ZL1 Top Speed

[ViperTomcat]

Considering the Z06 can just tickle 200...

My guess is 190 or so.

[radz28]

I really hope they don't limit it. The technology seems to be there, and top speed is always a nice bragging right, lol.

I think it's pretty safe to make some assumptions for a few of the mechanicals:

• *Transmission gear ratios (MG9)
  CTS-V
  2.660
  1.780
  1.300
  1.000
  0.800
  0.630
  2.900
  *Rear end ratio
  3.73

I was going to add ZR1 but that gearset is different (aside from the fact it's a different box I believe since it's transaxle). I think it's relatively safe to assume these ratios; I have nothing to back that up, yet, though.

According to pretty cool calculator site if I enter these mechanical values, the theoretical top speed in 6th gear is an unachievable 222 MPH, lol. Top speed in 5th gear is "only" 175, and we know CTS-Vs top speed for the manual transmission is more than 190 MPH, so I think it's safe to say it used 6th and just ran out of power. I didn't bother looking of the Cd of the car because I think there could be a substaintial diffference because of the aero' tricks for ZL1, so I just didn't bother. I'm even more thinking mid-180s is pretty reasonable, given more power, and with these assumptions.

[DevilKnightFalcon]

Originally Posted by radz28

I really hope they don't limit it. The technology seems to be there, and top speed is always a nice bragging right, lol.

I think it's pretty safe to make some assumptions for a few of the mechanicals:

• *Transmission gear ratios (MG9)
  CTS-V
  2.660
  1.780
  1.300
  1.000
  0.800
  0.630
  2.900
  *Rear end ratio
  3.73

I was going to add ZR1 but that gearset is different (aside from the fact it's a different box I believe since it's transaxle). I think it's relatively safe to assume these ratios; I have nothing to back that up, yet, though.

According to pretty cool calculator site if I enter these mechanical values, the theoretical top speed in 6th gear is an unachievable 222 MPH, lol. Top speed in 5th gear is "only" 175, and we know CTS-Vs top speed for the manual transmission is more than 190 MPH, so I think it's safe to say it used 6th and just ran out of power. I didn't bother looking of the Cd of the car because I think there could be a substaintial diffference because of the aero' tricks for ZL1, so I just didn't bother. I'm even more thinking mid-180s is pretty reasonable, given more power, and with these assumptions.

It will be electronically limited based on the components of the car. The reason the SS is restricted to 155 is because that is what the components are rated at even though the car is technically capable of going faster.

[radz28]

Originally Posted by DevilKnightFalcon

It will be electronically limited based on the components of the car. The reason the SS is restricted to 155 is because that is what the components are rated at even though the car is technically capable of going faster.

Which components? I'm just curious I'm mostly rationalizing my speculation based completely on their hype of the aero' tricks, because most of that stuff doesn't really begin to effect the car until, what, like above 120 MPH or something? But, again, I have nothing to support my stance, where you probably do.

Just speculating

[porcupinekiller]

Originally Posted by radz28

Which components? I'm just curious I'm mostly rationalizing my speculation based completely on their hype of the aero' tricks, because most of that stuff doesn't really begin to effect the car until, what, like above 120 MPH or something? But, again, I have nothing to support my stance, where you probably do.

Just speculating

I'm pretty sure the top speed is limited to what the tires are speed rated at.
At 250 mph the tires on the Bugatti Veyron will only last 15 min.!!!

[radz28]

Originally Posted by porcupinekiller

I'm pretty sure the top speed is limited to what the tires are speed rated at.
At 250 mph the tires on the Bugatti Veyron will only last 15 min.!!!

It looks like the F1 G2s are rated at 186+ while the OEM SS tires are rated to the same, too...

Don't you have to replace the wheels on Veyron, too, after like 20K miles?! Maybe that was an rumor, lol.

[CoolestCamaro873]

No reason to think it won't be the same as the CTS-V with 6-Speed Manual Trans: 191 mph! Incase they make it a little slower it should def do 180 mph!

[n!ght r!der]

700mph. I mean 190ish

[DGthe3]

Originally Posted by CoolestCamaro873

No reason to think it won't be the same as the CTS-V with 6-Speed Manual Trans: 191 mph! Incase they make it a little slower it should def do 180 mph!

Actually, there are 3 reasons to think it might be different:

• different size (though this is probably less than half a square foot different in cross section)
• different coefficient of drag
• different engine output

[Revo1]

[calbert1999]

Originally Posted by radz28

Since GM is really pushing the aero' tweaks for downforce, that leads me to believe ZL1 will reach high top speeds and operate comfortably at high speed. I'm thinking a top speed of 178. I'm a little concerned because of the 3.73s maybe cutting 5th gear a little short and that 6th is too tall to pull to top speed.

What do you think?

I don't think the ZL1 will go any faster than an SS would with a supercharger.
The top speed is simply based on factors like the RPM, Torque and speed limiters set on the engine. For example, the SS top speed is 155mph. That tops speed has nothing to do with anything other than the fact that that is what the limiter is set to.
With the limiter off, and the pedal to the metal with the LS3 engine the speed will continue to increase as long as the RPM's keep increasing as well. Add some forged internals and some accessories to the heads and away you go.
I'm already making 550hp. at the crank of my SS with a few mods. (no SC yet), which is what the ZL1 is rated at right now. So, realistically, the ZL1 is no faster than what I have now.

[Autobots]

After the zl1 comes out, salt flats would be a good place to open it up

[Number 3]

Originally Posted by DGthe3

Actually, there are 3 reasons to think it might be different:

• different size (though this is probably less than half a square foot different in cross section)
• different coefficient of drag
• different engine output

Was looking for someone to point out that it isn't just Cd, it's Cd*A.

A 1/2 square foot can be sizable, just not likely between two comparable size cars.

I believe the force equation is something like F = .5*Cd*p*A*V^2

p is the density of air.

You can see the force required goes up with the squrare of velocity.

And this is merely the Force to push the object through the air. You also have to overcome rolling resistance which if you have wider tires and more down force as well as more mass, you will also add to the Force required to move the vehicle.

All that being said, I couldn't possibly guess.

[CoolestCamaro873]

Originally Posted by DGthe3

Actually, there are 3 reasons to think it might be different:

• different size (though this is probably less than half a square foot different in cross section)
• different coefficient of drag
• different engine output

I understand exactly what you are saying. But, my point was that the CTS-V performance is something we may be able to use to sort of measure where the ZL1 may stack up performance wise. Someone pointed out that an SS with no limiter hit in the 170's mph top speed. I have no reason to believe that if GM can get the whale of a CTS-V to go 191 mph they can figure out how to make the ZL1 do the same. With the amount of time it took to get this car ready for production, I'm hoping the R&D department did their homework on this stuff! LOL