Track Preparation Checklist

[RElias21]

Guys is the SRF a different color from OEM brake fluid? Otherwise, how do you know when you've completely flushed out the OEM fluid the first time you switch to SRF?

Also, if I don't want to eat up my stock tires (and if I'm not sure if they have enough life for the track), any suggestions for a track oriented tire and size? I would be mounting on OEM 513s.

Lastly, where do you guys usually buy your fluid and pads?

THANKS!

[F80Speed77]

SRF is gold like stock fluid, ATE Blue is banned from sale in the US so I don't think there are any more dyed brake fluids available.

Key to bleeding is getting the air bubbles out unless you are doing a full flush. I usually give each wheel another 3 or so cycles after I stop seeing bubbles. I also like to bleed with the engine running and car on jackstands, I seem to get better bleeds that way.

I usually get SRF at the cheapest place I can find it. I'm dumb and like to try different things though and I've had good luck with Wilwood EXP 600 Plus lately this saves a whopping $20 lol, just get SRF. KNSbrakes has really good pricing on pads.

As for tires, I think the best lapping day tire at the moment is the Goodyear Supercar 3. It's faster than the Hankook RS4 and seems to wear at about a similar rate. It's down on wet grip compared to the Bridgestone RE71R and RT660 but those are stickier tires and wear much quicker.

You can't go wrong with a Michelin PS4S or Continental Extreme Contact Sport which both have phenomenal wet grip and more than enough dry grip to still have fun on track.

I'd go up a size in all of these tires on those wheels 265/35/19 Front and 285/35/19 rear.

[dvq]

Originally Posted by RElias21

Guys is the SRF a different color from OEM brake fluid? Otherwise, how do you know when you've completely flushed out the OEM fluid the first time you switch to SRF?

For a full flush, I typically just bleed each corner repeatedly until I've bled 1L worth of SRF. Then I know the OEM brake fluid has been completely flushed.

[NYG]

Originally Posted by RElias21

Guys is the SRF a different color from OEM brake fluid? Otherwise, how do you know when you've completely flushed out the OEM fluid the first time you switch to SRF?

Also, if I don't want to eat up my stock tires (and if I'm not sure if they have enough life for the track), any suggestions for a track oriented tire and size? I would be mounting on OEM 513s.

Lastly, where do you guys usually buy your fluid and pads?

THANKS!

Depends how fresh/hard you've been on stock fluid. If you're switching relatively fresh fluid with SRF it'll be hard to see. For a full flush, I use 2L.

[RElias21]

Originally Posted by NYG

Depends how fresh/hard you've been on stock fluid. If you're switching relatively fresh fluid with SRF it'll be hard to see. For a full flush, I use 2L.

Unfortunately, I just got my brake fluid flushed before you guys indicated that I want a different brake fluid for track use. And with how limited my driving is in the winter, it's literally super fresh.

Maybe I should do my first track day on this fluid before flushing again? Otherwise 2L it is!

[fanatic1]

Originally Posted by RElias21

Unfortunately, I just got my brake fluid flushed before you guys indicated that I want a different brake fluid for track use. And with how limited my driving is in the winter, it's literally super fresh.

Maybe I should do my first track day on this fluid before flushing again? Otherwise 2L it is!

For sure on your first track day, fresh stock fluid will be fine. Experienced track day folks like CanAutM3 use factory (fresh) fluid for track days with good result.

[NYG]

Originally Posted by RElias21

Unfortunately, I just got my brake fluid flushed before you guys indicated that I want a different brake fluid for track use. And with how limited my driving is in the winter, it's literally super fresh.

Maybe I should do my first track day on this fluid before flushing again? Otherwise 2L it is!

I don't hate this idea.

It's best for you to experience why a lot of us recommend SRF, especially for the stock setup. Even if it does boil, you'll know right away and it will still be good enough to drive home since they won't reach wet boiling points.

If you threshold brake and it's not 15F outside you'll feel your brake pedal get a little squishy.

[jfritz27]

OK, super-nerdy question here: If one wishes to flush the stock brake system, and ONLY use a maximum of 1 L of fresh fluid, and be anally quantitative in the process, how much volume should be flushed out at each corner?! Go!.... I realize it's "until it comes out looking fresh", but still....

Something like 200 mL per corner, maybe a bit more for rears & less for fronts, leaving a little to top off reservoir?

