Steering, Suspension, & Brakes

tips, technology, tools and techniques related to non-driveline mechanical components

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mgb260
Jim Nichols
Sequim,WA
(1968 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Really big brakes
Posted by: mgb260
Date: February 20, 2012 05:05PM

Even though this is on a Fiero, same principle. Just cut existing rotor off Ranger or Chevelle/Monte Carlo hub rotor to make hub. 2007 Ford Escape front rotor for one with rear disks.(11.9") Newer Ford Ranger twin slider caliper(or lighter Cobra,Camaro,Corvette aluminum versions). Chevy pattern can be drilled between on Ford rotor. Simple aluminum adapter. Check out the size of those pads!

[www.youtube.com]


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5803 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Really big brakes
Posted by: BlownMGB-V8
Date: February 20, 2012 07:21PM

Sure looks like a lot of weight to me.

Jim


mgb260
Jim Nichols
Sequim,WA
(1968 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Really big brakes
Posted by: mgb260
Date: February 20, 2012 07:49PM

OK, I did menton the lighter calipers, Cobra,Camaro,Corvette. You and Carl are starting to make me feel weight concious! I was just noting the homemade hubs and I never knew the Escape had such large rotors(11.9") or Rangers had such large pads. Actually Jim, they are the right thickness(.95") rotors for your Outlaw calipers. You could drill them Chevy pattern and mount behind your hubs.



Edited 1 time(s). Last edit at 02/20/2012 07:52PM by mgb260.


RobertE
Robert Edgeworth

(77 posts)

Registered:
02/19/2008 08:27AM

Main British Car:


Re: Really big brakes
Posted by: RobertE
Date: February 20, 2012 10:39PM

Would be interesting to compile information regarding big brake setups - whether they be off the shelf or do it yourself setups.

I often find myself questioning(as Jim mentioned) 1.Unsprung weight added and 2. Cost


mgb260
Jim Nichols
Sequim,WA
(1968 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Really big brakes
Posted by: mgb260
Date: February 20, 2012 11:13PM

Robert, Bigger will always be heavier, unsprung weight is important if you are racing. I have weighed stock MGB caliper (6lb) Toyota S12W finned large 4 piston(9lb) Mazda RX7 aluminum 4 piston(5lb) guessed at small Toyota 4 piston (7lb) because I don't have one. My guess is the Ford Ranger 2 piston slider weighs about 9lbs also. Think about cutting one in half and putting half on each side of rotor, bigger than MGB but not as large as it looks. Now imagine the same design in aluminum, a good example would be the comparison between the RX7 aluminum(5lb) and the large Toyota(9lb). So my guess would be the Cobra,Camaro and Corvette probably weigh around 5lb. Now I weighed the stock thin MGB rotor at 11lb and the vented Cressida rotor at 13lb. The thicker and over 1" larger diameter Escape rotor estimate at 15lb. Lets do the math for stock 6lb+11lb=17lb. Small Toyota 4 piston 7lb+13lb(Cressida vented)=20lb. Ranger caliper estimate 9lb+15lb(11.7" Escape vented)estimate=24lb. Subtract 4lb for Cobra,Camaro or Corvette caliper and we are back to 20lb again same as small Toyota and smaller Cressida rotor. I doubt if you will feel the difference in unsprung weight between 17lb stock and the 20lb upgrades but you will notice shorter stopping distance, more clamping force and less fade. The heavy finned Toyota S12-W is a favorite for the Z cars to autocross with,yes it is heavy but the piston size is bigger than Wilwood and it uses the same pads as 300Z and WRX. It really needs a 1" master cylinder. So does the Escape/Ranger setup. The small Toyota and RX7 piston size isn't much bigger than stock and had 7/8" master stock. Small Toyota/Cressida might fit in 14"wheels,15's would be better. Would need at least 16" wheels for Escape/Ranger setup. Long winded ,I know.



Edited 3 time(s). Last edit at 02/21/2012 04:58AM by mgb260.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5803 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Really big brakes
Posted by: BlownMGB-V8
Date: February 21, 2012 08:30AM

The unsprung weight will also have an effect on the ride, particularly in transitions like potholes. If you run a light wheel you can get down to as little as 11 lbs there from as much as 25 lbs or more, and about 25 for the tire. My Outlaw calipers are 2 lbs each, add another pound or so for pads. Using 2 piece rotors the hats run 1 lb each for aluminum and the rotors can be as little as 7 lbs for scalloped, less than that for the high tech carbon fiber/ceramic$$$. So it is certainly possible to have improved wheels, tires and brakes at less weight than stock. Adding it all up, we're at 11 lbs on the brakes, 22 with the wheels, and 47 with the tires which is really quite light. Aluminum hubs would get it down several more pounds. Air bags instead of springs remove 2 more pounds (half of that is unsprung) and are more responsive. That is potentially removing as much as 25 lbs per side, perhaps more. I'm pretty sure you'd be able to feel that much difference in the ride. I won't be able to get that low since my 17" wheels are heavier at about 16 lbs each which was sort of a disappointment, but they are at least very strong.

Incidentally, I do have a set of 11 lb wheels to sell. Centerline.

Jim


roverman
Art Gertz
Winchester, CA.
(2977 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Really big brakes, big rollers
Posted by: roverman
Date: February 24, 2012 05:19PM

Larger diameter wheels/tires should be less shocked by pot holes,dibbits, due to their larger rolling radius, unspung weight not withstanding. I wouldn't be supprised if air bags have a faster response/cycle time compared to steel springs. Maybe even faster than composite,because of lower mass and "rising rate". Not much has been said about the benefits of rising rate springs, but they provide better anti-roll,dive and squat properties. Many times a better ride quality is achieved because starting rate can be lower than conventional springs and they have more "resilliance' than other materials. Cheers, roverman.



