Endurance Racing Tips

Joined
May 11, 2021
Messages
19
Hello folks! My family is working on a new project car. I am hoping to pick the collective brain of BITOG.

The car is a 2011 Mustang with a 3.7l V6. We will be doing endurance racing, up to 14 hours at a time. Ford originally used 5W-20 in these engines. We are planning to run 15W-50. This is what Ford did on the Coyote engines with the Boss 302s. Factory 5.0l fill on GTs was 5W-20, the Boss got 15W-50 since it was designed for track use specifically. Obviously, we will be running good racing oil in the car. Thinking Redline or Amsoil right now, but I think any quality synthetic racing oil will work.

We are very limited on changes we can make in this series. External oil coolers, aftermarket race pans, etc won't fly. So I am very concerned about oil temps. I had a couple of ideas. I can run a factory Ecoboost, etc oil cooler mounted under the oil filter. I am aware these aren't all that effective compared to a quality external-mount cooler. But if coolant is at 200*, and oil is 280*, I have a hard time believing it won't have any effect. Certainly better than not using it. I am aware this will increase the heat load on the cooling system a bit, and that has to be managed, but we've already planned for cooling system. We have upgraded the radiator and will be sealing it at the core support, will be running a lower temp thermostat to bring the "floor" of the coolant temp down, have quality hood venting, etc. We are running a small aftermarket heater in the car using standard 5/8 heater hoses. So I am thinking of routing the coolant (which is coming from the lower rad hose after passing through the rad) through the heater core, then through the oil filter mount to feed it coolant that is as cool as possible.

The other thing I was thinking of is using a remote-mount filter kit (which IS legal). The plan there would be to use a quality filter-replacement block with -10 AN lines running to a remote filter block mounted on a frame rail away from heat sources and in a spot where ambient air is able to pass freely over it when the car is moving (filter currently sits behind the radiator). The goal here is twofold: 1. obviously, put the filter in the air stream where it might be able to shed some heat in the oil out of the filter, essentially using the filter as a heat sink, and 2. increase overall oil capacity with a larger filter. My thinking is that more oil overall means that each given amount of oil spends less time in the hot parts of the engine, so has a better shot at cooling down before it heads back to the bearings, etc to get reheated. This plan assumes that's true AND that I won't see any ill effects from running a HUGE filter.

This car would typically use an FL500 or FL820 filter. Since I am running lines to the remote filter mount, I can convert from the odd M22x1.5 filter to a standard 3/4x16 thread. I use the FL1A or Wix 51515R on my other cars, which I think is larger in capacity than the 500 or 820. I found another filter today that was apparently used on some heavier-duty trucks years ago, the FL299. It appears that this filter (from any quality manufacturer) would greatly increase the surface area (important for using the filter as a "heat sink") and capacity.

Is there any major disadvantage to running such a huge filter compared to factory? Oil pressure, etc? I can't see that happening, but worth asking.

Any thoughts on the rest of this plan or out-of-the-box ideas on how to keep an engine alive while wheel-to-wheel racing for extended periods?
 
If the filter is in the air stream, it's in the debris stream. Rethink that.
I agree. The idea of a large remote filter seems like a good one, but the risk/reward for putting it in an area with good airflow is not worth it, oil filters are fragile and its not like their design lends itself to cooling via airflow. Another thing to consider is that a remote setup with the lines creates more points of failure. If you and your team are experienced mechanics that know how to do it correctly then I say go for it, if not so much the benefits may not be worth just keeping it stock.

What do the rules specifically say about oil coolers? You mention that you are allowed to use a ecoboost cooler which from the way you describe is a block style water cooled deal. Can you use OEM external coolers (even a transmission cooler etc), or is this ChampCar style rules so any kind of external cooler will incur a point penalty?
 
Rules man, we need the exact wording of the rules. If you ain't "bending" the rules, you ain't racing.

