Brake Pads that work cold - 1g big brakes (auto)

[kiggly]

I'm trying to switch over to a manual brake setup and looking for some pads that have a little higher friction coefficient than the generic semi-metallics I've been running.

History:
The OEM setup with the 1g dual piston big brakes, OEM master, 1g turbo brake booster (7"&8" tandem), and an electric vacuum pump could hold the car on the line. This setup was of questionable long-term reliability, noisy, heavy, added electrical draw, and just a bunch of big parts. I ran a pressure sensor on the brake line at the end of last year and was surprised to see pressures as high as 2600-2700psi when holding it on the line.

Today:
Going through the system, I thought I could make over 2000psi with a modified pedal ratio (7.5:1) and a 3/4" master cylinder. Due to the packaging in the car and the lateral cage bar under my heels, my ability to push on the pedal was not as good as I was hoping and I can only make about 1700psi. I purchased a 5/8" master as the 3/4" had more extra stroke than I thought it would after the addition of the braided hoses from JNZ. I'm still concerned I will not be able to hold it confidently with the new master though. Measuring a couple stops in my driveway and looking at g's vs pressure, I'm coming out to the pads only gripping at about a 0.30 coefficient of friction.

If I can find some pads that are above 0.45 cold, I'll be in great shape. I do not know if anybody makes pads for a DSM that hit this when dead cold. What are the grippiest autocross or street pads that work cold? I emailed Brakeman and Hawk, but I'm still waiting to hear back from them on their drag race pads that are 0.6-ish mu, but don't work at high temps. I'm not too worried about that, but I do still stop the car with the brakes so I need something that is reasonable at a dull glow at least.

What experience does anybody have with pads for the 1g big brakes that are a high cold coefficient of friction?

Thanks,
Kevin

 

[ACM]

Porterfield R4-1 are the most aggressive pads I've ever used. Since I run a manual I've never had to worry about holding the car so I can't say for sure they will work. The wear rate isn't wonderful, but when I used to drive the car to events they worked too well, dead cold they would trigger the ABS really easily. Porterfield pads are essentially made to order - they didn't stock 2G AWD pads, but they would make a set whenever I called. If they have the 1G backing plate dimensions they can make a set.

Porterfield R4-1 description :
Developed and tested in the vintage racing community
the R4-1 gives an average friction level of .56 with peak levels
up to .600. Having tremendous stopping power, the R4-1 pad
material can reach upward of .5 friction level when pad
temperature is a very low 200°F. Drivers can still have a high
friction brake pad without the worry of the pad becoming too
cold to be effective when the car is driven only moderately. For
use when pad temperatures are under 600°F and peak
temperatures are not over 1000°F. Widely used on Vintage GT
and formula cars, the R4-1 has gained great popularity as an
excellent auto-cross, off-road and rally-cross pad material.