Oil starvation at the track -C5z06
 

One thing that I've read on these forums is how our engines can run dry in high banking situations and that scares me. I don't have 4-6k to throw at a motor so I want to protect it as much as possible. I know about filling the stock oil pan with an extra quart before track days but my concern is when I move to stickier tires. I think I need to avoid slicks unless I want to run a dry sump which again is $$. My car is dual purpose but not a daily by any stretch of the imagination.

What do you guys think of this as a safe alternative?

Batwing oilpan and at most R compound tires?

Nothing is fool proof but wanted thoughts from those who have been through multiple setups (and maybe motors too! :eek: )

A C5Z with an extra quart is fine with Hoosiers. If you want extra protection, you can get an accusump for about $400.

Isn't the C5Z a dry sump?

no you're thinking of c6z's and grand sports

I'm pretty confident that short of aero or slicks and just the right track, the C5Z is pretty stable as long as you overfill the oil by 1 qt. I've run California Speedway Roval configuration which has 14 degree banking into T 1-2 and corner speeds in the 140 range without issue. Lots of the C5Z racers on the CF seem to do fine with the stock oil pan and maybe an accusump.

:iagree:

Same track on slicks & 1 qt over, no issues with oil pressure although temps got up there. I tend to rev high, if I short shifted it probably would have been cooler.

:thumbs:

The issue with LS engines is long high G left hand turns. The oil gets pumped up into the engine and doesn't return quick enough. If you run a track with those types of turns then the 1 qt over may not be enough. One thing you can do to manage the problem is use higher gears when going through corners. You can run third at higher rpms at part throttle or run fourth at lower rpms at full throttle. A lot of racers ran Accusumps most DE people didn't since the cars were also street vehicles.

Bill

Bill, I'm aware of the high G left hand turn oiling issue. That is why I used the example of the Cal Speedway Roval. NASCAR T1 and T2 are 14 degree left hand turns with 145-150 entry speeds, around 5500 RPM in 5th with my 285/35 square tire setup. In that situation my C5Z has not had an issue. :thumbs:

I ran my car just about as hard as I could on slicks the last two years at Sebring with one quart over. The only thing I ever noticed was one time I got some oil in my intake. It wasn't very much but just enough to notice a burning smell.

Otherwise, running Continental GTI's I never had an issue. This was on stock suspension with shock and sway bar upgrades.

I agree with Bill. I think you have to really push them for a long time to possibly have an issue. Even then, I think the LS7 is more prone to these issues than an LS6. May people have run LS6's even in left handers without issue.

Thanks for the input guys. I was following another C5Z at Putnam a few weeks back and i couldn't hang with him in the corners since he had slicks and it made me want a sticker tire. Then towards the end of the day i saw him pull off with something wrong. I never asked but I immediately thought of oil starvation. Sounds like i'm safe for now though.

I thought the problem was right hand turns not left? I have the same stock motor I have raced for around 8+ years without blowing it up yet. With nothing more than 1 qt over it has raced countless times at ACS, once at Michigan int. speedway, and twice at Daytona int. speedway. It was run hardest 2 weeks ago at Daytona Runoffs and it is just fine max speed for me through the speed trap was 158mph.

Acusumps are worthless IMO because they dump their oil too quick. We are in sweepers for a very long time.

dumping too fast
 

Wondering what you mean by dumping too quickly?
I had been in an occupation for 25 years where I helped mechanical engineers choose equipment for fluid control and pressure applications. Running slicks at Thunderhill gave me an opportunity to consider different oil add on options for my '08 LS3. Not wanting to put out the money for a dry sump, I installed an Accusump. Setting the 3 quart canister next to me, allows me see when it actually dumps. Mine takes > than 20 seconds to empty and on our sweeping turn #2, it starts to dump at the end of the sweeper. I'm pretty encouraged with having an extra 18 or so seconds left in my oil tank.

How long do you go through sweepers?

signed "the Swagelok vette guy"

:thumbs: Great information. I like those kinds of facts! Are you using the manual valve or the electrical setup? I understand the mechanical flows back and forth quicker? :cheers:

To Bill, I don't understand what you mean by high RPM but not full throttle being better than high RPM with full throttle. How does the oil pooling in the head know any difference in throttle application? Is it not simply a matter of RPM?

I THOUGHT I had an oil issue but now believe it was a buggy version of efi Live. Of course that didn't come to light until AFTER I install a 3qt accusump.

Anyway I can roughly confirm Dirk's time estimate. I have a 13 psig air-side precharge and am amazed at how long it holds pressure to pre-lube my motor down to an empty sump. Thats going through the EPC on the new version of the canton solenoid valve.

Don't know if prelube is needed beyond the psychological benefit, but now my car always get a cold start with 25psig of oil pressure.

While I'm not a supporter of running an Accusump, I think there is something to be said for priming a cold engine, especially if you run a non-bypass oil cooler like I do.

On a cold start it takes a good 20 seconds of running before I see oil pressure on my dash gauge. That is with the DRM oil cooler with -10 lines. That's why I have a cutoff switch to disable the fuel pump and spin the engine to build oil pressure before i start it.:thumbs:

You might want to consider getting a data logger that will let you log external inputs. That way you can try slicks and find out if your oil pressures are outside of your comfort zone. The logger in my car, from Racepak, allows for inputs and I've spliced into the car's existing sensor.

Below is some data from my car from a couple of years ago. It is a C5Z06, and had an oil cooler, accusump, 10W30 oil (half a quart over full), and Pirelli slicks (DH compound). The car doesn't have any significant aero. The engine has since been rebuilt and I'm told the bearings looked great.

http://i610.photobucket.com/albums/t...psk5vepsmd.png

My oil pressure characteristics didn't like what I've shown until I became quicker at certain points on the track. So be aware that issues that other have or don't have may not apply to you. Data for you and your car can be helpful.

Left hand. Supposedly all of the oil gets pumped up into the rocker covers. That is why I always limited my rpms in turns especially when I could put down just as much power at the rear wheels in a higher gear and make it more controllable so I could move my foot off and on the throttle to balance the car and take advantage of the trialing throttle oversteer that is inherent in the C5/C6 Chassis.

Bill

How long in sweeper? Not sure Bustop to T1 at Daytona is taken flatout because of the left hand 31 degree banking. It is really a stupid simple track layout but its Daytona. A lap is 2 minutes. I think we are in the banking a long time.

Accusump says you get 15sec on the 3qt at idle startup. The claim to fame of these devices is start-up oiling and surges. I can't answer your question but we can figure it out. What is the volume output of the C6 oil pump at 6000rpm? How long does it take for an LS3 C6 to move 3qts? Is accusump 3qt capacity at idle 1000rpm 15 seconds really 2.5 seconds of oil at 6000rpm? A smart guy needs to do the math.

Aside from what might be empirical calculated facts what happens in real life? Our own early LS3 adopter, white Knight (chris) or was it subdriver ,can't remember, blew up 3 LS3's trying all the options (oil pan baffling, accusump) until the Avid drysump became norm for racing LS3's. I can tell you there is not 1 dot-R tired national championship winning LS3 that is not drysumped. There is no way anyone would spend $4000 on a drysump if $400 on an accusump would have solved the LS3 oil starvation problem. J Buttermore ex national champ tied in and works for GM has a drysumped LS3. Today anyone club racing an LS3 at anywhere near competitive laptimes is drysumped.

Carl just for reference, are you still running an LS6 with the stock batwing pan?

Whatever the 2004 zo6 comes with.