986 Race Car on Slicks - Engine reliability upgrades?
10-29-2012, 08:56 PM
#1
Instructor
Thread Starter
986 Race Car on Slicks - Engine reliability upgrades?
Hi Gents,
I currently run a 986 on R888s and Michelin Cups.
We are looking at changing class for next season and will be running on Slicks.
We already run a baffled sump and I am aware of the oil pump starvation issues.
TTP make a Twin oil pump setup. Does anyone have any experience of this?
What preventative measures would you recommend for running the car on slicks?
Cheers,
Sean
I currently run a 986 on R888s and Michelin Cups.
We are looking at changing class for next season and will be running on Slicks.
We already run a baffled sump and I am aware of the oil pump starvation issues.
TTP make a Twin oil pump setup. Does anyone have any experience of this?
What preventative measures would you recommend for running the car on slicks?
Cheers,
Sean
10-29-2012, 11:48 PM
#3
10-30-2012, 12:25 AM
#4
Former Vendor
Here is what the most recent Boxster that came in on slicks looked like after an on-track episode. Lots of parts for the trophy shelf from this one. BTW- an accu-sump is a band-aid for the real problem.
These engines don't suffer from starvation- they suffer from thermal breakdown-period.
https://www.facebook.com/media/set/?...4914693&type=1
Here is a sample.. More pics to post tomorrow as we pick up the rubble.
These engines don't suffer from starvation- they suffer from thermal breakdown-period.
https://www.facebook.com/media/set/?...4914693&type=1
Here is a sample.. More pics to post tomorrow as we pick up the rubble.
10-30-2012, 07:24 AM
#5
Instructor
Thread Starter
We run an Accu sump on 2 Lotus Exige track cars. It works, but I don't believe its the best solution.
I was hoping you'd reply Jake. But could you please expand.....?
So, you're saying its not oil starvation but engine temps that are the main issue?
We run additional cooling to the radiators (986 S, so 3 rads) and a smaller crank pulley. We monitor engine temps via a data logger and very rarely see anything over 90deg. Engine oils changed after every race weekend, we run Modil 1 and Millers Competition 5W-40, in 2 different cars.
Here is what the most recent Boxster that came in on slicks looked like after an on-track episode. Lots of parts for the trophy shelf from this one. BTW- an accu-sump is a band-aid for the real problem.
These engines don't suffer from starvation- they suffer from thermal breakdown-period.
https://www.facebook.com/media/set/?...4914693&type=1
Here is a sample.. More pics to post tomorrow as we pick up the rubble.
These engines don't suffer from starvation- they suffer from thermal breakdown-period.
https://www.facebook.com/media/set/?...4914693&type=1
Here is a sample.. More pics to post tomorrow as we pick up the rubble.
So, you're saying its not oil starvation but engine temps that are the main issue?
We run additional cooling to the radiators (986 S, so 3 rads) and a smaller crank pulley. We monitor engine temps via a data logger and very rarely see anything over 90deg. Engine oils changed after every race weekend, we run Modil 1 and Millers Competition 5W-40, in 2 different cars.
10-30-2012, 02:38 PM
#6
Three Wheelin'
Join Date: Oct 2004
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if you agree w/ jake's premise that thermal breakdown rather than starvation is the issue, then you would need a better oil cooler setup. i know that jake makes an adapter plate that replaces the OEM oil cooler; the plate can be plumbed to an external heat exchanger.
personally, i DO think starvation is an issue on slicks. i agree w/ jake that oil temps are a problem, but the physical layout of the motor can lend itself to problems w/ high lat G's.
porsche also recognized this problem; their solution was the X51 dual chamber scavenge pump OR the 'motorsports' modification. it involved larger scavenge pumps w/ some additional oil lines from opposite sides of the motor. they resolved this issue w/ some internal oil galleys in later motors, but i am not 100% positive at what model year they break in for the boxster. w/ the 996, it was the 3.6L.
personally, i DO think starvation is an issue on slicks. i agree w/ jake that oil temps are a problem, but the physical layout of the motor can lend itself to problems w/ high lat G's.
porsche also recognized this problem; their solution was the X51 dual chamber scavenge pump OR the 'motorsports' modification. it involved larger scavenge pumps w/ some additional oil lines from opposite sides of the motor. they resolved this issue w/ some internal oil galleys in later motors, but i am not 100% positive at what model year they break in for the boxster. w/ the 996, it was the 3.6L.
10-30-2012, 03:52 PM
#7
Former Vendor
Engines equipped with additional scavenge pumps as you describe still fail on the track, see wee them quite frequently. While these engines may have more scavenge capability; the passages within the case that move the oil back to the sump are not increased and become a limiting factor at higher volumes.
