I'm getting ready to install my 6-pot Wilwood BBK up front and the Stillen sport rotors + metal matrix brake pads in rear with SS brake lines all around.
When I consulted my 2003 owners manual, it stated "DOT 3 only, non-synthetic brake fluid" WTF??? That means I can't use Motul. What are you guys using in your Gs?

 

Brake fluid hygoscopic life is roughly proportional to wet boiling temperature.

Long lasting fluids have a low wet boiling point. Do you want to change every race weekend, month, or every year is the question you must answer.

 

motul rbf 600

 

I don't race my G. This is a street only vehicle. I am just wondering why the Infiniti owners manual states Dot 3 only, no synthetics. Since I am spening so much money on the brake upgrades, I thought the performance brake fluid would be the way to go. Do any of us G35 owners use the performance brake fluids?

 

If you are **** about brake maintenance, synthetic is the way to go. It has a higher boiling point and if you do a little weekend warrior stuff, it will help you with fading. If you are like most folks, you change your fluid maybe NEVER, Dot 3 is best because it will pick up free water and hold it in suspension.

Or I could just be full of Shi.............t

 

OK, but my manual says not to use synthetic or anything other than DOT 3.
Any reason for this? Or is Infiniti just being **** themselves?

 

Water, that's why. As I said, DOT 5 WILL NOT absorb water so it sits in your system rusting away at anything it touches. That's why you have to change it once a year.

You should change ANY brake fluid once a year anyway, but most don't.

 

Thanks for the clairfication! Dot 3 it will be.

 

In theory the oem pad, backing plate and oem thermal shims protect the caliper piston from heating up enough to boil oem brake fluid............assumming no moisture gets inside the system.

Pad fade should occur before the brake fluid boils.........however if you change pads or rotors this may not be the case or if you fail to flush the brake fluid TOTALLY when oem pads wear out and get changed.

Oem pads last about 20,000 miles or 18 months [+-].

The system was designed for a specific viscosity and higher performance fluids may be different.

Manufacturers don't require a particular brand otherwise they have to supply it so safer to just say DOT3 spec. By doing so OWNERS assume the responsibility to test their brake fluid to prove it meets DOT3 when old and used............not Nissan...........the term check brake fluid requires more than just checking the level it means check the quality..{MAKE SURE IT DOES NOT EXCEED 3.5% moisture or it has failed and is defective}......since this cannot be easily done the safest way is to just change it every 18 months.

 

A typical ultra expensive high performance brake fluid will absorb 4-5% moisture in as short as 2 weeks depending on enviroment!

http://www.bobbyarchermotorsports.com/pdf_2848_2.pdf

 

I'm running Motul RBF 600 as well. I ran the stock brakes (on my 2005 Coupe 6MT) at the track and like an idiot, I stayed out on the track one lap too long while expecting too much from my brakes. At the beginning of my last lap, I started to feel a little fade, but I figured I would just run the lap out and let it cool when I finished. Turns out that the 2 repeated hard stops from about 100 down to 30 or so was too much for my fading brakes. The last turn before the pit, I hit the brakes, the pedal went to the floor, and it felt like I was stepping on a wet sponge. Luckily I just let the car run straight into the dirt. It was bad enough that I didn't even try to steer so I wouldn't spin the car. After heading back in the pits, I checked out the hardware to find my fluid boiling, my rotors were over 1000 deg F (actually it hit a 1000, then read error on the IR thermometer since I exceeded the upper end), and my rear pad was crumbling away. Of course the pad only crumbled after it managed to score my rear rotors.

Anyway, not sure if you even care to hear my story, but I've since upgraded to a full StopTech setup front and back which came with Motul RBF 600. I ran another track day with the new brakes and between the improved rotor size, heat capacity, pad type, and fluid, I pounded on the brakes with no problems. There's better DOT 4 fluids out there, but for the price, I think the Motul RBF 600 is pretty good stuff with its high wet and dry boiling points. It's not all that cheap at $15 a bottle, and you'll need 3 bottles to fill and bleed your system, but with the amount that you've spent on your brakes already, $45 is really nothing.

 

The point is you need to match the pads and the brake fluid so that they are fairly close. So that the weakest links are matched....and consistent.

Having a modified pad needs a modified fluid.

Fade can be a wonderful thing, if it occurs as expected not in a sudden surprise.

Exotic expensive brake fluids need exotic expensive maintenance to live up to their potential.

Whether a brake fluid cost $1 or $20 per pint is not material in the the cost of a rear end collision or other accident.

Just as $75 vs $300 tires can seem cheap and petty after an accident.

People never accept the blame and say it's my fault because I was so cheap

 

With that being said, what would you recommend for the new brake system? The Wilwood rotors are massive and the pads are huge, dwarfing the rear rotors and calipers and I assume the front ones as well. Dave at AZC tells me there is no way I can get the brake fluid close to boiling with this setup, especially since this is a street car.

 

Each 60 mph to zero stop raises typical STOCK pads rotors by 100-150F [depending on front or rear] from ambient.

To calculate aftermaket vs stock just convert the rotor weight to a percentage increase and reduce the 150F. If an aftermarket rotor weights 20% more the temp gain will be 20% less or say 120F. The braking torque [HP] is simple MASS decel time distance.

Stops are cumlative if you don't have cool down time.

Street cars have a hard time boiling even stock system as that would require a half a dozen 60 stops in 1 minute [0>60>0>60>0 .....5 sec + 3sec +5+3.......100F +150F+150+150+150 +150 +150 ~~~= 1000F less say 200F cooling from 6 acceleration air flow ~~800F rotors..........when you finally get thru exercising your feet and the car is stationary the fluid will boil easily as the rotor heat is radiated into caliper.

These should help you make the necessary calculations:

http://www.delphi.com/pdf/techpapers/1999-01-0483.PDF
http://www.delphi.com/pdf/techpapers/2000-01-0445.pdf
http://www.delphi.com/pdf/techpapers/1999-01-0142.PDF

 

i know i'm bringing this thread back from the dead, but there's a lot of useful information here! i've been reading posts by Q45tech for a while and always find myself learning a bit more about how a car and its systems actually work. good read!