A few words about me, and the development of the Solstice/SKY.
My name is Steve Padilla, and I am the Ride, Handling and Steering Development Engineer for the Kappa platform. I have met some of you on the forum over the last couple of years, and lurk occasionally on the forum. I attended the first 1000 party, as well as participating at the press event in Oregon. I was also in England with the Solstices, and did tuning on the Kappa in Germany including the Nurburgring.
I was assigned in November, 2002, to develop the vehicle dynamics of the Solstice, having come fresh off co-development of the Chevy SSR. As the platform structural design began, I worked with people from the advanced group to do predictive math modeling of the car.
The limits of the niche and performance envelope of roadster competitors were defined by driving them and testing them. We had to pay attention to where the competition was, like the Miata, the Z3 and Z4, and the Honda S2000. The Toyota MR2 and the Porsche Boxter were also evaluated as part of understanding the market.
Contrary to popular belief, we did not set out to conquer the Miata. From extensive research, it became obvious there was room in the roadster market for the right combination of style, cost, and performance within the niche. While the Miata is undoubtedly one of the most successful in this niche, there were people who made the choice not to buy a Miata for various reasons, be it cost, practicality, or even size.
Once I was assigned and began to research the competition, I set out a personal goal that I kept to myself. I observed that some of the cars did certain aspects well, such as the Miata for ride, or the Honda S2000 for responsiveness, but also did not meet personal expectations, such as overall damping or roll stiffness on the Miata, or a minimum amount of ride comfort on the Honda S2000.
Simply put, I decided to develop the car I would love to own personally, essentially trying to create the ride, steering, and handling that I want in my own personal car. This combination was not, and I believe is still currently not met by the other cars in this niche.
So, I can say I personally achieved this goal, and luckily, it happens to match the same vision that the program management team had for these performance aspects of the Solstice, (including Bob Lutz).
I do not currently own a Kappa platform product, but I know I certainly will in the near future.
However, this assignment was not about what I wanted to do. Accepting the job of tuning the Solstice meant ensuring the ride, handling, steering, and related areas of braking were developed to deliver the promise of the styling of the car. In other words - the performance had to match the look of the car. So, not only did I have to match my own personal expectations, I had to satisfy requirements as determined by the Chief Engineer, the Vehicle Line Executive, my Vehicle Performance Manager, and many other evaluators.
On behalf of my other engineering team members, from the people who worked with me on tires, braking and chassis controls, suspension and steering, to the electrical and structural people and those people who work on all the different systems of this car, I want to thank all of you for your enthusiasm for this car. Working on this platform required sacrifice and lots of elbow grease, and cohesive teamwork, and it is satisfying and also humbling to see people that support the product and are so passionate about it.
Fortunately, I got permission from our internal communications people to post the questions and answers that I addressed at the Kansas City Meet on July 14 through July 16. It was a pleasure to meet and speak to so many of you owners, and I hope to see you all again at future events.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
My Air Conditioning makes noise. My dealer re-charged it but it still makes noise.
I do not have an answer for this, but I will check and respond. Your AC lines may be contacting somewhere, transmitting sound into the structure or occupant compartment.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
My differential makes a Clunking noise/whining noise/both. Is there any way to fix this? Is GM aware of the issue?
In short, yes, GM is aware of the issue. There is no 'fix' for shifting clunk or whine.
Addressing Misinformation:
The clunk and whine is not an indication of any near-term failure, it is unaffected by different fluids (and as a matter of fact only the recommended fluid and additive should be used), and cannot be solved by changing differential mount bushings to harder or softer bushings. The clunk and whine are unrelated issues to the pinion seal leaks.
Some facts:
Limited slip differentials tend to be more noticeable than open differentials. Whine can vary in intensity, and clunk can be more noticable if the differential is heated up. The source of the noise is the differential, not the transmission. Whine has some influence on break in, so avoid wide open throttle starts and vary the speeds in your car for the first 500-1000 miles. The effects of break-in are not huge, but severely treating your car in the first 1000 miles is not recommended and is certainly not good for the differential. The clunk is not as much of an issue in Solstices with the automatic transmission. The clunk is also dependent on driving style, and upshifting at a higher RPM can reduce clunk in your car.
All RWD differentials clunk to some extent, and most will exhibit some whine, even on competitive vehicles. The issue exists on the Solstice because we had to use common parts with the CTS/STS including the type of mounting. In the Solstice, the differential is mounted directly to the structure and noises coming from the differential have a direct noisepath.
We are looking at ways to sucessfully address this issue from an engineering standpoint for future cars, but there is no fix for current cars already produced. I am sorry to bring you that news, but I would rather be honest then mislead you.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
My Differential leaks at the pinion seal, why is that?
The pinion seal leak is a quality issue from the supplier that makes the differential, Getrag. The leak is solved by properly installing a new seal according to supplied procedure. It is not a safety issue. We have seen service that improperly installed the seal, creating a second leak after the initial repair. I do not know the details of the exact issue, but I do know it is NOT an issue with fluid seal material compatibility.
