IMGT3

Professional race teams are switching over to Prospeed RS683 Extreme Performance Brake Fluid. As a technical supplier to Andretti Autosport, the Prospeed RS683 brake fluid has outperformed the competition in the labs and on the track. Don't believe it? check out these two links. Chuck

Characteristics of brake fluid:

http://www.imgt3performance.com/prospeedrs683.aspx

Why RS683:

http://www.imgt3performance.com/prod...3-brake-fluid/

RENNLIST member March Special:

Buy three -- get one free! And free shipping!* (Enter quantity (4) plus promo code RS1 at checkout). PM me for codes for larger quantities or shipments to Canada.

*Free ground shipping guaranteed within the continental United States. additional charges may apply for Canada.

LVDell

At $40 for a .5L it is more expensive than SRF at $75 a liter. Nice that it is USA based since Castrol is UK based but in all my years I have never had my SRF let me down in racing or DE. You'd think the US based product would be cheaper since there is no import tax.

mglobe

After using SRF for several years, I just switched to Prospeed at my race shop's advice. I've never been happy with the soft pedal feel from SRF, & 683 is supposed to be less compressible. I'll be racing on it in two weeks & we'll see how it does.

LVDell

Soft pedal from SRF? Sounds like air in the system, not the fluid.

TRT41

I remember meeting the guys behind Prospeed RS683 at last years Club Race at HighPlains. Good to see an American brand getting wider distribution and offering more variety beyond SRF and Motul. I'll give it a try on my next brake fluid change.

IMGT3

It certainly is the air, but not exactly for the reason you think... silicate ester is the base used in Silicone based brake fluids, 13% (+/- stdev of 6%) of this material is air. as the fluid sustain damaging heat and pressure the base material experiences compression that leads to changes in pedal pressure after 15 to 20 minutes of peak breaking. Castrol SRF use Silicate Ester as a base material whereas Prospeed RS683 and all DOT 4 compliant brake fluids use borate ester (2% +/-1% air) as a base material. Silicate ester is a material that is related to silicone. Please note it is NOT silicon but is related. This fact allows the silicate ester based brake fluid to have a much higher wet ERBP. However, the downside to silicate ester as a base material in brake fluid is increased compressibility and a shorter shelf life.

Professional race teams who prep cars for a living who have experienced fade with silicate ester based fluids when sustaining high temperature and pressure for extended periods. The high temp formulation along with the stability of RS683 under the same conditions is where Prospeed begins to shine...it builds confidence as your pressing hard when others are less efficient...That's why race teams are starting to become believers.

LVDell

Thanks Chuck. I'll carry on our discussion back in the GT3 forum

IMGT3

cool!

onefastviking

I have never noticed what I would consider a soft pedal in your car, when have you felt this ? I have felt it in some 996's but whenever I have there has always been air in the system.
Do you feel this right after bleeding still ? If so maybe you should reconsider that bleeding conversation that we had previously.

As for the fluid, I think you will be happy with your race shops advice.

mglobe

It's better right after a flush and then seems to get worse with use. It's not been like what you get when you boil the fluid. Been there, done that. That's why I switched to SRF. It's just not as firm as I've felt in other cars. Particularly noticeable coming into T10 going CCW at TWS.