Brake Assist
 

Just got a copy of the new brochure (the one oilman posted up recently).

Under active safety its says the cars has ABS, EBD, EBA, DSC and TCS.

EBA is Emergency Brake Assist. In the press pack which most have seen it clearly states the following:

"Brake assist is not used on the RX-8, in order to preserve the direct, linear brake feel demanded of a genuine sports car"

So howcome is it now included in Euro spec cars, do they think we cant brake for ourselves?

Re: Brake Assist
 

At least in Germany, the Mazda brochures are not really famous for accuracy. I would guess that the RX-8 will not come with EBA in Europe (if it does it would NOT be another reason for getting an RX-8).
The latest RX-8 brochure over here says it has a double wishbone rear suspension (not true). According to Mazda Germany, the MX-5 has a McPherson suspension setup (not true).

Pardon me - but what is the difference between EBA and ABS ?
Didn't brakes work fine before all this ? I'm sure I used to have cars that stopped OK with far less acronyms !

So - What is the difference ? EBD I understand - DSC and TCS I can cope with but EBA I am struggling with ....

Morgan.

EBA means that if the car's brain decides that your abrupt switch from the gas pedal to the brake pedal along with the initial fast application of the brake pedal indicates that you are in an emergency braking situation, it takes over and increases brake pressure to the max. It is sad but true that a device like that makes sense for most drivers on the road who are not capable of real hard braking, but in a sports car, EBA tends to turn all hard braking into emergency braking which does not make any sense for most situations. At least that is e.g. the current criticism of "sport auto" with regard to the Mercedes Benz brake assist system.

Werner is correct. My understanding of EBA is that if it decides you are braking hard it must be an emergency, and it will 'assist' you and apply even more pressure to the brakes.

I presume it will then use EBD to distribute the braking appropriately, which will force the ABS to cut in!

It is a 'safety' feature for the majority of drivers, but another case of the electronics in the car deciding what is best.

It seems strange that Mazda acknowledges the fact that this can ruin the driving experience for keen drivers, then goes and adds it to the car anyway.

At least the DSC/TCS can be switched off if required.

Maybe the brochure is wrong.

EBA is not the same as power (or servo) assisted braking.

Servo assisted braking (which is what the press pack is presumably talking about) 'multiplies up' the force applied by your foot to the brake pedal during normal braking. Pretty much every modern car has this. The only ones that don't (as far as I know) are hardcore track-orientated machines such as Caterhams. The reasons for its omission are that (a) you tend to get more 'feel' with unassisted brakes, because the range of pressures that you apply to the pedal is much greater and (b) cars like this are not often used for shopping trips etc. and owners don't generally complain about needing to apply plenty of welly to the controls (same as power steering etc).

Emergency Brake Assist only applies when the car's systems detect that you are trying to stop as quickly as you possibly can. It then applies maximum braking (regardless of exact pedal pressure) until you release the force on the pedal.

ABS just stops the wheels locking under braking (as I'm sure everyone knows).

I'd be very surprised if what the press pack appears to say is true (i.e. that there will be no servo assist). The brakes on my Caterham need a fair bit of force, even for a car weighing only 500kg. Unless there have been some radical developments in pad technology etc. I cannot imagine unassisted braking being viable for a 1300kg car intended for day-to-day use.

Simon,

I think the press pack was referring to EBA not being used and not servo assisted brakes.

Like you I dont expect for one minute that the brakes are unassisted.

If the brakes are as good as they claim, why do we need EBA anyway? If you are driving hard you want to feel the brakes for yourself without the interference of EBA.

I read somewhere that the SWITCH DSC OFF disconnects ALL the electronic helps (ABS, ESP, ...)

From my understanding, switching off the DSC only turns off the DSC and nothing else.

I was under the impression that the car does not come with EBA, and I hope it does not. Don't need a computer telling me how hard to brake! :)

Also, if it is included, I hope it is not like the system used by other manufacturers, which works as follows:

Not only will it brake for you, but if you partially lift off the brake the car will continue full braking until the car has stopped! The only way to turn it off is to lift off the pedal altogether.

Praying this is not the case for the RX-8! :)

Yes, but the DSC messes with the brakes as well!

From what I've read DSC has got three modes, "on", "emergency" and "completely off". In emergency mode it will still kick in when the ABS is activated, but you can switch it off completely by holding down the DSC button for ten seconds or so.

The new German brochure also mentions "Brems-Assistent" under safety features. I sure hope that is not true :(
Along with the tall gearing, this would be reason #2 not to get an RX-8. Still way more reasons to get one, though ;)