Is the car a automatic or manual?? If manual, does the automatic version of that car come with a radiator that has a transmission cooler built in??? Use that radiator and use the tranny cooler as a oil cooler.
 
5w-20 oil is for EPA cafe credits. Call Mobil oil or Redline or HPL and ask how their oil holds up at those temps. More oil is better for many reasons but when 10 qts of oil is 300*f it is the same temperature as 5 qts of oil at 300*F. Oil is hotter between the parts that it is in the pan.
 
Hello folks! My family is working on a new project car. I am hoping to pick the collective brain of BITOG.

The car is a 2011 Mustang with a 3.7l V6. We will be doing endurance racing, up to 14 hours at a time. Ford originally used 5W-20 in these engines. We are planning to run 15W-50. This is what Ford did on the Coyote engines with the Boss 302s. Factory 5.0l fill on GTs was 5W-20, the Boss got 15W-50 since it was designed for track use specifically. Obviously, we will be running good racing oil in the car. Thinking Redline or Amsoil right now, but I think any quality synthetic racing oil will work.
The higher the viscosity of the oil the higher the resulting oil temperatures. Just going from 5w-30 to 15W-50 might increase the oil temperatures quite a lot (e.g +20 degree C/ +35 F).

Also at high temperatures tungsten-based oil additives work quite well (and better than moly-based ones). Not sure if available in the US market, but in Europe Ravenol racing oils might be of interest, e.g.: Ravenol RUP 5w-40 - Group V base oil, moly&tungsten included in good amounts and quite high HTHS for a 5w-40 (HTHS: 4.26) .

They also have racing oils in the 5w30 viscosity (e.g. Ravenol RSP 5w-30), so in an engine designed for 5w-20 a racing 5w30 might give you sufficient MOFT and reduced temperatures even at extreme loads. The lower viscosity will gain additional HP as well.
 
Mobil Supercar might be a good fit for this.
 
Mobil Supercar might be a good fit for this.

While Mobil Supercar is an excellent oil, it is an oils designed for street use and long OCIs. Racing oils are designed for track use and are a different class.

I intended to write Ravenol RCS 5w-40 not RUP 5w40:
While Ravenol RUP 5w-40 exists as well it not that much racing oriented as the RCS.
 
The under filter cooler on my 2 Nissan's is plumbed in right after the inlet of the water pump - where the pump pulls the coolant out from the bottom of the rad - so it gets good flow as well as it would be at its coolest temperature in the cycle. Is there such an outlet possibly on your setup?

Back when I worked on some 1/4 mile stock cars we got rid of the thermostat altogether and ran just a washer - to restrict flow enough that it actually had time to cool in the rad. It took some experimentation to get it the right size of course.
 
While Mobil Supercar is an excellent oil, it is an oils designed for street use and long OCIs. Racing oils are designed for track use and are a different class.

I intended to write Ravenol RCS 5w-40 not RUP 5w40:
While Ravenol RUP 5w-40 exists as well it not that much racing oriented as the RCS.
"Mobil 1™ Supercar 0W-40 is proven in high performance North American sports cars and suitable for use in everyday driving and high performance track events." From the link
 
While Mobil Supercar is an excellent oil, it is an oils designed for street use and long OCIs. Racing oils are designed for track use and are a different class.

I intended to write Ravenol RCS 5w-40 not RUP 5w40:
While Ravenol RUP 5w-40 exists as well it not that much racing oriented as the RCS.


Mobil 1 Supercar passes Porsche A40… Go watch the video on what that test entails. It’s quite amazing a test. And it is run on a simulation of a race track.
 
