190 - Front discs / pads?

[rovexCDTi]

Road brakes aren't really designed for that lol If you want to do that you need track pads, but they will then be rubbish when cold.

I always copper grease the hubs as well so that the wheels act as a heatsink. They dissipate quite a lot of heat that way, and being a large mass of aluminium they cool quickly.

[Trophy Blue Tourer]

Jakg!! Morning!

The groved/dimpled/drilled discs are to enable the "gases" to escape from between the pads and discs and they definatly help with the cooling mate!! - so effectivly you have uprated the pads but not the discs - well except in diameter of course

Now excuse the following bit!! you probably know this already!! but not everybody does!!

Now your car is a collection of "heat engines" the mass of the car acts as a collector of potential energy (inertia) the engine converts fuel into energy (heat) and uses it to accelerate the car to the speed you select - if you then select neutral and allow it to "coast" it will roll a very long way as it "bleeds" energy off against the rolling risitance of the tyres/air drag - conversley if you shorten the distance the car stops in then some of that "potential energy" will have to be got rid of and thats the brakes job which they do by converting it back to heat energy (which then needs to be lost by the disc/pad/hub combination) the more heat you can lose from the brakes in a shorter time will prevent the D/P/H combo (and in particular the pads) overheating and the friction coeffciant of the (pad) material changing (fade)

The advanage gained by fitting bigger discs is 2 fold !! 1/ greater leaverage for the pads by being further out from the center of the hub and 2/ a greater surface area to lose the heat from (via radiation to the passing air) - the surface area of the 190 pads is actualy slightly less than the Std (smaller disc) brakes as you knoiw from doing the brake conversion this also increase the % of the disc surface area in contact with the pad at any one time increasing the cooling to heating area ratio (in the cooling ratio favour) - its an increadibly involved subject about which I know a little!! and far to involved to go into on a forum!!

The next point is of course that a car of X weight travelling at Y speed will always have Z inertia (potential energy) as X or Y increases then Z will to of course and the way cars (road and mostly before anybody jumps in about Hybrids!!) are currently built means that the brakes are the unit designed and fitted currently and the more efficiant (up graded) the brakes are at cooling then the quicker you can remove the potential energy and the quicker (within the limit of the tyres grip) the car will stop! - lower temps will also mean less wear on the pads/discs giving longer life to of course!!

The next subject would be material coefficiants !! how heat can change those (and permanatly if they get hot enough!!) and thats a WHOLE other subject!! suffice it to say that "fast road pads" are not the same material spec as the OME jack of all trades made to a price pads!!

To sum up mate!! I wouldnt go back to OME pads that probably wont help!! - treat yourself to some groved/drilled discs (vented goes without saying of course as the OME ones are!!) and the better discs tend to be better materials with better design of the vents let alone the groves/dimples etc !! - unhapily in life better things tend to be more exspensive of course and the qualitly/use/proformance/price trade off is yours to make alone mate!!

All the above is just IMO of course and I'm not going to be drawn into long arguments!!

On the subject of the greasing of pads!! the only areas that need a "little" lube are the end surfaces of the "ears" where they sit/move along against the caliper and carrier strictly speaking thats it! this helps the pad move smoothly when squeezed against the disc AND to move away (fractions of a mm!!) when released!! - it also helps the surfaces not corrode swell and "stick/jam" in the carrier - the famous "binding" brake!! far more common than the piston sticking TBF but often overlooked/not realized as the brakes are stripped down to find the fault!! - check out most jap cars (that I have seen anyway!!) they tend to have a "springy" stainless steel clip on cover between the the carrier and the pad to minimise the corrosion/swell problem!!

Copperslip on the backs of the pads is usually applied to help absorb vibrations (squeal) it will usually work Ok as long as the material missmatch isnt to bad!! - some pad/disc combinations just dont work and changing one or the other is the only answer!! - During the 90's Worth brought out a rather clever "spray adhesive" for the trade which was simply applied to the back of the pads and of the many thousands of pad sets we fitted we never had ANY come back for squeal!! -although to be fair we always fitted good quality pads!! - we also had many many customers come to complain about the terrible brakes the local quickfits fitted (you can't get better than etc -YEH!! RIGHT!!) the first port of call was always the worth spary can !! LOL! a nice little earner!! - these days pads often come with a preapplied adhesive patch (it melts and activates the first time it gets hot!!) which shouldn't be greased of course!! - some come with a simple fiber pad - that can be greased if you want they are all aimed at achieving the same goal of reducing/controling unwanted vibrations/noise (squeal) from the brakes!! - it's always happening of course!! just in the ultra sonic range that we cant hear!! - why do you think some dogs run after cars barking??

Sorry about the post length !! I went into lecture mode as i'm a bit bored this morning!!

HTH?? - well somebody anyway!!

Andy

[Trophy Blue Tourer]

Originally Posted by Jakg

I copperslipped the back of the pads, but not the edges - didn't know you needed to. They aren't making any funny noises...

See my post above!! the last 2 paragraphs sorry it's a bit long!!

Originally Posted by rovexCDTi

Road brakes aren't really designed for that lol If you want to do that you need track pads, but they will then be rubbish when cold.

I always copper grease the hubs as well so that the wheels act as a heatsink. They dissipate quite a lot of heat that way, and being a large mass of aluminium they cool quickly.

Well I would try the better discs first or as rovex says you will end up with brakes that need warming first and wont work well if you need them sudenly on the motorway after spending a few miles criusing!!

And what he said about copperslip on the hubs is dead right too it will also prevent the wheels coroding and sticking on the hubs as well and is something I do with out even thinking about it !!
Sorry I left it out of the above post really !! BLAST!!!

Andy

[Jakg]

Ok I was too harsh - they smoke but they will not fade!