G forces from track activities are simply the straw that breaks the Camels back.. Its not what starts the issue.
We actually remove some factory equipment to keep engines alive on the track and have only had one on-track failure in the history of our program. That failure was induced by a broken oil pump drive shaft that shut the oil pump down and killed the internals. As a result the LN billet oil pump drive was developed.
We have even campaigned the M96 engine in Grand Am series racing with zero engine failures with the same mods that we apply to street engines. There are a lot of ingredients to this success, the biggest being the liquid that keeps the engine alive.
G forces from track activities are simply the straw that breaks the Camels back.. Its not what starts the issue.
We actually remove some factory equipment to keep engines alive on the track and have only had one on-track failure in the history of our program. That failure was induced by a broken oil pump drive shaft that shut the oil pump down and killed the internals. As a result the LN billet oil pump drive was developed.
We have even campaigned the M96 engine in Grand Am series racing with zero engine failures with the same mods that we apply to street engines. There are a lot of ingredients to this success, the biggest being the liquid that keeps the engine alive.
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10-30-2012, 04:14 PM
#8
I've run mine (3.6L M96, 345rwhp) on cup size yoko slicks for the past few months. Upgraded baffles, motorsports air/oil separator, increased bearing clearances, Carillo rods, Mobil1 Racing 0-50. Scary low oil pressure on the banking of Cal Speedway at full throttle (160mph+), under cornering, under braking etc. Still alive so far, but can't believe it lives with those oil pressure numbers.
Will likely just dry sump the motor soon. Or at least for the next 3.8 to 4.0L conversion that will go in it.
Will likely just dry sump the motor soon. Or at least for the next 3.8 to 4.0L conversion that will go in it.
10-31-2012, 02:38 PM
#9
Instructor
Thread Starter
if you agree w/ jake's premise that thermal breakdown rather than starvation is the issue, then you would need a better oil cooler setup. i know that jake makes an adapter plate that replaces the OEM oil cooler; the plate can be plumbed to an external heat exchanger.
personally, i DO think starvation is an issue on slicks. i agree w/ jake that oil temps are a problem, but the physical layout of the motor can lend itself to problems w/ high lat G's.
porsche also recognized this problem; their solution was the X51 dual chamber scavenge pump OR the 'motorsports' modification. it involved larger scavenge pumps w/ some additional oil lines from opposite sides of the motor. they resolved this issue w/ some internal oil galleys in later motors, but i am not 100% positive at what model year they break in for the boxster. w/ the 996, it was the 3.6L.
personally, i DO think starvation is an issue on slicks. i agree w/ jake that oil temps are a problem, but the physical layout of the motor can lend itself to problems w/ high lat G's.
porsche also recognized this problem; their solution was the X51 dual chamber scavenge pump OR the 'motorsports' modification. it involved larger scavenge pumps w/ some additional oil lines from opposite sides of the motor. they resolved this issue w/ some internal oil galleys in later motors, but i am not 100% positive at what model year they break in for the boxster. w/ the 996, it was the 3.6L.
Our engine is a M96.21.
Do you have any part numbers for the X51 pump and lines, or know of a supplier?
Uprating the oil cooler is something we will be looking at regardless. But currently oil temps haven't been an issues for any of our race cars (4 in total).
10-31-2012, 05:22 PM
#10
Instructor
Thread Starter
Engines equipped with additional scavenge pumps as you describe still fail on the track, see wee them quite frequently. While these engines may have more scavenge capability; the passages within the case that move the oil back to the sump are not increased and become a limiting factor at higher volumes.
G forces from track activities are simply the straw that breaks the Camels back.. Its not what starts the issue.
We actually remove some factory equipment to keep engines alive on the track and have only had one on-track failure in the history of our program. That failure was induced by a broken oil pump drive shaft that shut the oil pump down and killed the internals. As a result the LN billet oil pump drive was developed. Noted, thank you
We have even campaigned the M96 engine in Grand Am series racing with zero engine failures with the same mods that we apply to street engines. There are a lot of ingredients to this success, the biggest being the liquid that keeps the engine alive. What oil would you recommend?
G forces from track activities are simply the straw that breaks the Camels back.. Its not what starts the issue.
We actually remove some factory equipment to keep engines alive on the track and have only had one on-track failure in the history of our program. That failure was induced by a broken oil pump drive shaft that shut the oil pump down and killed the internals. As a result the LN billet oil pump drive was developed. Noted, thank you
We have even campaigned the M96 engine in Grand Am series racing with zero engine failures with the same mods that we apply to street engines. There are a lot of ingredients to this success, the biggest being the liquid that keeps the engine alive. What oil would you recommend?
