Track oil fill level?
Thread Starter
Instructor
Joined: Dec 2014
Posts: 139
Likes: 10
From: Boston MA
Track oil fill level?
Have those of you that Tracked Z51 "overfilled" the oil ~ 0.5Qt ABOVE the top xxxx mark on the dip stick. Given GM reduced the fill capy in '15 not sure if the track overfill is still recommended. I'm a little concerned "overfilling" given problems some have had but that could have been due to missed 500 Mi change and foaming.
Vehicle Data 15 C7 Z51
Capacities and Specifications
Engine Oil with FILTER 6.2L LT1 Z51 9.8 Qt
Engine Oil without filter 6.2L LT1 Z51 9.5 Qt
Oil (Street) Mobil 1 5W30
*Oil (Track) Mobil 1 15W50 *0.5 Qt ABOVE normal fill xxx
Vehicle Data 15 C7 Z51
Capacities and Specifications
Engine Oil with FILTER 6.2L LT1 Z51 9.8 Qt
Engine Oil without filter 6.2L LT1 Z51 9.5 Qt
Oil (Street) Mobil 1 5W30
*Oil (Track) Mobil 1 15W50 *0.5 Qt ABOVE normal fill xxx
Last edited by 15C7Z51; Mar 10, 2015 at 06:42 PM. Reason: hilight oil info
Drifting
Joined: Oct 2014
Posts: 1,673
Likes: 199
Good question. I am going to the track on Saturday and I had the same question. A service technician at a local corvette shop told me to go half quart less. At Ron Fellows school the technician said he overfills the car.
Anyone can answer this question?
Anyone can answer this question?
Thread Starter
Instructor
Joined: Dec 2014
Posts: 139
Likes: 10
From: Boston MA
I just completed 2 days at Watkins Glen. It was my plan to do 15W-50 to the normal full level at top of xxxx. Well **** happens and I accidentally put a little too much in ~ 0.5 Qt maybe a little less. trying to get out (turkey bastor) from dry sump can no luck. I decided just to go with it as it is recommended for track. I had ZERO issue. Looked at all Cosworth data around oil pressure and temp and all seemed fine. I checked oil after each session following correct procedure- it did very slowly come down (2000 mi and this was first track event). By day two it was down to the normal xxxx full line and it did not go below that for the balance of day 2.
Many if not most trackers appear not to overfill from what I read here but from my experience you can be a little overfilled and did not present an issue for me
Many if not most trackers appear not to overfill from what I read here but from my experience you can be a little overfilled and did not present an issue for me
Le Mans Master
Joined: Jul 2000
Posts: 6,559
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From: North Dallas 40 TX
Is one a “poser” if they just like a really firm suspension? What if they like the look of the Z51 hybrid wing? Or superior accident avoidance?
By some definitions, isn’t everyone who doesn’t use the full performance capabilities of even a Base Corvette most of the time just a “poser”. Really cars are just for getting from A to B. we should all just be buying economy sedans with just enough seats for our families. Anything else is just someone being uppity.
By some definitions, isn’t everyone who doesn’t use the full performance capabilities of even a Base Corvette most of the time just a “poser”. Really cars are just for getting from A to B. we should all just be buying economy sedans with just enough seats for our families. Anything else is just someone being uppity.
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Safety Car
Joined: Jul 2018
Posts: 4,303
Likes: 2,055
From: Margate, FL
I believe GM wants the oil level at touch over due the assumption that at higher RPMs you'll burn a bit off during the event. So just a CYA?
I added enough to keep it at the top of the hash marks (full) and never saw any drop on track.
I added enough to keep it at the top of the hash marks (full) and never saw any drop on track.
Melting Slicks
Joined: Nov 2019
Posts: 2,528
Likes: 1,567
Is one a “poser” if they just like a really firm suspension? What if they like the look of the Z51 hybrid wing? Or superior accident avoidance?
By some definitions, isn’t everyone who doesn’t use the full performance capabilities of even a Base Corvette most of the time just a “poser”. Really cars are just for getting from A to B. we should all just be buying economy sedans with just enough seats for our families. Anything else is just someone being uppity.
By some definitions, isn’t everyone who doesn’t use the full performance capabilities of even a Base Corvette most of the time just a “poser”. Really cars are just for getting from A to B. we should all just be buying economy sedans with just enough seats for our families. Anything else is just someone being uppity.
Sr.Random input generator
Joined: Jan 2008
Posts: 7,802
Likes: 2,231
From: Sammamish, WA
The dry sump we have is a very simple design that doesn't scavenge oil in multiple spots, and does not create negative crank case pressure, either.
Advanced
Joined: Aug 2005
Posts: 92
Likes: 42
From: Jacksonville, IL
My 2 cents - I'll follow the advice/guidance of the GM Engineering team on this one... per my manual (2019 GS) - "Z51 Performance Package, Grand Sport, Z06, and ZR1: Check the oil level often during track events and competitive driving and keep the level at or near 0.5 L (0.5 qt) above the upper mark that shows the proper operating range on the engine oil dipstick. After the competitive driving, remove excess oil so that the level on the dipstick is not above the upper mark that shows the proper operating range."
Safety Car
Joined: Jul 2018
Posts: 4,303
Likes: 2,055
From: Margate, FL
How far above the top mark would this 0.5 qt track level be? 
I think the hash area is about an 1" long and the manual says if its low then add 1 quart.
If so then 1" = 1 quart, thus track level would be 1/2" above.
I think the hash area is about an 1" long and the manual says if its low then add 1 quart.
If so then 1" = 1 quart, thus track level would be 1/2" above.
Safety Car
Joined: Dec 2012
Posts: 3,858
Likes: 1,863
From: St. Louis Metro East IL
Guys, it's not about that, there's a possibility of oil starvation in certain cases, and extra oil is insurance for that. 2014 C7 Z51 was initially released with 10.3 quart capacity, but GM reduced it to 9.8 quarts in the last minute to reduce frothing, etc. in street use.
The dry sump we have is a very simple design that doesn't scavenge oil in multiple spots, and does not create negative crank case pressure, either.
The dry sump we have is a very simple design that doesn't scavenge oil in multiple spots, and does not create negative crank case pressure, either.
Sr.Random input generator
Joined: Jan 2008
Posts: 7,802
Likes: 2,231
From: Sammamish, WA
It's not a typo. The system is designed for 10.3 quarts, which was later dropped to 9.8 quarts to address complaints of frothing, etc. The engineers still wanted people to use the full 10.3 quarts at the track, which is why we have that recommendation. There was a production hold in the beginning, where I believe GM replaced the 10.3 quart max dip sticks with 9.8 quart max ones.
