Oil Pressure Loss in Braking

[ddd4114]

Sorry for the delay. I've been busy, and it took a while to go through all of my notes.

Cliff's Notes:

1. Bought car in early 2011 and did occasional track days for the rest of the year. Changed the oil twice and saw no wear metals. I used Mobil 1 0w20 oil.
2. Started monitoring oil temperature in the pan at the beginning of 2012. Noticed that oil temperature was ~280 degF after a few laps. This was while running HPDE on all-season tires.
3. By the summer, I was using summer tires, and I noticed that oil temperatures had climbed to ~300 degF after a few laps. In the next oil sample, I found that lead was 9ppm.
4. Installed Boss 302 oil cooler, and at the next event, oil temperatures dropped to ~270 degF. However, my oil analysis results still came back with elevated lead.
5. By the end of 2013, I was using NT-01 tires, pushing the car harder, and oil temperatures started getting back into the 280 degF range. At this point, I had been using Mobil 1 5w30 oil.
6. At the beginning of 2014, I ditched my previous data acquisition system for an AiM Solo DL, so I could no longer measure oil temperature. However, I continued to send oil samples to Blackstone for analysis, and lead was consistently ~8ppm.
7. In the summer of 2014, I upgraded my suspension and gained a lot of grip. I also started running in TT instead of HPDE.
8. At the beginning of 2015, I replaced my Solo with an Evo4, and I started monitoring oil temperature again. I also switched to Mobil 1 0w40 oil. Oil temperature was still in the 280 degF range, and there were no changes in my oil analysis results. When I installed the Evo4, I also installed an oil pressure transducer, and I found that oil pressure was dropping to ~25 psi under braking.
9. Soon afterward, I installed the Moroso 10-qt oil pan, and while oil pressure loss wasn't nearly as bad, it still existed.
10. This summer, I started using Hoosier R7's, and I found that oil temperature remained in the ~280 degF range except for Road America (which got the oil into the 290 degF range). At this point, I had switched to Mobil 1 15w50 oil. I also found that increasing the oil fill to 12 qt (in the 10-qt Moroso pan) provided better resistance to oil pressure loss.
    
11. A few weeks ago, I installed the Mishimoto oil cooler, but I broke my transmission before I was able to really test it. However, even with no 3rd gear, oil temperature was in the 260 degF range. While installing the cooler, I change the oil and sent a sample for analysis. Surprisingly, the results came back with no lead.
    

I don't think I'm missing anything, but let me know if you have any questions.

 

[Department Of Boost]

Fantastic man, thanks for the notes. Do you have a link to the big pan?

 

[ddd4114]

Yup, here you go: http://www.americanmuscle.com/moroso-aluminum-oilpan-1113gt.html

 

[Department Of Boost]

Thanks.

It looks to me like it's possible to sneak the pan up in there with the motor still in the car. Lifted a bit of course. What do you think? I don't have an intake or front cover on right now. I need to do an oil pump too. It would be a good time I think.

It says it's for Coyote motors only. I don't think it's an issue using it on a 3v. What says you guys?

 

[Pentalab]

Sorry for the delay. I've been busy, and it took a while to go through all of my notes.

Cliff's Notes:

1. Bought car in early 2011 and did occasional track days for the rest of the year. Changed the oil twice and saw no wear metals. I used Mobil 1 0w20 oil.
2. Started monitoring oil temperature in the pan at the beginning of 2012. Noticed that oil temperature was ~280 degF after a few laps. This was while running HPDE on all-season tires.
3. By the summer, I was using summer tires, and I noticed that oil temperatures had climbed to ~300 degF after a few laps. In the next oil sample, I found that lead was 9ppm.
4. Installed Boss 302 oil cooler, and at the next event, oil temperatures dropped to ~270 degF. However, my oil analysis results still came back with elevated lead.
5. By the end of 2013, I was using NT-01 tires, pushing the car harder, and oil temperatures started getting back into the 280 degF range. At this point, I had been using Mobil 1 5w30 oil.
6. At the beginning of 2014, I ditched my previous data acquisition system for an AiM Solo DL, so I could no longer measure oil temperature. However, I continued to send oil samples to Blackstone for analysis, and lead was consistently ~8ppm.
7. In the summer of 2014, I upgraded my suspension and gained a lot of grip. I also started running in TT instead of HPDE.
8. At the beginning of 2015, I replaced my Solo with an Evo4, and I started monitoring oil temperature again. I also switched to Mobil 1 0w40 oil. Oil temperature was still in the 280 degF range, and there were no changes in my oil analysis results. When I installed the Evo4, I also installed an oil pressure transducer, and I found that oil pressure was dropping to ~25 psi under braking.
9. Soon afterward, I installed the Moroso 10-qt oil pan, and while oil pressure loss wasn't nearly as bad, it still existed.
10. This summer, I started using Hoosier R7's, and I found that oil temperature remained in the ~280 degF range except for Road America (which got the oil into the 290 degF range). At this point, I had switched to Mobil 1 15w50 oil. I also found that increasing the oil fill to 12 qt (in the 10-qt Moroso pan) provided better resistance to oil pressure loss.
    
