Maintenance...

[D-O]

How often do folks flush/replace fluids on a car that sees track use?

For instance, I have done six track days and a thousand or so miles of regular driving on the gearbox oil. Time for a change?

Six track days and a few thousand miles on the diff oil. Okay?

Three track days and a very few road miles on the engine oil (Castrol 10/60).

I flush the brake fluid (RBF600) once a year at the start of the season. Sufficient?

How about the coolant?

Are more frequent valve adjustments needed?

Pads, rotors, and calipers are carefully inspected before and after every track day and whatever is required is done. No taking chances here.

What else?

Thanks.

[Obioban]

Brake fluid and oil every spring.

With a mix of street and track, I do coolant, trans and diff fluid every time the car says it's due for "inspection". Same for valve adjustments.

The inspection interval is is by gallons of gas burned, which pretty directly correlated to how hard the car is driven. Doing it every inspection interval is already 2x the factory recommendation.

^all assuming factory fluids, other than brake fluid. Lots of "race" fluids have much shorter functional lives, among other downsides they bring. But, I'm not racing, so I don't need to suffer those downsides.

[D-O]

Thanks Ian.

Other than the brake fluid I am using all factory fluids.

How many track days do you customarily do in a season?

D-O

[Obioban]

Thanks Ian.

Other than the brake fluid I am using all factory fluids.

How many track days do you customarily do in a season?

D-O

More before I had a kid 🤣

Pre kid I was doing 10-15 events a year. Post kid, 1-5. Same (OBD calculated) rate of fluids changes for both, for the last 20 years.

[D-O]

10-15 events per year! I am sure plenty of those were more than one day - that is a bunch of track time.

Have you altered any of your inspection/service intervals? Thought I read this could be done via NCS.

Kids will do that. Mine are nearly off the payroll!

[Obioban]

I haven’t altered them. Twice as often as recommended seems sufficient to me 😜

[bigjae46]

I change my oil every 3 track weekends, change all of the fluids every 6 track weekends. Everything is seeing much higher temps but I am curious to see what kind of temps the diff and gearbox see. I will eventually collect some data.

I probably change the gearbox far more often than needed. More of a habit.

The diff, I am confident 6 months is about right. The fluid sees a lot more wear and debris from the clutch packs in the LSD. As the FM breaks down the behavior of the LSD unit changes and also accelerates wear on the clutches. So if you have a ZF, stock or any unit with a wearable clutch pack then you will want to keep fresh fluid in the diff.

The coolant is really easy for me. I fill with distilled water and water wetter and I have a drain hose connected to the block drain. Takes me 15 minutes with zero mess. I also do it to see how muddy the water looks - in the past that has indicated the beginnings of a water pump failure.

Oil - just cheap insurance to keep fresh oil and a fresh filter in the engine. If anything, I'd replace the filter often.

I vacuum out the power steering fluid from the reservoir and refill with each oil change. Every so often, I'll vac/refill the reservoir, start the car and turn the wheel back and forth and repeat a couple of times. This is the one fluid I should change more often. You can remove the lines from the PS pump but then you risk cavitating the pump and damaging it which is why I vac/fill, turn the wheel, and repeat.

[bigjae46]

Lots of "race" fluids have much shorter functional lives, among other downsides they bring. But, I'm not racing, so I don't need to suffer those downsides.

Great point when I look at my change intervals. I think the OE fluids minus brake fluid are superior to almost every race fluid. The downside is cost. Diff fluid for one. The SAF-XJ +FM is 6x the cost of Redline 75w-150. The only reason I don't use the BMW fluid is I want to minimize the old clutch material being recycled throughout the bearings and LSD unit.

I even ran BMW brake fluid on track for awhile. Never had a problem but I've since switched to Motul RBF-600 for an extra margin of safety.

I still use BMW 10w-60.

[Obioban]

Only more expensive once with FCP…

[elbert]

My maintenance schedule is not based on any scientific evidence. Car is about 98% track use.
I probably didn't change the trans and diff fluids often enough earlier, so I'm trying to make up for it with more frequent changes to keep them as healthy as possible.
As for the engine oil, I had to replace the rod bearings before and would like to delay doing them again for as long as possible.
I hate chasing air bubbles out of brake lines. I find it much easier to avoid all that by just putting in fresh fluid.

Intervals:
- engine oil change every 2 to 3 weekends (Castrol 10w60 Euro or whatever it's called now)
- transmission about 5 weekends (finally ran out of Pentosin MTF so will be switching to Motul I think)
- diff when I do the trans (Castrol Syntrax)
- brake fluid flush 2 weekends or 3 months, whichever comes first (Motul 600)
- coolant every 2 years or so (BMW)

[bigjae46]

- transmission about 5 weekends (finally ran out of Pentosin MTF so will be switching to Motul I think)

I know BMW says DCT-F is equivalent to MTF...just hesitant to make the change. Would love to get away from Redline MT90.

[elbert]

I vacuum out the power steering fluid from the reservoir and refill with each oil change. Every so often, I'll vac/refill the reservoir, start the car and turn the wheel back and forth and repeat a couple of times. This is the one fluid I should change more often. You can remove the lines from the PS pump but then you risk cavitating the pump and damaging it which is why I vac/fill, turn the wheel, and repeat.

Yeah, I also need to change my PS fluid more often. I'm sure that pump is not cheap nowadays. The Motul ATF has been holding up pretty well for me.

[elbert]

I know BMW says DCT-F is equivalent to MTF...just hesitant to make the change. Would love to get away from Redline MT90.

Agreed about the DCTF, I think that's why I'm leaning toward Motul. IIRC Motul 111133 meets MTF-LT2, but it is also very viscous so I haven't committed to the switch yet.

https://www.motul.com/en-US/products/34781?id=34781&product=MOTUL+GEAR+POWER+75W-80

I've never liked Redline transmission fluid either -- seems to be smooth initially but breaks down very quickly.

[Obioban]

I still have 3 gallons of MTF LT2