xxlap1xx

So i'm hitting the track in 2 weeks, street of willow. I wanted to change to dot 4 brake fluid, but i heard that the dot 4 fluid wont work anymore after it's been overheated, even after cool down. I just wanted to know if that's true or not.

Does anybody recommend me to change to Dot4 or just stay stock? This is my second time hitting the track, the first time was willow spring, big track. But this time is the SOW, small track, so i need to use the brake a lot more.

Any trackers have any opinions? Thanks!

Jaku

all fluid had dry and wet boiling point, some has much better wet boiling point that keeps the fluid working not too bad after overheat and absorbing moisture and such

that's not how they classify DOT 3, 4 or 5.1, so don't let pp tell you the wrong info about DOT4

those racing fluids that has extremely high boiling point are all DOT4, so go ahead and use those "higher boiling point" fluid

if you keep stock fluid, you might even overheat your fluid before your pads

call me i will tell you where to buy Motul 600 and bleed them

itsnoe30

I would go big and get the 5.1.

I just ran a few 45 minute sessions at Serbing a few weeks ago, in an e36, with minimal fade. On the other hand, someone there with an S on unknown fluid seemed to cook his brakes...

Jaku

wat kinda 5.1 do you use? wat's the boiling point?

DOT 3, 4 or 5.1 should not be considered here for track use!!

LegendaryHarry

super blue?

xxlap1xx

What's up jaku Long time no see! So u recommend the Motul 600? I guess Im going to buy it then Listening to the pro is always a good idea haha. Is one bottle enough (500ml) ? Does changing the Dot4 brake fluid will effect the clutch? BTW thanks for the info!

ZDan

Off-the-shelf Valvoline DOT4 works fine for me at the track (totally stock AP1 on Kumho VR's and Ecstas).

I know a lot of people recommend ATE Super Blue around here, but the one time I used it (Watkins Glen last year) the pedal got progressively softer over the course of two track days.

itsnoe30

Off the shelf NAPA brand. I want to say the wet bp is 600, but I'm not entirely sure. I'll figure it out at some point and report back.

feintmotion86

Fist off, any fluid that has been "cooked" won't work. The fluid itself develops air bubbles in the system which causes the eventual failture, since the air bubbles compress causing messed up pedal feel and inaccurate caliper contraction.

That doesn't really make any sense, because ATE super blue's dry and wet boiling points are significantly higher than valvoline syn DOT 4. ATE is a superior product in my experience.

Also it is untrue that all racing or high temp fluids are DOT 4, because I'm using a DOT 3 that has a 574 degree boiling point. its an SSBC fluid.

If you're using street tires, ATE super blue seems to be the best cost to benefit ratio since you're most likely not going to see temps high enough to utilize a more expensive fluid like motul.

Or, you can buy the SSBC fluid I'm using, with a 574 degree boiling point for around 7 bucks a bottle and tell the other fluids to screw off.

mikegarrison

Most people will recommend that the wet boiling point is a more useful comparison than the dry boiling point. However, if you replace your fluid every event, then the dry boiling point may be the more useful comparison.

Figure on 1 liter of fluid for a complete flush. You won't need that much, but you will need more than 500 ml.