[ANSWERED] Stiffer suspension for standard Z06
01-22-2016, 03:26 PM
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[ANSWERED] Stiffer suspension for standard Z06
Original question is here.
AliZ51 asked:
Can you explain the calibration differences between a standard Z06 and the Z07 package. We know that the Z07 (FE7) suspension is stiffer than standard Z06 (FE6) but many Z06 owners like to have a stiffer suspension without the Z07 package. Some forum members/ Z06 owners researched and found that the springs, shocks, and stab bar bushings are stiffer on the Z07 and these parts can be purchased from any GM dealer. The concern is with MR calibration or if there is any negative effect for adding these parts without proper calibration.
If calibration is in fact needed, would GM offer the calibration for purchase (similar idea to rough track calibration on Z07) through GMPP?
Can this be also available for Z51 owners with MSRC?
Can you explain the calibration differences between a standard Z06 and the Z07 package. We know that the Z07 (FE7) suspension is stiffer than standard Z06 (FE6) but many Z06 owners like to have a stiffer suspension without the Z07 package. Some forum members/ Z06 owners researched and found that the springs, shocks, and stab bar bushings are stiffer on the Z07 and these parts can be purchased from any GM dealer. The concern is with MR calibration or if there is any negative effect for adding these parts without proper calibration.
If calibration is in fact needed, would GM offer the calibration for purchase (similar idea to rough track calibration on Z07) through GMPP?
Can this be also available for Z51 owners with MSRC?
Tadge answered:
Chassis tuning is quite a complex melding of art and science. Despite our massive computational capability, no one has yet invented a way for computers to create the optimal combination of tire construction, bushing rates, spring rates, stab bar torsional stiffness, and shock tuning to ensure optimum handling in conjunction with great ride. Analytical techniques help us to define suspension geometry (kinematics), the stiffness of each individual component, and get us into the ball-park on spring and stab bar rates. However, much of the final tuning is still done the way it has been for over 100 years: Talented, skillful drivers use their subjective impressions supplemented with measured data to continuously improve our initial specification to achieve that elusive perfect balance of ride and handling. Of course modern cars, especially Corvette, then overlay enormously complex electronic controls of ABS, Traction control, launch control, stability systems, eLSD, and ride modes. Both the mechanical and electronic system are balanced to meet legal requirements and performance expectations from customers in all countries and environmental conditions. As the factory, we are obligated to thoroughly validate everything we sell, which requires a lot of engineering resources. That is why we sell packages of equipment and can't let customers order every imaginable combination of chassis set ups, brakes, tires and aero packages. We always shoot for the combinations that most customers will like and then tweak from there.
Jim Mero leads our chassis tuning work and is supported by many others. I asked him for a description of the Z06 Chassis options to clarify the content and talk a little about the philosophy:
Chassis tuning is quite a complex melding of art and science. Despite our massive computational capability, no one has yet invented a way for computers to create the optimal combination of tire construction, bushing rates, spring rates, stab bar torsional stiffness, and shock tuning to ensure optimum handling in conjunction with great ride. Analytical techniques help us to define suspension geometry (kinematics), the stiffness of each individual component, and get us into the ball-park on spring and stab bar rates. However, much of the final tuning is still done the way it has been for over 100 years: Talented, skillful drivers use their subjective impressions supplemented with measured data to continuously improve our initial specification to achieve that elusive perfect balance of ride and handling. Of course modern cars, especially Corvette, then overlay enormously complex electronic controls of ABS, Traction control, launch control, stability systems, eLSD, and ride modes. Both the mechanical and electronic system are balanced to meet legal requirements and performance expectations from customers in all countries and environmental conditions. As the factory, we are obligated to thoroughly validate everything we sell, which requires a lot of engineering resources. That is why we sell packages of equipment and can't let customers order every imaginable combination of chassis set ups, brakes, tires and aero packages. We always shoot for the combinations that most customers will like and then tweak from there.
Jim Mero leads our chassis tuning work and is supported by many others. I asked him for a description of the Z06 Chassis options to clarify the content and talk a little about the philosophy:
Jim Mero writes:
The differences between the Z06 (FE6) and Z07 (FE7) suspension packages are:
During the process of development of both these packages, our philosophy has remained the Z07 would be geared towards track performance with road behavior falling where it may, and the FE6 needs to be a more balanced car. Good FE6 road behavior in touring is a much more significant objective than that in the FE7. Using that philosophy, we feel we have met the objectives. Having said that, we worked very diligently to make the FE7 a well-rounded daily driver and the FE6 a very competent track performer.
