[ANSWERED] Motor Trend 2015 Z06 vs. 2015 GT-R Nismo
03-06-2015, 05:04 PM
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[ANSWERED] Motor Trend 2015 Z06 vs. 2015 GT-R Nismo
Original question is here.
Bwright asked:
You mentioned in this week's answer to the Ask Tadge question on overheating that there are, "Lots of interesting back stories behind recent media tests." In light of that, what are your thoughts on the recent Motor Trend test of the new Z06 vs. the GT-R Nismo at Willow Springs? Any interesting back stories on that or any other recent media tests?
You mentioned in this week's answer to the Ask Tadge question on overheating that there are, "Lots of interesting back stories behind recent media tests." In light of that, what are your thoughts on the recent Motor Trend test of the new Z06 vs. the GT-R Nismo at Willow Springs? Any interesting back stories on that or any other recent media tests?
Tadge answered:
To be perfectly honest, both Chevrolet and Motor Trend were surprised by the test results - both the lap times achieved and the subjective comments on handling which did not match their impressions from the first drive story at Road Atlanta. Obviously the GT-R Nismo is a supremely capable machine engineered for precisely this kind of track work, so nothing against them, but we thought we would do better. After the story was published, we decided to examine that car closely and do a follow up test at Willow Springs.
We first discovered an alignment setting error in the rear. We knew something was wrong with their test car because of Randy's oversteer comments. In the words of our development engineer, Jim Mero, "The car is tuned for a small amount of understeer, but we found out the rear caster was inadvertently set to 2 degrees instead of 0 degrees. This causes ride and roll oversteer". We try to keep the Corvettes used for media tests in perfect condition, but didn't this time, and the alignment clearly had an effect on handling and driver confidence.
We also learned the Nissan was using octane booster, as it will cut power when running the 91 octane pump fuel available locally. Generally speaking, higher octane enables more aggressive spark calibration and higher power. While the Z06 is certified for 91 octane fuel, adding octane boost will offer greater resistance to spark retard and detonation under thermally challenging conditions (reduced likelihood of power reduction when intake temps go up). Racing fuel (100 octane) available at the track improves this robustness even further. We will be recommending that customers who track their car, especially at higher temps, use the highest octane fuel available.
Although we do track testing at quite a number of tracks around the country, we never tested at Willow Springs, so we decided to rent the track and check the performance of the Z06 ourselves. We looked at it as an opportunity to learn something. What Randy told us and we confirmed is that the track has an unusual combination of speed and roughness.
We used exactly the same car Motor Trend tested, as well as a second car, an 8 speed automatic. With proper suspension alignment, we saw a marked improvement in handling.
We also used the opportunity to tweak the calibration of the magnetic ride dampers in Track mode (Tour and Sport modes unchanged), and were able to improve the vehicle’s dynamic behavior. Since we think that calibration is uniquely suited to very rough tracks, our plan is to offer it through our Performance Parts department for customers who frequent those types of venues. So it was a good exercise for us.
We invited Motor Trend to test the car again with suspension alignments corrected and give us feedback on the new calibration. They are planning a follow up article based on Randy's experience, and since we don't want to "scoop" their story I won’t say specifically what the results were. However, I can say we were very satisfied. Look for it soon!
To be perfectly honest, both Chevrolet and Motor Trend were surprised by the test results - both the lap times achieved and the subjective comments on handling which did not match their impressions from the first drive story at Road Atlanta. Obviously the GT-R Nismo is a supremely capable machine engineered for precisely this kind of track work, so nothing against them, but we thought we would do better. After the story was published, we decided to examine that car closely and do a follow up test at Willow Springs.
We first discovered an alignment setting error in the rear. We knew something was wrong with their test car because of Randy's oversteer comments. In the words of our development engineer, Jim Mero, "The car is tuned for a small amount of understeer, but we found out the rear caster was inadvertently set to 2 degrees instead of 0 degrees. This causes ride and roll oversteer". We try to keep the Corvettes used for media tests in perfect condition, but didn't this time, and the alignment clearly had an effect on handling and driver confidence.
We also learned the Nissan was using octane booster, as it will cut power when running the 91 octane pump fuel available locally. Generally speaking, higher octane enables more aggressive spark calibration and higher power. While the Z06 is certified for 91 octane fuel, adding octane boost will offer greater resistance to spark retard and detonation under thermally challenging conditions (reduced likelihood of power reduction when intake temps go up). Racing fuel (100 octane) available at the track improves this robustness even further. We will be recommending that customers who track their car, especially at higher temps, use the highest octane fuel available.
Although we do track testing at quite a number of tracks around the country, we never tested at Willow Springs, so we decided to rent the track and check the performance of the Z06 ourselves. We looked at it as an opportunity to learn something. What Randy told us and we confirmed is that the track has an unusual combination of speed and roughness.
We used exactly the same car Motor Trend tested, as well as a second car, an 8 speed automatic. With proper suspension alignment, we saw a marked improvement in handling.
We also used the opportunity to tweak the calibration of the magnetic ride dampers in Track mode (Tour and Sport modes unchanged), and were able to improve the vehicle’s dynamic behavior. Since we think that calibration is uniquely suited to very rough tracks, our plan is to offer it through our Performance Parts department for customers who frequent those types of venues. So it was a good exercise for us.
