baron95

I'm a first time Corvette owner (2015 Z51 2LT A8 Shark Grey), purchased 4 days ago. I love the car - great capabilities, yet quite comfortable.

I am a NASA HPDE Instructor and occasional racer (just to keep skills up), and have driven and instructed on a variety of street cars on road circuits.

I'm shocked at what GM is expecting Stingray Z51 owners to do to drive on a track, which I have never been required to do on any other car, from cheap Mustang GT to Porsche GT3.

As I understand it, when I go to the track, I have to:

• Remove front wheels to install cooling rings with safety wire.
• Flush the brake fluid and replace with hi-temp DOT4 fluid.
• Flush the oil system and replace the oil with 15W50, and overfill it.
• Set alignment to track settings.

During track driving only the driver seat may be occupied - no one can be in the passenger seat - no instructor/coach allowed!!!

Then, after the track I have to:

• Pull the front wheels to remove the cooling rings, or it will cause corrosion.
• Flush the brake system and put DOT3 fluid back!!! Why?! Why can't this car run all the time with DOT 4?
• Flush the oil system and replace the oil with 5W30 Dexos spec which is "the only approved oil" or risk voding warranty.
• Set alignment back to standard settings.

Is this a joke? We are talking about $700+ in expense at normal shop/dealer rates for each track day!!! This for a car that is supposed to be the "track package" model?

What are people who are tracking their Stingray regularly doing?

Should we have a petition into GM to clarify that DOT4 and 15W50 and cooling rings can be left in the car for the warm weather season, if multiple track events are planned?

Any other ideas/suggestions?

C7-Beast

My 15 came with DOT4 brake fluid. Not understanding why GM would ever suggest DOT3 in a Corvette.

I get why they suggest the heavier weight oil. The oil will get pretty hot and the 50w will not be as thin as the 30w. I also would not want to race my car then use the same oil off the track. During normal driving, the 50w oil is too thick and may starve the bearings for oil over time.

I think the brake cooling rings are most likely not needed. They are suppose to rust quickly if left on the car. Not sure why GM could not have used a different material to ensure they won't rust but I'm no engineer.

DEXOS is simply a certification. Many companies like Castrol refuse to pay GM for this certification even though their oils exceed this specification. I don't like M1 and never have. I'll use the 5w-30 as recommended but I could care less if it's DEXOS certified.

I used non DEXOS in my 11 CTS-V and in the 4 years I owned it, never had any issues. The manual even said, you can use an API certified oil if DEXOS is not available. In the last 2 years, GM took that exception out. Why? So they can ensure they get every dime of money by forcing you to use a product that someone simply paid GM to certify. I call BS.

nmerhaut

I agree with you completely. My '09 Z06 was gas and go. I don't have the time and the expense account to do that kind of prep 6-7 times a summer. Why not leave the 15W50 oil in if you only drive it in the summer? I understand leaving the rings on the front may cause them to corrode from rain,etc.

I asked my instructor about it but he hasn't gotten back to me on it.

I wonder how many track guys are following the prep to the letter.

I used Motul in the Z and would switch to that for the track and leave it in.

Since my local track has been undergoing management problems, my HPDEs days may be waning.

Glad you broached this subject and perhaps other veteran drivers will respond.

arcticblast

This is part of the reason that I recently dropped out of the HPDE at the MSP during the Bash in BG. This type of prep would require me to have a local shop in BG and an extra day before and after to do the changes.
And my car is a 2015 Z06, which I thought was track capable from the factory.
To be honest, I was told that the only required modification was the DOT4 brake fluid change. However, the other changes are 'suggested'.
This in addition to almost $700 track insurance for the two day event.
I am, however, a novice on track. And I do respect the advise of more seasoned veterans. So instead of the extra time and money, I decided to drop out and give someone else the spot.
Another dream of mine that may remain unobtained.
But I will be at the Bash in a 2015 Z06, so I still consider myself blessed.

baron95

I don't mind switching to a quality DOT4 brake fluid. The issue is GM telling us to switch back, after tracking, to DOT3. Why can't they design a brake system that works with quality DOT4 all year or at least all warm months? There is little difference between fresh (i.e. dry) quality DOT3 and DOT4. It is only as they stay in longer (i.e. start absorbing moisture) that the DOT4 higher wet boiling point comes into place. If you are switching out every event, it is just trowing money out for no reason.

