she's great, but the brakes...
Discussion
Two weeks ago, when I took out the beast for the first time, I said, that breaking performance was not an issue, since I did not know the handling yet.
Now I feel more confident in handling than braking. When braking down from 150kph into a bend, the brakes generate a howling noise together with slight vibrations.
If I was to change my standard front brakes, I am not ready to invest £300 for a "johno-type" break. (large discs & caliper adaptor)
I thought that EBC grooved and semi-drilled standard sized discs and green stuff should be sufficient, for fast road use (if traffic allows!). I think of maybe 1 track day/ year, just for fun.
Where can I order this set-up? Tower View's entry level is "johno's-type". and EBC to not sell on-line. EBC not available in Luxembourg.
EBC say that green stuff is not suitable for track days. --> red stuff.
Cheers Patrick
Now I feel more confident in handling than braking. When braking down from 150kph into a bend, the brakes generate a howling noise together with slight vibrations.
If I was to change my standard front brakes, I am not ready to invest £300 for a "johno-type" break. (large discs & caliper adaptor)
I thought that EBC grooved and semi-drilled standard sized discs and green stuff should be sufficient, for fast road use (if traffic allows!). I think of maybe 1 track day/ year, just for fun.
Where can I order this set-up? Tower View's entry level is "johno's-type". and EBC to not sell on-line. EBC not available in Luxembourg.
EBC say that green stuff is not suitable for track days. --> red stuff.
Cheers Patrick
I did this last week 
Try RMCarspares, and mention that "Matt Hosking had a set off them two weeks ago for his TVR", that way they should know what bits you want.. (assuming the S3 takes the same as the S2 (1.5). They were really helpful and should be able to organise European delivery for you at a reasonable cost, the price of the parts was the cheapest I found in the UK by far anyway.
www.rmcarspares.co.uk/
Cheers
Matt.
PS Greenstuff box says they can be used for "Light Cars" on trackdays I think..
>> Edited by M@H on Friday 12th April 10:34
Try RMCarspares, and mention that "Matt Hosking had a set off them two weeks ago for his TVR", that way they should know what bits you want.. (assuming the S3 takes the same as the S2 (1.5). They were really helpful and should be able to organise European delivery for you at a reasonable cost, the price of the parts was the cheapest I found in the UK by far anyway.
www.rmcarspares.co.uk/
Cheers
Matt.
PS Greenstuff box says they can be used for "Light Cars" on trackdays I think..
>> Edited by M@H on Friday 12th April 10:34
. Just to make sure I get the right bits, are the part numbers GD086SI and 2415SI for disks and pads respectively? Correct:
GD086SI Sierra 1.8/2.0 (non ABS) Front Groove Brake Disc
2415SI Sierra 1.8/2.0 (Non ABS) Front GreenStuff Brake Pads
Cheers
Matt.
I spoke to them by phone and they were most helpful, sound a bit "small" but thats often better in my book.. If enough of us buy from them we might get a discount in future..
>> Edited by M@H on Friday 12th April 11:03
GD086SI Sierra 1.8/2.0 (non ABS) Front Groove Brake Disc
2415SI Sierra 1.8/2.0 (Non ABS) Front GreenStuff Brake Pads
Cheers
Matt.
I spoke to them by phone and they were most helpful, sound a bit "small" but thats often better in my book.. If enough of us buy from them we might get a discount in future..
>> Edited by M@H on Friday 12th April 11:03
HI,
still bedding in but the improvement is quite dramatic.. Immediate grip even with slight pressure and when cold.. pedal feels much firmer too. Having previously put them on the Puma I'll tell you now, expect heat shimmer off the disks after short bursts of heavy braking, I thought something was wrong at first and ended up driving along stopping every 1/2 mile and checking the disk temperature.. they cool down again really quickly...
..also expect smoke (and smell) as the paint burns off the pads for the first few miles..
Cheers
Matt
still bedding in but the improvement is quite dramatic.. Immediate grip even with slight pressure and when cold.. pedal feels much firmer too. Having previously put them on the Puma I'll tell you now, expect heat shimmer off the disks after short bursts of heavy braking, I thought something was wrong at first and ended up driving along stopping every 1/2 mile and checking the disk temperature.. they cool down again really quickly...
..also expect smoke (and smell) as the paint burns off the pads for the first few miles..
Cheers
Matt
P.S £106 for discs and pads (+ free delivery) but I gained a bit as they had an offer on at the time (buy discs, pads 1/2 price).. should be about £118 now I think (P.S Demon Tweaks want about £145 + delivery)
PPS. Probably will do a trackday or two with that setup as any Kevlar based pad should be ok I assume, I basically wanted them to be better on the road though.
Cheers
Matt.
>> Edited by M@H on Friday 12th April 11:11
PPS. Probably will do a trackday or two with that setup as any Kevlar based pad should be ok I assume, I basically wanted them to be better on the road though.
Cheers
Matt.
>> Edited by M@H on Friday 12th April 11:11
quote:
Drilled ???
EBC ones are cross dimpled so there aren't the potential problems of cracking.. they're called "spotties".
One of the claimed benefits of drilled/grooved rotors is it allows gases to escape from the gap between the rotor and the pads. Since the dimple is just a recess in the rotor rather than a channel to fresh air, does it still work as well?
found this on the web 
"The precisely placed machined dimples serve several key purposes; first they increase the friction coefficient between the pad and disc. The pad "bites" on the leading and trailing edges of dimple, in addition the non-dimpled area experiences more pressure per square-inch which leads to increased friction.
