What's a reasonable starting point for fluid change intervals?
 

What's a reasonable starting point for fluid change intervals, in the number of track days? My car is stock N/A, EHP tires, XP8 / Club Racer, has an oil cooler installed, and "level of abuse" is around 2:16 at Thunderhill Bypass.

Engine - Redline 5W30
Brake/Clutch - Motul RBF600
Transmission/Differential - Motul Gear 300

You're using good stuff.

Engine - normal oil change interval, as long as your oil cooler is suffient and keeping your temps under 250F (stock oil temp is read post-cooler, so oil temp peak is higher)

Brake fluid - Whenever the feel degrades, or your reservoir is dark

Clutch fluid - once a year (use leftover brake fluid from a bleed)

Trans/Diff - Every 5 days, or 15k miles, whichever comes first.

:eyebulge:

Edit: I just realized this is every 5 TRACK days. Makes perfect sense now, move along.

Emm, so I should have changed my tranny fluids twice already this year, this might explain why my first and second dont want to engage right after a track day (as in, right after when driving home).

These are just ballpark recommendations. Adapt them to your useage, habits, and pace.

Would a limit of 10 days per oil change be a good starting point?

BTW, I think these initial guidelines would be very useful for noobs in "Quick and dirty guide to track prepping your car".

Good idea!

Used oil analysis is the best way to determine intervals...

Recommended Oil
 

Mike,


I track my car and would love your advise on what oil I should be running. I will purchase from you as well. My car has a Cosworth SC and P&L oil cooler but the oil cooler is not very efficient. My temps are near 300 at the end of my run sessions. Currently running 15w50 Mobile 1 synthetic but it just makes me nervous it's too thick. I'm very aware of the engine failures with our cars and oil temp to be a factor.


Please help!
Thanks,


Mike

You need to fix that oil temp issue first, but I don't recommend running thicker than a 30 weight on this car.

Running too thick an oil ALSO results in higher temperatures, due to friction. Try a 30 weight first, and then keep an eye on your oil temps, and proceed from there.

Not mike, but from what I have read here I would guess that his first question would be, why are you using 15W50 oil? The car is supposed to use 0W20, ok yeah yours is supercharged, so maybe 5W30 or even 10W40 could make sense, but 15W50 is way too much. Remember the thicker the oil, the more heat it retains and the harder it becomes to cool down.

Actually from a senior member from this forum. According to his analysis a forced induction motor under extreme summer conditions being tracked the viscosity of the lower weight oil breaks down causing a loss of pressure then failure. I have been somewhat nervous about it that's why I'm asking.

Thanks Mike! Going on to your site and purchase some goodies today!


Thanks Mike Shelton

If you use a full synthetic as mandated by Subaru, the oil won't break down. Sometimes, following directions pays off!

My UOA analysis really suggests different.

http://www.ft86club.com/forums/showthread.php?p=2452143