I cannot relay the exact warranty rates, as I do not have the exact information, but we are aware of the issue and have been working to resolve it. This issue also has been seen on the cars that share the differential (Cadillac CTS/STS/SRX).
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Does using 87 Octane cause damage to my engine? Do I get a performance benefit if I use higher octane fuel?
Using 87 Octane, if your engine does not knock, will not damage your engine. The engine software detects knock, and will retard spark timing automatically to eliminate it. If you hear engine knock, it means that your engine has retarded the timing as far as it can go, and you should increase the fuel octane you are using. The base calibration for the engine is set to perform best with 91 octane fuel. Running at 87 octane in most conditions will have some effect in reduced performance (acceleration) but may or may not be detectable and is dependent on the driver. Running low octane fuel in high temperature conditions like today (100 degrees) is most certainly causing your engine to retard timing to eliminate knock. The higher the temperature outside, the more performance effect you may detect using 87 octane fuel.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
There are two pieces of tape under my Solstice. What are they there for? Mine are starting to come off. They are on every Solstice.
<Just Kidding!>
These pieces of tape hold the car together. Do not remove them.
</Just kidding!>
I will ask our body people, but they are probably there for either shipping protection, or to act as some sort of backing or support for sealant or foam. I am sure there are no ill effects by removing them.
It might help to have a picture of them in addition to your description, so please take a picture and post it if you can.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Chuck Mallett told me he was involved in the development of the Kappa platform. What did he do during the design of the car? He also told me he was involved in the build of the Hot Rod Solstice.
Chuck Mallett and/or Mallettcars was never involved with the development of the Kappa platform. Perhaps you misheard him. When I met Chuck, it was the first time he drove a Solstice, and was at the first 1000 delivery party in August, 2005, when the development of the car had already been finished. His first attempt at swapping a V8 into a Solstice was on VIN 6Y000206 in late 2005, well after start of production. I was partially involved with the Hot Rod Solstice, and can tell you Mallettcars was not involved in the development of that car, either.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Are you going to offer a V6 or V8 on the Kappa platform?
This platform, as has been stated before, was designed around the Ecotec 4 cylinder family of engines. This is not new news, Doug Parks (previous Chief Engineer), Mark Reuss, and Bob Lutz have stated the same thing in the press over the last two years. The current structure does not support a V6 or V8 in a production environment without substantial modification. Obviously, aftermarket companies like Werks, Archie, and Mallett have shown that a V8 can be stuffed in, but I suspect if you ask any of them, it is not a "bolt in" "weekend" job (or it would be a lot less expensive to do). The resulting clearances are very tight and would make some of our packaging people cringe.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Why did GM chose the tire (RS-A) for this car? How did you choose the tire for this car? What was considered when designing this tire? My dealer told me that there is a specific design of this tire that I have to get when replacing it, is this true?
We chose an all season tire for this car to avoid situations where people who buy this car and drive it do not find themselves stranded in winter months in small amounts of snow. Most, if not all competitor vehicles in this niche use summer only tires that are not designed for even minimal amounts of snow traction or maneuverability. With the styling and price point of the Solstice, we thought there would be a need for some snow traction and maneuverability, if we could provide competitive performance for the other areas of the tires.
Fortunately, we were able to find an optimum point among the many areas of tire performance to achieve competitive seasonal handling performance, while providing superior shallow snow maneuverability to other entries in the roadster niche. Other areas that matter are ride, noise, mass, and fuel economy contribution, and even the styling of the tire. All of these in addition to regulatory requirements are considered when developing a new tire.
On the website www.gm.com, there is an explanation that all General Motors tires designed for use on our vehicles have a Tire Performance Criteria, or TPC, label imprinted on the sidewall. This label is independent of the tire manufacturer. If we developed the tire for use on our vehicles, it has this label.
When replacing your tires, it is recommended you replace them with Original Equipment Manufacturer size and brand tires for your Solstice, with the TPC label on them. There are at least two versions of the Solstice sized Goodyear RSA, one is used exclusively on the Solstice, and the other is used on a very different sized and shaped competitor vehicle and is not optimized for a good balance of ride and handling characteristics on the Solstice/SKY. The design and performance criteria for tires has a large range within which we can tune the different aspects of a tire. Using a different tire on your Solstice, especially mixing different tire constructions even if they have the same brand name on the sidewall, can cause unexpected results in handling, ride, or steering.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Do modifications void the warranty?
I encourage you to look up the Magnuson-Moss Act. Usually, only failures that happen, or repairs that are required that are a result of a modification can be denied, such as a differential failure or transmission failure being denied warranty coverage because you installed a modification that increased engine power.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
Why is the window switch where it is? It is very inconvenient.
I know that the placement of many switches and controls are determined primarily by Design Staff. I do know we have had lots of feedback on this, and I will ask for more detail on this issue.
__________________ I don't suffer from insanity, I enjoy every minute of it!
#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles
It's never too late to have a happy childhood. But the second one is up to you and no one Else.