As for the oil, Mustang Boss 302 and GT Perf Pack run fine street and track on factory standard 5W-20 (IIRC) and GTRs and Porsches run fine street and track on 0W-40 (IIRC). Why was GM incapable of designing an engine that can work well street and track on a single oil spec, for their "performance, track ready" halo car?

The cooling rings are another kludge. Why can't GM engineer proper brakes that get sufficient cooling for street and track and/or track cooling aids that don't rust out if left installed? This is their performance halo, "track ready" car, is it not?

As for the alignment, I made it a condition of taking delivery of my car, rings installed by dealer and a track alignment. First the dealership asked me for what the alignment sets were (I had to refer them to the manual pages and send them the track prep guide). Then after 3 hours they claimed they couldn't do it, because there is a tool required in the instructions that no dealer has. When I pressed they spent another 3 hours and managed to get close to the camber, and would only do it with a disclaimer on the work order that they set it up to "customer specs" and all sorts of whining.

I'm shocked that not many people or the press have made noises to GM about this. I find it puzzling and embarrassing for a performance/track-ready car to require hours of service and replacement of fluids before you can do a track day on it.

If I track with 5W-30 and the engine blows and car is towed to Chevy dealer is my warranty void?

If I am driving to or from the track on 15W-50 and my engine blows and car is towed to Chevy dealer is my warranty void?

If I am driving with DOT4 fluid (not approved for street by GM) and my brakes fail and I hit someone, am I risking a reckless operation persecution?

Insanity. What manufacturers put on their manuals have consequences for owners.

11B250

I agree with you 100% I don't know what other manufacturers require though, so I didn't know that this wasn't the norm.

I'm pretty sure my '15 requires DOT 4 though. The cap says DOT 4 ONLY on it, not sure why yours is otherwise?

the oil thing is crazy. Why couldn't they have designed the vehicle to run on 1 oil? and those cooling rings... I really don't get them. Do any other track car require something like that?

baron95

I'm traveling right now (typing on an airplane), and unfortunately can't double-check, but, my owners manual says DOT3, the online owners manual says DOT3, and I'm nearly certain that when I looked in the reservoir the cap said DOT3 ONLY on it.

Does anyone one has a 2015 Z51 with DOT4 brake fluid indicated in the brake reservoir?

C7-Beast

Yup, I do...



2015 Z51 build date 10/10/2014

jedblanks

Dot 4 has higher temp rating but that rating quickly degraded and therefore doesn't last as long as dot 3. But if you do some research you will find that dot 5.1 (NOT DOT5 silicone!!!) has the higher temp ratings and similar durability to dot 3.

As far as alignment settings those are for better performance at the track and setting them back is for better durability. So pick your poison.

For the oil, I'd run rotella t6 5w40 heavy duty oil and forget about it. Although changing after track might be a good for wear reasons. Either that or like another poster suggested run 15w50 during track season and just give it a little longer to warm up for street driving.

Brake safety wire is probably a good idea and possibly a requirement.

Remember that the manual was written for end users that don't know anything about cars and also as a CYA for manufacturer.

baron95

Thank you for answering and for posting the picture.

Is your car a manual or A8?

I tried to read the labels on your picture (not having my car in front of me for reference), but it got blurry when I zoomed in.

I see the plastic reservoir, but can't read the label on top of that. I see DOT4 on the black label next to the reservoir, but I wasn't sure if that was the brake fluid or clutch fluid.

Could you please clarify?

Thank you.

I may be wrong (again, forgive me, I'm not near my car), but I think you may be mistaking the clutch fluid (which in fact GM specifies DOT4 brake fluid *for the clutch*) with the brake fluid which GM specifies as DOT3 on the manual and IIRC on my car brake reservoir.

C7-Beast

You're right. The DOT4 is for the clutch in my M7. The print on the top of the brake fluid reservoir says DOT3. My bad.

baron95

Got it. Thank you for clarifying.

I hate not being able to go to my car and check. And also having to be away on a trip, the first day the weather turned nice since I bought it.

Rob Willis

The engine oil is the biggy.

If you want to leave the alignment alone afterwards you will probably get increased inner tire wear, thus why they suggest going back.

