DOT 4, 5.1, or 5, New brakes in race car. Options

[motorvated]

Just upgraded to 911 suspension and brakes and ready to fill with brake fluid. Car will be raced first with 1.8 L four, then 215 c.i. Aluminum V-8. Since the system is almost all empty of fluid, now is the time to consider switching to DOT 5 silicone based brake fluid. Any suggestions or recommendations.

Thanks,

Mike S.

[brant]

Dot 4

[ThePaintedMan]

(IMG:style_emoticons/default/agree.gif) No silicone brake fluid in any kind of track car. I have been using ATE Super Blue, which has a decent boiling point at a good price. As I add more power, I expect to move up to something with an even higher BP, like Wilwood or AP Racing. As a habit I also change fluid before any kind of track outing - the longer it's in the car, the more water it picks up, dropping the BP. That's why there is a "wet" and "dry" BP listed.

[NeunEinVier]

For DOT 4, consider Motul RBF 600, dry boiling point 594F (312C), wet boiling point 401F (205C). Or RBF 660, dry boiling point 617F (325C), wet boiling point 400F (204C).

[campbellcj]

I can't speak to the merits of the others, but I've also been fine with high-end DOT 4. Endless and Motul most recently.

[Cracker]

I run SRF in both of my race cars...never a problem. Dot 4

Tony

[brant]

You will need high end like the motul with the v8

But not the 1.8
Start with fresh and clean calipers and cheap fluid. If bleeding an open system (rebuilt calipers/ lines) go through a quart of something cheap to get the air/bleeding done

The stock valve or even after market adjustables are hard to bleed without patience or bench bleeding, hammers, trips around the block, or a pressure bleed. You'll go through a lot of fluid

Then full flush to something like ate

You won't over heat good stock brakes with race pads at your hp and weight

You will with the v8/track experience
Not while your getting addict... I mean started.
Run good pads like the kfp's. you can get brake fade from over heating pads also.

Remember a small bore racing 914 is all about momentum. The fastest ones don't use their brakes too often.

[Cracker]

Something else to consider. If I were you, I'd just put off the shelf dot4 fluid to start. If you haven't tracked a 914 before...you'll be taking it easy. If you have, you'll be trying to get your head around how to drive it properly. There is plenty of time for you to grow into your car within a performance setting and testing your braking system too. I pay about $75 per liter for my fluid - just an idea. Start cheap, verify systems are all go, have fun learning the car (I doubt you'll be driving 10/10th's), and then upgrade once the car and driver are on the same page. All the best!

PS: Can you clarify what you mean by race? Track day, NASA, HSR, SCCA???? It looks like a hot rod in your avatar...

Tony