Brembo 6-Piston Brake Upgrade
Aug 31, 2006 | 07:15 AM
#31
Originally Posted by x838nwy
EVOBrakes
Thanks for the confirmation. I was 90% sure about those concepts but obviously lack some real-world numbers.
Can you shed any light on the reason for different piston diameters (on the same caliper)? I mean, you often see 44 and 40, or 20,28 and 22 or something just to give some random examples. I've been told this keeps wear constant, but I'm not quite sure how. Is it to account for the flex in the calipers or the effect of torque on the caliper (rotor pulling on the pads so to speak)? I would have thought this was fairly minor....
Anyway, here's a link to bias numbers (estimates) - https://www.evolutionm.net/forums/sh...3&page=1&pp=15
As many may have gathered, I do have a strange obsession with brakes!!!
Thanks for the confirmation. I was 90% sure about those concepts but obviously lack some real-world numbers.
Can you shed any light on the reason for different piston diameters (on the same caliper)? I mean, you often see 44 and 40, or 20,28 and 22 or something just to give some random examples. I've been told this keeps wear constant, but I'm not quite sure how. Is it to account for the flex in the calipers or the effect of torque on the caliper (rotor pulling on the pads so to speak)? I would have thought this was fairly minor....
Anyway, here's a link to bias numbers (estimates) - https://www.evolutionm.net/forums/sh...3&page=1&pp=15
As many may have gathered, I do have a strange obsession with brakes!!!
Most people just think I'm weird - 
Leading pistons are smaller to help the pad wear evenly i.e. no taper from the leading edge to the trailing edge.
The reasoning is as follows. The result of braking is debris formulation between the pad and rotor - this debris 'travels' down the pad and forms/reforms bonds - the breaking of which provide stopping. Some amounts of gases are formed as well although this as we know is much improved by technology of pad materials. There are harder and softer materials all intermixed so picture a mudslide through mountains on each surface and they are pressed against each other. Did I really say that??
As we move towards the rearward edge the debris is piling up and perhaps not working as well - the larger piston in the rear pushes harder - viola - even wear!
There is also reference to the leading edge of the pad trying to dig in - so this may help that as well as the chamfer on the edges. The slot in the middle of some pads is also an exit path for this debris.
I read this PHD paper which had an excellent description of how pads work with soem high magnification photography - I'll try and dig it up.
Aug 31, 2006 | 07:17 AM
#32
Originally Posted by Kee1pride
haha I was reading this thread till i got to x838nwy's huge post.
cliffnotes? lol
cliffnotes? lol
You can either learn it - or rely on someone who has
Aug 31, 2006 | 07:22 AM
#33
Originally Posted by x838nwy
In my VERY HUMBLE opinion, I think there's a good amount of marketing out there. Billet calipers I assume to mean those machined from a block of stock material. These I think have potential. From experience, materials with desirable properties tend to be a pita to cast. So in theory, a machined from billet caliper is more flexible as far as materials go. However, to get the weigth down and get it looking nice and everything, a lot of machining is required and depending on companies, it might not be worth it.
Besides, as far as materials go (talking steel only) it's really strength that you gain, not stiffness. If your design is stiffness-limited, going for a better material might not be all that sensible. Unless of course we're talking about some NASA alloys or something...
Besides, as far as materials go (talking steel only) it's really strength that you gain, not stiffness. If your design is stiffness-limited, going for a better material might not be all that sensible. Unless of course we're talking about some NASA alloys or something...
Forged (best grain structure - no voids - fewer machined surfaces)
Billet (no voids but interrupted grain structure in places - and sharp edges are harder to remove)
Cast (shape is limitless - but voids, inclusions, and limited material choices are issues)
The design is probably more important than that though - i.e the forged Dynalite - even if made from unobtanium is JUST TOO SMALL.
Aug 31, 2006 | 07:28 AM
#34
Originally Posted by x838nwy
Stiffness depends on the material property. Steels tend to have, for all intents and purposes, the same modulus. This holds true whether it's a casting or a forging.
Alloys of Aluminium is a different story, there are some that are extremely stiff but to my knowledge no one makes calipers out of them. In any case, their stiffness has more to do with material rather than whether they're forged or cast.
Forging IMO is a way to shape the caliper and ensuring a more consistent piece. It's quite difficult to get minimum-weight shapes with just the casting process. Small(ish) fillets and thin sections are normally tricky to cast. Plus, the material from which you want to make you caliper out of may not be the easiest thing to cast so I suppose you'd cast to a fairly simple shape then forge to shape.
Also in a part where you have to machine small channels, any porosity is going to be a nightmare (and considering the shapes of calipers, not always detectable till you break a tool in it or something). So forging to me is sensible anyway.
Having said that there are foundries that can create works of art so it's neither one way or another clear-cut.
All in all, I don't think there's a huge amount of difference. However, i am a little suspect of some caliper with really defined machines shapes like these ones:
I wonder how the sharp corners cope with thermal stresses and so on. Can't be good surely. (these are discontinues, I think).
