more agile movement and a smaller steering angle.
In a series of S-bends, TVD provides exhilarating corner exit performance with no understeer. Crisp turn-in after hard braking is equal to highly skilled driving without a TVD. Even during deceleration, the TVD constantly controls the drive force to preserve agile and smooth turn-in.
The TVD has three operating modes, independent of the RC F Drive Mode Select function:
The RC F’s unique cockpit meter display shows the rear-wheel torque distribution as a bar graph within the tachometer and, if selected from the display menu, as two orange columns in the multi-information display.
It would be no surprise that a car of the RC F’s track capability would offer torque vectoring to sharpen handling response. The news here is that the RC F uses the electronically controlled Lexus Torque Vectoring Differential (TVD). The TVD uses precisely controlled multi-plate clutches, rather than the vehicle’s brakes, to optimally distribute torque to each rear wheel whether or not the accelerator is pressed.
The design aim with a TVD-equipped RC F was to make full use of the vehicle’s yaw moment for turning posture so good that it would feel as if the steering angle and direction of the vehicle travel were solidly joined.
Electronic control and precision electric actuator motors that are adjusted in units of 1/1,000-second ensure the appropriate amount of torque is distributed to each rear wheel. TVD can generate torque transfer regardless of how large or small the engine torque is, creating a yaw moment around the center of gravity and realizing movement similar to the LFA with its 48:52 front/rear weight distribution.
The driver won’t notice the TVD’s seamless operation but rather will simply enjoy the feeling of using the accelerator pedal to help steer the car through corners.
Lexus meticulously tested the TVD at the Nürburgring and circuits in Japan to fine-tune its operation and cooperation with the new coupe’s Vehicle Dynamics Integration Management (VDIM) system.
The TVD distributes torque to match the conditions of the moment, ensuring dynamic response when negotiating S-bends, for example. It improves vehicle attitude in low-to-mid speed corners, providing more agile movement and a smaller steering angle.
In a series of S-bends, TVD provides exhilarating corner exit performance with no understeer. Crisp turn-in after hard braking is equal to highly skilled driving without a TVD. Even during deceleration, the TVD constantly controls the drive force to preserve agile and smooth turn-in.
The TVD has three operating modes, independent of the RC F Drive Mode Select function:
- STANDARD (default setting) provides an ideal balance of agility and firmness.
- SLALOM emphasizes nimble steering response and the agility of a smaller vehicle.
- TRACK emphasizes stability during high-speed circuit driving.
The RC F’s unique cockpit meter display shows the rear-wheel torque distribution as a bar graph within the tachometer and, if selected from the display menu, as two orange columns in the multi-information display.
Last edited by 05RollaXRS; 03-14-20 at 12:27 AM.
03-14-20, 12:48 AM
#11
Racer
Thread Starter
I’ve actually test driven a TVD car. Quite nimble...the salesman really had me geek out in the modes like slalom. I’m curious as to the RCF weight differences are in relation to TVD since I see the car’s curb weight listed from 3,950-ish to 4,060-ish...what’s the 110lbs differences? It can’t be just the TVD...
03-14-20, 08:02 AM
#12
So, I've had the car for a few weeks now and (15' non-TVD), and wanted some feedback on non-TVD owners on how they use the car. I don't mean to track this car but will occasionally make the nice morning canyon drive. Even then, my driving mannerisms are hardly what I consider spirited. How do you guys drive it? Meaning are you on throttle when you take a corner? Do you feather it? Do you brake then just accelerate out? Is there a way to minimize the nose-diving, plowing, undresteer-y effect of the car?
Just want some feedback at how non-TVD guys do it.
Just want some feedback at how non-TVD guys do it.
03-14-20, 08:27 AM
#13
Lexus Test Driver
Are you braking prior to turns, then accelerating through the turns? My non-TVD will nose dive with hard braking in sharp turns, so braking before turning works much better for me. Even the Lexus TVD descriptions states if helps as you accelerate through the turns, so maybe try braking more prior to hard cornering could help?
