Do non Z51 Stingrays have an electronic rear end

[try2pas]

Do NON Z51 Stingrays have an electronic rear end like the Z51 Stingrays have?

 

[Hib Halverson]

Nope.

The eLSD is only on Z51s and Z06es.

 

[try2pas]

So what happens, exactly, in the rear end electronically wise? Like does it actually change the ratio when needed to accelerate better out of a corner or something like that?

 

[LLC5]

So what happens, exactly, in the rear end electronically wise? Like does it actually change the ratio when needed to accelerate better out of a corner or something like that?

It doesn't change the gear ratio at all, that is fixed. What the e-diff can do is selectively send power to a left or right axle (based on onboard sensors) through a computer controlled clutch pack on each axle. It is a very sophisticated system but you won't get the most out of it driving on the street (you may not even know it is there on driving on the street), it is meant for track use and racing conditions.

 

[Hib Halverson]

So what happens, exactly, in the rear end electronically wise? Like does it actually change the ratio when needed to accelerate better out of a corner or something like that?

It does not change the drive axle ratio. What it does is vastly increase the functionality of the rear end's differential.

A conventional, clutch-type limited slip differential (LSD) has a set of wet plate clutches which, when high torque levels are applied to the differential, attempt to restrict the differential effect such that both wheels apply torque to the road equally, rather than all the torque going to the wheel with least traction.

The amount of slip or lack thereof between the rear wheels not only has an effect on how the car accelerates but it can have a huge effect on how the car handles and brakes going into and out of turns.

The limitation of a limited slip is that it's slip bandwidth is quite narrow, that is: it offers only a set amount of limited slip determined by the clutch pack preload and the friction of the clutch plates. It can never have "all slip", it can never have "no slip" and it has a set level of slip control, ie: the limited slip action is very limited in its effect.

The electronic limited slip differential or "eLSD", as the GM folks call it, is a hydraulically-operated, computer-controled clutch replaces the conventional LSD clutch pack. The terms are a bit of a misnomer because this clutch, when released has the drive axle acting like it has an open differential (all-slip) and when fully-applied, locks the diff. (no slip). The eLSD clutch can also provide any level of "limited slip" between open and locked.

The effect of the eLSD on handling is huge. In fact, GM uses the eLSD to replace some of the brake intervention used by previous versions of the Corvette's stability enhancement sysetm (SES) or "Active Handling"

(snip)It is a very sophisticated system but you won't get the most out of it driving on the street (you may not even know it is there on driving on the street), it is meant for track use and racing conditions.

Indeed it is a "sophisticated system" but the last part of "LLC5's" statement is an over-simplification and is demonstrably incorrect.

The eLSD was not developed purely for track and racing use. Admittedly, it's a mainly a handling performance improvement and aggressive drivers can make better use of it than those who do not drive hard, but it is incorrect to state that it's "...meant for track use and racing conditions."

The eLSD improves acceleration, handling and braking when the car is driven hard. It also improves the performance of the car's SES by eliminating some of the need to use differential braking when Active Handling is enabled to enhance the vehicle's stability. In fact, the eLSD's controller is linked directly to the SES controller.

Back in 2013, for a story in "Corvette Magazine" on the C7s drive axle, I interviewed Tadge Juechter about the eLSD. Here's a little of what he said: "Since 1998, we've had electronic stability systems which use the brakes," Tadge Juechter told us. "If the car yaws too much or too quickly, a brake is applied to decrease yaw angle. It works, but it's a little bit clumsy because it, also, slows you down. The electronic limited slip enhances stability without slowing you down–a useful trait in performance driving situations.

"An eLSD has a huge amount of authority over vehicle dynamics. When you can adjust that continuously and instantaneously, you can change vehicle dynamics as fast as you can turn the (steering) wheel. There are three calibrations: 'tour', 'sport' and 'track'. In each, the eLSD has a little different operation.

"Say you're on the track," Juechter continued. "You approach a turn and, as you turn in, (the eLSD) can be open, which lets the car rotate quickly into the corner but then, as soon as the car sets-up; the clutch tightens to stabilize the car though the corner. As you begin to exit the turn, it tightens more–almost like having a locker. As you're trying to get traction out of the corner, the diff locks and both tires get equal drive torque. It makes the car so easy to drive

"On the road, at less than highway speed, the eLSD is only lightly clamped to make the car more responsive to steering input, but, if you go faster; you don't want the car twitchy. The steering needs to be less sensitive, so, as speed increases, the diff controller will start applying the clutch. If you're on the 'freeway', you're really flying and trying to stay in your lane; the eLSD really clamps down and the steering response gets slow and that helps high-speed stability."

 

[c4c5specialist]

HI there,

There are also other factors not being mentioned here that need to be addressed.

The CHASSIS CONTROL MODULE is the gateway module to all interaction between eLSD, ABS/TCS/AH, ECM, and I forgot EPS and F55 Magnetic ride control.

This is not just clamping force of the clutch within the differential for torque biased power transfer between left and right wheels.

Yes, the eLSD does the actual work, but the complex calculations that interact between all these modules listed above ALLOW CORRECT FUNCTION under all driving conditions. This means street, road course, autocross, drag racing and any other driving events.

Even the instrument panel cluster reads the data from the Chassis control module to give you the eLSD readout about power transfer.

Allthebest, Paul

 

[LLC5]

It does not change the drive axle ratio. What it does is vastly increase the functionality of the rear end's differential.