Sorry, but why are you lowering the temperature of the thermostat?
Lower temperature "floor". Thermostats start opening gradually at their specified temperature. We want to be fully open and flowing at 195* and stay below 200* period. Allowing the thermostat to open earlier will run the engine cooler at all times.
If the filter is in the air stream, it's in the debris stream. Rethink that.
Can you tell me more about this racing series?
Is it 24hrs of Lemons?
I agree. The idea of a large remote filter seems like a good one, but the risk/reward for putting it in an area with good airflow is not worth it, oil filters are fragile and its not like their design lends itself to cooling via airflow. Another thing to consider is that a remote setup with the lines creates more points of failure. If you and your team are experienced mechanics that know how to do it correctly then I say go for it, if not so much the benefits may not be worth just keeping it stock.

What do the rules specifically say about oil coolers? You mention that you are allowed to use a ecoboost cooler which from the way you describe is a block style water cooled deal. Can you use OEM external coolers (even a transmission cooler etc), or is this ChampCar style rules so any kind of external cooler will incur a point penalty?
Yes, debris is a concern. But I would disagree that being in an airstream will absolutely be in the way of debris. We can install an air deflector up from a fog light hole, for example. If we ran the oil filter like this, it would likely be mounted to the inside frame rail and protected by a screen. Keeping it safe from track debris would be a priority, though.

Everyone on my team likes to think we're good mechanics lol. But it has taken us 2 days to get the seat mounts properly fabricated (complicated by the size of one of our drivers (me), the need to get the seat low, but adjustable up and forward for drivers that are 6" shorter, etc.).

Anyways, yes, Champ Car, not Lemons. I believe any external oil cooler would incur the penalty, yes, even a factory style. We are already starting at a 5 lap disadvantage, and we have to take another lap or two for other "mandatory" changes (driveshafts on these cars tend to come apart over 120 MPH or so and we may take a penalty for an adjustable panhard bar just to get the rear axle positioned back after lowering). We heavily considered using the factory AC evaporator and trying to fly it under the radar just in case...but we decided it wasn't the risk of it running into the cabin and trying to leakproof it.
5w-20 oil is for EPA cafe credits. Call Mobil oil or Redline or HPL and ask how their oil holds up at those temps. More oil is better for many reasons but when 10 qts of oil is 300*f it is the same temperature as 5 qts of oil at 300*F. Oil is hotter between the parts that it is in the pan.
This was my thought as well at first. But then I got to thinking, the less time a particular "molecule" of oil spends between a bearing, the more time it has to cool off a bit. If there's more capacity for oil overall, that will happen. I don't really know if that's how it would actually work...but seems like a good thing to try.

The higher the viscosity of the oil the higher the resulting oil temperatures. Just going from 5w-30 to 15W-50 might increase the oil temperatures quite a lot (e.g +20 degree C/ +35 F).

Also at high temperatures tungsten-based oil additives work quite well (and better than moly-based ones). Not sure if available in the US market, but in Europe Ravenol racing oils might be of interest, e.g.: Ravenol RUP 5w-40 - Group V base oil, moly&tungsten included in good amounts and quite high HTHS for a 5w-40 (HTHS: 4.26) .

They also have racing oils in the 5w30 viscosity (e.g. Ravenol RSP 5w-30), so in an engine designed for 5w-20 a racing 5w30 might give you sufficient MOFT and reduced temperatures even at extreme loads. The lower viscosity will gain additional HP as well.
Your point about the higher viscosity oil running hotter is well taken. But I think the extreme engine temperatures will exist either way, and my thought was that a higher viscosity oil might maintain its protection and shear stability as the temps get way up there and the oil needs to not thin out too much. I've noticed dramatic pressure changes after very short (by comparison to this) 30-minute sessions on my other car.

Several people have mentioned the beloved Mobil 1 Euro 0W-40. I have been running it in a 427w for a couple years. The car sits in the garage a lot (800 miles in 2 years, mostly at autocross or a racetrack) so I wanted a street oil with a good additive and detergent package. It's worked well, but does lose a significant amount of oil pressure at the track. Usually idling at 20 PSI or so coming off track, when it's closer to 35 PSI after just driving around town. I can't imagine that a 14-hour race won't require a thicker oil just to maintain proper oil pressure as temps get extremely high.

