04-12-2018, 01:20 PM | #1 |
Drives: 2017 SS 1LE SIM Join Date: May 2017
Location: AZ
Posts: 59
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eLSD questions
My eLSD reader constantly shows 2% slip (or higher) while just coasting.
at dead stop it shows 0, which is correct. What does everyone elses read when just cruising? Under acceleration? Obviously I understand under acceleration it will be different. Thanks in advance |
04-12-2018, 03:37 PM | #2 |
LT4 M6
Drives: 2018 ZL1 1LE Join Date: Nov 2010
Location: Bloomington, IN
Posts: 1,249
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Mine is at 0 when driving straight.
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04-12-2018, 05:15 PM | #3 |
Drives: 2017 Hyper Blue SS 1LE Join Date: May 2017
Location: Wilmington, NC
Posts: 90
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2%
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04-12-2018, 08:45 PM | #4 |
LT4 M6
Drives: 2018 ZL1 1LE Join Date: Nov 2010
Location: Bloomington, IN
Posts: 1,249
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I paid closer attention driving this afternoon. It goes between 0 , 1, and 2 percent. But its usually 0.
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04-13-2018, 02:15 AM | #5 |
1LE Convert
Drives: 2018 ZLE Join Date: Apr 2017
Location: Mountain View, CA
Posts: 369
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I also see 2% a lot.
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04-13-2018, 06:03 AM | #6 |
Drives: '18 1SS 1LE Join Date: Sep 2017
Location: Pennsyltucky
Posts: 2,580
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I always thought that was an odd display.
Is the 2% the speed difference between the shorter front tires vs the taller rear tires? I vaguely remember seeing 0-2% while driving, but it's not something I'm going to monitor much while driving around the streets. I'll look tonight when I take the car out. |
04-13-2018, 07:08 AM | #7 |
Drives: 2017 1SS 1LE Join Date: Jun 2016
Location: Detroit, MI
Posts: 1,000
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I saw 1% on mine this morning. I'd guess that this display measures LH vs RH rear wheel speeds to calculate the slip, and if that's the case I'd think 0-2% is normal for straight line driving. There's going to be a slight difference in rolling radius of the tire based on corner weight, tire pressure, and even a little bit of the tire's construction itself. I'd also not be surprised if there's a tiny bit of an error between the wheel speed sensors. Could be other sets of sensors on the car, but wheel speeds make most sense to me.
I'll do some poking around to see if I can find a more solid answer, because now I'm curious how it's actually calculated as well lol.
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Last edited by Alpha1BC; 04-13-2018 at 07:22 AM. |
04-13-2018, 08:15 AM | #8 | |
Drives: 2017 1SS 1LE Join Date: Jun 2016
Location: Detroit, MI
Posts: 1,000
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Quote:
In short, the eLSD % number is the percent of lockup the eLSD is at. 100% corresponds to max lockup which I think is a differential breakaway torque of 2000 Nm (high performance supplement says 200 Nm, but my guess is that it's a typo based on the corvette forum response. 200 Nm seems like a really low breakaway torque). The wheel slip number is showing the average rear wheel slip vs. the average front wheel slip, so a small percentage when driving should be expected. For the more in-depth wheel slip description, this value isn't to be confused with different rotational speeds from different rolling radius in the front vs. the rear. In order for a tire to produce traction forces, there has to be some amount of slip. In the case of driving straight, this means that the rear driven wheels are actually spinning slightly faster than you'd expect based on rolling radius and vehicle speed. The reverse is true for any non-driven wheel or when braking; those wheels will actually be spinning slightly slower than expected. The faster you go, the larger this slip ratio becomes because more tire traction force is required to overcome aero drag. At 0 speed it should be at 0 (but per the post above, sometimes this number calculation doesn't do a good job at low speeds). At 45 mph, I was seeing 1% wheel slip. I'd imagine at highway speeds, it's possible to see 2 or even 3% wheel slip.
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04-13-2018, 12:37 PM | #9 |
Drives: 2017 SS 1LE SIM Join Date: May 2017
Location: AZ
Posts: 59
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thanks for the response. glad this got cleared up!
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04-13-2018, 07:16 PM | #10 |
Drives: 17' 1SS 1LE GBA-Black Join Date: Mar 2017
Location: TLV
Posts: 833
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Dumb question: How do I configure to be able to see the eLSD display?
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04-14-2018, 06:23 AM | #11 | |
Drives: '18 1SS 1LE Join Date: Sep 2017
Location: Pennsyltucky
Posts: 2,580
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Quote:
Lower display is a bar graph of what would be considered rear tire slip. Cruise is nothing, slowing down is nothing, but acceleration gives you a reading. Hard acceleration from a low speed will light up the graph pretty good. Mild acceleration while cruising will light up a bar or two. |
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04-14-2018, 12:32 PM | #12 |
2017 Krypton SS 1LE
Drives: 2017 SS 1LE Join Date: Jul 2017
Location: Virginia
Posts: 13
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04-14-2018, 05:14 PM | #13 |
Drives: 17' 1SS 1LE GBA-Black Join Date: Mar 2017
Location: TLV
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04-15-2018, 08:57 PM | #14 |
Drives: 2018 SS 1LE Join Date: Apr 2016
Location: Oxnard Ca
Posts: 241
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I would think it has to do with the road as well. Highways tend to drain better and slight difference in the grade from left to right of the road surface. Also a long sweeping turn with the grading of the highway will tend to make the rear slip a bit more.
I have noticed with tracking the car on CW track the left side tire are a bit more worn than the right and my is at 1% to 2% constant now on a flat road with very little grading. |
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