In the thread nominating this question, it appears that the emphasis is more on track than sport or touring. Increasing the spring rates on the FE6, would not allow us to meet our objective for the philosophy of that package as stated above.
Also, the Pilot Super Sport tire on the FE6 is a great tire but does not have the amazing grip provided by the PS Cup-2 tire. So when more roll stiffness is introduced to the car with a tire that is not as strong, tire saturation is a concern, which would be the case of the FE7 package paired up with the Pilot Super Sport tire.
Back to Tadge.
The differences between the Z06 (FE6) and Z07 (FE7) suspension packages are:
- Spring rates – The Z07 spring rates were calculated to keep the cars attitude consistent at speed using the downforce loads from the stage 3 aero. Because of this, the rates and ratio of the front spring to the rear spring differ between the FE6 and FE7.
- MR Dampers and calibration – besides the enormous flexibility we have to add damping electrically, there are also mechanical components that can be changed to make the electronics even more aggressive. These mechanical components are used in conjunction with the proper calibration uniquely for FE6 and FE7 for optimum performance
- Stabilizer bar bushings - These have a significant amount of influence on the TLLTD (Tire Lateral Load Transfer Distribution) which is basically a ratio of the percent roll stiffness of the front relative to the rear. The roll stiffness is comprised of the springs, stab bars and stab bar bushings. We used the stab bar bushings to obtain the appropriate TLLTD for each chassis in conjunction with the different spring rates as mentioned in point 1.
During the process of development of both these packages, our philosophy has remained the Z07 would be geared towards track performance with road behavior falling where it may, and the FE6 needs to be a more balanced car. Good FE6 road behavior in touring is a much more significant objective than that in the FE7. Using that philosophy, we feel we have met the objectives. Having said that, we worked very diligently to make the FE7 a well-rounded daily driver and the FE6 a very competent track performer.
In the thread nominating this question, it appears that the emphasis is more on track than sport or touring. Increasing the spring rates on the FE6, would not allow us to meet our objective for the philosophy of that package as stated above.
Also, the Pilot Super Sport tire on the FE6 is a great tire but does not have the amazing grip provided by the PS Cup-2 tire. So when more roll stiffness is introduced to the car with a tire that is not as strong, tire saturation is a concern, which would be the case of the FE7 package paired up with the Pilot Super Sport tire.
Back to Tadge.
More from Tadge:
Thanks to Jim for that summary.
So to summarize, we can’t offer every imaginable combination because the resource cost and validation risk is too high. We try to focus on thoroughly optimized packages that address different customer’s needs. Since we introduced the Z06, we have already expanded our offerings to allow the CCM brakes on the standard car without spec'ing Z07. Those brakes do offer some attributes that customers desire without the super-aggressive tires and aero. Even though that is a "bolt on" combination, we had to go back and do all the testing to validate functionality. Note this does not mean iron and CCM brake are interchangeable. The CCM brakes have higher capacity than the steel brakes, so we don’t recommend putting the iron brakes on a "cup"-tired car.
And to answer the question directly: Yes, you could purchase the Z07 parts and bolt them on to a Z06, but we don't feel it would be worth the cost or effort. The initial perception might be that the car seems more responsive due to the high rates, but there won't be any real performance gain and it will definitely hurt the performance in other areas. It would be cost-prohibitive for us to do the optimization work to offer custom shock and chassis controls to optimize that system through service parts. We do appreciate the thinking however, we are always looking for ways we can configure the car to satisfy customers.
Thanks to Jim for that summary.
So to summarize, we can’t offer every imaginable combination because the resource cost and validation risk is too high. We try to focus on thoroughly optimized packages that address different customer’s needs. Since we introduced the Z06, we have already expanded our offerings to allow the CCM brakes on the standard car without spec'ing Z07. Those brakes do offer some attributes that customers desire without the super-aggressive tires and aero. Even though that is a "bolt on" combination, we had to go back and do all the testing to validate functionality. Note this does not mean iron and CCM brake are interchangeable. The CCM brakes have higher capacity than the steel brakes, so we don’t recommend putting the iron brakes on a "cup"-tired car.
