High HP Subaru Recommendations

[Skooma]

Just finished assembling and did the first start of a new engine and curious what is recommended for an EJ257 that will be making upwards of 600whp? Will be running between 40%-80% ethanol all the time. I ran Motul 5W40 X-cess for over 120k miles in the last engine, a stock EJ207 that was around 400whp most of its life, and it never burned a drop of oil with 3k mile OCI's and might stick with that, but I've never done any oil analysis on it. That engine is still fine, I just built a 2nd one that can handle more power. I plan on doing shorter OCI's on this new one after reading about ethanol diluting the oil, so probably 1.5k-2k OCI's from now on.

 

[Kira]

Impressive.
I doubt there are any members / Subaru owners here with practical experience at these power levels.

 

[Al]

Impressive.
I doubt there are any members / Subaru owners here with practical experience at these power levels.

Correct.

 

[#18FAN]

I'd ask Dave At HPL that's what I'd be using oils cheap motors aren't.

 

[bluesubie]

What are the clearances like between the two engines? Can the EJ257 still use a 40 grade oil? Regardless, I probably would not use the regular Motul 8100 oils. Maybe 8100 Power or 300V if you want to stick with Motul or go with HPL as @#18FAN suggested. Check the HPL stickies at the top of this forum for more info.

 

[#18FAN]

What are the clearances like between the two engines? Can the EJ257 still use a 40 grade oil? Regardless, I probably would not use the regular Motul 8100 oils. Maybe 8100 Power or 300V if you want to stick with Motul or go with HPL as @#18FAN suggested. Check the HPL stickies at the top of this forum for more info.

Dave will have the answer big horsepower race engine's is his daily bread and butter trusted by high end engine builders across the country.

 

[facility1]

Royal Purple XPR 5w-30 is a good oil for your use, or Torco SR-5 5w-30

 

[Cujet]

HP per cylinder is a solid indicator of viscosity requirements in conventional designs. There are a great many high specific output engines that survive quite well on a robust XW-40 synthetic oil. However, when one moves into the rarefied territory of 150HP per cylinder, on standard sized bearings, it is beyond the capability of standard design parameters. Expect adequate results until a deviation in some parameter such as temp or pressure. Having worked with stupidly powerful 4 cylinder turbocharged road-race engines, nearing 200HP per cylinder, some of which were considerably smaller in displacement than you are dealing with, I've never seen conventionally designed endurance engine use anything but the very best 50 viscosity oils, while ensuring sub 200ºF oil temps at all times.

As I am sure you know, "when" it is possible to manage oil temp to exactly the desired number, one can use any reasonable viscosity. The guys successfully using 0W-X oils tend to shoot for (example) 160ºF oil temps, with software output limitations when coolant, oil temp and pressure parameters are exceeded.

 

[chris719]

300V, HPL, M1 X2 5W-50 if on a budget

 

[Astro14]

I would think it depends on the oil temperature as much as anything else. Any idea what temps you’re going to experience?

I would reach out directly to @High Performance Lubricants with your details - sump size, oil temp, intended use - and see what they think.

FWIW, my Mercedes both push around the same HP, but from a much larger turbocharged engine. I run the Mobil 1 0W40 FS in one of them (until my supply of cheap M1 is used up) and HPL 5W40 supercar in the other. Those two oils would be a starting point for my recommendation.

But I would really like to know what oil temps you’re seeing in this.

 

[burbguy82]

I have experience with that level of power, but not in a small engine. Heat is going to be the biggest concern IMO......has to be. That power has to go somewhere, and it wont all be at the tires.

I am kind of surprised that you do not already know this...... being as you stated you put together the engine......and if you didnt do it yourself, what does the builder say? IMO, that would the most important opinion of all

VR1 is made in 10w30, or 20w50 and is likely the most proven of all the race oils.