*The FL5 Track Junkie Thread*

[svvitch]

I knew that when I purchased though it wasn't a surprise @Tougefl5

Jason are they just making a thinner core?

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[siwelnosaj]

I knew that when I purchased though it wasn't a surprise @Tougefl5

Jason are they just making a thinner core?

Yes, they are making a thinner core and changing the flow pattern

 

[svvitch]

Got it

 

[Rhorn]

Well, I survived my first track day in the CTR, and the conditions were ideal other than the track getting sprayed down with antifreeze by an overheating Mustang before my first session. Brakes got a little soft on me after about 15 minutes, but those of you familiar with CMP understand…. The way this car can put power down through the front wheels out of slow corners is magic. Violates the laws of physics. There’s definitely more time to be found, but I was pleased with my first time out. I’m slow in T8 and way slow at the kink. Water temps peaked at 215, but I did see indicated oil temp reach 275. Backed off for half a lap and it dropped to 250.

When your brake pedal start to get mushy from the brake fluid overheating do you have to do a brake fluid flush to reset the fluid? Or is the fluid still good.

 

[TARZAN]

When your brake pedal start to get mushy from the brake fluid overheating do you have to do a brake fluid flush to reset the fluid? Or is the fluid still good.

Sounds like you may have boiled some of the fluid. Could just do a quick bleed to get any air out, but I prefer to just do a flush with a full bottle of SRF since it only takes a few more minutes (and FCPEuro lifetime replacements).

What fluid are you running and how much did you use to flush it last?

 

[m3bs]

When your brake pedal start to get mushy from the brake fluid overheating do you have to do a brake fluid flush to reset the fluid? Or is the fluid still good.

I’m really not sure if it was fluid or pads. I had fresh SRF, with Ferodo DS3.12 and DS1.11, as well as titanium spacers. The pedal came right back for the next turn, but I was a bit more conservative after that. I’m going to switch to PFC fluid before I go again.

 

[TARZAN]

I’m really not sure if it was fluid or pads. I had fresh SRF, with Ferodo DS3.12 and DS1.11, as well as titanium spacers. The pedal came right back for the next turn, but I was a bit more conservative after that. I’m going to switch to PFC fluid before I go again.

In my experience, Castrol SRF has been phenomenal throughout a past full season of use on my GTI compared to other fluids I've used. I expect similar performance when I take the FL5 out later this month.

Using ATE 200 in the past, I would need to bleed after every track day. Was this your first flush with it and did you only use 1L?

I remember some people mentioning it doesn't mix with other fluid remnants.

 

[m3bs]

It is my understanding that the SRF fluid has been changed several times over the past year, including just before I got the car last month, but I didn't do it so I cant be positive. I've boiled fluid in other cars, and the pedal went away completely. This just got mushy, and I overshot my turn-in point. Some of the Porsche guys have reported soft pedal when SRF got really hot, suggesting an issue with fluid compressibility. I've never used it before.

 

[Rhorn]

Sounds like you may have boiled some of the fluid. Could just do a quick bleed to get any air out, but I prefer to just do a flush with a full bottle of SRF since it only takes a few more minutes (and FCPEuro lifetime replacements).

What fluid are you running and how much did you use to flush it last?

For reference this never happened to me, was just asking what to do if I ran in that situation.

I am using SRF and did basically 3 bottles because I messed up the first time (forgot to to the e-brake cycling) so I have more than enough SRF fluid in my lines.

 

[TARZAN]

It is my understanding that the SRF fluid has been changed several times over the past year, including just before I got the car last month, but I didn't do it so I cant be positive. I've boiled fluid in other cars, and the pedal went away completely. This just got mushy, and I overshot my turn-in point. Some of the Porsche guys have reported soft pedal when SRF got really hot, suggesting an issue with fluid compressibility. I've never used it before.

Interesting for sure. Are you on stock lines? I wonder if that has something to do with it, but I'm doubtful. Curious what you end up finding.

I've done quite a lot of brake flushes when I worked as a technician, but I'm no race engineer, maybe someone else can chime in. Pad fade, to me, feels more like a gradual drop off where the pedal firmness is there, but the car isn't slowing down as fast. Anytime I feel a mushy/softer pedal, I usually associate that with the hydraulics.

SRF has the highest wet boiling point of all fluids on the market if I'm not mistaken.

I wonder if you're somehow hitting the limitations of the dry boiling point, since the fluid was fresh prior to the track day and shouldn't have absorbed a lot of moisture yet.

Some of the other fluid options like PFC and RBF700 have higher dry boiling points. If you do switch to one of those, I guess you'd need to change the fluid more often as it'll absorb more moisture with the lower wet boiling point.

 

[Rhorn]

Anybody experienced a “chirping” noise when bleeding brakes? As soon as I start pumping the brake pedal I get this noise and it goes away after a little bit. My best guess it’s related to the vacuum pump. Ran out of time tonight to grab the stethoscope but hoping to take a look at it after work tomorrow.

Any updates?

 

[TARZAN]

For reference this never happened to me, was just asking what to do if I ran in that situation.

I am using SRF and did basically 3 bottles because I messed up the first time (forgot to to the e-brake cycling) so I have more than enough SRF fluid in my lines.

Gotcha, I figured that may have been the case after I typed my response lol.

Another reason I just do a full flush is because the shelf life isn't very long, and can degrade once the seal is opened. I usually just have a sealed bottle handy to take with me in case I need it at the track.

Strongly recommend buying SRF from FCPEuro (or any of the other fluids they stock) so you can take advantage of the "free" lifetime replacements. Will save a lot of money in the long run since you receive full store credit for returns after the initial purchase is returned, and a replacement order is made.

 

[Rhorn]

2) Integrated bracket for optional transmission cooler: Built in provision on the back side of the radiator to easily add an optional transmission cooler to further reduce coolant temps by unburdening the coolant system (the OEM design uses the coolant system to cool trans fluid via the heat exchanger on the front of the transmission). The placement on the backside of the radiator is to minimize interference with the radiator and maximize efficiency.

For the transmission cooler, what would that be running off of? Would it just be coolant linked up to the transmission?

 

[m3bs]

I’ve been using PFC RH665 in my other cars, flushing at least one bottle through after every event. WBP is irrelevant, IMO.

 

[TARZAN]

I’ve been using PFC RH665 in my other cars, flushing at least one bottle through after every event. WBP is irrelevant, IMO.

Gotcha, that makes sense for your use case then. My car is also my daily driver.

I got tired of bleeding after every event haha. SRF lasted me a full season which was 8 days of driving with no noticeable drop off, so I found it to work well for dual duty, changing it seasonally. I guess WBP matters more when extending the service interval like I was.

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