We invited Motor Trend to test the car again with suspension alignments corrected and give us feedback on the new calibration. They are planning a follow up article based on Randy's experience, and since we don't want to "scoop" their story I won’t say specifically what the results were. However, I can say we were very satisfied. Look for it soon!
Last edited by jvp; 03-12-2015 at 07:51 AM. Reason: fixed some punctuation and spelling
03-06-2015, 07:30 PM
#3
Heel & Toe
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Original question is here.
03-06-2015, 08:03 PM
#4
Melting Slicks
Second that. Excellent response. Leaving satisfied.
03-06-2015, 11:06 PM
#7
Thank you very much.
03-06-2015, 11:21 PM
#8
Drifting
Thanks Tadge for the answer and for your time and effort.
03-07-2015, 04:16 AM
#10
Lol, can we get a redo? I can't believe excuses like that are being made. Not anyone's fault GM can't deliver a correctly prepped car for test but their own. Stay tuned for when the car is ready. Lol.
03-07-2015, 04:21 AM
#11
Burning Brakes
follow up question
Will I be able to get a Z07 suspension calibration for my Z06? Assuming I have the better springs, bushings, etc. Seems like something that could be offered through dealer down the road.
03-07-2015, 08:28 AM
#12
Melting Slicks
Nice answer, Tadge. Seems forthright.
Thought so about Nissan. Nissan has a history of gaming the process--Octane booster? Maybe Chevy should demand impounds on comparison cars....
But, Chevy should be more careful and detail-oriented when providing equipment for comparison testing. Car mags sell cars--you never want to let detail failures cost you good pub and this Z06 v GT-R Nismo article has proliferated all over the net.
Looking forward to the update--although it is must better to get it right the first time....
Thought so about Nissan. Nissan has a history of gaming the process--Octane booster? Maybe Chevy should demand impounds on comparison cars....
But, Chevy should be more careful and detail-oriented when providing equipment for comparison testing. Car mags sell cars--you never want to let detail failures cost you good pub and this Z06 v GT-R Nismo article has proliferated all over the net.
Looking forward to the update--although it is must better to get it right the first time....
03-07-2015, 08:29 AM
#13
Turn 12!
Great news!
Thanks JVP for Quarterbacking this entire process.
Thanks JVP for Quarterbacking this entire process.
03-07-2015, 08:36 AM
#14
A rematch would only be fair but why in the hay would they not have made sure the car was set up properly before the compare.
03-07-2015, 08:50 AM
#15
Safety Car
Totally understand the issue about the 91 oct vs. whatever the other manufacturer used. And, IMHO, if MT didn't know this... or at least make sure both parties knew before the test... then that is shoddy reporting on their part (and I've been a subscriber for 30yrs...and yes, I know to take all reviews/tests and read with caution).
Definitely appreciate the answers to the questions.
03-07-2015, 08:59 AM
#16
But, Chevy should be more careful and detail-oriented when providing equipment for comparison testing. Car mags sell cars--you never want to let detail failures cost you good pub and this Z06 v GT-R Nismo article has proliferated all over the net.
When I worked there, the alignments were completed with great accuracy. If I were to guess, because the guys doing alignments were pretty damn sharp, there were probably a ton of people checking the calibration of the the equipment.
This is not an excuse, just info on how the work gets done at the Proving Grounds.
Last edited by vette friend; 03-07-2015 at 09:06 AM.
03-07-2015, 09:00 AM
#17
Melting Slicks
Motor Trend coming to Laguna Seca in a couple weeks ? I saw MT on the calendar then the name was pulled and Mazda was inserted. This happens quite frequently when a magazine comes to Laguna. Keeps the public away.
03-07-2015, 09:01 AM
#18
Thanks Tadge! Love the constructive approach and detailed feedback!
Phil
Phil
03-07-2015, 09:13 AM
#19
Burning Brakes
All talk of ringers and rematches aside... I absolutely loved how the Corvette team took a set back, analyzed it, corrected deficiencies and realized tangible improvements as a result.
That is the mark of real professionalism.
That is the mark of real professionalism.
03-07-2015, 09:27 AM
#20
Burning Brakes
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Exactly. This is like going into a prize fight and not being in perfect condition. Certainly GM knew the stakes here. I do understand that the test car(s) get put through the ringer and beat on mercilessly. But GM testers and engineers certainly have the funds to make sure each car used for testing in these types of condition is gone over with a fine-tooth comb.
Totally understand the issue about the 91 oct vs. whatever the other manufacturer used. And, IMHO, if MT didn't know this... or at least make sure both parties knew before the test... then that is shoddy reporting on their part (and I've been a subscriber for 30yrs...and yes, I know to take all reviews/tests and read with caution).
Definitely appreciate the answers to the questions.
Totally understand the issue about the 91 oct vs. whatever the other manufacturer used. And, IMHO, if MT didn't know this... or at least make sure both parties knew before the test... then that is shoddy reporting on their part (and I've been a subscriber for 30yrs...and yes, I know to take all reviews/tests and read with caution).
Definitely appreciate the answers to the questions.