The Racelogic traction control system works by cutting injector pulses depending on the amount of slip it detects using the ABS sensors. It does not use the brakes per se and works very well regardless of the type of differential you use.

I would say that it works even better in a clutch-type differential like the one we're running.

 

From a technical description of the Honda VSA. Integral to this type of VSA is the yaw sensor. We're not talking about the cheesy BMW "electronic LSD" which is what you were describing.

Vehicle stability assists (VSA)

Upper leading and lower trailing links form Watt's linkage that causes the rear wheel to travel at an optimal rearward angle.
The fundamental principle of various production vehicle stability systems, such as Bosch's VDC (Vehicle Dynamics Control), Cadillac/Delphi's StabiliTrak, Toyota's VSC (Vehicle Stability Control), and now Honda's VSA (Vehicle Stability Assist), can be explained by Shibahata's method. All these systems add side-slip control to ABS/traction control systems. They handle sudden changes in vehicle behavior, enabling the driver to control the situation. Honda's system is based on the concept of stabilization through control of the front wheels (in a front-wheel-drive car) without reducing the pleasure of driving.

Rear wheel's travel allows increased cabin/luggage space.
The VSA uses the ABS/TCS architecture to which a unique electronic control unit and an algorithm are added. Input sources include wheel-speed sensors, yaw-rate sensor, lateral acceleration sensor, steering angle sensor, engine speed sensor, and brake switch. The ECU has main- and sub-CPUs. The system applies an appropriate individual brake, and modulates the engine's torque output as required by the situation.

In an oversteer situation, the system calculates the driver's intended "target" from lateral acceleration, steering angle, and vehicle speed. If the vehicle's actual yaw rate exceeds the target, the VSA brakes the outside front wheel to reduce yaw, thereby regaining stability.

In an understeer situation the system intervenes by reducing engine torque output, and if necessary, by braking the inside front wheel. This creates an inward moment, putting the car on the driver's intended line.

 

That's because the Racelogic is a bolt on, aftermarket system.

OEM TCs use the brakes, just like stability control.

 

Brakes, springs, tires, shocks, sway bars, DBW throttle, LSD, weight distribution, alignment, yaw sensors, aero lift/downforce, etc. - they ALL have a role in traction. But that's not really germane to the discussion of 00-05 S2000s vs 06-09 S2000s with VSA turned on vs 06-09 S2000s with VSA turned off, and their respective handling differences. ALL S2000s have the same LSD setup so why bother discussing it at all in this thread?


I have nothing constructive to add, since I've never driven an S2000 while the VSA was turned on. I'd love to take one around an autocross course a couple times though. I can't really find any reports from owners who experimented with VSA in track/autocross situations either.

 

The way I look at VSA is this - Think of the handling limits of a car on a scale from 1 to 10, with 10 being the max "handling" the car can take. Honda's VSA does not raise the limit of what is capable. It does not make the car capable of reaching 11. Rather, it keeps you from going past 7. So if you do something, accidentally or intentionally, that makes the car reach or exceed 7/10's of it's limit, it will interfere. This is fine on the street, but if you are driving at 8/10ths or more at an autocross or track, then you actually see it decreasing handling potential.

 

I'd like to see someone run VSA in the rain on an autocross course.

 

What you say would be true IF you could individually control left/right/front/rear thrust and braking. But you can't.

Some VST systems can and do. Therefore a good system in bad conditions could out-drive you (without VST) simply because you don't have 4 brake pedals and 4 gas pedals, regardless of how good a driver you are. You can't control a corner that's on the edge when the others aren't.

Steve

 

It is not "handling control". It is "traction control", and "vehicle stability assist". It is not a performance measure designed to change handling. It is an extremely effective safety measure for everyday driving. Nothing more, nothing less.

I see your point that it does effect handling. But for what purpose? VSA will help you big time if you loose the rear end. Power-steering sure looks cool, but it's not faster. However, launching with tire-slip is faster.

So; VSA might add, or take away, depending on what you want to do. That's why we can turn it off with a switch.

 

I think we agree. My analogy was more directed towards the OP's original question.

IMO, when the car doesn't do what I tell it to do, that's when I feel like I'm not in control. For some, it's the opposite.

 

it sucks. seriously.