If you are protecting your business knowledge then thats fine, I understand, so then tell me to ship my motor over to you, you'll upgrade it and post it back. Or alternatively give me a list of developed parts you'd recommend I purchase from you.
Or please share some of your knowledge of preventative measures you'd suggest I take?
Cooling - understood, but as yet temps have not appeared to be an issue for us. Ambient temps in the UK are generally a fair bit less than the US! However you may tell me due to the design of some of the oil galleries 'Hot spots' are created, which in turn with greater oil starvation could become a problem for us?
Oil starvation - common sense tells me this will be an issue with higher G's. What do you do in respect to this?
11-02-2012, 09:02 AM
#11
Three Wheelin'
Join Date: Oct 2004
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TFBoxster -
i don't think the X51 kit is made anymore....
Call Charles Navarro at LN Engineering; i believe they make a better kit that covers both heads instead of just the one side & that the prices is similar to what porsche charged for the X51 mod.
As to oil temps? If i recall, Jake's testing has shown that cool water temps don't coincide w/ cool oil temps on these cars. Since the factory dash only reports water temp, it lulls people into thinking their motors are cool when in fact oil temps are through the roof.
Since you have a purpose built car, i assume you are measuring the oil temps directly. If you are not, start.
i don't think the X51 kit is made anymore....
Call Charles Navarro at LN Engineering; i believe they make a better kit that covers both heads instead of just the one side & that the prices is similar to what porsche charged for the X51 mod.
As to oil temps? If i recall, Jake's testing has shown that cool water temps don't coincide w/ cool oil temps on these cars. Since the factory dash only reports water temp, it lulls people into thinking their motors are cool when in fact oil temps are through the roof.
Since you have a purpose built car, i assume you are measuring the oil temps directly. If you are not, start.
11-02-2012, 09:52 AM
#12
Former Vendor
The delta between oil temp and coolant temp has been measured at more than 50F on the track in summer operating conditions using our 28 channel race-technology data acquisition system. The oil temps are always hotter than coolant temps on track, even in 48F operating conditions that we have carried out testing in.
Don't ever use an OBDII based oil temperature reading to base anything from, the values are calculated and are not absolute. Only use a stand alone oil temperature gauge with the sender in the oil sump. You will quickly see that oil temps of 260F are not uncommon and we have seen as much as 290F on a 95 degree day at Road Atlanta doing test work.
Don't ever use an OBDII based oil temperature reading to base anything from, the values are calculated and are not absolute. Only use a stand alone oil temperature gauge with the sender in the oil sump. You will quickly see that oil temps of 260F are not uncommon and we have seen as much as 290F on a 95 degree day at Road Atlanta doing test work.
11-02-2012, 06:00 PM
#13
The delta between oil temp and coolant temp has been measured at more than 50F on the track in summer operating conditions using our 28 channel race-technology data acquisition system. The oil temps are always hotter than coolant temps on track, even in 48F operating conditions that we have carried out testing in.
Don't ever use an OBDII based oil temperature reading to base anything from, the values are calculated and are not absolute. Only use a stand alone oil temperature gauge with the sender in the oil sump. You will quickly see that oil temps of 260F are not uncommon and we have seen as much as 290F on a 95 degree day at Road Atlanta doing test work.
Don't ever use an OBDII based oil temperature reading to base anything from, the values are calculated and are not absolute. Only use a stand alone oil temperature gauge with the sender in the oil sump. You will quickly see that oil temps of 260F are not uncommon and we have seen as much as 290F on a 95 degree day at Road Atlanta doing test work.
11-02-2012, 06:08 PM
#14
Former Vendor
I quickly learned to never use a diagnostic tool to gain actual values for temperatures within these engines. When using standalone aviation grade instruments, sensors and data loggers we have seen huge deviations from what the OBDII port provides.
Some M96 engines don't even incorporate any sensor that can measure oil temperature as its a calculated value thats a projection based upon the coolant temperature. I only trust my own sensors and instruments, but thats just me.
Some M96 engines don't even incorporate any sensor that can measure oil temperature as its a calculated value thats a projection based upon the coolant temperature. I only trust my own sensors and instruments, but thats just me.
11-02-2012, 09:38 PM
#15
I quickly learned to never use a diagnostic tool to gain actual values for temperatures within these engines. When using standalone aviation grade instruments, sensors and data loggers we have seen huge deviations from what the OBDII port provides.
Some M96 engines don't even incorporate any sensor that can measure oil temperature as its a calculated value thats a projection based upon the coolant temperature. I only trust my own sensors and instruments, but thats just me.
Some M96 engines don't even incorporate any sensor that can measure oil temperature as its a calculated value thats a projection based upon the coolant temperature. I only trust my own sensors and instruments, but thats just me.
