Can anybody explain why most modern sport cars have 4 channel brake system but the S2000 only has a 3 channel brake system?

 

You'd probably have to ask the engineers this question, but I'm guessing that the real issue was/is incremental cost.

Besides, the brakes on the S work just fine as is, IMO. (edit - for most drivers under most conditions)

 

Failover safety. In the event of a failure, you only lose two wheels at diagonal sides of the car instead of a single wheel. In the event of a brake system failure you then have "more control". This is hearsay though, I just remember this being mentioned at some point and made a mental note.

 

There's also the issue of ABS systems not all being alike. Yeah, I'd like both rear wheels to be driven by independent channels but I can't tell the difference when at 10/10ths in an autocross. The brake system ain't a problem like it has been in other, lesser cars (old Snetra SE-R and GM podunk-mobiles come to mind)...

 

OK rubbed two brains cells together.

The S2000 has a differential (duh) on the rear wheels. What happens if one wheels locks and the other doesn't? The differential would have to sort out the mess. By pulsing the rear brakes in sync you are preventing catastrophic differential damage.

Perhaps modern sports cars with a differential needs a "3 Channel" system?

 

Most of our competitor's systems are 3-channel systems, as well. The only need for a 4 channel system is on a stability-control system where you need independent control and boosted brakes to a specific caliper. The fourth channel provides the information for traction/stability and applies brake power to a specific corner.

 

A 4 channel system will allow the ABS to engage any 1 wheel independently from the other 3. This would allow a car to achieve maximum braking at each of the 4 wheels. A 3 channel system will be slightly limitted, since loss of traction at 1 rear wheel will cause the ABS to reduce braking to the other rear wheel, since it shares the same channel. Neither system would have any effect on the differential, since both systems would prevent the wheels from locking.

 

Supra Turbo had a 4 channel system whilst the normally aspirated version had a 3 channel system. Neither had stability control and the turbo version had a limited slip differential much like our own. (except for the fact that it doesn't get busted with 300HP)

*Gernby is correct in what he has stated. Maximum braking.

 

hmmm......

so, if ABS kicks in DUE to one wheel losing traction, has it kicked in on the other wheel as well???

is there a difference between how the system works on the front wheels compared to the rears??

 

If a rear wheel begins to lock, ABS will be activated on BOTH rear wheels (on a 3 channel system). If a front wheel begins to lock, ABS will be activated on just that wheel.