GT6 mk3 brake upgrade

[ASP123]

Hi all,

I am considering doing the wheel stud upgrade when the weather warms up and thought I should look at the brakes at the same time. The car is a gt6 mk3 rotoflex. 
What are the options for improving the braking performance? I’ve seen some 4 pot kits advertised for around £500, are they worth doing or over kill?

 

thanks in advance 

[JohnD]

Braking has non-intuitive physics!   For instance wider pads does NOT mean more friction!   Friction is only proportional to pressure between the rubbing surfaces.   Make the rubbing area greater and the pressure perbunitbarea goes down!

Four pots only work if they mean you can move the centre of pressure of the pads outwards, so that the leverage on the axle is greater.   That means bigger wheels and wider discs.

Why do you think you need "better brakes"?   If you can lock-up the wheels, that's more braking (& less stopping!) than you can use.     If you have fade, and a really batted dive road driver, a pass-stormer or a racer may, the vented discs ate a better option.

John

[Clive]

big studs definitely good.

Not so sure about the real advantages of some of the braking kits.  And I although I think John has a point about friction, I think in a dynamic system such as brakes, and indeed tyres, it is not the whole story. (ie why do people fit wider tyres to get more grip, if a narrow tyre with smaller contact patch should, according to the above theory, give the same level of grip, which it plainly doesn't!)

Anyway, back on point. The simple brake upgrade is to use quality pads. And that means mintex 1144 compound. (part you require is MGB633 1144) available at about £45 a set upwards. If feeling flushed, Ferodo ds2500 are better again though with less cold bite, but twice the price. Mine are lasting very well

If you have the very late metric calipers, the above pads will fit straight in. If you have teh earlier, imperial versions, they use a larger pad retaining pin so the hole needs drilling out a smidge. 

Of course, John has essentially asked the million dollar question. What is wrong with your brakes?

 

[dougbgt6]

Another vote for Mintex 1144s, they make a fantastic difference, Club Shop sell them for £55 + postage. Which is a good deal. I would be apprehensive about buying from Fleabay, are they really Mintex?

Metric callipers were fitted to very late mk3s which were no longer rotoflex. But who knows what’s been replaced on your car over the years! 😊

I’m also a fan of servos, an option on earlier mk3s, standard on late. The servo makes braking much more like a modern, much easier.

db

[Pete Lewis]

12mm or 7/16" studs are the best upgrade for a few ££s 

mintex 1144  def worth  a try , must be bedded in correctly  and easy to fit 

servo wont improve braking but makes more easy and lighter pedal action 

dont waste silly££ on must have upgrades  use ££s for fuel and drive more

why do you think you need an improvement ????   how many miles do you cover in a year 

its all relevant 

most of us have said must haves cost a fortune and generally bring expensive  and ongoing problems you cant solve 

unless you have the know how to develop the offering 

pete

 

[mpbarrett]

and another vote for Mintex 1144 made an enormous difference to the brakes on my Herald. Worth every penny.
But you need to get everything else right, good (or new) disks, new fluid, well bleed system with no air,  working rear, and hand, brakes etc.

Mike

[Pete Lewis]

echo that 

Pete

[Clive]

2 hours ago, dougbgt6 said:

Another vote for Mintex 1144s, they make a fantastic difference, Club Shop sell them for £55 + postage. Which is a good deal. I would be apprehensive about buying from Fleabay, are they really Mintex?

 

db

Yep, they are. Plenty of big sellers on ebay these days. £50.59 delivered https://www.ebay.co.uk/itm/MGB633-M1144-MINTEX-RACING-Brake-Pad-Set-disc-brake-front/401625909401?epid=1268157017&hash=item5d82c50899:g:6ZAAAOSwKA5b2Du1

But worth the extra tenner if the earlier calipers fitted. 

Mke has made a great point. Many cars have brakes that are not set up correctly or poor condition. And then a newfangled set is fitted, surprise surprise much better. Probably as good as a newly built std setup (with proper pads!)

A servo can help bridge the gap in leg effort for brakes when swapping between modern and old cars. 

My car has vented discs at the front, very specifically for trackdays and the alps. Brake fade is real with old cars when driven hard, and a friend had smoke pouring out of the front wheels of his auto stag when he lost brakes going down stelvio. (grease melted in teh bearings causing the smoke, none on the discs and fresh pads plus a sachet of grease I found in my boot got his the last 1000 miles)

[Nigel Clark]

Another vote for Mintex 1144 here! My GT6 braking system is standard other than the disc pads and seems to cope well enough with 2.5 litre power and fairly enthusiastic road use.

If you want a lighter pedal, add a servo but even that isn't really necessary. The standard GT6 braking system is good enough for all but track day/competition use in my opinion.

Nigel

[JohnD]

I would advocate Mintex 1155s, but then I race it.   With venteds, totally abolished fade - I'm the last of the late brakers.

1144 probably good for almost any road use.

J.

[ASP123]

Hi all, thanks,for the replies. 
no reason in particular for the upgrade, just thought that if I’m working on that area I could do them at the same time. 
sounds like a set of mintex are the way forward. 

[SpitFire6]

Hi,

 four pots are an upgrade if used with larger disks. Four pots modulate better, especially with unequal bore sizes. Four pot alloys are much lighter. Four pot alloys are available with OEM volume sizes so that the master cylinder remains unchanged if required. Four pots have sex appeal.

DS2500 pads. 10mm thick disks. Replaced at 8mm.

Cheers,

Iain.

[DerekS]

I've used 1144's for a number of years now and they are superb. What I do every so often -especially just before an MOT- is to give them a workout, 3 or 4 emergency stops. It seems to take the glaze off them and sharpen them up. Beware the Greenstuff pads, spawn of the devil!