Limited Slip/abs

[DeltaMike]

Hope it's ok to start this topic....
There's smart folks on this forum that can tell me if the stock Elio ABS will act like a good limited slip (eg Torsen). Not that familiar with how that actually affects 'go' traction and not just 'stop' (which I think I understand from Av antiskid).

 

[Jeff Miller]

Stability control and abs are standard but I don't think we have seen any specifics as to what that means

 

[NSTG8R]

ABS (Anti-lock Braking System) doesn't have anything to do with the 'go' aspect of driving, it just prevents the wheels from locking during hard braking, or braking on a slick surface...Kind of like pumping the brakes in the 'old days'. It attempts to maintain traction between the wheels and the ground.

Limited slip refers to the differential (LSD- Limited-Slip Differential). This directly affects the 'go' aspect of driving, particularly on slick surfaces, or under hard acceleration. It ensures that an equal amount of torque goes to each wheel, which prevents one wheel (the one with less torque required to spin) from getting all the power, like an Open Differential. If you have an open differential on slick stuff, you'll at best have a hard time getting going, and most likely just sit and spin.

 

[skygazer6033]

Electronic traction control actually works similarly to ABS only on acceleration. A conventional differential sends the power to the wheel with the worse traction so it just sits and spins. ETC measures both wheel RPMs and modulates brake pressure to the one that's spinning. That evens out the torque and greatly improves traction. Probably not as good as limited slip but close. Especially effective on FWD cars.

 

[DeltaMike]

Electronic traction control actually works similarly to ABS only on acceleration. A conventional differential sends the power to the wheel with the worse traction so it just sits and spins. ETC measures both wheel RPMs and modulates brake pressure to the one that's spinning. That evens out the torque and greatly improves traction. Probably not as good as limited slip but close. Especially effective on FWD cars.

Ahhh, this is good. I was pretty certain auto ABS worked like Av antiskid but the traction control (go mode) was not so clear to me. Now this makes sense. Basically it senses the spinning wheel on ice and says "that is not realistic for a differential in a turn" and provides braking on the free spinning wheel sufficient to bring it within differential turn parameters, if I got it right. And I'm assuming we believe the Elio will come with this standard. Good compromise. I know the Torsen differential, tho very good, is expensive and not certain it could he fitted to the Aisen.
Hey another somewhat related curiosity question. Seems I picked up that the AMT was from a Versa. But then I looked up that car and it is only a 4speed. Am I missing some facts?

 

[skygazer6033]

DeltaMike, I believe you to be in error on the AMT. I think the Versa to use a CVT. The AMT used in the Elio is the Aisin MC5 used in the Toyota Yaris and several others. This transmission is the Aisin BC5 5-speed manual with computer controlled servos and actuators to handle the clutch and shifting.

 

[DeltaMike]

DeltaMike, I believe you to be in error on the AMT. I think the Versa to use a CVT. The AMT used in the Elio is the Aisin MC5 used in the Toyota Yaris and several others. This transmission is the Aisin BC5 5-speed manual with computer controlled servos and actuators to handle the clutch and shifting.

Yaris, yesis, of corsis! That's where I went wrongis (and drove autocorrect crazy!) Love this forum where you guys (gender non-specific, of course) can steer me back. Is the AMT unique to Elio tho based on the manual of the Yaris?
Speaking of which (if only loosely), does anyone know or can speculate how one does a dual-diagonal hydraulic brake system in a three wheel Elio? Asked Jerome. Didn't know.

 

[Bert]

Yaris, yesis, of corsis! That's where I went wrongis (and drove autocorrect crazy!) Love this forum where you guys (gender non-specific, of course) can steer me back. Is the AMT unique to Elio tho based on the manual of the Yaris?
Speaking of which (if only loosely), does anyone know or can speculate how one does a dual-diagonal hydraulic brake system in a three wheel Elio? Asked Jerome. Didn't know.

You don't. It will be interesting to see how the ABS works on the Elio, but I'm thinking the "anti skid" aspect of the rear wheel will be separate from each front wheel. Kind of a triple threat, if you will..

 

[DeltaMike]

You don't. It will be interesting to see how the ABS works on the Elio, but I'm thinking the "anti skid" aspect of the rear wheel will be separate from each front wheel. Kind of a triple threat, if you will..

Yeah, I should have been more clear. My understanding is that for some years, the hydraulic circuit for the left rear brake was paired with the right front brake (long before ABS, even before power brakes, me thinks). And the right rear with the left front. This was an advancement over the previous braking (hydraulic) circuitry in which all brakes were lost if the single braking circuit were lost. Or even the scheme in which the front brakes were lost (along with most braking) if the only hydraulics remaining after a failure were the rear brakes. That's all good with a four wheel braking system. So...what about the design of hydraulic circuitry of a Elio?

 

[Bert]

Yeah, I should have been more clear. My understanding is that for some years, the hydraulic circuit for the left rear brake was paired with the right front brake (long before ABS, even before power brakes, me thinks). And the right rear with the left front. This was an advancement over the previous braking (hydraulic) circuitry in which all brakes were lost if the single braking circuit were lost. Or even the scheme in which the front brakes were lost (along with most braking) if the only hydraulics remaining after a failure were the rear brakes. That's all good with a four wheel braking system. So...what about the design of hydraulic circuitry of a Elio?

Ah. Correct on most cars. The diagonal system was considered an early safety device, rightfully so. When you started seeing cars with two well master cylinders, you also saw separation of braking ability, either front to rear, or diagonally.
The portioning valve valve gained value when it also "closed" the fluid flow through a line "if" too much fluid flowed to fast! If is still used in some systems and works well, allowing braking from the remaining brakes at the wheels. Some braking systems are very intense, having this system inside the master cylinder even.
My guess, and it's only a guess, is this will also be a part of the inline brake line to each wheel, in order to give you two braking points, if one point fails. Speed sensors at each hub will be used as part of the anti lock system, as well as traction control. The system is very safe, and the price of having it has fallen greatly, as a lot of companies can, and will, supply what is needed.