Then again, the applications are very different. The 427w has twice the horsepower and gets absolutely hammered on for 30 minutes straight, whereas we will be driving this 305hp engine with a view toward it finishing the race. Different driving styles might be a big difference.
 
I wouldn't bother with 15W-50. Just run a stout 5W-20 or 10W-20. High Performance Lubricants No VII Euro 5W-20, with an HTHS of 3.26 cP, would be my choice.

The remote oil filter can reduce oil temps if kept in the right place. I personally don't fear hot oil. I would do the remote mount for the increased oil capacity. If you can run dual remote filters, I'd run two big XG8As.

I run my 3.7L V6 hard with high oil temps on 20 grade oils, plus going extended drains of 15-20k miles. The UOAs look great, and it doesn't skip a beat.
 
Considering the 3.7 was used in the F150 with a significant towing capacity (at least 5000lbs) and still spec'd for 5w20 in that application, I wouldn't get too crazy out of the gate adding coolers, etc. Run a decent Xw40 or Xw50 weight oil and get an analysis after the first race. I suspect it will hold up better than you expect. The 3.7 isn't putting out crazy power or known for shearing oil.
 
I wouldn't bother with 15W-50. Just run a stout 5W-20 or 10W-20. High Performance Lubricants No VII Euro 5W-20, with an HTHS of 3.26 cP, would be my choice.

The remote oil filter can reduce oil temps if kept in the right place. I personally don't fear hot oil. I would do the remote mount for the increased oil capacity. If you can run dual remote filters, I'd run two big XG8As.

I run my 3.7L V6 hard with high oil temps on 20 grade oils, plus going extended drains of 15-20k miles. The UOAs look great, and it doesn't skip a beat.
I don't fear hot oil, I fear overheated oil lol. Oils do break down or at least become much less protective at some point. I may be wrong in what you're doing with yours, but I don't really think that any amount of street driving is anywhere close to wheel-to-wheel racing for fourteen hours straight. To my mind, there's a reason that Ford switches from 5W-20 to 15W-50 on all the factory high-performance applications, and we're going to be pushing this engine harder than they probably planned for even on those. So I consider that the minimum as far as I can understand things.

Considering the 3.7 was used in the F150 with a significant towing capacity (at least 5000lbs) and still spec'd for 5w20 in that application, I wouldn't get too crazy out of the gate adding coolers, etc. Run a decent Xw40 or Xw50 weight oil and get an analysis after the first race. I suspect it will hold up better than you expect. The 3.7 isn't putting out crazy power or known for shearing oil.
Same as above imo. Normal towing (especially with a reasonable load like 5000 pounds) isn't anywhere close to the strain we'll be putting on this engine. Towing loads usually run at 3000 or less RPM going down the road and only kick up higher when you're on an incline. Then RPMs drop as soon as you get on the other side. There's times when the engine gets a nice break.

For this environment, there will be stretches where the engine will be at 5500+ RPM for about 60 seconds straight, with no letoff of the gas, going up to 140 MPH. Then speed drops, we downshift and go back up to the same 5000-6250 RPM window, up and down in that range for about a minute and a half. And then do it all over again. This is basically a 14-hour drive, with RPMs never dropping below 5000 RPM. I don't see there being any factory/street application that's analogous to that.

I do take the point that the engine is good and has reasonable power levels to help it survive. I don't want to go too crazy, but I will be honest that it's heavy on my mind. Problem we run into is that we don't know exactly where oil temps/pressures will land when pushed this hard for this long. If we don't plan right for the race, we may show and blow in the first two hours. And that would really suck. So I don't mind overdoing things a bit if it definitely won't hurt and might help, you know what I mean?

I do fully intend to get testing done afterward and track data throughout the first race (oil pressure, oil temp, etc). But we have to survive the event for that to help 😅🤣
 
Back
Top