MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Uprated Brakes

I've no doubt this has been covered but I couldn't find it in the recent archive soi here goes.

I will very shortly be receiving my Fast Raod engine for my '65 wire wheeled roadster.

So I thought it would be a good idea to uprate the brakes.

I have a choice of just poutting improved pads (Power Stop green stuff) with standard calipers and discs or installing new V8 discs and pads or installing a powerstop V8 system of discs and pads.

Anything other than the first choice will involve new calipers so what's involved.

I prefer the all Powerstop route so where do I get the calipers?

Thoughts anybody?
Vee6

A fast road engine shouldn't mean you have to change the brakes. When working properly the standard brakes are perfectly adequate. Don't be tempted into thinking that grooved or perforated discs make a big difference, because they don't. In fact they warp more easily than solid discs, wear more quickly, and the grooves or holes fill up with rust and crap quickly so are of no benefit anyway.

You can't install V8 discs without using V8 calipers. The V8 disc is too thick for the standard caliper. Similarly, a servo doesn't make the brakes more powerful, it just eases the effort needed to push the pedal.

My advise, for what it's worth, is just get the standard brakes working well.

Mike H
Mike Howlett

Thanks Mike,

Before the car came off the road the brakes worked fine. However any improvement would be good. So I guess you'd recommend the current standard set up and the uprated pads then?
Vee6

If your brakes can stop you safely from 80MPH with a standard engine, then they can stop you safely from 80MPH with a more powerful one, too.
Steve Simmons

I agree with the others - if you want to improve your stopping distances, upgrade the tires.

You need to upgrade your brakes if your tires are so good you can't threshold brake or lock them up anymore (if near stock and you can't something else is wrong), or if you'll be doing many more hard stops in a short time than previously and you're worried about fade (unlikely on the street).

If you only upgrade the front brakes you need to be sure you don't upset the brake balance - upgrading the fronts on many vehicles feels like an improvement (the pedal is easier) but in fact results in worse stopping distances.
Mike Polan

Agree with others tyre grip stops the car.

A std pad say has a cof of .33 compared to greenstuff of .45.

Cambridge motorsport and Rally design sell the Wilwood vented kit. The piston spec can be varied to balance brakes but unlikely to fit with wires.


Hi spec have a selection probably same problem

http://www.hispecmotorsport.co.uk/rover.htm

Tim at Frontline should have Hi spec kit available.

Paul
Paul

The standard system has plenty of stopping power. Just get the best quality discs and mintex V8 pads.

The single master cylinder is more reliable than the later type.

I have this set up on my Rally car and i amvery happy with it!

Talk to MG Motorsport. They use the same set up for the endurance race cars, and they can supply high quality discs.
André

I've used Hawk Ferro carbon pads in the past with other cars and been very happy with them. I recently replaced my existing pads with the Hawk pads. The pads have much more friction bite and require substantially less pedal pressure with a '67 unboosted system. They are very disk friendly. The disks have gone from a dull silver look to a bright mirror like finish. If you use the original style brake shoe material your rear won't be doing as much braking because of the reduced pedal pressure. One way to compensate for this would be to install the larger late gt rear brake cylinders.
On my '67 gt the rear brake cylinders are not as large as the late model gt. I recently "upgraded" to the late model wheel cylinders and it made a barely noticeable improvement. There does not appear to be any tendency to rear lock up, or the rear wanting to swap ends when aggressivly braking into a hard corner.
Barry
Barry Parkinson

I agree with everyone's comments regarding basic brake performance. To add to Mike-Steve-Andre's thoughts, a well maintained stock brake system should pull a B down in a reasonable distance, maybe even from 100, given a decent roadbed. But, with with an upgraded engine also comes better acceleration. Basic reaction time may remain the same, but the improved vehicle will now travel a bit to a lot further (depending on the upgrade) during the eye to foot interval, thus shortening the available stopping distance before the hard curve ahead turns into a ditch or a tree or a phone pole. That said, it's a combination of tire grip and overall braking efficiency that either limit or improve the mechanical side of things. It's reaction time, road conditions, and driver experience, the prime variables, that can make even the best brakes and tires (and steering) a moot point. So, in the end, firm leak-free hydraulics, quality pads, and correctly adjusted clean drums will go a long way to getting the most pleasure out of a fast trip down a twisty road while keeping your passenger's knuckles from turning an even whiter shade of pale... Green Stuff pads and shoe linings are a good place to start if the rest of the system is already in excellent condition. Add to that a refresher course in performance driving (or at least acknowledge that this car is not what it used to be...) to get the most out of the new found power.
Mark C

Barry,

Agreed the Hawk pads are excellant and can withstand high temps above Greenstuff and Mintex, and available for Wilwood set up but not sure about std B or V8.

If used with sticky tyres the increased weight transfer will unload rears and a reduction in rear pressure should help rebalance and avoid swopping ends.

