308 Very Big Brakes, WITH 360 parking brake

Hi Guys,

Here is the BIG one

308 Very big brake upgrade, with 360 parking brake.

Brief description of work:
Front: Brembo 360 Big Brake kit for the 360 = 355x32 Brembo drilled discs with Brembo F-50 calipers.
Rear: 328x28 Girodisc Ferrari 360, drilled discs with 36-40 Brembo calipers, (from 360 challenge) AND 360 parking brake

Why

Basically, I have faded the fluid and pads on everything I have ever driven hard, auto X-ing or on the track, (time trials and drivers schools, not the real thing J.
I have read about the “inadequate” stock brakes on F Chat from 308 owners, 355 owners, 360 owners tracking their cars and even F-40 owners complaining about “Not enough Brakes”.
To back up a bit, I enjoyed 356 C disc brakes on a stripped out speedster auto x machine, installed cross drilled, vented 911-S front brakes on my pumped 914-4 auto x car, with, ironically 308 rear calipers with vented, cross drilled discs, so I have some experience with doing brakes.

I like driving fast and enjoy controlling the car through throttle steer and wanted to really maximize the braking capability of my car, for safety reasons and with a desire to maximize “manual” braking on the excellent 308 platform. 308s do not have ABS or the even better EBD electronic wizardry. We cannot just mash the pedal to the floor and wait for the electronics to get us stopped or slowed down in the shortest possible distance, We have to slow the car the old fashioned way, by foot, paying particular attention to locking and unlocking, to attain the shortest stopping distance..
So, my theory is that better control is available with less pressure and more leverage, that is, larger diameter discs.

· How?

My very first post even before buying a 308 was asking how to upgrade the rear brakes. I had read about 6 months worth of F chat articles on maintenance and improvement and felt that “Brakes” was an area I wanted to upgrade. I read Eric Dahl’s fine articles on the complexities of trying to upgrade and what he had done at Brembo, developing the Brembo 308 upgrade.

So after doing the suspension bushings QA-1 shocks and stiffer springs, I upgraded to 360, 18 inch wheels so I could use current tires, and I began looking into brakes, (kind of knew that I would need 18s to clear the calipers).

I bought some 355 Brembo calipers from Philip Airey and started working out how to make them work and noticed that the 360 Brembo calipers were RADIAL mount, as opposed to lug mount, - much simpler to fine tune. I was still hopeing to make a brake proportioning valve compensate for the weight balance and transfer. After all, the 355, 360, F40 and F50 all used the same caliper pistons front and rear.

So, I bought a set of 360 calipers, began doing the math, regarding the front to rear weight transfer and the appropriate torque balance. At this point, I contacted Martin at GIRODISC , and told him of my desire to do a big brake upgrade and that I had a line on a F-50 set of calipers and rotors. I was beginning to sense that I needed more force up front. We worked through a lot of iterations, finally deciding that the 360 used as a rear caliper, 38-42, was too big for the F-50s 40-44 piston balance. He found a set of 360 challenge calipers with 36-40 pistons that would fit the 328mm rotor and provide a balance that was only 2% heavy on the rear, (as compared to 308 stock). What the hell, I have bigger stickier tires on the back and have lowered the car to provide a bit less weight transfer to the front, so 2% more rear bias is pretty close.
It looked like were getting close to a good balance, so I put in the last second bid at $700 for the F-50 calipers and rotors and got them.
I bought a Willwood 1-1/16th tandem master cylinder, which worked out between the stock and 308/Brembo MC area to total piston area.

I’m fading, More to come,
chris


· Engineering, (Girodisc brake worksheet).
· Procurement/Machining
· Costs, (about $5k at this point).
· Results
· What I have learned along the way,
· Recommendations

My best to all of you wishing to slow for a beer.
chris

 

Hi Greg,

I have taken Eric Dahl's recommendation and had the front lugs on the uprights machined the same, even had helicoils installed just like the factory. This enabled me to mount the main calieprs on the front lugs, pics to follow soon.

Here are a couple of photos of the 360 caliper and the custom bracket.

One of the nice things about having it done on a cnc mill is that the machinist can change a dimension or two on the computer and the part will be rendered, as drawn - so if you give me the dimension from the inboard face of the disc to the mounting lug and the disc diameter and thickness, he can make them for you fairly easily.

More to come tomorrow, been a hard day today.

hth,
chris
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Hi Dave,

How does your 360 parking brake work? Does it hold on a steep grade?

I am just about to start on the cables. My plan is to have longer cables made with housings that run from the chasis to the caliper bracket, as in the stock 360 set up. First, I need to determine length and make sure the 308 operating mechanism has sufficient travel and leverage to make the P brake work. It looks like the stock nylon cable guide on the chasis is slightly above the height of the pulley on the caliper, so i will take 2 1/8th cables with swaged ends, hook them to the P brake caliper lever arms, run the through the guides and pulleys of the 308 actuating mechanism, take the slack out of the two cables, then clamp them together to test the efficiency of this set up. If this works well, I will have cable housings made to go from the P brake to a custom mount on the chasiss, then have steel ends swaged on the cable and right/left male threaded ends put on the cables, so that a turn buckle can be used to make the needed wear adjustments.
So, that's the plan.

How did you do yours?

curious,
chris

 

Thanks Dave,

I just started removing the old cables last night, most of the stuff was corroded tight.

chris

 

Happy Days,

After having the uprights machined for the main caliper mounting on the front, having custom brackets machined to mount the 360 Brembo parking brake in the stock caliper location and installing longer e brake cables running through the stock actuating pulleys, IT WORKS.

I put a couple of lug bolts through the rear hub and tried to turn the rear axle and I couldn't budge it with my biggest breaker bar.

I don't know if it will hold on a san francisco hill or not but it works or lock 'em up at 50, but it works.

I think with a bit of adjusting on the main cable and the rear calipers i can make significant leverage improvements over what was on the car.

The Wilwood 1 - 1/16th master cylinder just fits. Still need to mount the proportioning valve, extend the front brake line to the mc and gut the stock prop valve, then bleed it and away we go.

Happy fathers day to you dads out there,
chris