11. A few weeks ago, I installed the Mishimoto oil cooler, but I broke my transmission before I was able to really test it. However, even with no 3rd gear, oil temperature was in the 260 degF range. While installing the cooler, I change the oil and sent a sample for analysis. Surprisingly, the results came back with no lead.
    

I don't think I'm missing anything, but let me know if you have any questions.

I see in other forums, various vendor's notes etc, that the Boss oil cooler / oil heater has been used in conjunction with a real oil cooler. Some have noted the boss oil cooler reduced oil temps by 20 f. Some have claimed 30-35 F redux with the mishimoto cooler. I have not seen any data when the 2 are used together, although that combo is touted as being pretty good. Setrabs site is interesting. They make several oil coolers, in various dimensions. In some applications, I can see where one of their coolers could still fit into a tight space. ( folks with blower's have the front mounted HE to deal with, which leaves little space for an oil cooler, depending on the HE dimensions. Throw in an auto tranny cooler, and it gets more complex).

You advised against plumbing 2 cooler's in series. I have not done that with eng oil cooler's, but have done it with auto tranny coolers, with good results. I found a higher BTU one to replace the oem tranny rad, but it's too thick, so went to plan B, and installed a low profile bar + plate type cooler in series with oem cooler. b4, the atf temp would skyrocket from 170f to 200+ in just 5-7 secs..(wot + blower). Now it just goes from 170 to 172...stays put. The T stat in the bar + plate rad operates on viscosity.

http://www.setrabusa.com/products/oilcoolers/engine/index.html
http://www.setrabusa.com/products/oilcoolers/index.html

 

[ArizonaGT]

Thanks.

It looks to me like it's possible to sneak the pan up in there with the motor still in the car. Lifted a bit of course. What do you think? I don't have an intake or front cover on right now. I need to do an oil pump too. It would be a good time I think.

It says it's for Coyote motors only. I don't think it's an issue using it on a 3v. What says you guys?

Contact Dean @ Rehagen--I know they have a road-race oil pan for a 4.6L engine available now, but only one.

 

[Department Of Boost]

Contact Dean @ Rehagen--I know they have a road-race oil pan for a 4.6L engine available now, but only one.

I'll text him. Thanks!

 

[kcbrown]

Sorry for the delay. I've been busy, and it took a while to go through all of my notes.

Cliff's Notes:

1. Bought car in early 2011 and did occasional track days for the rest of the year. Changed the oil twice and saw no wear metals. I used Mobil 1 0w20 oil.
2. Started monitoring oil temperature in the pan at the beginning of 2012. Noticed that oil temperature was ~280 degF after a few laps. This was while running HPDE on all-season tires.
3. By the summer, I was using summer tires, and I noticed that oil temperatures had climbed to ~300 degF after a few laps. In the next oil sample, I found that lead was 9ppm.
4. Installed Boss 302 oil cooler, and at the next event, oil temperatures dropped to ~270 degF. However, my oil analysis results still came back with elevated lead.

The above gives no indication that the Boss 302 oil cooler was installed in conjunction with any external oil cooler. If that's the case, then the Boss 302 oil cooler ("heater" around here ) alone is responsible for a 30 degree drop in oil temperatures in your car.

Frankly, I don't find that surprising. The effect of that oil cooler is to distribute the cooling capacity of the radiator more evenly throughout the engine, and particularly to put some of it into the oil. As long as the radiator has the capacity to spare, that oil cooler should have an effect. It's why the use of the cooler really should occur in conjunction with installation of a larger capacity radiator.

