Aladin Sane
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I am in no big hurry, plenty to do before I have to worry about stopping.
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My problem on the Tiger is matching the rear brakes to the big Wildwood brake kit on the front, so this is not the solution for me. It may well work with stock Tiger front brakes, but I would need to know a little more about your parts spec to comment.
The Wilwood kit needs 15" wheels so a lot more options on the rear
This is not my first go around with rear discs, and I have learned a bit more since my 1980 approach of simply finding something that will fit on the rear, while using a proportioning valve to try and match the front brakes. Complicating the issue is weight transfer and all that entails, tire grip, tire size, pad coefficients, pad area, calliper piston area, rotor OD, fore/aft car balance, pedal ratio, proportioning valve slope, master cylinder bore, deceleration rate, centre of gravity height, ............ This latest rear brake design attempts to take these issues into account.
If one wants to use more common .40 street pads on the rear, then more clamping force is needed in combination with a larger OD rotor, to match the Wilwood fronts. The 93-98 Lincoln MK Vlll single 45.2mm piston calliper, on an 04 Mustang Cobra 11.65 OD rotor, in combination with a .37 slope Wilwood proportioning valve is a good match to the Wilwood front kit with .046 pads.
A .75” bore, dual circuit master cylinder is used to keep the hydraulic pressures up and leg pressure down as there is no servo in the system. Nothing new here, and I used one from a Ford Courier pickup. With the .75 master, leg force will be acceptable using the stock Tiger pedal ratio - a higher ratio pedal would be better.
The system is fitted now but I am now redesigning the bracket to rotate the calliper downward to gain a bit more calliper to frame clearance. These brakes will not fit using the stock 13” wheels.
The only bespoke part is the mounting bracket to fit the Lincoln calliper. Machine work is required to bore the hub on the Cobra rotor, drilling the rotor for our stud pattern, and facing the stock hub to insure it is flat.
I did not know that the 87-88 Turbo TBird was the sameHoghead, Good solution to balance the larger Wilwood front brakes. The 87-88 Turbo Tbird and others View attachment 18305 View attachment 18306 uses the same caliper with a smaller diameter rotor with stock Alpine 4 bolt pattern. You would need a different bracket.
Gentlemen, My sole intent is "Fitting Rear Disc Brakes to a STOCK Alpine / Tiger Rear Axle" not a different carrier/axle.
Application of the "KISS" principle: Keep it simple stupid, helped me stick to the stock Alpine&Tiger axle/carrier. An additional safety feature, fairly inexpensive without lots of modification for the everyday Sunbeam Alpine was and is my goal.
Even the simple idea of letting the prospective buyer purchase rotors direct from a Vendor and then preparing or having prepared the rotor to fit the hub makes for a potential Logistical problem in that not all potential buyers would have the expertise or machine shop available to drill and align the rotors for their Sunbeam.
I cannot see that you state a problem. (QUOTE)
Take a look at the Wilwood front kit specs - 11.75 rotors, radial callipers with 4 x 1.75 pistons, and with a nominal friction rating of .046.
The problem is that this is a lot bigger than stock Tiger/Alpine and needs correspondingly larger rear brakes for a balanced system.
(QUOTE) What needs to be changed? BTW, what is a .37 slope proportioning valve? Sounds like it limits rear pressure to 37% of front pressure. (QUOTE)
Making it more confusing is that it is really not a proportioning valve at all but more of a regulator.
Not all proportioning valves are the same slope nor the same knee point. The slope is the rate at which rear brake line pressure builds, after the point where pressure limiting begins (knee point).
Google is your friend - https://www.apcautotech.com/getmedi...f-bf7e4451801b/brake-proportioning-valves.pdf
(QUOTE) If that is case, I'd say you should use Saturn calipers and experiment with rotor diameter. (QUOTE)
More likely both a larger OD rotor, and larger piston area calliper is needed with the Wilwood front kiT
DanR: Same machine work for the Saturn Rotor.My problem on the Tiger is matching the rear brakes to the big Wildwood brake kit on the front, so this is not the solution for me. It may well work with stock Tiger front brakes, but I would need to know a little more about your parts spec to comment.
DanR's COMMENT: My idea is to adopt a caliper compatible to only stock front brakes. The Saturn calipers are 32mm pistons.
Hoghead: ....."so this is not the solution for me."
DanR: Assuming again, the reference is to the Saturn?
Hoghead: Complicating the issue is weight transfer and all that entails, tire grip, tire size, pad coefficients, pad area, calliper piston area, rotor OD, fore/aft car balance, pedal ratio, proportioning valve slope, master cylinder bore, deceleration rate, centre of gravity height, ............ This latest rear brake design attempts to take these issues into account.
DanR: Agree there are complicating issues you mentioned, but I believe have been
successfully applied.
Hoghead: The system is fitted now but I am now redesigning the bracket to rotate the calliper downward to gain a bit more calliper to frame clearance. These brakes will not fit using the stock 13” wheels.
DanR: "These brakes.... " for clarity, are some you have mounted on your Tiger! I am not yet satisfied that the Saturn Caliper will fit the 13" Wire or Steel Alpine/Tiger wheels.
Hoghead: The only bespoke part is the mounting bracket to fit the Lincoln calliper. Machine work is required to bore the hub on the Cobra rotor, drilling the rotor for our stud pattern, and facing the stock hub to insure it is flat.