Edited 1 time(s). Last edit at 02/24/2012 05:20PM by roverman.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5803 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Really big brakes
Posted by: BlownMGB-V8
Date: March 02, 2012 02:08PM

Over the weekend Bill Young reminded me (As Jim and others have. OK sometimes it takes me awhile.) that with .810" rotors I would only have .140" of play with my 24mm Outlaw calipers, and I realized that would be near ideal spacing for 16 ga stainless heat shields behind the brake pads, which is becoming more common with the new hotter pad materials. I may even have some stainless of the right thickness on hand. So again at Bills suggestion I found that Speedway Motors does carry .810" scalloped rotors in 11.75" and 12.19" diameters. After giving it some thought, today I ordered the 12.19" rotors, about $120 for the pair shipped. The two remaining parts needed to make this happen are the caliper mounts which I will make, and the hats. Plus the pads which in the end could cost as much as the rest of the package combined. Although I have been a little concerned about the gap between the calipers and the rotors, I will address that when they get here. It may be simpler and easier to just cut down the web of the calipers to fit. The shims might not work that way, but the gap will be closed up. I really wanted an off the shelf part without having to modify the calipers, but at that price I just couldn't pass these up. $80 each for Willwood hats may not be that bad, I'm looking for a better deal there too but based on past searches don't have much hope.

The rotors weigh 6.13 lbs. Aluminum hats are about 1.6 lb each I think, the calipers are 2 lbs and pads probably about a pound, so about 11 to 12 lbs per side complete. Pretty darned good I think. I also have plans to make up a set of alloy hubs to move the mounting flange out a bit and that will drop a little more weight off if I do. Anyway I think the entire package with wheels and tires may be less than stock. Rostyle wheels are 16.3 lbs, almost identical to my 8-1/2 x 17 Weld wheels. I can't find a weight for the OEM 165/78-14" tires but I doubt it's much less than the 26 lbs my Sumitomo's weigh, the stock rotor is 8.6 lbs (with the bolts which aren't used on a slip-on rotor) so even with the hat bolts the scalloped rotor is lighter by half a pound. I know for certain the calipers are a good bit lighter, maybe by as much as 5 lbs, but I can't seem to lay my hands on one right now. Then there is another couple of pounds for the air bags, the stock hub is 7.3 lbs so there's at least a couple pounds there too, and as Art mentioned, a larger diameter (and wider) tire will ride better, especially as the air pressure can be lowered due to the larger contact patch.

In the end I expect the car to ride pretty good and be responsive. but the real point here is that it is possible to fit "Really Big Brakes" to the car, not pay a weight penalty, and not break the bank in the process. So far I have about a hundred in the calipers, 120 in the rotors, figure another 175 in the hats and then the pads which could be anything from 30 to 300+. Figure about $400 plus pads for 12" vented brakes. That's really not much worse than just putting new brakes on the car.

Jim


roverman
Art Gertz
Winchester, CA.
(2977 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Really big brakes, aluminum hubs
Posted by: roverman
Date: March 04, 2012 01:34PM

Jim B. and clan, you might consider the series II Mazda RX7 aluminum hub. Light ,strong with (5) on 4.5" bc. I made billet alum, inner bearing/seal adapters to fit smaller Mustang II spindle dia's. RX7 hub distance betwween bearings is narrower than most , which allows one to "fudge" on hub location with longer than RX7 spindles. Onward, roverman.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5803 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Really big brakes
Posted by: BlownMGB-V8
Date: March 04, 2012 03:21PM

Art, does it have enough meat to drill a 5 on 4.75 BC between the pattern?

Also, how far outwards is the flange if mounted on an MGB spindle?

Jim


roverman
Art Gertz
Winchester, CA.
(2977 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Really big brakes, RX 7 ?
Posted by: roverman
Date: March 09, 2012 07:45PM

Jim and clan, since I don't have a MGB spindle handy....... I shall check the series II hub for 4.75" potential.I''m guessing the MGB bearings are .5"-.75" further apart than Series II ? Onward, roverman.


roverman
Art Gertz
Winchester, CA.
(2977 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Really big brakes, RX 7 hub ?
Posted by: roverman
Date: March 12, 2012 08:12PM

Series II is 3" wide and 5.75" od. Possibly use shoulder studs to alter bc. Cheers, roverman.


roverman
Art Gertz
Winchester, CA.
(2977 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Really big brakes, which hat ?
Posted by: roverman
Date: April 03, 2012 11:03PM

Just re-reading Carrol Smith's,(RIP.), book "PrepareTo Win". He is talking about race cars, but says NEVER use any aluminum other than 2024 T6 condition for rotor hats ! Steel is also ok. Reportedly, other aluminums can't take the heat. Not sure which manufacturers disclose their choice of aluminum. Cheers, roverman.


NCtim
Tim Shumbera
Western North Carolina
(238 posts)

Registered:
01/19/2012 04:35PM

Main British Car:


Re: Really big brakes
Posted by: NCtim
Date: April 22, 2012 08:02PM

Jim,

Where did you buy the Outlaw calipers and what series did you buy? Sounds like you got a deal!

NCtim


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5803 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Really big brakes
Posted by: BlownMGB-V8
Date: April 22, 2012 09:59PM

I did Tim, just happened across them on ebay. I suspect the 24mm rotor size caused fewer bids, and I might still cut them down to use the .810 rotors.

I don't recall the series right off. They have the 3.5" mounting and a fairly generic looking rectangular pad with a single bolt.

Jim



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