'19 Z06 track fluids
 

Thoughts for 19 Z06 M7 (about 1000 of its 4000 total miles on the track) I want stuff that warranty safe but the best protection I can get on the track (but I think as long as we use stuff that's the same certifications it's fine)

Manual Transmission
Redline D4 ATF? - this is on my todo NOW a little over 10 hours of track time (per the manual do it at 10 - but a bunch of these were in rain/snow track time - so temps were irrelevant) This weekend had the transmission gauge get a "yellow block" around it in one session - so it was quite warm... no limp mode - but close.

Rear Diff
I replaced after my first event per the manual with the fluid from the dealers parts counter - that good or should I run something else?

Brake
Flushed with GM's DOT4 stuff in April... but just went to XP12/XP10 pads and making a lot more heat and figure this should go too...

Clutch
gonna do the "ranger method" - but what's the recommendation here for fluids?

Anything else I'm missing? Recommendation on blinker fluids? :D

Redline is the best stuff.
Us it in the Diff also
Brake fluid Castrol SRF usually lasts better than any other.
clutch I'd use SRF also but it does need swapped out very often.

I am in an identical situation with the exception that I have GS instead of Z06.

After first event, I replaced the diff fluid with OEM fluid, and I am going to continue to us the OEM fluid. I am using SRF brake fluid since the first event. It held up very well for 5 events and 8 months. I am going to flush and replace prior to next event. I going to use either Redline or Amsoil for the trans fluid. As for clutch, I tried to use the Ranger method with OEM fluid, but the fluid was always clean. Curious on how difficult it is to flush and replace clutch fluid in a traditional way.

Let us know which way you are going to go.

Z51 here...
Rear Diff = Mobil 1 Synthetic Gear Lube LS 75w-90
M7 tranny = Mobil 1 Synthetic ATF Multi Vehicle (Dexron III Spec)
Brakes = Motul RBF660 (with Raybestos ST-43 pads)
Clutch = Pentosin DOT 4 LV (ranger method flush)

I had a "service rear axle" message on my first track day. The car cooled off during lunch and the message went away, but came back during the next session. So to be safe I changed out the rear diff fluid for my next track event and had no more issues.

I've used Redline and Royal Purple fluids in my previous track car (Nissan 350Z), but for the C7 the fluids above are in spec and available locally.

Redline D4 ATF for sure. I always get mine from Walmart.com

We have a lot (like 100+) local track guys we take care of and 90% of us/them run Amsoil in the diff and trans. SRF is the only brake fluid I recommend if you're an intermediate or advanced driver. It will also work great in the clutch.

I would also recommend shorter intervals for rear diff and manual transmission fluids. You'd be surprised to see what 8-10 hours on track will make the fluid look like. Based off the hundreds of cars we maintain for track use, I'd cut that back to 5-6 events (~5-6 hours) of track time between changes if you're an intermediate or advanced driver.

SRF is usually good for once per year or 6-10 events, depending on driver and how hard you are on the brakes.

Richi:

In the other thread, you recommend to follow the owner manual for oil change to 15W50 for track use to keep the warranty. If I may ask, why aren't you recommending following the owner manual for diff and trans fluid?

GM doesn't have a requirement to use their factory fill fluids for the trans and diff fluids. They do require the car is prepped for track per their instructions, which includes running 15w50 engine oil. When we had our C7Z I changed the engine oil much more frequently than GM or the oil life monitor recommended.

They do recommend how often you should change the fluids, but based on our experience I recommend changing that stuff much more often if you want to take good care of the car. GM doesn't mind if you perform maintenance more often while you're under warranty.

In the manual, GM recommends GM Part 88861800 for M7 Tranny and Dexron GM part 88862624 for Diff.

I see, now, that the magic word is Recommended not required.

Which Amsoil do you recommend for the manual transmission? All I see on their website is for automatic.

Thanks again,

If you were gonna just do 6 or 8 hot laps in a 2019 GS would it make sense to change the stock brake fluid to SRF? I'm just taking advantage of this one opportunity to run a few laps on this track and dont intend on tracking the car after that.
Also, my '19 manual says to keep the 0W-40 in the engine but run it about 1/2 qt high during the session and remove the 1/2 qt after the session.
I'm running stock tranny and diff fluids, all with about 1000 miles since putting them in.
Thanks for any advice, a rookie here I am.