[NYG]

Originally Posted by jfritz27

OK, super-nerdy question here: If one wishes to flush the stock brake system, and ONLY use a maximum of 1 L of fresh fluid, and be anally quantitative in the process, how much volume should be flushed out at each corner?! Go!.... I realize it's "until it comes out looking fresh", but still....

Something like 200 mL per corner, maybe a bit more for rears & less for fronts, leaving a little to top off reservoir?

Hard to say. The lines won't carry much but rears will have more. Need to figure out volume in your calipers/master cylinder booster/etc.

[CanAutM3]

Originally Posted by RElias21

Unfortunately, I just got my brake fluid flushed before you guys indicated that I want a different brake fluid for track use. And with how limited my driving is in the winter, it's literally super fresh.

Maybe I should do my first track day on this fluid before flushing again? Otherwise 2L it is!

Brake fluid is hygroscopic, meaning that it absorbs moisture. Fresh really means fresh, your fluid should be no more than 6~9 month old even if your car was just sitting in the garage. I usually flush once per year at the start of the track season.

The stock fluid works decently fine, but you will get a firmer and more consistent pedal feel with more specialized fluids such as SRF. I've used the stock fluid for many years simply because BMW was paying for the flush every second year as part of the included maintenance program. It worked well enough that it did not justify the added cost for me.

[CanAutM3]

Originally Posted by jfritz27

OK, super-nerdy question here: If one wishes to flush the stock brake system, and ONLY use a maximum of 1 L of fresh fluid, and be anally quantitative in the process, how much volume should be flushed out at each corner?! Go!.... I realize it's "until it comes out looking fresh", but still....

Something like 200 mL per corner, maybe a bit more for rears & less for fronts, leaving a little to top off reservoir?

IL is plenty sufficient to flush the system. The colour of the fluid remains the best indication. You need to flush a fair bit more on the first claiper you bleed (best to start the farthest away from the master cylinder) because you need flush out what is left in the master cylinder tank. Don't forget, there are two sides to flush on each of the front calipers.

[MaX PL]

Originally Posted by RElias21

Unfortunately, I just got my brake fluid flushed before you guys indicated that I want a different brake fluid for track use. And with how limited my driving is in the winter, it's literally super fresh.

Maybe I should do my first track day on this fluid before flushing again? Otherwise 2L it is!

you don't need 2L to flush. as most others have said, 1 L is sufficient.

[RElias21]

Originally Posted by CanAutM3

Brake fluid is hygroscopic, meaning that it absorbs moisture. Fresh really means fresh, your fluid should be no more than 6~9 month old even if your car was just sitting in the garage. I usually flush once per year at the start of the track season.

The stock fluid works decently fine, but you will get a firmer and more consistent pedal feel with more specialized fluids such as SRF. I've used the stock fluid for many years simply because BMW was paying for the flush every second year as part of the included maintenance program. It worked well enough that it did not justify the added cost for me.

Awesome. Thanks.
I just got it flushed last month, so June would only be about 4 months out.

I may roll with the OEM fluid this season, or at least my first time, and then go from there.

[CanAutM3]

Originally Posted by RElias21

Awesome. Thanks.
I just got it flushed last month, so June would only be about 4 months out.

I may roll with the OEM fluid this season, or at least my first time, and then go from there.

[D_SheerDrivingPleasure]

Any issue mixing .5L of SFR 600 with 1L 660 for a full flush?

I am preparing for my first ever flush and I have anxiety about forcing air into the system if I don't have adequate volume in my pressure bleeder?

[RElias21]

Here's another question for you guys.

As a first timer, and wanting an instructor with me for the rides, what kind of event should I be looking for on motorsportreg?
Should I be sticking just to the BMW events or any event?

Thanks.

[MaX PL]

Any event from the top orgs is fine. PCA, BMW, SCDA, Chin, NASA, etc.

[edycol]

Originally Posted by CanAutM3

Brake fluid is hygroscopic, meaning that it absorbs moisture. Fresh really means fresh, your fluid should be no more than 6~9 month old even if your car was just sitting in the garage. I usually flush once per year at the start of the track season.

The stock fluid works decently fine, but you will get a firmer and more consistent pedal feel with more specialized fluids such as SRF. I've used the stock fluid for many years simply because BMW was paying for the flush every second year as part of the included maintenance program. It worked well enough that it did not justify the added cost for me.