Paul
Paul

I use the standard system on my race car, but with V8 size pads from Hawk.

http://shop.cambridgemotorsport.com/menu_templates/thumb_menu.cfm?menu_temp=brakes.cfm&dep_id=10&prod_ass=1&ass_id=46&CFID=888162&CFTOKEN=22817553

The race compound I use if quite squeely under light braking - it would drive you potty on the road - and have quite an aggresive bit. Very good though.

The standard system with these pads will happily haul the car down repeatedly from high speeds to hairpin speeds with no fade in a 20 minute race. You should never have to work the brakes as hard as that on a road car. If you are doing you need to consider some advanced driving lessons!

Personally I would forget green stuff.
T Crossley

I used front brake pads from a TR8 (Bendix D8). More surface area and they fit right in.
FWIW

Bruce
Bruce Mills

I just installed Green Stuff front pads. I have no complaints but also haven't noticed a big difference from whatever was on the car before. I haven't tried them under extreme conditions yet, such as a steep twisty downhill.
Steve Simmons

I agree with everthing that has been said, almost. If you have stock rear wheel cylinders rather than the GT upgrade, stock shoes should be fone. The increased bite inthe front brakes should help make up for the rear's tendency to lock prematurely. Try just upgrading the fronts before buying the rear shoes. If you're not pleased with the outcome, install the uprated shoes as well, but you may end up going back to the old shoes or adding the GT cylinders to compensate.
Jeff Schlemmer

I fitted EBC discs and Greenstuff pads to my 80 GT as the old components needed changing. They seem to need rather more pedal pressure for urgent stopping than standard. Last week, coming over a humpbacked bridge to find 2 tractors stopped in the road ahead I confirmed that they do not affect front/rear balance with all 4 wheels locking at 40mph.
I found that on the 'parade laps' at MGCC Silverstone there was less fade than before - but as always this is also a comparison between worn components and new.
Vic
V Todman

Other than less fade in race conditions I haven't read anything suggesting the greenstuff is any better than stock at stopping your car. You will notice a big difference with the Hawk ferro carbon. I don't believe they are more expensive than the green stuff.
Barry
Barry Parkinson

I've never quite understood the perceived need to upgrade the brakes on an MGB used on the street.

A properly functioning MGB brake system is more than capable of locking the wheels. A more powerful brake system will only make it lock sooner. You don't really want to lock the wheels anyway. A sliding tire has less friction than a rolling one.

In racing or rallying, upgraded brakes are useful more for their increased resistance to brake fade, than for their greater grabbing ability, although, the wide tires used for racing are harder to lock up.

Again, a properly functioning MGB system shouldn't experience any brake fade in a single stop. Only with repeated hard stops should fade show up. If that is occurring, you're probably not driving prudently for the street.

Paul Noble

Following a v8 transplant in my MGBGT I upgraded the brakes to satisfy the insurance companies. I used Rover SD1 Vitesse 4-pot calipers, redrilled Peugout 505 Turbo vented discs, sleeves on the caliper bolts, braided hoses, and roadster wheel cylinders at the back. The discs are the same diameter as standard MGB discs but nearly three times thicker.
My car is not quite finished yet so I haven't tried out the brakes, but the opinion of other owners using this system is that fade is no longer an issue... a fraction of the cost of the wilwood set up, albiet with heavier calipers.
Nick Bentley

Paul
with a later model with "power" brakes, the pad may not make much difference. With the non-boosted brakes, a hi friction pad reduces pedal pressure and is most welcome for everyday, as well as performance driving.
Barry
Barry Parkinson

A couple years ago To improve braking I replaced the discs with new standard ones and installed MGB V8 pads from Moss (Mintex I think). I believe the braking was improved a bit but the V8 pads dust up alot. I can't keep my Mini Lites clean for more than a day or two. I never had that problem before. I won't use them again. How are the green stuf pads on dusting?
Bob Ekstrand

Bob
You didn't ask about Hawk Ferro carbon, but after about 300 miles of driving I cleaned my alloy wheels. They had a little dust and looked better after the washing. Probably should be washed more often than that. Much less dust than my prior pads.
Barry
Barry Parkinson

Different pads will have different the friction plot during a brake application. High initial "bite" with friction gradually decreasing through the stop as speed drops off is considered to be the easiest to control (most "user friendly"). A climbing friction level through the stop is considered the most difficult to control (least "user friendly") although pads with this characteristic are popular due to high friction level and fade resistance.

Hawk pads tend to be in a cof of .4 to .47 and Greenstuff .45, Mintex about same with OEM perhaps .35

High speed stops generate a huge amount of heat and there is certainly potential on UK roads to have an emergency stop situation from well over 100mph.

The problem with Hawk pads is that they tend to squeal and I believe the dust is more corrosive. Greenstuff also produce dust when pushed and the ceramic redstuff (can be used on both road and track) may be a better option.


Paul
Paul

Paul is correct, the Hawk ones do have a tendency to squeel or squeek - particulalrly on the higher spec pads.
The dust is a bit nasty and is difficult to clean off the wheels once it has baked on.

Shouldn't be a problem if you clean you car regularly. If you are lazy like me however.... Glad I had my minilites powder coated black!

Tony
T Crossley

This thread was discussed between 17/06/2005 and 22/06/2005

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.