Best Performance Choice - Grand Sport or Z51
09-26-2017, 10:07 AM
#1
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Best Performance Choice - Grand Sport or Z51
There have been many threads about this subject, with most claiming the Grand Sport is the best performance car. In reality the answer to this question depends upon the type of performance event that a C7 is used for.
The Z51 and Grand Sport have identical engine horsepower and torque outputs, transmission ratios and differential ratios. The Grand Sport is 3.5" wider, has bigger brakes, wider tires, a more aggressive spoiler package and is 25 to 65 pounds heavier than a Z51 with MRC / without MRC.
For track events, a Grand Sport is a better choice, because of its superior grip due to its bigger brakes, wider tires, and more aggressive spoiler package.
For quarter mile drag racing and standing half mile and mile speed events, a Z51 is a better choice, because of its lower drag and marginally lower weight due to its narrower body and tires and less aggressive spoiler package.
While it's true that GM claims a Grand Sport with the Z07 Package and its sticker Cup tires is capable of a quicker 0-60 MPH time (3.6 seconds) than a Z51 (3.7 Seconds), the fact of the matter is that with a proper burnout a Z51 is not traction limited and can launch without wheel spin and produce 60 foot times (low 1.7's / high 1.6's) and 0-60 MPH times identical to that of a Z07 Grand Sport. A Z51 has marginally quicker acceleration above 100 MPH due its lower weight and drag.
What's the best choice for those who don't intend on racing a C7? The version whose appearance you like the best. They're both awesome looking!
The Z51 and Grand Sport have identical engine horsepower and torque outputs, transmission ratios and differential ratios. The Grand Sport is 3.5" wider, has bigger brakes, wider tires, a more aggressive spoiler package and is 25 to 65 pounds heavier than a Z51 with MRC / without MRC.
For track events, a Grand Sport is a better choice, because of its superior grip due to its bigger brakes, wider tires, and more aggressive spoiler package.
For quarter mile drag racing and standing half mile and mile speed events, a Z51 is a better choice, because of its lower drag and marginally lower weight due to its narrower body and tires and less aggressive spoiler package.
While it's true that GM claims a Grand Sport with the Z07 Package and its sticker Cup tires is capable of a quicker 0-60 MPH time (3.6 seconds) than a Z51 (3.7 Seconds), the fact of the matter is that with a proper burnout a Z51 is not traction limited and can launch without wheel spin and produce 60 foot times (low 1.7's / high 1.6's) and 0-60 MPH times identical to that of a Z07 Grand Sport. A Z51 has marginally quicker acceleration above 100 MPH due its lower weight and drag.
What's the best choice for those who don't intend on racing a C7? The version whose appearance you like the best. They're both awesome looking!
Last edited by RPOC7R; 09-26-2017 at 10:33 AM.
09-26-2017, 10:13 AM
#2
E-Ray, 3LZ, ZER, LIFT
Member Since: Sep 2007
Location: NE South Carolina
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^^^
Agree with "most" of your arguments. However for drag racing the 60 foot times with all Vettes are traction limited. The wider GS rear tires provide better traction off the line. Need a direct comparison between, base, Z51 and GS. Bet the 60 foot times are better with the GS with equal tires. That will offset the weight and aero issues at 100+ mph, IMO.
If you are correct, the base car that is lighter and without the drag of a spoiler would be fastest!
Agree with "most" of your arguments. However for drag racing the 60 foot times with all Vettes are traction limited. The wider GS rear tires provide better traction off the line. Need a direct comparison between, base, Z51 and GS. Bet the 60 foot times are better with the GS with equal tires. That will offset the weight and aero issues at 100+ mph, IMO.
If you are correct, the base car that is lighter and without the drag of a spoiler would be fastest!
Last edited by JerryU; 09-26-2017 at 10:18 AM.
09-26-2017, 10:29 AM
#4
Le Mans Master
Completely with your statement. However, as I have drag raced all my life I learned long ago that 60' times are extremely important , but you win at the stripe and top end means just as much if not more in a 1/4 mile . Here's where another factor comes in place...weight. Three cars, GS, Z51 & Base all with the same engine, similar gearing , equal wheel burnout time and equally skilled drivers (if that is possible 
) the lighter car will win every time. But I love the look of all three and if I was buying one today I'd lean toward the GS simply for looks and package content.
Just saying!
09-26-2017, 10:40 AM
#5
Race Director
I knew a 'which is faster' Z51 vs GS thread would be coming right on the heels of yesterday's "Stingray vs Grand Sport - is my logic reasonable?" thread.
09-26-2017, 10:46 AM
#6
E-Ray, 3LZ, ZER, LIFT
Member Since: Sep 2007
Location: NE South Carolina
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Completely with your statement. However, as I have drag raced all my life I learned long ago that 60' times are extremely important , but you win at the stripe and top end means just as much if not more in a 1/4 mile . Here's where another factor comes in place...weight. Three cars, GS, Z51 & Base all with the same engine, similar gearing , equal wheel burnout time and equally skilled drivers (if that is possible ) the lighter car will win every time. But I love the look of all three and if I was buying one today I'd lean toward the GS simply for looks and package content. Just saying! Been drag racing since I saw Garlets at a drag strip when he was running eight ‘97s before he installed a blower! Lately more watching and making 0 to 60 “Banzi Runs” with my ProStreet Rod with its set back 8.2 Liter BB, 850 Holley double pumper, long tube headers, 4 bar link rear and having 53% of its weight on 16.5 inch section width, sticky Micky Thompsons!
When I got my September 2013 built C7, Z51 felt its tire width was a bit anemic! Same width tires as on my C6 Z51 and more hp. Plus it’s parked next to my Street Rod in the garage and could hear it chuck when I pulled in!
Have no measurements of 0 to 60 mph times with my Grand Sport and as with all my DD’s in 55 years of driving it’s a standard shift. In a drag race, an A8 would beat me even with a novice driver! (The Street Rod has a race prepared TH400.)
As you note, getting equal drivers is not really possible but over a number of runs with the same driver the results with all three would be interesting!
Last edited by JerryU; 09-26-2017 at 11:26 AM.
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09-26-2017, 11:53 AM
#7
The Z51 and Grand Sport have identical engine horsepower and torque outputs, transmission ratios and differential ratios. The Grand Sport is 3.5" wider, has bigger brakes, wider tires, a more aggressive spoiler package and is 25 to 65 pounds heavier than a Z51 with MRC / without MRC.
09-26-2017, 07:28 PM
#8
Le Mans Master
True, the GS is a bit more engineered for the twisties. Not that it doesn't go straight in a hurry. but reality says :
Who the hell knows ?"
We'll just have to wait and see. 
Who the hell knows ?"
We'll just have to wait and see.