And to answer the question directly: Yes, you could purchase the Z07 parts and bolt them on to a Z06, but we don't feel it would be worth the cost or effort. The initial perception might be that the car seems more responsive due to the high rates, but there won't be any real performance gain and it will definitely hurt the performance in other areas. It would be cost-prohibitive for us to do the optimization work to offer custom shock and chassis controls to optimize that system through service parts. We do appreciate the thinking however, we are always looking for ways we can configure the car to satisfy customers.
Last edited by jvp; 01-22-2016 at 04:09 PM.
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01-22-2016, 06:13 PM
#2
Safety Car
I think we have to thank Tadge and Jim from bringing us the Z07 pack to purchase in the first place. The CCBs are turning out to be a bit too rich for my blood but I do think they belong on there with the package as offered for sale.
None of the previous 'vettes come even close to the aggressive tune on the C7 Z06 Z07. It is refreshing and a strong point for this generation.
Anyone know what the challenge is with the rear sway? I'm referring to this statement: "The answer is because we are packaging the largest rear stab bar we can in both the FE6 and FE7." So much for what Motor Trend requested - a softer rear sway. Pobst disagrees with Mero here and I have to agree with Mero. Softening the rear never made much sense to me.
None of the previous 'vettes come even close to the aggressive tune on the C7 Z06 Z07. It is refreshing and a strong point for this generation.
Anyone know what the challenge is with the rear sway? I'm referring to this statement: "The answer is because we are packaging the largest rear stab bar we can in both the FE6 and FE7." So much for what Motor Trend requested - a softer rear sway. Pobst disagrees with Mero here and I have to agree with Mero. Softening the rear never made much sense to me.
Last edited by SBC_and_a_stick; 01-22-2016 at 06:16 PM.
01-22-2016, 06:50 PM
#3
Re: sway bar. I believe that any thicker sway bar will hit the muffler when the suspension unloads. At least the big Pfadt bars on my C6Z did.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
01-22-2016, 07:05 PM
#4
Safety Car
Re: sway bar. I believe that any thicker sway bar will hit the muffler when the suspension unloads. At least the big Pfadt bars on my C6Z did.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
Ahh, yes, of course it would be straightforward technically to pass the calibration along. Personally I think the Z07 pack was designed as a bundle to price discriminate. Not nearly as ruthless on the pocket as Porsche's $50k manual transmission premiums (thinking upcoming 911 r here) but in that same category. You get a lot for the dollar and it works together, but in small part it is a price bundle.
Last edited by SBC_and_a_stick; 01-22-2016 at 07:06 PM.
01-22-2016, 07:25 PM
#5
It is very cool that we can have this type of interaction with the team that builds our cars. Thank you Tadge / Jim.
I don't know why there would be a new validation or engineering required. The question was, if we buy the FE7 hardware package, would you make the software (that already exist) available for a fee. That's all. If the tire type is a problem, then you can add a disclaimer that these parts are meant for use with cup tires. I always see threads for people who buy Z07 package C7 and they turn around, sell the tires to get street tires since they have no intention of tracking the car. There are many Z06 guys who couldn't get Z07 package in 2015 due to constraints or don't want Z07 package for one reason or another. Anyway, I am thankful that they took the time to answer this question.
I don't know why there would be a new validation or engineering required. The question was, if we buy the FE7 hardware package, would you make the software (that already exist) available for a fee. That's all. If the tire type is a problem, then you can add a disclaimer that these parts are meant for use with cup tires. I always see threads for people who buy Z07 package C7 and they turn around, sell the tires to get street tires since they have no intention of tracking the car. There are many Z06 guys who couldn't get Z07 package in 2015 due to constraints or don't want Z07 package for one reason or another. Anyway, I am thankful that they took the time to answer this question.
Last edited by 5thGear; 01-22-2016 at 11:02 PM.
01-22-2016, 08:37 PM
#6
Le Mans Master
Ali, it appears Jim states that beyond the simple electronic variation, there are also mechanical component differences between the FE6 and FE7 MR components (internal valving I'd assume), so a simple offering of software wouldn't be adequate to make the "package complete". I suppose that is why Tadge concluded that the effort wouldn't be worth the result.
