Why does GM limit the top speed on the C7?
06-16-2014, 07:20 AM
#42
Maybe something else to think about, and Im just kinda guessing here, maybe the non Z-51 are limited due to the lack of oil cooler, diff. cooler and transaxle cooler, I seem to remember when I ordered my Z-51 that these coolers come with this option.
06-16-2014, 07:22 AM
#43
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There are two C7 operating systems out there. I have only seen mine, which looks like the above. I am wondering if the other one is not limited.....maybe an older OS? Not sure.
06-16-2014, 07:29 AM
#44
This is on the Z-51 and I take it the non Z-51 don't and or have smaller, which is why GM may limit the speed on some of the vets, like I said in my last post, Im just guessing here.
•larger 19-inch front and 20-inch rear wheels
•dry sump oil system
•Electronic Limited Slip Differential
•larger front brakes (13.6 inch vs. 12.6 inch) with black calipers
•specific shocks, springs and stabilizer bars
•differential and transmission cooling
•unique Aero Package that reduces lift for high-speed stability
•Michelin® Pilot® Super Sport® ZP summer-only tires (DISCLOSURE) that are aggressively tuned to provide outstanding handling, grip and road-holding capability
•available Magnetic Selective Ride Control and Performance Traction Management
•HD Cooling
•Slotted Brake Rotors
•Performance Gear Ratios
•larger 19-inch front and 20-inch rear wheels
•dry sump oil system
•Electronic Limited Slip Differential
•larger front brakes (13.6 inch vs. 12.6 inch) with black calipers
•specific shocks, springs and stabilizer bars
•differential and transmission cooling
•unique Aero Package that reduces lift for high-speed stability
•Michelin® Pilot® Super Sport® ZP summer-only tires (DISCLOSURE) that are aggressively tuned to provide outstanding handling, grip and road-holding capability
•available Magnetic Selective Ride Control and Performance Traction Management
•HD Cooling
•Slotted Brake Rotors
•Performance Gear Ratios
06-16-2014, 07:37 AM
#45
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good point, the "other" OS may be for Z51s....i wonder it someone with a Z51 and HPT can have a quick look at their OS version for me (us)?
06-16-2014, 07:49 AM
#46
06-16-2014, 11:11 AM
#47
Racer
Last edited by Randy WS6; 06-16-2014 at 11:16 AM.
06-16-2014, 11:35 AM
#48
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yep it would be interesting to see a build date vs os version comparison list.
i know mine is a later build (march I think) and mine had the limiter. obviously it isn't Z51 based.
i know mine is a later build (march I think) and mine had the limiter. obviously it isn't Z51 based.
06-16-2014, 11:36 AM
#49
Burning Brakes
I recall one of the first cars to get on a dyno having the computer intercede at 190mph. Of course, on the dyno, there is no aerodynamic limitations (though probably hard to get fans that can keep enough air in the nose to hold that time for any period).
I also wouldn't be surprised if the coupe and convertible had different settings.
I also wouldn't be surprised if the coupe and convertible had different settings.
06-17-2014, 06:02 AM
#50
I wonder if it makes a different if in track mode, verses other modes, just trying to use the process of elimination here, I hear people driving there cars at the track, and I take it they are mostly in track mode?? I do run mind in track mode sometimes, and Im just guessing guys.
At first I read about the 135 limiter, I did thought it was BS, sorry JIM2092, I had mine over 135 and hear a lot of others doing it also, and some really higher speeds when people take theirs to the track. When I get a chance I will try mine in another mode other than track mode.
At first I read about the 135 limiter, I did thought it was BS, sorry JIM2092, I had mine over 135 and hear a lot of others doing it also, and some really higher speeds when people take theirs to the track. When I get a chance I will try mine in another mode other than track mode.
06-17-2014, 01:08 PM
#51
The limiter is easily adjusted with hptuners. I dont have my tuning laptop with me right now, but if you pull up a c7 file, I guarantee the top speed is also limited...
06-17-2014, 02:47 PM
#52
Pro
I have a base 2LT A6 (all stock) and have seen 151 in track mode?
06-17-2014, 03:40 PM
#53
Race Director
For what it is worth I voluntary limited my top speed in the outdated 08 C6 by switching to 4:10 differential. And the sky hasn't fallen.
I still have loads of fun.
Top speed is for dreamers and a very small number of mile participants.
I find it curious how so many are concerned with a car's top speed.
Hay if you want bragging rights go out and earn them.
Hard work is always more rewarding than a store bought item or something given.
I guess in the end it is all about distractions to get through the day.
I still have loads of fun.
Top speed is for dreamers and a very small number of mile participants.
I find it curious how so many are concerned with a car's top speed.
Hay if you want bragging rights go out and earn them.
Hard work is always more rewarding than a store bought item or something given.
I guess in the end it is all about distractions to get through the day.
06-19-2014, 10:15 AM
#55
Melting Slicks
In real world, wind resistance on the C5 was supposed to "limit" the top speed to about 175; on a dyno with no wind resistance....
the computer is supposed to shut it down at 190.
Yes, GM bought that engine.
I would presume the C7 is also limited.
Whomever runs the dyno is supposed to put in the tire rating....then the dyno computer will shutdown when speed hits max for the tire....saw that on a C4 - hit 201 when the dyno stopped.
Of course, "computer limited" goes out the window if the owner has modded the chip.
06-24-2014, 10:12 PM
#58
Race Director
I know the C5s were indeed limited by the computer.
In real world, wind resistance on the C5 was supposed to "limit" the top speed to about 175; on a dyno with no wind resistance....
the computer is supposed to shut it down at 190.
Yes, GM bought that engine.
I would presume the C7 is also limited.
Whomever runs the dyno is supposed to put in the tire rating....then the dyno computer will shutdown when speed hits max for the tire....saw that on a C4 - hit 201 when the dyno stopped.
Of course, "computer limited" goes out the window if the owner has modded the chip.
In real world, wind resistance on the C5 was supposed to "limit" the top speed to about 175; on a dyno with no wind resistance....
the computer is supposed to shut it down at 190.
Yes, GM bought that engine.
I would presume the C7 is also limited.
Whomever runs the dyno is supposed to put in the tire rating....then the dyno computer will shutdown when speed hits max for the tire....saw that on a C4 - hit 201 when the dyno stopped.
Of course, "computer limited" goes out the window if the owner has modded the chip.
The limiter (I'm taking you guy's word for it) is there for these "dyno" top speed runs, I guess.
Jimmy
Last edited by jimmyb; 06-24-2014 at 10:15 PM.