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MG MGF Technical - URGENT brakes question

Hi all.

In a bit of a hurry here.

Put the F in to have a brake squeal and handbrake problem looked at, and have just been told that she needs new rear discs and pads (as well as freeing a jammed caliper). I've told them to hold off doing anything to the discs and pads whilst I investigate aftermarket alternatives. They're reluctant to hang on too long, though, as they've very little space to keep the car around.

SO - this strikes me as a good chance to upgrade the brakes. Currently standard set up all round, and we're assuming that the front pads 'n' discs are OK. Is it worth getting aftermarket discs, either for cost or performance? We're talking fast road, rather than any real track usage.

Will consider changing front discs and/or pads to match, but would appreciate it if I can do this at a later date. I'm prepared to accept unbalanced braking for a while whilst I save up for the fronts.

Recommendations?

Cheers,
Jamie
J Wakeham

Hi,

There's an enormous amount been written recently about aftermarket brakes. Have a trawl through the archives.

I don't think you'll get anyone advising upgrading the rear brakes first. It's just too dangerous to be overbraked at the rear, no matter how careful you are - you can't control other people's behaviour.

Regards, Kes.
Kes

Hi Kes

Just got off the phone to the dealer - apparently the pads and discs are *just* in a road-safe condition, so I'm going to baby her home later tonight (as they want their space back asap, and having seen how cramped their yard is I don't really blame them). This'll give me time to order stuff in - so the thread is now rather less urgent!

I take the point about upgrading rear first. Suppose I should just bite the bullet and do the whole lot. Annoying to chuck perfectly good front discs and pads, though. Doubt I'd get much on Ebay for them.

Having spent some time trawling the archives, I'm still not quite sure what the best you can get under MPI 6-spoke wheels is. Anyone know if Mr Satur's "uprated discs" at 138 quid fit (doesn't actually say on his site how big they are)? And how they compare to EBC Turbo-whotsits?

Would a sensible choice be the front-only uprated version at 195 pounds, and a rear set at 138? Doesn't really tell you on the website what the difference is. Will the 280mm front set go under my wheels without jiggery-pokery?

Is it worth a set of braided hoses to go in at the same time? What do they actually do?

And what pads should I mate to all of this?

Finally, should I even consider fitting these myself? I don't mind playing about, but I'm not exactly an experienced tinkerer and I'd rather not kill myself.

Sorry to go on, but this is seeming very hard to get my little head around - too many options!

Thanks,
Jamie
J Wakeham

Jamie,

A simple, but effective solution is to get yourself along to Techspeed and ask them to fit Roversport grooved discs and Mintex 1144 pads all round. I ran this combination for a while (before moving to the AP 4 pot calipers at the front) and it works very well.

You could also use Mintex 1177's which is Rob Bell's setup, as the 1144s have gone up in price and are the same as, if not more expensive than, the 1177s now. The 1177s are harder than the 1144s and so should wear the discs faster, but Rob's done reasonably well out of the them. I'll be moving to 1177s on the rear shortly.
Dave Livingstone

If you just want standard disks try this web site. https://sslrelay.com/buypartsby.co.uk/discs_details.php?recordID=5892

I have used them, the discs were Lucas and delivered in a day or two.

Rob is pulling together a list for a bulk purchase of rear 1177. I think he need 3 more people. So sign up!
Steve Ratledge

Jamie,

The basic reason for uprating brakes is fade from heat.
Uprating pads to Greenstuff say 500 deg to the Mintex range say 750deg.

Pads with organic content produce outgas with the Heat and the pads faded, so grooves and cross drilling will help this issue.

The amount of brake force applied will be increased with a higher pad cof, Mintex 1177 is the highest but come with a warning not for road use.

Braided hoses reduce compliance and will give a firmer pedal feel.

Tyres stop the car so good quality, F1's are still top of pile, wet braking is very dependant upon depth of grooves.

Increasing front disc size may increasing stopping distance for road use, see Rob's site. I've not seen a full spec of any of aftermarket systems, but if balanced properly will give more heat capacity and a sharper feel.

Paul
Paul

Thanks, everyone.

So is it actually legal to use 1177s on the road? And given that I don't concieve of a lot of track use, might I be better getting 1144-66 instead?

I've come to the conclusion, having read Rob's site, that it'll be easy enough and so much cheaper to fit them myself. I assume that the rear pads are pretty much the same process as the front?

Will I end up killing myself if I do something like replacing the rear discs with Rover Motorsport/EBC/Mike Satur 240mm and the rear pads with Mintex/Greenstuff, replace the front pads with similar, but leave the (currently perfectly servicable) front discs in place with a view to 240mm or 280mm when they wear out?

Thanks,
Jamie
J Wakeham

I run Mintex 1177s at the rear and Greenstuff at the front for noremal road driving, its a good working set up for this application

For tracks go for the 1177's all round

So sign up with Rob for a set of 1177 rears!
Neil

Just found this on the Mintex site...

[1155-1177]... is purely designed for competition use and under no circumstances should be used for normal road applications

Does this actually make them illegal, or merely not recommended? What do I tell my insurance company if I get them?

Cheers,
Jamie
J Wakeham

Jamie,

You will find this disclaimer on most race products.

With pads usually race pads do not operate very well from cold which is a big disadvantage with a road car.Disclaimer may also apply to some Calipers

Perhaps Roche would be person to ask re Insurance position as if an accident happens and the car is fitted with race pads this could nullify insurance.

Re Heat 4 quick stops from 60 may generate say 500deg of heat which is within a road pad like Greestuff or Mintex. A stop from 140 may generate 700deg which is twice legal limit and prob outside a road pad range unless using say Hawk ferro carbon.

Changing pads for track days may be the best solution re Insurance.

Changing to same size grooved or drilled disc will just improve position re pad fade, I am not aware of disclaimers re these type of replacement discs.

Paul
Paul

Paul,

thanks for that. So if 99% of my usage is on the road (yet to actually get my F on a track, if truth be told), I'll do much better to get 1144 over 1177 or Greenstuff over Redstuff anyway as they actually brake more strongly under 'normal road use' pad temperatures?

Read Rob's page on the Big Brake fallacy: seems mostly to refer to maintaining balance (therefore do the same to the front and the back?) and to ABS getting confused. I'm pretty sure my F doesn't have ABS (if it does, it's not bloody working!) but even so, as far as I can tell the major advantage of bigger discs (if not getting 4 pot calipers which I can't afford) is greater heat dissipation. Heat isn't likely to build up too much on the road, so standard sized rotors make sense. Grooves 'n' drilling do seem to be useful even in a road context, however, so I'm finding myself tending towards 1144s on either EBC, Roversport or MS 240mm rotors. The EBCs seem cheapest...

Thanks for helping, everyone.

Jamie
J Wakeham

Jamie,

Brakes are basically all about Heat. The GP last weekend illustrated this with Williams removing brake ducting for cooling leaving the car with no brakes.

F1 also use a 13in diam wheel to fit brakes so not huge
diam brakes but carbon carbon can grip at high heat without outgassing, but pull 4g due to sticky tyres.

Certainly cheapest option to start with is a set of uprated road pads front and rear.

Grooves and drilling are probably more important with Halfords pads as probably more organic content.

If you wish to consider brakes in more detail, these site's are worth a read

http://www.grmotorsports.com/brakes.html

http://www.stoptech.com/whitepapers/rear_brake_upgrade_is_bigger_better120601.htm

http://www.zeckhausen.com/testing_brakes.htm

Paul
Paul

This thread was discussed between 10/05/2004 and 11/05/2004

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