Traction Control / TVD

[BillNick]

Just wanted to start a discussion really.

Last few weeks of damp roads, I have to say I am very impressed with the traction control system and/or TVD on my RCF.

Saves the rear at just the right time but without completely removing the fun factor.

I had an IS250 before and the traction used to just completely cut the power leaving you a sitting duck in the middle of the road after you just tried to get out of a turning quickly....

I wonder if the TVD option on my car is helping? Though I guess that is all about keeping traction right, then when it's actually lost the traction control takes over? - boring techy stuff I know but I am very impressed and it gives me full confidence in the wet/damp. Can't wait to get the Michelin's fitted after xmas too (car came with Bridgestone).

Anyone else want to share their experience(s)?

[B1RMA]

I really like the TVD system on our cars, there is an excellent nerds in depth guide to it which I'll try and find because the guy explains hot V turbochargers etc so well and goes into some depth about the TVD.

Some find it counter intuitive but I just let it get on with it and I'm fine with that. Everything to help traction on powerful rear wheel drive cars is a bonus. My V12 twin turbo AMG with 620+ BHP going to the rear wheels had an optional Quaife diff fitted but it would still cause the odd brown trouser moment on a damp road, but I guess it could have been worse.

I was quite happy to have it in the RCF something I wouldn't do with other car marques due to complexity and potential other maintenance costs, but it's a Lexus so it'll be fine for the long term.

[BillNick]

Agreed, I am very happy (and confident) letting it do its thing....

I do want to find out how the TVD changes it behavior across the different modes  - any idea where we can find that out on paper?

[B1RMA]

3 minutes ago, BillNick said:

Agreed, I am very happy (and confident) letting it do its thing....

I do want to find out how the TVD changes it behavior across the different modes  - any idea where we can find that out on paper?

I will find it because the guy who presents it does an excellent job

[BillNick]

Great thanks. Is it an RCF specific review or just TVD?

I wonder if the full online owners manual will explain how the TVD settings change from Standard >> Slalom >> Track?

[B1RMA]

1 minute ago, BillNick said:

Great thanks. Is it an RCF specific review or just TVD?

I wonder if the full online owners manual will explain how the TVD settings change from Standard >> Slalom >> Track?

This is the video I think it is the RCF TVD this guy does some really in depth guides that are excellent viewing

 

[hockeyedwards]

Ooft Engineering Explained is such a dopeeee channel!

[BillNick]

This is what I have found regarding the modes....which is pretty obvious I know, was hoping for an explanation of how its operation is altered.

1. Standard: This is the system’s default setting and is best suited to managing agility and stability in everyday driving conditions.
2. Slalom: The Slalom setting maximizes steering response and is best suited to tight hairpin bends and twisting back roads.
3. Track: As the name suggests, ‘Track’ mode is best suited for circuit driving, placing an emphasis on high-speed stability.

[hockeyedwards]

*whispers in fancy computer calculations relevant to each mode* 🤣

[BillNick]

Indeed we are getting a bit deep (I am a getting a bit deep)..... let's just sing praise for the TVD and all it's wizardry lol

[Rob RCF]

I still don't fully understand how the planetary gears on each side of the diff work after watching a few of these types of videos. I can get the clutch pack progressively locking one or both axles to the diff, but the planetary gears just get glossed over. One commenter mentions that it allows both wheels to maintain the correct ground speed while applying more torque to one side... this just kinda blows my mind, it's hard to visualise.

For me I think I notice the TVD less in the wet. In the dry you can feel the back end pushing you around corners sometimes and it's very satisfying. In the wet the back can kick out even with moderate power application no matter what mode I'm in, but maybe it's less likely in track mode? Not sure.

I think the thing with the TVD is that it's somewhat subtle in what it does and how it does it across the different modes, so it all ends up being quite subjective. I think Slalom might be the most "fun" in terms of giving you that rotation feeling on tight corners. Whereas track mode prioritises stability and performance.

[ColinBarber]

2 hours ago, Rob RCF said:

this just kinda blows my mind, it's hard to visualise.

here's something else to get your mind around - the ECU control:

40-6.pdf

[Rob RCF]

2 hours ago, ColinBarber said:

here's something else to get your mind around - the ECU control:

40-6.pdf 1.88 MB · 2 downloads

Thanks for posting that, very interesting read from the ECU engineers. Particularly the bit towards the end where they discuss problems controlling the motor angle and how they changed their approach to make it more robust in different temperatures etc. The end result is it always feels natural. Pretty special bit of tech back there.

[B1RMA]

2 hours ago, ColinBarber said:

here's something else to get your mind around - the ECU control:

40-6.pdf 1.88 MB · 3 downloads

Excellent find thanks, a bit of week-end reading there for me.