I gave them a LOT of abuse tonight, and they handled it very very well

[rover54]

Originally Posted by Trophy Blue Tourer

Jakg!! Morning!

The groved/dimpled/drilled discs are to enable the "gases" to escape from between the pads and discs and they definatly help with the cooling mate!! - so effectivly you have uprated the pads but not the discs - well except in diameter of course

Now excuse the following bit!! you probably know this already!! but not everybody does!!

Now your car is a collection of "heat engines" the mass of the car acts as a (1)collector of potential energy (inertia) the (2) engine converts fuel into energy (heat) and uses it to accelerate the car to the speed you select - if you then select neutral and allow it to "coast" it will roll a very long way as it "bleeds" (kinetic) energy off against the rolling risitance of the tyres/air drag - conversley if you shorten the distance the car stops in then some of that (3)"potential energy" will have to be got rid of and thats the brakes job which they do by converting it back to heat energy (which then needs to be lost by the disc/pad/hub combination) the more heat you can lose from the brakes in a shorter time will prevent the D/P/H combo (and in particular the pads) overheating and the friction coeffciant of the (pad) material changing (fade)

The advanage gained by fitting bigger discs is 2 fold !! 1/ greater (resistance to torque, pads have nothing to lever against) leaverage for the pads by being further out from the center of the hub and 2/ a greater surface area to lose the heat from (via (surface convection and) radiation to the passing air) - the surface area of the 190 pads is actualy slightly less than the Std (smaller disc) brakes as you knoiw from doing the brake conversion this also increase the % of the disc surface area in contact with the pad at any one time increasing the cooling to heating area ratio (in the cooling ratio favour) - its an increadibly involved subject about which I know a little!! and far to involved to go into on a forum!!

(4)The next point is of course that a car of X weight travelling at Y speed will always have Z inertia (potential energy) as X or Y increases then Z will to of course and the way cars (road and mostly before anybody jumps in about Hybrids!!) are currently built means that the brakes are the unit designed and fitted currently and the more efficiant (up graded) the brakes are at cooling then the quicker you can(5) remove the potential energy and the quicker (within the limit of the tyres grip) the car will stop! - lower temps will also mean less wear on the pads/discs giving longer life to of course!!

The next subject would be material coefficiants !! how heat can change those (and permanatly if they get hot enough!!) and thats a WHOLE other subject!! suffice it to say that "fast road pads" are not the same material spec as the OME jack of all trades made to a price pads!!

To sum up mate!! I wouldnt go back to OME pads that probably wont help!! - treat yourself to some groved/drilled discs (vented goes without saying of course as the OME ones are!!) and the better discs tend to be better materials with better design of the vents let alone the groves/dimples etc !! - unhapily in life better things tend to be more exspensive of course and the qualitly/use/proformance/price trade off is yours to make alone mate!!

All the above is just IMO of course and I'm not going to be drawn into long arguments!!

On the subject of the greasing of pads!! the only areas that need a "little" lube are the end surfaces of the "ears" where they sit/move along against the caliper and carrier strictly speaking thats it! this helps the pad move smoothly when squeezed against the disc AND to move away (fractions of a mm!!) when released!! - it also helps the surfaces not corrode swell and "stick/jam" in the carrier - the famous "binding" brake!! far more common than the piston sticking TBF but often overlooked/not realized as the brakes are stripped down to find the fault!! - check out most jap cars (that I have seen anyway!!) they tend to have a "springy" stainless steel clip on cover between the the carrier and the pad to minimise the corrosion/swell problem!!

Copperslip on the backs of the pads is usually applied to help absorb vibrations (squeal) it will usually work Ok as long as the material missmatch isnt to bad!! - some pad/disc combinations just dont work and changing one or the other is the only answer!! - During the 90's Worth brought out a rather clever "spray adhesive" for the trade which was simply applied to the back of the pads and of the many thousands of pad sets we fitted we never had ANY come back for squeal!! -although to be fair we always fitted good quality pads!! - we also had many many customers come to complain about the terrible brakes the local quickfits fitted (you can't get better than etc -YEH!! RIGHT!!) the first port of call was always the worth spary can !! LOL! a nice little earner!! - these days pads often come with a preapplied adhesive patch (it melts and activates the first time it gets hot!!) which shouldn't be greased of course!! - some come with a simple fiber pad - that can be greased if you want they are all aimed at achieving the same goal of reducing/controling unwanted vibrations/noise (squeal) from the brakes!! - it's always happening of course!! just in the ultra sonic range that we cant hear!! - why do you think some dogs run after cars barking??

Sorry about the post length !! I went into lecture mode as i'm a bit bored this morning!!

HTH?? - well somebody anyway!!

Andy

Just to correct you, a body that is stationary has potential energy, a body that is in motion has kinetic energy.


Inertia is a bodies resistance to change and would be very low (almost zero) for a body in motion travelling in a straight line on free running wheels.

Potential energy, kinetic energy and inertia are three different things and shouldn't be confused.

You cannot remove energy, only convert it from one energy state to another state.


1.Potential engery cannot be collected, it exists by virtue of a body at rest and is calculated based on the mass of the body at rest. Inertia and potential energy are not the same. Potential energy is stored energy, whereas inertia is the resistance for a body to change its state. i.e from being at rest to moving.

2 An engine converts energy stored in fuel into three things, power as measured by BHP and torque at the flywheel, heat energy that is ejected into the cooling system and exhaust; finally noise which is a form of energy.

3 When are car is travelling it has kinetic energy, not potential energy as you have stated, kinetic is used up and becomes potential energy when the car comes to rest.

4 Should read kinetic energy and no mention of inertia.

5 Should read 'convert kinetic energy back into potential energy'.