50 weight oil suggestion

Does it really matter which 50-grade oil you use for a test? If it works then find a racing suitable oil, but for a simple and quick experiment it shouldn't matter.
 
Have you considered a straight grade 30 weight oil? Sounds like you're generating a lot of heat.
 
Losing oil pressure at higher rpm usually isn't a viscosity issue. It sounds more like a cavitation issue.

If you want to try a 50 grade though, High Performance Lubricants Bad Ass 5W-50 is where I would look first. Red Line also makes a 5W-50 and Driven has DT50.

What engine are we talking about here? How much boost from what size turbos? Approximate power numbers? How long are the endurance races?
A few UOA/VOA that I have seen for DT50 show it in 40 grade territory. It is an oil developed for Jake Raby and the VW Type 4 and Porsche aircooled engines. DI50 or HR1 might be better.

Although, I would lean toward an offering from HPL or Red Line 15W-50. The VR1 20W-50 suggestions are good as well.
 
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I did some math on a viscosity calculator. The bottle of Moly ep added to the mobil 1 10w40 hm would take the oil from 12.6@100cst to about 15@100cst
W the qs hm 10w40 of 15.9 i run in my truck and a bottle of EP at 220 brings my cst to 19.54. I didn't realize Mobil 1 was that thin at 12.6, try the QS.
 
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A few UOA/VOA that I have seen for DT50 show it in 40 grade territory. It is an oil developed for Jake Raby and the VW Type 4 and Porsche aircooled engines. DI50 or HR1 might be better.

Although, I would lean toward an offering from HPL or Red Line 15W-50. The VR1 20W-50 suggestions are good as well.
Reason for 15w50 over say 10 or 5?
 
Based on this gentleman's description of his issue, how can we just throw out our favorite brand??? It's obvious that his issue is not the oil, but the inability to control said oil temp. Throw in a 40, a 50, you'll have the same issue in 7 laps.

How big is your oil cooler??? How is the air flow to it??? Are you racing at elevation??? What speeds??? Are the speeds high enough to cool, or do you need fans??? How is the ducting to the cooler???
 
Based on this gentleman's description of his issue, how can we just throw out our favorite brand??? It's obvious that his issue is not the oil, but the inability to control said oil temp. Throw in a 40, a 50, you'll have the same issue in 7 laps.

How big is your oil cooler??? How is the air flow to it??? Are you racing at elevation??? What speeds??? Are the speeds high enough to cool, or do you need fans??? How is the ducting to the cooler???
No oil cooler. Oil doesn't go to the turbos. They are self contained grease lubbed and serviceable. Water cooled. Massive radiator. Rad duct. Massive fans. Header wrap. Looking to do heat shield product. Not high above sea level. It's parking lot racing. Autocross. So maybe 50mph @ moments. Heat extractor (louvers) in hood.
 
Based on this gentleman's description of his issue, how can we just throw out our favorite brand??? It's obvious that his issue is not the oil, but the inability to control said oil temp. Throw in a 40, a 50, you'll have the same issue in 7 laps.

How big is your oil cooler??? How is the air flow to it??? Are you racing at elevation??? What speeds??? Are the speeds high enough to cool, or do you need fans??? How is the ducting to the cooler???
 

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No oil cooler. Oil doesn't go to the turbos. They are self contained grease lubbed and serviceable. Water cooled. Massive radiator. Rad duct. Massive fans. Header wrap. Looking to do heat shield product. Not high above sea level. It's parking lot racing. Autocross. So maybe 50mph @ moments. Heat extractor (louvers) in hood.
Yes sir, I am familiar with comp turbochargers. I am glad you are using them. If you used oiled turbos and you had the issue you are having, you be out of a lot of cash replacing them.

The fact that you can get a few laps before you are having issues highlights the well planned under hood thermal management you put in your car.

The constant on/off throttle of auto cross/road racing coupled with the oil sloshing around and having less contact time with the metal oil pan for heat transfer will result in high oil Temps.

I believe you're a $600 bolt on oil cooler and some Walmart x-40 A40 $30 dollar oil away from curing your issues. Even a mishimoto oil cooler kit off Summit will cure your issue. Although for the price, you can home brew better if you have time.

Also, what are you using to monitor oil temps?? What ecu you running??? For a few bucks you can home brew a arduino that can measure and log. It's very important to know your oil Temps.

Nice ride, BTW.
 
Losing oil pressure at higher rpm usually isn't a viscosity issue. It sounds more like a cavitation issue.

If you want to try a 50 grade though, High Performance Lubricants Bad Ass 5W-50 is where I would look first. Red Line also makes a 5W-50 and Driven has DT50.

What engine are we talking about here? How much boost from what size turbos? Approximate power numbers? How long are the endurance races?
I'm in agreement here, this sounds like cavitation and it's likely happening all along and just drops enough oil pressure to trip the system when the oil gets thin enough.

Oil pressure increases with RPM, typically until you hit the pump pressure relief, unless you are overwhelming the relief and then it goes beyond. A loss in oil pressure points to a supply problem to the pump.

Since this is an LSx topic, I'm going to tag @clinebarger so he can perhaps provide his expertise.
 
Yes sir, I am familiar with comp turbochargers. I am glad you are using them. If you used oiled turbos and you had the issue you are having, you be out of a lot of cash replacing them.

The fact that you can get a few laps before you are having issues highlights the well planned under hood thermal management you put in your car.

The constant on/off throttle of auto cross/road racing coupled with the oil sloshing around and having less contact time with the metal oil pan for heat transfer will result in high oil Temps.

I believe you're a $600 bolt on oil cooler and some Walmart x-40 A40 $30 dollar oil away from curing your issues. Even a mishimoto oil cooler kit off Summit will cure your issue. Although for the price, you can home brew better if you have time.

Also, what are you using to monitor oil temps?? What ecu you running??? For a few bucks you can home brew a arduino that can measure and log. It's very important to know your oil Temps.

Nice ride, BTW.
Thanks for the replies. The ecu is a holley dominator
 
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