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I am looking at new C8 LT1 or LT2 with the Z51 option.
what is the electronic differential and how is it different from a non-Z51.
is the final drive ratio changed with the Z51?
Thanks!
I am looking at new C8 LT1 or LT2 with the Z51 option.
what is the electronic differential and how is it different from a non-Z51.
is the final drive ratio changed with the Z51?
Thanks!
You will find the video at the link below informative. At about 1:30, it discusses the differential functions with some very nice illustrations.
C8s have 5 (yes, FIVE) overdrive gears. Any version will be loafing along in top gear on the highway with no significant effect on fuel economy between versions. I'm talking about the narrow body base cars. Z06s get worse economy, clearly.
Thanks. Just what I needed!
Any idea what mpg and rpm at 75mph difference is between the 2?
(lots of numbers and letters in this car!)
😂
Attached are charts showing the speed vs rpm in each gear for each model.
As for MPG I don't think the claimed mpg for each is different. But its going to depend on how you drive. Folks on the forum report numbers like 15 mpg and others 20+ mpg.
I also think your menu set ups the engine/shift parameter will have an impact on that. If you set it Tour, it will favor higher gears, and will use all 8 gears. It will tend to downshift less.
If engine/shift is set to track, you will find yourself cruising at 75 in 6th gear - in automatic shift mode.
Simply put, your mileage may vary. And it depend more on your driving than on which model you choose.
I am looking at new C8 LT1 or LT2 with the Z51 option.
what is the electronic differential and how is it different from a non-Z51.
is the final drive ratio changed with the Z51?
Thanks!
If you want to know what the eLSD does and why it's far better than the simple basically 1960's Prostration in the Base C8 this is a summary. The appendix has the full, long Ask Tadge Post: http://netwelding.com/eLSD_VS_Posi.pdf
There are links to several Videos about how Positraction works and Kolk, the GM engineer who works on the very complex eLSD software.
yeah, I was wondering how long it would take for someone to mention that.
I get 28 mpg with my C6 LT1 at 75 mph in flat Florida. I was just wondering what the difference is between the three different ratios.
I haven't checked my C2 in a while, but 14 seems to come to mind.
Thanks for all of the info. I will check with the big volume sellers and in 2 weeks I hope to get a Torch Red black interior coupe.
Save The Wave!!!
2025 C8 Stingray of the Year Finalist - Unmodified
2024 C8 of the Year Finalist - Unmodified
Look at what people who autocross have to say about ELSD. Many don't like it as it intervenes (like it or not) in a way that slows them down in tight corners.
Look at what people who autocross have to say about ELSD. Many don't like it as it intervenes (like it or not) in a way that slows them down in tight corners.
Sure could not touch my oversteering modified '67 Corvair in an autocross! Mine had every HD option offered by GM that year, quick steering ratio, HD Springs, Sway Bar, Metallic Brakes. I added headers, carb mods, Plus One 14-inch wheels with sticky Continental 714 tires (when Plus One and Low Profile were not words used at the time.) Yep nothing better than the *** end sliding out helping it turn! But can set the car up to oversteer, as most autocrossers do!
Just had to learn how to drive on a road course when someone prevented you from taking your planned line thru an apex. Was fun but only had a split second if going too fast for a turn to counter steer line Tony Stewert in his dirt car. Nope in that case don't want eLSD to help!
Thank you for posting this video. I have never seen a more complicated transmission in my life. About halfway thru the video I decided to buy an extended warranty on my z51. 🤣
Thank you for posting this video. I have never seen a more complicated transmission in my life. About halfway thru the video I decided to buy an extended warranty on my z51. 🤣
Its complex with respect to s simple manual, but in my opinion its way easier to understand than an automatic transmission. Not saying "more reliable", just saying I can understand it better.
^^^ Yep, essentially two 4 speed standard transmissions with all gears in constant mesh. Shift Forks and Synchro's moved with hydraulic actuators rather than a manual stick!
Each "4 Speed" connected to its own multiplate clutch much like a standard shift. Not a slushbox, fluid coupled torque converter so "feels" different when in bumper-to-bumper traffic as the 1st gear clutch MUST slip below 4/5 mph so engine doesn't stall! When in bumper-to-bumper traffic do as most with standard shifts. Don't try to creep forward following the car in front. Let it get a few car lengths ahead ready to stop again, then pull up and stop. Not essential, just smart!
^^^ Yep, essentially two 4 speed standard transmissions with all gears in constant mesh. Shift Forks and Synchro's moved with hydraulic actuators rather than a manual stick!
Each "4 Speed" connected to its own multiplate clutch much like a standard shift. Not a slushbox, fluid coupled torque converter so "feels" different when in bumper-to-bumper traffic as the 1st gear clutch MUST slip below 4/5 mph so engine doesn't stall! When in bumper-to-bumper traffic do as most with standard shifts. Don't try to creep forward following the car in front. Let it get a few car lengths ahead ready to stop again, then pull up and stop. Not essential, just smart!
Just to further illustrate what I think is the complexity of the automatic transmission, I circled in green the torque converter, and what appear to be separate clutch packs, and in blue what think is a bunch of solenoid and hydraulic control valves in the bottom of the unit.
^^^^
Yep, typical of many gear automatic transmissions. For some, each gear has a clutch pack that locks a carrier with Sun and Planetary gears. Valve body is complex with many small passages and ball bearing check valves etc. The 3 speed HD TH400 that was used in muscle cars is what I have in my street rod. With HD parts they can handle ~1000 hp. I modified the valve body with a kit to make it 100% manual, no automatic shifting. Key was removing some of those ball bearing check valves! Later put it back as tough on the 3rd gear clutch pack if you take off in 3rd!
Z51 info
Yep, essentially two 4 speed standard transmissions with all gears in constant mesh. Shift Forks and Synchro's moved with hydraulic actuators rather than a manual stick!
