[MichaelDelaney]

I am using Motul 600 and Goodridge stainless steel lines with Porterfield R4S pads and stock diameter Brembo crossdrills. I have never tried ATE Super Blue but the blue stuff is not DOT legal...yellow is. The other autocrossers tell me the ATE stuff is great. Never tried Castrol either. At the very least you should change these every 6 mo. since moisture can get into the lines but the more changes, the better.

Castrol SRF has the highest wet BP of any brake fluid (518F).Next is Motul600 (421F). All others are around 280F including ATE Super Blue. Some people rely on the dry boiling point instead. Each fluid manufacturer has it's own compressibility and pedal feel.


DOT 3 & 4 are for ABS-disc, DOT 2 is for drum, and stay clear of high silicone DOT 5 if you have ABS.

I believe Gvtec is using Valvoline DOT 4. (Edited: originally I had said Mobil 1 based on a misread of an old SHO thread we had together).

More info to follow...I'm just in a bit of a hurry right now....

 

[MichaelDelaney]

...Interesting how the dry temp is off from MD's quote. Not a missprint on my part... maybe Pegasus?

I don't know. My quote says wet BP Castol 518 and Motul 421 above and that's what you have on the Pegasus list there...maybe another quote? (and no, I did not edit my post

)

When you and I talked awhile back, you had said you were going to try Mobil1 and so I assumed that there was one available when you had mentioned it but I guess they didn't make one...my mistake.

I'm glad I use Motul...good racing heritage and performance....still pricey though....how much does valvoline go for BTW (wet and dry BP)?

 

[MichaelDelaney]

it's amazing and dangerous to watch people allowed to go lapping with regular brake fluid. You see them pull into the pits with rotors on fire or the brake pedal all the way to the floor (that's their new upright pedal position!) and their brake fluid boiled off. Nuts. don't know how one of our local tracks can allow it but I guess that's what a waiver is for...you're on your own out there...talk to the other drivers before you lap to see who has what equipment (oh you still have stock brake fluid,... I see) and to get their Banzai Quotient (like IQ except the BQ measures their level of experience and anger management). This way you know who not to hang around on the track to avoid any later "issues"...

 

[MichaelDelaney]

naw...no crack involved among our crew...I think you've just been pulling too many G's with that SC'd gsr and the blood was centrifuged away from your head during a hard sweeping lefthander ....

 

[MichaelDelaney]

2 bottles are plenty...

 

[MichaelDelaney]

source: s2ki.com

Arranged by DRY boiling point:

DRY: 401F -- WET: 284F --- DOT3
DRY: 446F -- WET: 311F --- DOT4
DRY: 502F -- WET: 343F --- Valvoline SynPower
DRY: 509F -- WET: 365F --- Motul 5.1
DRY: 527F -- WET: 302F --- AP Racing 551
DRY: 536F -- WET: 392F --- ATE Superblue/TYP200
DRY: 590F -- WET: 410F --- AP Racing 600
DRY: 590F -- WET: 518F --- Castrol SRF
DRY: 593F -- WET: 420F --- Motul RBF600
DRY: 610F -- WET: 421F --- Neo-Synthetic Super DOT 610

Arranged by WET boiling point:

DRY: 401F -- WET: 284F --- DOT3
DRY: 527F -- WET: 302F --- AP Racing 551
DRY: 446F -- WET: 311F --- DOT4
DRY: 502F -- WET: 343F --- Valvoline SynPower
DRY: 509F -- WET: 365F --- Motul 5.1
DRY: 536F -- WET: 392F --- ATE Superblue/TYP200
DRY: 590F -- WET: 410F --- AP Racing 600
DRY: 593F -- WET: 420F --- Motul RBF600
DRY: 610F -- WET: 421F --- Neo-Synthetic Super DOT 610
DRY: 590F -- WET: 518F --- Castrol SRF


Castrol has the best wet boiling point and so if you want to keep your brake fluid in for a longer time it's the way to go and why it's expensive. Remember brake fluid is hygroscopic meaning it likes to attract and absorb any water moisture from the air. So the wet boiling point becomesthe more relevant one as you keep the fluid in longer. Notice that Motul RBF600 (the brand I use) has a higher wet BP than Valvoline...and although the Motul is pricier than the Valvoline, it is affordable...unlike the Castrol which is for Ferrari owners.....

 

[MichaelDelaney]

please stay away from DOT 5 (silicone) brake fluid especially if you have ABS....

DOT 5 is SILICoNE based, which means you can't mix it with DOT 3 or DOT 4 fluids; it reacts chemically and forms a precipitate. If you want to use DOT 5, you have to disassemble the whole system and flush it thoroughly. Ditto if you are running DOT 5 and want to change back to DOT 4 or 3. You can mix DOT 3 and DOT 4 with no problems, but I wouldn't. DOT 3 will absorb water....; DOT 4 doesn't as much, but needs to be changed more often. For most performance-oriented people, DOT 4 is probably the best compromise. DOT 5 is a ***** to work with, and very expensive; I tried it awhile ago and although it prevents boiling and loss of braking power from loss of pedal height because of the improved boiling pt, it is much spongier initially, difficult to work with.

 

[MichaelDelaney]

you usually have to bring your brakes UP to operating temp. in colder weather. once you have a baseline temp., the amount of heat generated from converting kinetic energy to braking is dependent on how many times you brake hard per lap, the design of the rotor to wick away heat, and the efficiency of your brake ducting.

In the rain when it's colder, people tend to use smaller ducts but keep the same brake fluid that they would use when it's warmer outside.


I suggest that you chose the wet temp. spec that best suits your braking conditions on the hottest days and then adjust your ducting accordingly to the ambient conditions. It's easier to bring the brake operating temp. up than it is to cool it down sufficiently to prevent boil off and having your pedal sunken down to the floor board ( a very uninspiring feeling when it happens to you and you're already in the middle of the track at full throttle at speed, driving in anger against the stopwatch) .