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skank (01-23-2016)
01-23-2016, 09:35 AM
#8
Le Mans Master
I'll take it! Any insight these guys are able to add to the forum is much appreciated. I've never been on a forum that received actual manufacturer support before so I'm always eager to read their response to questions.
01-23-2016, 10:29 AM
#10
Le Mans Master
I'm also wondering if I should add some Z07 swaybar bushings to my Z51...
01-23-2016, 10:34 AM
#11
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01-23-2016, 11:12 AM
#12
Ali, it appears Jim states that beyond the simple electronic variation, there are also mechanical component differences between the FE6 and FE7 MR components (internal valving I'd assume), so a simple offering of software wouldn't be adequate to make the "package complete". I suppose that is why Tadge concluded that the effort wouldn't be worth the result.
I think SBC_and_a_stick really nailed it that this is more about marketing than anything. At this point I'm going an aftermarket route anyway that I anticipate will work out better than the Z07 package in the end. We'll see when I can get back to the track.
01-23-2016, 11:15 AM
#13
Here's the previous thread on this.
https://www.corvetteforum.com/forums...fferences.html
Last edited by Poor-sha; 01-23-2016 at 01:15 PM.
01-23-2016, 11:48 AM
#14
Re: sway bar. I believe that any thicker sway bar will hit the muffler when the suspension unloads. At least the big Pfadt bars on my C6Z did.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
I figured this would be the answer and what irks me is that we're asking for a way to install the exact same config as is already validated as FE7, just after the fact. It's a not a request for a factory sanctioned mix and match scenario - just give/sell us the right software to go with the parts.
Which of course begs the question: what cosmic balance of legal requirements, performance expectations, country specific requirements, wheel rates, tire saturation, environmental conditions, ride, handling, and planet alignment allowed the suspension components, calibration and aero additions used on the coupe and the convertible to be exactly the same??? (is there an emoticon for raspberry?)
01-23-2016, 11:49 AM
#15
01-23-2016, 11:56 AM
#16
Le Mans Master
Well then...thanks guys!
01-23-2016, 12:11 PM
#17
In addition to allowing the CCB without the tires and suspension upgrade, its also allowed to option the aero without the suspension or tires. I guess that combination was validated too.
I just wish they would have spent the time, resources and money to validate the body colored vents option with the Spice package so I wouldn't have to paint the shark grey vents white on my brand new car...
I just wish they would have spent the time, resources and money to validate the body colored vents option with the Spice package so I wouldn't have to paint the shark grey vents white on my brand new car...
01-23-2016, 12:14 PM
#18
Le Mans Master
Thank you for the insight. Were the bushings noticeably stiffer? I'm shocked it made such a large difference!
01-23-2016, 01:50 PM
#19
Le Mans Master
What kind of cost variation is there between the route you went and doing an essential FE7 upgrade? You think the cost/benefit will add up for you?
01-23-2016, 02:07 PM
#20
I'll look around and see if I have any but I don't know if the PDR will convey the way the car felt.
The DSC Sport setup likely costs more than the FE7 parts (depends in part on how much GM would charge for the calibration if they offered it). However, I didn't get FE7 because of ride concerns and the DSC system has a great ride.
So far I've been pretty competitive in my FE6 car with other folks in FE7 cars so the real question is how much of an improvement will the DSC setup yield? Given their lap time improvements on the Gen V Viper and Porsches I have pretty high expectations.
Ahhh, I gotcha. Maybe Tadge didn't understand that the intent was to literally upgrade the entire car to FE7 essentially.
Seems to me what you just had put on your car seems perfect for your use and how hard you're running the car.
What kind of cost variation is there between the route you went and doing an essential FE7 upgrade? You think the cost/benefit will add up for you?
Seems to me what you just had put on your car seems perfect for your use and how hard you're running the car.
What kind of cost variation is there between the route you went and doing an essential FE7 upgrade? You think the cost/benefit will add up for you?
So far I've been pretty competitive in my FE6 car with other folks in FE7 cars so the real question is how much of an improvement will the DSC setup yield? Given their lap time improvements on the Gen V Viper and Porsches I have pretty high expectations.