In addition the dimples serve as a reservoir for spent pad material and gasses, which means resistance to glazing and fading. Brake fade is the most common problem during performance driving. Brake fade occurs for several reasons. All friction materials have an optimal working temperature where the coefficient of friction is the highest. When the temperature exceeds the point of maximum friction the coefficient of friction curve starts to decline. At a certain temperature, certain elements of the pad can melt or smear causing a glazed pad. At really high temperatures the friction material, as well as resins used to bind the material, can vaporize creating a gas. This phenomenon, known as "out gassing" results in the pad hydroplaning on a layer of gas between the pad and rotor. The dimples serve to remove this material and gas from the friction surfaces, preventing dangerous fade conditions.
In simple terms, I suppose the dimples just store the gas for a very short time as the disks spins until it is free of the pads when it can expel it.
I think I believe it.......
"The precisely placed machined dimples serve several key purposes; first they increase the friction coefficient between the pad and disc. The pad "bites" on the leading and trailing edges of dimple, in addition the non-dimpled area experiences more pressure per square-inch which leads to increased friction.
In addition the dimples serve as a reservoir for spent pad material and gasses, which means resistance to glazing and fading. Brake fade is the most common problem during performance driving. Brake fade occurs for several reasons. All friction materials have an optimal working temperature where the coefficient of friction is the highest. When the temperature exceeds the point of maximum friction the coefficient of friction curve starts to decline. At a certain temperature, certain elements of the pad can melt or smear causing a glazed pad. At really high temperatures the friction material, as well as resins used to bind the material, can vaporize creating a gas. This phenomenon, known as "out gassing" results in the pad hydroplaning on a layer of gas between the pad and rotor. The dimples serve to remove this material and gas from the friction surfaces, preventing dangerous fade conditions.
In simple terms, I suppose the dimples just store the gas for a very short time as the disks spins until it is free of the pads when it can expel it.
I think I believe it.......
quote:
in addition the non-dimpled area experiences more pressure per square-inch which leads to increased friction.
This is against the law of physics!
Remember the excercice in physics course.
The same block of wood will generate the same friction force (measured with a spring gauge) when pulled over the table with small area side than wide area side.
Same force (whether gravity on wood or piston force on pads) on different areas will generate the same friction.
The effect of higher pressure due to dimples is again jeopardized by the smaller contact area.
The additional edges (grooves & dimples) may increase friction.
The gas cavity theory and noise generation could make sense
Cheers Patrick
quote:
The same block of wood will generate the same friction force (measured with a spring gauge) when pulled over the table with small area side than wide area side.
Same force (whether gravity on wood or piston force on pads) on different areas will generate the same friction.
In school the teachers simplified this to make it easy to explain(i.e. they lied to us!). In the real world, this is only nearly true. The cooefficient of friction actually varies slightly with pressure. If you plot friction force against normal force for a constant contact area for tyre-versus-road, pads-versus-disc or whatever for a wide range of contact pressure, you get a curve not a straight line.
Incidentally, when you tune your car's handling with anti-roll bars you are taking advantage of the same effect.
Cheers,
Peter Humphries (and a green V8S)
So this curve then of force against friction? run that by me again Peter, from the point when you said 'In school......' 
The level of information here never ceases to amaze me (or is that baffles me??)
So, bottom line, have you not tried this type of disc yet then Peter?? must be slipping, I'm sure they'll be seen on the Green Beast at some point during the season. (or you've already done the homework and dismissed them from your competition stock library)
Harry
The level of information here never ceases to amaze me (or is that baffles me??)
So, bottom line, have you not tried this type of disc yet then Peter?? must be slipping, I'm sure they'll be seen on the Green Beast at some point during the season. (or you've already done the homework and dismissed them from your competition stock library)
Harry
I need a drink, what the hell am I doing here at work on a glorious Friday evening? 
quote:
So this curve then of force against friction? run that by me again Peter, from the point when you said 'In school......'
The level of information here never ceases to amaze me (or is that baffles me??)
So, bottom line, have you not tried this type of disc yet then Peter?? must be slipping, I'm sure they'll be seen on the Green Beast at some point during the season. (or you've already done the homework and dismissed them from your competition stock library)
Harry
Looked at them but as the GNP of the Isle of Wight was spent on replacing the cracked drilled discs on the 520 last year, decided anything that had anything that looked like holes in them were a non-starter. Also couldn't work out why they were any better than lots of grooves. In the end went in favour of plain grooved rotors on an ally bell. There is just about 8 mm gap between the rotors and the inside of the 16 inch ex Tuscan racer wheels I am using. That will teach me to tell Dave and Mark that I needed bigger brakes...
Really come to the conclusion that EBCs only have one thing good about them and that is they are relatively cheap. Now running Ferodo 3466 and the difference is simply staggering. But they are about 2-3 times the cost of the EBCs but at least they work. more than once or twice and they have some real feel and bite.
Steve
www.tvrbooks.co.uk
>> Edited by shpub on Friday 12th April 19:55
Really come to the conclusion that EBCs only have one thing good about them and that is they are relatively cheap. Now running Ferodo 3466 and the difference is simply staggering. But they are about 2-3 times the cost of the EBCs but at least they work. more than once or twice and they have some real feel and bite.
Steve
www.tvrbooks.co.uk
>> Edited by shpub on Friday 12th April 19:55
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