[Z06] Oil Starvation on Track - Hard Data!
05-09-2009, 11:37 AM
#21
Drifting
since you already have the tools set up, would you be so kind & do another run with your car having the updated "fix" parts? Then we could also confirm if the said "fix" parts (ARE & Lingenfelter tank, '09 system, etc....) actually works/fix this said issues. Great job & thx again.
05-09-2009, 12:32 PM
#24
Race Director
Nice write up, Dreaming. Well thought out and concise. It would be interesting to see the data on the LS2 & 3 in similar conditions. I bet it wouldn't be that different. Besides, who would be pulling 1.2G on the streets? ...and on Goodyear runflats!
I wonder if a superior oil could protect vital engine parts even @ a zero pressure situation....(yup!)
I wonder if a superior oil could protect vital engine parts even @ a zero pressure situation....(yup!)
05-09-2009, 12:47 PM
#25
Safety Car
Great info and nice write up. I'll avoid tracks with long lefts. I've heard that high sustained g lefts were a problem for our cars but your data confirms the anectodal evidence. Thanks much!!!
05-09-2009, 12:48 PM
#26
Melting Slicks
Member Since: Nov 2000
Location: Merritt Island Florida
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VERY nice finding
My car is upgraded in all department except for the block which is stock and so is pil pump.
This winter i upgraded to a ARE stage 2 system.
On my first hard lap around the ring it failed after right after Mercedes curve, a long double left hander with a third 180 degree left coming up right after the double left hander (F1 part of the track).
My car has seen its fair share of track days and 1.4 G and over happen all the time (Hoosier and turn + compression)
Someone told me a batch of 2007 engines had to tight tolerance on rod bearings , leading to this kind of failure ?
Now it seems that GM has a real problem for the customers that take the car to tracks with long sustained G`s in left hand turnes ?
not good
Anyone i can email pictures to, so you can see a REALLY bad crank/rod failure ?
Crank is so bendt that i cant turn it over even when heads, piston and rods are out.
regards
Rune
This winter i upgraded to a ARE stage 2 system.
On my first hard lap around the ring it failed after right after Mercedes curve, a long double left hander with a third 180 degree left coming up right after the double left hander (F1 part of the track).
My car has seen its fair share of track days and 1.4 G and over happen all the time (Hoosier and turn + compression)
Someone told me a batch of 2007 engines had to tight tolerance on rod bearings , leading to this kind of failure ?
Now it seems that GM has a real problem for the customers that take the car to tracks with long sustained G`s in left hand turnes ?
not good
Anyone i can email pictures to, so you can see a REALLY bad crank/rod failure ?
Crank is so bendt that i cant turn it over even when heads, piston and rods are out.
regards
Rune
05-09-2009, 12:59 PM
#27
Drifting
Member Since: Dec 2005
Location: Bend, Oregon Black / Ebony 2LZ 2006 Z06 C6Z06 owner since 2/7/2006
Posts: 1,926
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Absolutlely a great write up and have confirmed what most have believed without hard documentation. Definitely could use more data from other tracks. Sustained 1.2G on run flats and stock suspension is not likely. Most 1.2G+ we see on our HUD is momentary G's in OEM setup. I bet GM has done their testing and are comfortable with the performance of the C6Z in stock configuration, but I do believe that we are at the limits of the oiling systems. Any mods to improve handling combined with certain circumstances as Dreaming has demostrated, you will most likely need to improve the oiling system.
Dreaming, what tires and suspension do you have on your car?
Tom
05-09-2009, 02:26 PM
#29
Le Mans Master
Excellent writeup. Looking forward to more data.
05-09-2009, 03:27 PM
#31
1.2 G's can be done in stock form on a banked track. My local track have around 6 banked turns out of 13 turns. I hit 1.06 up to 1.2 on all those banked turns every lap. I notice pressue drop only when my oil temps are above 260 which is why i run 15w50 and upping to 15w60 oil next time.
05-09-2009, 03:51 PM
#33
Melting Slicks
Thread Starter
I believe the larger oil (LPE or '09) tank will give you more time at the high-G's before the pressure drop... for example, >1.0G for 6-7 seconds (?). And that's a LONG time to sustain those G's...
Last edited by Dreamin; 05-09-2009 at 03:59 PM.
05-09-2009, 03:53 PM
#34
Melting Slicks
Thread Starter
05-09-2009, 03:57 PM
#35
Melting Slicks
Thread Starter
Rumor is they only tested with the stock tires... I think it would be very difficult to sustain the high-G's on the stock tires. I see "Instantaneous G's" of >1.6G... but sustained G's is tough...
05-09-2009, 03:59 PM
#36
Melting Slicks
Thread Starter
05-09-2009, 05:14 PM
#39
Burning Brakes
Fantastic write-up! This information is so vital to better understand what is going on with the oiling system during a track event. This hard data puts the kibosh on some theories. 
05-09-2009, 05:43 PM
#40
Melting Slicks
Member Since: Oct 2007
Location: Northwestern Connecticut
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St. Jude Donor '10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20-'21-'22-'23-'24
Great job, Finally some decent threads on here, not just rims, what radio station do you listen to, etc!
I wonder if adding an accusump would void the warrantee? Common sense says no, GM might not believe in common sense though!
I wonder if adding an accusump would void the warrantee? Common sense says no, GM might not believe in common sense though!