I'd harbor to guess those brake cooling rings do very little.

jwbert

If you do several track days per season you are going to use up
your rotors anyway, so why not just replace the stock rotors that
require the silly cooling rings with DBA 4000 (T3's)rotors from KNS that
do not require rings? As far as pads go, while your at it, might as
well just put in a set of more durable track pads, and they are so
easy to switch back and forth on the C7. Put the Motul 600 in and forget it, bleed out your calipers after each track event and this way you always have fairly fresh stuff in the system. The oil issue I haven't
come up with a clear answer yet, I usually change after a track day
anyway, but I have been wondering about the wisdom of maybe saving
the 5W30 I drain out with only 500 or 1000 miles on it and putting it
back in after the track day with a fresh filter? On my old Z06 I used the
0W40 European blend, but still changed after every 2 track days or so,
depending on what kind of oil temps I saw on track. I do my own alignments on the four post lift, so changing back and forth, although still a pain in the ***, can be done. Again on the old Z06 I compromised with running a 1.4 or 1.5 camber and just left it for
street use, didn't tear up my tires, but then I don't put on a lot of
street miles. While at Spring Mountain for the level two class, I had the
opportunity to run a car with street alignment and then track alignment, (0.4 neg camber vs 2.0 neg camber) the difference was
remarkable, but one would have fun on track with either one. So I
guess what I'm saying is the track prep is probably a requirement for someone running 8/10th or better, but if one took it easy, you could
get by with doing very little prep other than brake fluid, which I feel is
mandatory. Spring Mountain runs stock GM pads and rotors.

4GS7

GT Performance Pack and Boss302s run 5W50 factory fill. 8.5 quarts. 100 dollar oil changes.

AORoads

While $700 is quite a bit, does anyone have concerns that a day of "racing" may be more stressful on an engine, trans, brakes, clutch, tires, etc. and its related fluids than 5,000 miles of normal driving? And if so, doesn't it make some sense to switch them?

After all, many owners are willing to switch out their brake pads because they're really not made for street driving. Maybe brake fluid that's been cooked and/or kept at high temps all day is partially used up? Or oil at 15/50? Maybe? Just asking the question(s).

EcoBrick Bob

I am wondering if a straight weight oil like 40W synthetic might be a better choice, or if you're in slightly cooler temps, 30W synthetic. That is what my boat engine requires, and it gets run at high RPMS(steady 5000+ RPM) for a mile or 2 at a time. (22' Ebbtide - 70-77mph) We also have a 140 DEG T-stat which is what Yamaha installed in our 454, now 502..... Mercury Marine in their Chevy's now spec 40 weight.

Comments??

baron95

First of all I have tracked many different types of cars, and I can easily make rotors last a season or more. As for pads, I'll be using Carbotech XP10s. None of this is the subject of the thread - I've been driving/instructing for years, and will know what the car needs.

The issue is that GM is covering their *** (under threat of voided warranty) with an an unworkable set of before/after track day preparation.

I can manage the temperature of any engine, any transmission and any brake system, any tire on track. That is not the issue.

The whole point of buying a Corvette Z51, is that it is supposed to be track capable/ready with no additional investment. If you have to change everything, what is the point of the Z51 package? Posing?

Yes, any car can be made better. But what GM is saying is "you must do these unworkable things before tracking and undo them after tracking or you risk your warranty". They are not saying "the car is good to go as is, but if you want it to run even better do these things".

P.S. If you think that hammering the pins in/out your Brempo calipers in time after time after time to change the pads back and forth, and loosen/tighten the bleed valves time after time, is risk free and worry free you are mistaken. As every mechanical system, the less you disrupt it the better off you are. Same for doing/undoing the bolts to replace the rotors. You are one over torque away from a big expense and/or catastrophic failure.

baron95

Why are you posting this? The Mustang GT Track Pack (through MY2014) and Performance Package (MY2015) use 5W20 plain jane oil (8 quarts). I owned a 2012 one, tracked it dozens of time, kept the same oil year round, per Ford's recommendation without an issue and know many other Mustang GT and 302 owners who did the same.

302S is a race car, non-street legal, so not even worse discussing, since street to track preparation does not apply.

baron95

It will not likely be a better choice.

1 - It would void your warranty, if you had a problem and it was found out that you used it.

2 - Straight 40W oil will be very, very hard to get to all the places it needs to get to, fast enough on engine start and while the engine is cold. I just finished a track day at Lime Rock Park, where the morning temps were near freezing. I would not want to have straight 40W oil on a modern engine that requires 5W on the cold end.

Now, 0W-40 is likely a better track/street all around oil than 5W-30, but again you have warranty concerns, since it is not approved/recommended by GM.

In any event, the whole point of the thread is the unworkable recommendations from GM to even do one lap on track on their "track ready" halo Z51 Stingray model. Since C6 Z51, C6 Grand Sport, C6 Zo6 had no such unworkable limitations, is this a step back?