I can't help but wonder what actual head-to-head and apples-to-apples measurements the people who decry that oil cooler have done. Yes, of course it'll heat up the oil when it's cold. But it'll also cool it when the oil is substantially hotter than the outlet side of the radiator. The main problem is that it may lose some effectiveness under extreme conditions, as the temperature at the outlet side of the radiator gets closer to that of the oil, but if that's really the case, then it means the cooling capability of the radiator is nearly exhausted, and that implies that the proper answer is to fix that, if possible. Doing so might not be possible, however, and if that's the case, then an external oil cooler in a separate air stream is likely to be the only remaining option.

But that doesn't mean the Boss 302 oil cooler is worthless!

You're almost certainly better off with the Boss 302 oil cooler in conjunction with an external unit than with the external unit alone.

 

[Pentalab]

The above gives no indication that the Boss 302 oil cooler was installed in conjunction with any external oil cooler. If that's the case, then the Boss 302 oil cooler ("heater" around here ) alone is responsible for a 30 degree drop in oil temperatures in your car.

Frankly, I don't find that surprising. The effect of that oil cooler is to distribute the cooling capacity of the radiator more evenly throughout the engine, and particularly to put some of it into the oil. As long as the radiator has the capacity to spare, that oil cooler should have an effect. It's why the use of the cooler really should occur in conjunction with installation of a larger capacity radiator.

I can't help but wonder what actual head-to-head and apples-to-apples measurements the people who decry that oil cooler have done. Yes, of course it'll heat up the oil when it's cold. But it'll also cool it when the oil is substantially hotter than the outlet side of the radiator. The main problem is that it may lose some effectiveness under extreme conditions, as the temperature at the outlet side of the radiator gets closer to that of the oil, but if that's really the case, then it means the cooling capability of the radiator is nearly exhausted, and that implies that the proper answer is to fix that, if possible. Doing so might not be possible, however, and if that's the case, then an external oil cooler in a separate air stream is likely to be the only remaining option.

But that doesn't mean the Boss 302 oil cooler is worthless!

You're almost certainly better off with the Boss 302 oil cooler in conjunction with an external unit than with the external unit alone.

He said in a previous post that the boss cooler was replaced with the mishimoto cooler, and that the two were never used at the same time.
The boss cars also got the boss radiator, which is aprx 1.75" thick vs the 1" thick oem eng rad. The boss rads are thicker, presumably to dump the extra heat from the boss oil cooler.

I'm sure he would have an optimum setup if both boss cooler + mishimoto were both used ....even with the oem eng rad.

 

[ddd4114]

I still think the Boss oil cooler is a good solution for somebody on a tight budget or for cars that will have difficulty packaging another air-to-liquid heat exchanger for whatever reason. I've used this style of oil cooler on other engines, and they definitely help to keep temperatures in check. Of course, an external cooler will always be more effective.

There are two reasons why I wouldn't want to run the Boss cooler and an external cooler in series:

1. It's already kind of a pain in the ass to package one or the other. While I'm sure I could make it work, it would be tight. Also, the oil filter is already close enough to the crossmember.
2. The main reason is pressure drop. Both the Boss cooler and an external cooler will reduce the oil pressure (and therefore flow) at the main gallery. Granted, the pressure drop across the Boss cooler is probably much less than the external plumbing, but it adds up. While the cooler oil will help maintain high pressure, it seems a little counterproductive to do this kind of setup when the end goal is to reduce pressure loss in the main gallery.

Also, my coolant temperature isn't much better. I have the OEM radiator, and I regularly see coolant in the 220-230 degF range. I would rather not have the flow reduction from the Boss cooler along with the additional thermal load.

 

[Department Of Boost]

Contact Dean @ Rehagen--I know they have a road-race oil pan for a 4.6L engine available now, but only one.

Texted with Dean last night. The FR500 pans that he has are $1000!!

 

[ArizonaGT]

I never said they'd be cheap!

Even the Boss 12-quart pan is 1200$ or so. I went with the Steeda steel 10-quart ($350) and just fill 12 quarts anyways (works fine w/ my external oil cooler & lines).

 

[Department Of Boost]

I never said they'd be cheap!