A conventional, clutch-type limited slip differential (LSD) has a set of wet plate clutches which, when high torque levels are applied to the differential, attempt to restrict the differential effect such that both wheels apply torque to the road equally, rather than all the torque going to the wheel with least traction.

The amount of slip or lack thereof between the rear wheels not only has an effect on how the car accelerates but it can have a huge effect on how the car handles and brakes going into and out of turns.

The limitation of a limited slip is that it's slip bandwidth is quite narrow, that is: it offers only a set amount of limited slip determined by the clutch pack preload and the friction of the clutch plates. It can never have "all slip", it can never have "no slip" and it has a set level of slip control, ie: the limited slip action is very limited in its effect.

The electronic limited slip differential or "eLSD", as the GM folks call it, is a hydraulically-operated, computer-controled clutch replaces the conventional LSD clutch pack. The terms are a bit of a misnomer because this clutch, when released has the drive axle acting like it has an open differential (all-slip) and when fully-applied, locks the diff. (no slip). The eLSD clutch can also provide any level of "limited slip" between open and locked.

The effect of the eLSD on handling is huge. In fact, GM uses the eLSD to replace some of the brake intervention used by previous versions of the Corvette's stability enhancement sysetm (SES) or "Active Handling"



Indeed it is a "sophisticated system" but the last part of "LLC5's" statement is an over-simplification and is demonstrably incorrect.

The eLSD was not developed purely for track and racing use. Admittedly, it's a mainly a handling performance improvement and aggressive drivers can make better use of it than those who do not drive hard, but it is incorrect to state that it's only track or racing enhancement.

The eLSD improves acceleration, handling and braking when the car is driven hard. It also improves the performance of the car's SES by eliminating some of the need to use differential braking when Active Handling is enabled to enhance the vehicle's stability. In fact, the eLSD's controller is linked directly to the SES controller.

Back in 2013, for a story in "Corvette Magazine" on the C7s drive axle, I interviewed Tadge Juechter about the eLSD. Here's a little of what he said: "Since 1998, we've had electronic stability systems which use the brakes," Tadge Juechter told us. "If the car yaws too much or too quickly, a brake is applied to decrease yaw angle. It works, but it's a little bit clumsy because it, also, slows you down. The electronic limited slip enhances stability without slowing you down–a useful trait in performance driving situations.

"An eLSD has a huge amount of authority over vehicle dynamics. When you can adjust that continuously and instantaneously, you can change vehicle dynamics as fast as you can turn the (steering) wheel. There are three calibrations: 'tour', 'sport' and 'track'. In each, the eLSD has a little different operation.

"Say you're on the track," Juechter continued. "You approach a turn and, as you turn in, (the eLSD) can be open, which lets the car rotate quickly into the corner but then, as soon as the car sets-up; the clutch tightens to stabilize the car though the corner. As you begin to exit the turn, it tightens more–almost like having a locker. As you're trying to get traction out of the corner, the diff locks and both tires get equal drive torque. It makes the car so easy to drive

"On the road, at less than highway speed, the eLSD is only lightly clamped to make the car more responsive to steering input, but, if you go faster; you don't want the car twitchy. The steering needs to be less sensitive, so, as speed increases, the diff controller will start applying the clutch. If you're on the 'freeway', you're really flying and trying to stay in your lane; the eLSD really clamps down and the steering response gets slow and that helps high-speed stability."

The eLSD was not developed purely for track and racing use. Admittedly, it's a mainly a handling performance improvement and aggressive drivers can make better use of it than those who do not drive hard, but it is incorrect to state that it's only track or racing enhancement.
- See more at: http://www.corvetteactioncenter.com...electronic-rear-end.html#sthash.QN4Bp2YN.dpuf







Where exactly did I use the word "ONLY"? I clearly stated that an owner may not even notice it during street driving.

 

[Hib Halverson]

Where exactly did I use the word "ONLY"? I clearly stated that an owner may not even notice it during street driving.

Good point. I misquoted you.

I'll rewrite my post above to correct that..

 

[LLC5]

Good point. I misquoted you.

I'll rewrite my post above to correct that..

Thank you.

E-diff was meant for track use (but NOT only) which is why it is only available in Z06 and Z51 for now and are both track based vehicles and options that of course can be used on the street. I am sure that GM has made the e-diff very street worthy. Even your quote with Tadge Juechter verifies this as he talks about the improved handling and safety at track speeds, and at the end of the quote states that e-diff clamps slightly at freeway speeds and tightens the steering. You do not need an e-diff to accomplish the last part of his quote about street driving, but you do need one to substantiate his claims about on track superior handling. I think the e-diff is fantastic and well worth it for track days, but for street driving (as in driving with out trying going to jail) it is a bit of overkill IMHO.

 

[Fitz]

Thank you.

E-diff was meant for track use but for street driving (as in driving with out trying going to jail) it is a bit of overkill IMHO.

Nah! Ever go for a 'spirited drive' early on a Sunday morning right after sunup, before the local constabulary is awake Ma and Pa kettle go out for church? Out here in the desert there are plenty of roads to no where.......

 

[LLC5]

Nah! Ever go for a 'spirited drive' early on a Sunday morning right after sunup, before the local constabulary is awake Ma and Pa kettle go out for church? Out here in the desert there are plenty of roads to no where.......

Yeah, that was kind of my point, what your describing is street racing and not street driving.

Hope you stay safe and lock up free........