You are mentioning hygroscopic and SRF in the same post, so I will chime in on this.
Regular brake fluid is hygroscopic. SRF is Hydrophobic.
If the system is not thoroughly flush with SRF the first time (at least 3ltr) there is a potential for serious issues.
If one flushes the system with 1 or 2ltr of SRF there is definitely some old fluid left. As you mentioned, regular fluid is hygroscopic and will attract moisture. Since SRF is hydrophobic, it repels old fluid that has excessive moisture content. That creates a very dangerous situation where moisture is collecting in molecules that are hygroscopic and a lot of it. Eventually, that will create a wet pocket which will turn itself into an air pocket.
If one uses SRF, an appropriate bleed using ABS pump should be used, and first time at least 3ltr of SRF, which of course, is uber expensive.

[dvq]

Originally Posted by edycol

You are mentioning hygroscopic and SRF in the same post, so I will chime in on this.
Regular brake fluid is hygroscopic. SRF is Hydrophobic.
If the system is not thoroughly flush with SRF the first time (at least 3ltr) there is a potential for serious issues.
If one flushes the system with 1 or 2ltr of SRF there is definitely some old fluid left. As you mentioned, regular fluid is hygroscopic and will attract moisture. Since SRF is hydrophobic, it repels old fluid that has excessive moisture content. That creates a very dangerous situation where moisture is collecting in molecules that are hygroscopic and a lot of it. Eventually, that will create a wet pocket which will turn itself into an air pocket.
If one uses SRF, an appropriate bleed using ABS pump should be used, and first time at least 3ltr of SRF, which of course, is uber expensive.

Are you sure that's the case? I've seen this repeated multiple places but haven't seen this marketed by Castrol at all. If anything wouldn't it just be less hygroscopic and not hydrophobic?

[fanatic1]

Originally Posted by dvq

Are you sure that's the case? I've seen this repeated multiple places but haven't seen this marketed by Castrol at all. If anything wouldn't it just be less hygroscopic and not hydrophobic?

Originally Posted by dvq

Are you sure that's the case? I've seen this repeated multiple places but haven't seen this marketed by Castrol at all. If anything wouldn't it just be less hygroscopic and not hydrophobic?

You've got the best brake temp use case in California, Laguna Seca. Like you, 2L flush works really well from stock to SRF for me and 1L flush for refresh.

[edycol]

Originally Posted by dvq

Are you sure that's the case? I've seen this repeated multiple places but haven't seen this marketed by Castrol at all. If anything wouldn't it just be less hygroscopic and not hydrophobic?

SRF is hydrophobic, hence a high wet boiling point. It is a good long term fluid if you do not want to deal with more often changes.
The question is: is it worth it? There are superb regular brake fluids that would deliver exceptional performance during 6-9 month period. I worked for oil company as test driver, and we used a lot of brake fluids as a comparison when we were developing fluids. ATE of all fluids was most consistent and one of the least hygroscopic. The problem with ATE TYP200 is 280c dry boiling point if the vehicle or track is too hard on brakes. You can go Motul RBF600 or 660, TRW has a racing fluid (developed from Lucas line up when they bought Lucas in 90's).
You can most definitely go SRF, I am just saying be a bit careful with flushing. If you do it right the first time after that is just like a regular flush.

[NYG]

Originally Posted by edycol

SRF is hydrophobic, hence a high wet boiling point. It is a good long term fluid if you do not want to deal with more often changes.
The question is: is it worth it? There are superb regular brake fluids that would deliver exceptional performance during 6-9 month period. I worked for oil company as test driver, and we used a lot of brake fluids as a comparison when we were developing fluids. ATE of all fluids was most consistent and one of the least hygroscopic. The problem with ATE TYP200 is 280c dry boiling point if the vehicle or track is too hard on brakes. You can go Motul RBF600 or 660, TRW has a racing fluid (developed from Lucas line up when they bought Lucas in 90's).
You can most definitely go SRF, I am just saying be a bit careful with flushing. If you do it right the first time after that is just like a regular flush.

The benefit of SRF on a vehicle with good brake cooling is the duration between changes so it usually isn't worth the price.

On the F8X (with stock brake cooling), SRF is worth every penny because you WILL boil your fluid - often (assuming race pads and threshold braking). The difference between SRF and all the other common fluids is that the SRF will still be useable after it boils. I've had so many track days ruined using Motul, PFC, Stock, Brembo, etc brake fluids. I regret that I avoided SRF for so long.

My Z06 has incredible stock brake cooling and I still use SRF regardless of premium. Only fluid I trust will last me an entire season but I still refresh it every couple of track days.