I'd run a 5w50 (or there abouts) as is recommended in the Boss.
Thanks for the reply! I believe the engine in the Boss was a little bit different than mine, but 5w50 may be worth a shot. I was thinking 5w30 and 50 is a big jump, but I can always do a few early UOAs and also datalog my oil pressure at WOT when warm and see how it goes. It is stupid hot on the track.
What are your expected race durations and expected max oil temperatures? Are you adding any additional oil coolers?
If you expect max oil temperatures above 250 F I'd go thicker than 5W-30. Look at what Ford recommends for track use and in their GT500 and GT350, 5W-50.
The expected duration is about 30 minutes for actual race. Out for longer (45-60 min) practicing, but won't be running as hard. I am working a cooler setup for the oil, trans and diff. Needs a little fabrication for fitment with the intercooler taking up so much room. Luckily I'm getting pretty good at TIG welding these days so I'm just a staycation away from fixing this =).
I would expect to see temps in excess of 250F for sure. Any specific oils you'd recommend for withstanding temperature without losing protection versus only bumping viscosity?
I would go with Red line 10W-40 and do a UOA at 1k, and see what is going on.
Thanks for the reply, I'll definitely consider it. Any concern with the cold viscosity at 10 and protection at startup? I love boost season in Houston when it gets "cold" out, however I doubt I'll ever drive in anything approaching 32F. Tires don't really work then anyway.
Will be reading, thank you!
Blowers can move the torque curve down, or they usually just add torque across the range. That means high cylinder pressure is possible at lower RPM. Lower RPM means more time on the big ends under load which puts extra squeeze on the oil film.
Add track time and certainly elevated sump temps, and I'd never run less than 40 grade for the hot side of the equation. Starting oil temps will never be less than say 40*F as this is a toy car and will not be parked outside at Chicago/O'Hare during a snow storm so nothing needed less than 15W which is good down to 0*F.
Your need is for film strength and shear resistance. Motul 300V or Redline will do both of these easily. No need for early changes unless lab says so. Do UOA every 500 miles until you get a handle on oil and any issues that may arise like fuel dilution. They both do as well there as any oil on the planet.
Run strong body oversized filter if it will fit around headers and other plumbing. Put big plate magnet on pan with epoxy. Run filter magnet. Run magnetic drain plug. Try to keep any Fe metals that do get tossed from embedding in piston skirts.
The bigger filter media area is to allow cold oil to circulate through the filter media w/o opening any by-pass. Don't worry about filter efficiency, in this case you want flow over catching every minuscule spec. If it's iron, the magnets will catch it. If it's bronze or aluminum it won't hurt much
Don't over-speed the motor if at all possible unless you have serious money in your rods and bolts ...
The torque and horsepower are super linear with my setup, but obviously more than stock. I'm sure cylinder pressures are higher.
You are right the car will never see below 40F, tires don't work anyway then. So this further makes me feel better about others recommending higher cold viscosity oils. I'll definitely consider the Motul 300V and Redline oils. UOAs are pretty cheap and miles don't come fast, so it's not a big deal to do 500mi tests to get started. I will definitely do that.
Filter has decent clearance the way I remember it. I'll see if I can get a bigger filter. Currently using the standard size filter (Mobil 1 M1-212). I am working on fabricating coolers, totally agree with that and the magnetic drain plug. Good idea about adding a magnet to the pan. Could probably even fab something up to the pan instead of epoxy, I can weld aluminum.
I saw some high performance Mustang a while back at the Auburn auction. Completely stripped to be a race car. Cage, single driver seat, tow hook etc.
5w50 on the oil cap.
Was that also a Boss 302 based one? They definitely had 5w50, but slightly diff engine build as I remember it.
How has the EP 5-20 performed to date? I thought you engine would call for a 5-50 synthetic.
It calls for 5w20 in the manual, even for track use it just says to change it after every outing.
• Change your axle lubricant and friction
modifier after the initial (first) hour of
high-speed operation; thereafter
change the axle lubricant and friction
modifier every 12 hours (under these
• Change your transmission oil after each
event where your vehicle is subjected
to individual on-track sessions
exceeding 15 minutes.
• Change your engine oil and filter after
So far I think it's performed well. Haven't seen any shavings on the magnetic plug. Only 5,200 miles in so far though and 3 oil changes. Haven't done any UOAs yet but about to with the current oil in it when I change it. Of course thats only once I figure out what I'm changing it to!
I would go for Motul 300V 5w40 and change every 3000 miles, and a highly tuned engine needs race oil.
P.s: Don't plow into any crowds
Heard good things about Motul and will def consider it.
Hah, haven't hit any crowds yet. Stock the car is surprisingly sticky and easy to handle. Now with double the power it's easy to skid through 1st, 2nd and part of 3rd. Personally I just avoid doing burnouts with people in front of the car. I think it's mostly people being stupid, don't think it has much to do with the car's performance.
This. Nix on the 5w50; too prone to shearing out of grade. AMSoil AMO or Z-Rod are also very resistant to shear, and have high ZDDP content.
Does your car have an oil cooler? Rejecting heat from an 850HP engine in Texas heat must be a challenge that the original cooling package in the car wasn't designed for.
Thanks! Trying to learn about shearing and 5w50 vs 10w50. Is there more shearing because of the wider range of viscosity from cold to hot causing the 5w50 to lose viscosity? Something different about the composition of the oil that causes the excess sheering problems?
I am working on the oil cooler (trans & diff too!) and yea I'm actually amazed how well the stock system keeps up. The Performance Pack does have an upgraded "Ford Racing" radiator from the factory, as well as a better diff and big (6 piston) front brakes. Few other things too.