 

[kcbrown]

I still think the Boss oil cooler is a good solution for somebody on a tight budget or for cars that will have difficulty packaging another air-to-liquid heat exchanger for whatever reason. I've used this style of oil cooler on other engines, and they definitely help to keep temperatures in check. Of course, an external cooler will always be more effective.

There are two reasons why I wouldn't want to run the Boss cooler and an external cooler in series:

1. It's already kind of a pain in the ass to package one or the other. While I'm sure I could make it work, it would be tight. Also, the oil filter is already close enough to the crossmember.
2. The main reason is pressure drop. Both the Boss cooler and an external cooler will reduce the oil pressure (and therefore flow) at the main gallery. Granted, the pressure drop across the Boss cooler is probably much less than the external plumbing, but it adds up. While the cooler oil will help maintain high pressure, it seems a little counterproductive to do this kind of setup when the end goal is to reduce pressure loss in the main gallery.

Also, my coolant temperature isn't much better. I have the OEM radiator, and I regularly see coolant in the 220-230 degF range. I would rather not have the flow reduction from the Boss cooler along with the additional thermal load.

It would have been interesting to see what effect on the oil temperature you'd see if you had replaced the main radiator with something that has more capacity once you had the Boss oil cooler in place. Unfortunately, you're now past that point.

 

[Vorshlag-Fair]

Texted with Dean last night. The FR500 pans that he has are $1000!!

Yea, that was the Boss 302-R 12 qt pan (above at left, next to the OEM Coyote pan at right), and Dean is selling them at a good price. We just put one of these in a 2013 GT earlier this week. It has a few trap doors around the oil pump pick-up, and.... its..... big?

The normal $1200 price tag for this Boss-R oil pan doesn't include a new oil pan gasket (above), which also serves as a windage tray. We picked up a new one from Ford, to be safe.

Swapping the OEM oil pan for this Boss-R pan requires dropping the front subframe. We hung the motor from the engine crossbar hoist, shown above.

With the subframe down a foot or so you can wrestle the oil pan out and the new one in place. Would also be a great time to do full length headers, but I don't know if they fit around this massive oil pan.

It was 3.6 hours of work on a lift to do this, in case you were wondering. The subsequent 12 quart synthetic oil change cost a few extra dollars over a normal 8 qt fill, and will from now until eternity.

This was done on a dedicated track car with aero and 18x11" wheels but.... I don't think it was really necessary.

Again, its probably good insurance, but its not something I would ever recommend on anything not professionally raced. That same $1200 in parts + 3.6 hours of labor would almost pay for proper full length header upgrade, which would add real power and lower lap times. But safety + reliability modifications cost money, even when it doesn't add much of either.

 

[Department Of Boost]

Thanks for the heads up. I'm just going to pass. The car will only see 4-5 more track days then GT350R time.

 

[ddd4114]

FINAL UPDATE OF THE SEASON: Everything still seems fine.

I ran two sessions at Mid-Ohio this past weekend (when it wasn't raining), and the oil temperature didn't go much over 270 degF. I still didn't have 3rd gear since I broke the transmission at my last event, but it turns out that 4th gear with 245/40R18 tires and 3.55 rear gears is perfect for a lot of the club course. I was running almost to the rev limiter at the end of many straights, so I probably wouldn't be getting the oil that much hotter if I also used 3rd.

Despite the somewhat high oil temperature, oil pressure was decent. It dropped to ~40 psi a couple times, but that isn't terrible.

Here is a graph of my fastest lap. Speed is in black, oil pressure is in red, oil temperature is in pink, and longitudinal acceleration is in blue:

I'll be back next season with a new (used) transmission, and hopefully, I won't have to worry about oil pressure anymore.

 

[claudermilk]

I'm certainly no expert, but that looks pretty good to me. If it were my car I wouldn't be worrying about it.

 

[Department Of Boost]

I'm certainly no expert, but that looks pretty good to me. If it were my car I wouldn't be worrying about it.

Yeah, this.

What is the old shade tree mechanic math on oil pressure? 10psi/1,000rpm. And I assume that is using the assumption that the motor is under load.

What is the "load" while compression braking? I can't imagine it's zero. But it can't be as much as being WOT either.

 

[ArizonaGT]

40 is fine; the 302R AIM file doesn't even alarm until under 30psi.