Hello, does anyone know what MM size Master Cylinder a 365 GTB/4 DAYTONA has? 17mm, 19mm, 23mm, 25mm???? Thanks in advance. Charles
There are 12" rulers out there w/metric guage on the other edge, put a crescent wrench on that bolt & measure the gap.
Charles, Daytonas (Ferrari 365 GTB/4) are considered vintage. Members in the vintage section will likely be able to tell you what size, what color, who made it (not just the company but whether it was Tony or Vito...) and anything else you may want to know. Regards, Art S.
Thanks Guys, I will post the question on Vintage. The reason I am asking about MM size is because I would like to do a rotor and caliper upgrade on my 308. Charles
AK Jim ask about my 308 brake upgrade. I am restricted in brake rotor size because of wheel size. I am keeping my 16" wheels. The largest rotor size I can use is 12", the same size the 288GTO uses. I have 12" Brembo slotted rotors with aluminum hats. Girodisc has a 308 upgrade for $3,000.00 their setup allows the use of 16" wheels and the OEM MC. I will be using a set of Brembo/Porsche 944 Turbo calipers, these are the same ones the 348 uses. I will remove the "P" word. The 308 Master Cylinder is 22mm that is 1mm less than the 911Turbo master cylinder. This is the reason I am asking about different sizes of Ferrari master cylinders. The piston size of the 308 is 2 x 48=96mm. The 944T/Ferrari 348 caliper sizes are front 4 x 36=132mm rear 4 x 30=120mm. With a piston size of 132, I feel I need a MC size of 23mm or larger. The 911 Turbo uses the same piston sizes as the 944T. In the event that I may need a larger MC I need to know the different Ferrari MC sizes. The Ferrari uses a 4 bolt MC, most MCs are 2 bolts.
Sorry I don't have more time to do the math at the moment, but go back and check your calculations. Then also compare the total AREA of the pistons, not just the diameter. I don't think the total area of the 4 piston caliper is going to be that much more than the 2-piston units. Also consider that the fluid volume will likely be much smaller and the flex of the newer calipers will be much less..... I think your stock M/C should be fine. If it does feel a little mushy when you're done, you could consider a set of braided steel brake lines. Just a thought.... and a quick one at that. Hopefully it helps. Jon
Thanks Jon, I think you are correct 22mm should be fine. I wanted to know what my MC options would be. My MC is only a year old. Charles
One more thing to consider: Many brake "upgrades" result in longer stopping distances. Tires stop cars, brakes help them do it. So you have avoid upsetting that apple cart. If you end up drastically changing the front to rear proportion of your braking (at the juncture between the tire and road), you can end up with the effect of having too much braking force at the front and the front wheels lock up prematurely. I've been there, done that, the brakes feel great, and it's totally easy to modulate them at threshold braking, but the car doesn't stop worth a damn. So.... if you aren't upgrading the rears as well, you may be heading in the wrong direction. One way to easily increase braking force at the rear is to use pads with a high cF... but you have to talk to the supplier. I got pads for the back of my race car in 4 different compounds from Hawk (stock, HPS, HP+, and "Black") and juggled them around until the proportion worked out with the "Blue" pads I used in front. Made a big difference, I ended up with one "black" and one HP+ in each caliper! Sort of strange, but it works. The moral of the story is don't f around with what the factory spent a lot of time figuring out unless you have good reason too and it's worth the trouble. Jon
Thanks Jon, I will be very careful. Since I already have the calipers and rotors from a previous project I can do this swap for almost nothing. I purchased the "High Performance Brake System" Book, it confirms your information. Thanks again Charles
You're most welcome....... I think I have a copy of that book somewhere too. Oh, and I wasn't trying to be anything less than encouraging about your project. Go for it, especially if the parts are paid for!!