When you say 6-8 hot laps, what do you exactly mean by that? Is it time trail, or low speed lunchtime/charity laps?

Your trans and diff fluid should be fine, but you may need to switch your brake fluids to something that can withstand very high temp. Motol 600 is cheaper alternative.

Its roughly 30 minutes of track time on the F1 Circuit of the Americas in Austin, with an HPDE instructor in the right seat....not parade laps, basically driving up to my limit. Not looking to go nuts, beat a time, just enjoy myself running around the circuit.
I know how I was on the brakes at Spring Mountain in their cars and I doubt it would be any different @ COTA.

CASTROL SRF


The SRF is the absolute best brake fluid on the market, period. If you want the best the Castrol SRF is it. Due to it’s extremely high dry & wet boiling points.

Boiling Point:
Dry: 310°C (590°F)
Wet: 270°C (518°F)

Size Per Bottle:
1 Liter

Castrol SRF Brake Fluid’s unique silicon ester technology absorbs less water than conventional glycol ether fluids and prevents the fluid’s high temperature performance from deteriorating. Its wet boiling point of 270°C is vastly superior to the minimum requirement of 155°C demanded by the current US DOT 4 specification. Its ability to withstand temperatures in excess of 300°C and superior resistance to the effects of absorbed water have established Castrol SRF Brake Fluid as the world’s premier fluid for the hydraulic brakes used in all forms of motorsport and racing.

To clarify - not 30 mins all at once but just 5 or 6 laps then some cool down time between sessions? If so the stock brake fluid might be fine as long as your not pushing it. If you want to push hard and have some safety margin Motul 600 would be advisable. The problem with brake fluid is once its cooked and boiled the pedal goes to the floor and you have zero brake pressure. As you can imagine this is really, really bad. Thus given the cost upgrading to proper racing brake fluid is cheap insurance.

I wonder what brake fluid they run at Spring Mountain... anyone know?

Honestly I don't know how the session will go. Its some class time and then time on the track. I'm sure it will be a couple laps warming up the car and then a few laps at whatever speed I become comfortable with.
I'll try and find out what the agenda is from the source edgeaddicts.com
Also emailed Spring Mountain to see if they'll tell me what they are running.
I think I will swap over to the Motul or SRF just to be on the safe side. Any issues mixing that with factory fill just in case I don't get every single drop of factory fluid out?
The Owners Manual says that if high performance brake fluid is used, replace it with GM approved fluid before driving on public roads. I don't think I will have that ability as I don't live where the track is (3.5 hrs from home).
I may have to skip this if requirements get too restrictive.
Thanks guys for your help. Excuse my ignorance on the subject.

You are fine not switching back - the REASON they say to switch back on public roads is the higher temp fluids absorb water in the air - so after like 6 months-ish... they are not as good... so to prevent you from leaving the DOT 4 / high temp stuff in and potentially losing brakes on the street - they want you to go back to a DOT 3 fluid.

I think it it good idea to replace brake fluid to increase the safety margin. I drive to and from the track with high performance brake fluid. In fact, I have been using the same SRF for 5 events without a problem. SRF has very high wet boiling point. Other cheaper fluid should work just as good, however it can't be used on street for as long as SRF. If you are not going to track your car, and this event is just one off, I would use cheaper alternative like Motol 600, then replace it with OEM recommendation at the first opportunity.

Being on the track could turn to be an addiction; be ready for that. Be safe, and have a good time.

Thanks fish and goathead….
Sounds good! Think I will acquire the Motive Bleeder set up and swap it out before I go and then change it when I get back.

"Being on the track could turn to be an addiction; be ready for that"

Yeah thats what I am afraid of! We do have a local track here and I would like to try that some time. After doing Spring Mountain and then having this opportunity to run the F1 course I didn't want to pass it up. I'm sure the local track will be a must do at some point!
A friend of mine runs the Big Bend Open Road Race every year and has been bugging me to do that as well. Who knows, maybe some day.

Our cars come to life on the track. I don't think one can experience the C7 capabilities anywhere else.

I would also be interested in knowing which Amsoil products you recommend for both the manual transmission as well as the differential. I have always used Amsoil products in my track cars where possible, but am new to the Corvette. Interesting that Amsoil recommends ATF for both manual and automatic transmissions.