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My estimation from last year seems to be pretty close using the same transmission gears from base model with the steeper transfer ratio, but not sure on how he comes up with his max speed theory? Obviously it has plenty of power to break 200 and I’m not concerned if it doesn’t, though just wondering how he’s coming up with the well over 200mph estimate? 6th at 200mph is 6900rpm where it’s making ~600hp, so it does sound like it will. Regardless, it’s funny how the dragstrip calculator was spot on as well...
When questioned, GM engineers said C8 Z06 top speed would be between the C6ZR1 (205) and the C7 ZR1 (212). My guess is it will be with the low wing/spoiler, however maybe the Z07 wing's drag is low enough that the Z07 will have the higher top speed.
Last edited by AzDave47; May 22, 2022 at 02:15 PM.
When questioned, GM engineers saidC8 Z06 top speed would be between the C6ZR1 (205) and the C7 ZR1 (212). My guess is it will be with the low wing/spoiler, however maybe the Z07 wing's drag is low enough that the Z07 will have the higher top speed.
Didn’t know that, makes sense given the hp falls in between the two though appears it won’t be at peak power like the other two at their top speeds.
It can be calculated very accurately if we know some variables however these variables can be estimated very closely..
I will post a thread on that later on with some calculations
But my initial guess is 186-188 mph for Z07 package and 205-207 mph for the base model
I think the highest downshift speed listed in the manual is actually the max speed in the downshift gear. The C8Z also loses a good bit of horsepower on the 5-6 at 188mph. If the aero drag is less than the 590 or so rwhp that it shifts into at 6th gear, then it'll still be able to accelerate past 188. I'm thinking non-Z07 aero may hit 200. 6th gear isn't great though.
The manual say 188 mph gears 6 to 5, and the chart above says 197. I'm wondering where the discrepancy is.
The manual is stating the highest down shift allowed, not the highest speed in the gear. So it makes sense that the max down shift speed is lower than max speed in the gear as the rpms need to be less, but maybe my estimated chart is off as I’m making an assumption about the trans gear ratios being the same.
The manual is stating the highest down shift allowed, not the highest speed in the gear. So it makes sense that the max down shift speed is lower than max speed in the gear as the rpms need to be less, but maybe my estimated chart is off as I’m making an assumption about the trans gear ratios being the same.
Could be. My estimated top speed in each gear lined up exactly with the owner's manual max downshift speeds. The difference in my graph and your estimate above, is that we used different tire diameters. In my graph, I forced the tire diameter in my graph to cause my speed/rpm to match the dash image below. However; small errors here translate to larger errors at higher speeds, so one guess is probably as good as another.
My estimation from last year seems to be pretty close using the same transmission gears from base model with the steeper transfer ratio, but not sure on how he comes up with his max speed theory? Obviously it has plenty of power to break 200 and I’m not concerned if it doesn’t, though just wondering how he’s coming up with the well over 200mph estimate? 6th at 200mph is 6900rpm where it’s making ~600hp, so it does sound like it will. Regardless, it’s funny how the dragstrip calculator was spot on as well...
Good graph people need to realize the gearing with RPM 197 on this graph is the same gear as the SR going into 6th at about 150. When the Z goes into 6th it's at the same torque and 170 more hp than the SR too. Should easily get through 200mph.
It can be calculated very accurately if we know some variables however these variables can be estimated very closely..
I will post a thread on that later on with some calculations
But my initial guess is 186-188 mph for Z07 package and 205-207 mph for the base model
That's a big difference IMO. Not like it matters. Most of us will never get near it or care. I know I have been at instant death speeds in my Hellcat, but not worrying about hitting that 202 top speed
That's a big difference IMO. Not like it matters. Most of us will never get near it or care. I know I have been at instant death speeds in my Hellcat, but not worrying about hitting that 202 top speed
... but some of us are able to do this at proper venues.
Could be. My estimated top speed in each gear lined up exactly with the owner's manual max downshift speeds. The difference in my graph and your estimate above, is that we used different tire diameters. In my graph, I forced the tire diameter in my graph to cause my speed/rpm to match the dash image below. However; small errors here translate to larger errors at higher speeds, so one guess is probably as good as another.
The tire diameter is pretty much a given being the size is known though I realize there can be a slight difference in actual specs vs calculated. The screenshot can also have a variance being the tach can lag at the speed it accelerates and I believe the speedometer is skipping numbers counting as well, so definitely could be slightly off in a snapshot.
/\ lots of small assumptions that create an error band but we both agree that it doesn't appear to hit 200mph in 5th. It unfortunately loses almost 100hp on the 5-6 shift, so the question becomes, can it still overcome air drag and accelerate after the power loss on the 5-6 shift.
/\ lots of small assumptions that create an error band but we both agree that it doesn't appear to hit 200mph in 5th. It unfortunately loses almost 100hp on the 5-6 shift, so the question becomes, can it still overcome air drag and accelerate after the power loss on the 5-6 shift.
If the aero drag is similar to C6ZR1 and it’s making similar hp as the C6ZR1 at the same speed, then I’d say 205 in 6th might be a fair guess.
Top speed