Only issue issue I find happens if you suddenly lift off the throttle because there is a mid-corner dip going downhill and you suddenly lift off to slow down through the turn. Suddenly, the weight shifts forward in the car, but I increased the cold tire pressure to 39 psi rear and 37 psi front (warm, they go up about a couple of psi) and with more stiffness on the front tire, it greatly improved the attitude if you have sudden throttle lift-off where there is a dip especially in a downhill turn.
I’ve actually test driven a TVD car. Quite nimble...the salesman really had me geek out in the modes like slalom. I’m curious as to the RCF weight differences are in relation to TVD since I see the car’s curb weight listed from 3,950-ish to 4,060-ish...what’s the 110lbs differences? It can’t be just the TVD...
If one has moonroof on LSD RCF then the RCF CF might even be lighter since the CF roof is about 23 lbs lighter than the steel roof. The moonroof is probably about 50 lbs heavier than the steel roof. Lowered CoG and added rigidity is the benefit of CF roof. Some of the earlier RCFs had TVD as a stand-alone option so they could be had with any option even with a moonroof. Those definitely were on the high side of the weight range.
Last edited by 05RollaXRS; 03-14-20 at 09:02 AM.
03-14-20, 09:27 AM
#14
Racer
Thread Starter
Are you braking prior to turns, then accelerating through the turns? My non-TVD will nose dive with hard braking in sharp turns, so braking before turning works much better for me. Even the Lexus TVD descriptions states if helps as you accelerate through the turns, so maybe try braking more prior to hard cornering could help?
03-14-20, 09:31 AM
#15
Racer
Thread Starter
Yeah, braking before entering the turn and then getting on the gas and feeding power through and out the turn is a good approach. TVD works well in braking under turning as I described above, it will stop faster and rotate the car by applying opposite torque on the rear wheels (more on the inner side and less on the outer). You can carry around 67 - 68 mph speed through long sweeping turns no problems. Once you try getting to 70+ mph, the front tires will start to chatter as if it is fighting for grip.
Only issue issue I find happens if you suddenly lift off the throttle because there is a mid-corner dip going downhill and you suddenly lift off to slow down through the turn. Suddenly, the weight shifts forward in the car, but I increased the cold tire pressure to 39 psi rear and 37 psi front (warm, they go up about a couple of psi) and with more stiffness on the front tire, it greatly improved the attitude if you have sudden throttle lift-off where there is a dip especially in a downhill turn.
I did the calculation once and net difference of a carbon fiber/TVD RCF with a steel roof RCF with similar option packages (and steel roof) would be around 20 lbs. The TVD unit itself is 57 lbs in total, but CF shaves off around 32 in total. LSD is around 15 lbs or so. The difference is negligible as MT got 12.5 seconds@114 mph with a performance package RCF.
If one has moonroof on LSD RCF then the RCF CF might even be lighter since the CF roof is about 23 lbs lighter than the steel roof. The moonroof is probably about 50 lbs heavier than the steel roof. Lowered CoG and added rigidity is the benefit of CF roof. Some of the earlier RCFs had TVD as a stand-alone option so they could be had with any option even with a moonroof. Those definitely were on the high side of the weight range.
Only issue issue I find happens if you suddenly lift off the throttle because there is a mid-corner dip going downhill and you suddenly lift off to slow down through the turn. Suddenly, the weight shifts forward in the car, but I increased the cold tire pressure to 39 psi rear and 37 psi front (warm, they go up about a couple of psi) and with more stiffness on the front tire, it greatly improved the attitude if you have sudden throttle lift-off where there is a dip especially in a downhill turn.
I did the calculation once and net difference of a carbon fiber/TVD RCF with a steel roof RCF with similar option packages (and steel roof) would be around 20 lbs. The TVD unit itself is 57 lbs in total, but CF shaves off around 32 in total. LSD is around 15 lbs or so. The difference is negligible as MT got 12.5 seconds@114 mph with a performance package RCF.
If one has moonroof on LSD RCF then the RCF CF might even be lighter since the CF roof is about 23 lbs lighter than the steel roof. The moonroof is probably about 50 lbs heavier than the steel roof. Lowered CoG and added rigidity is the benefit of CF roof. Some of the earlier RCFs had TVD as a stand-alone option so they could be had with any option even with a moonroof. Those definitely were on the high side of the weight range.