Alloys of Aluminium is a different story, there are some that are extremely stiff but to my knowledge no one makes calipers out of them. In any case, their stiffness has more to do with material rather than whether they're forged or cast.
Forging IMO is a way to shape the caliper and ensuring a more consistent piece. It's quite difficult to get minimum-weight shapes with just the casting process. Small(ish) fillets and thin sections are normally tricky to cast. Plus, the material from which you want to make you caliper out of may not be the easiest thing to cast so I suppose you'd cast to a fairly simple shape then forge to shape.
Also in a part where you have to machine small channels, any porosity is going to be a nightmare (and considering the shapes of calipers, not always detectable till you break a tool in it or something). So forging to me is sensible anyway.
Having said that there are foundries that can create works of art so it's neither one way or another clear-cut.
All in all, I don't think there's a huge amount of difference. However, i am a little suspect of some caliper with really defined machines shapes like these ones:
I wonder how the sharp corners cope with thermal stresses and so on. Can't be good surely. (these are discontinues, I think).
Their rotors are from the same foundry that makes Mountain blanks (I think). Good rotors.
I don't like the aqua velva blue either
Aug 31, 2006 | 10:17 AM
#35
Evolved Member
Joined: Nov 2003
Posts: 1,496
Likes: 0
From: Bangkok
yeah.. the blue/turquoise is a little strange. I wouldn't go anywhere near it if I had a red car...
buying Japanese calipers is a bit hit and miss as far as i'm concerned. Seems Endless has quite good support in the US? Over here it's basically blind faith. FWIW, I'm a fan of project Mu, but if I ever get brake kits, it will prolly be from a non Japanese comapany cos I won't have to go all James Bond just to work out what the heck I'm buying!!!
Man... not only did I hijack this thread. I pretty much took its mum hostage and banged its sister.... very sorry about that....
buying Japanese calipers is a bit hit and miss as far as i'm concerned. Seems Endless has quite good support in the US? Over here it's basically blind faith. FWIW, I'm a fan of project Mu, but if I ever get brake kits, it will prolly be from a non Japanese comapany cos I won't have to go all James Bond just to work out what the heck I'm buying!!!
Man... not only did I hijack this thread. I pretty much took its mum hostage and banged its sister.... very sorry about that....
Aug 31, 2006 | 11:30 AM
#36
Newbie
Joined: Aug 2006
Posts: 15
Likes: 0
From: Manhattan, New York
Originally Posted by EVOBrakes
No cliffnotes cuz it ain't easy.
You can either learn it - or rely on someone who has
You can either learn it - or rely on someone who has
Aug 31, 2006 | 03:01 PM
#37
Originally Posted by ThunderboltVIII
Wait a second, you're the guy who sells all of those mean *** brake kits on E-Bay, right?
no - but he sounds cool so I wish I was
Ebay freaks me out so I don't bother...
I sell lots of pads and rotors and lines - and the occasional Brembo BBK.
And btw...
Movit kits are pretty good - - all Porsche/Brembo etc type stuff.
Rotora is Taiwan - the drifter company
Last edited by EVOBrakes; Aug 31, 2006 at 03:06 PM.
Aug 31, 2006 | 06:57 PM
#39
Evolved Member
Joined: Nov 2003
Posts: 1,496
Likes: 0
From: Bangkok
Originally Posted by ThunderboltVIII
Have you ever heard of or had experience with Movit or Rotora brakes?
There is a guy on here with a Movit kit. Can't remember who. My only worry about the Movit kit would be the replacement pads. If they use their own shape, that would be a pita to get. I mean you can get AP/Brembo even Alcon pads quite easily. I don't know about Movit however.
EVOBrakes, can you shed some light on this?
Aug 31, 2006 | 08:55 PM
#40
He uses all the Porsche stuff - so it's Brembo pretty much I think.....pads are not too big a problem for most of them
Definitely a Porsche 2 piece rotor - I can tell by the vane design.
AKAIK - he adapts it to other cars - he's good with teh mill/lathe
he hates all customers too - so it's even better..LOL
He was around before all these import BBK companies sprung up....made a kit fo r the 96 Impala SS - that kind of stuff.
I haven't looked at his site lately - but I doubt you'd see a chinese rotor on there....
From some site
Why not some other Brand Big Brake Kit
(1) The Movit kit is extremely street friendly due to sealed pistons in the Porsche caliper
(2) Readily available supply of spares, pads, rotors compared to other big brake kits. Rotor cost is less than with other big brake kits for example the Brembo kit.
(3) The Porsche Calipers – even though they are made by Brembo, have much larger bolts (12mm vs. 8mm for the Brembo) – thereby preventing any caliper flex – even under repeated heavy braking.
(4) Porsche Rotors are cross drilled (during casting) – not by actual drilling. This method prevents spider cracks around the vent holes in heavy heat conditions that causes other cross drilled rotors to start failing.
(5) The Porsche rotors have a phenomenal ability to shed heat, so much so, that if you use Race Pads with this kit, you have to monitor your brake temperature to see if you want to BLOCK your brake cooling duct. Otherwise you brakes will be running so cool, you will not achieve the optimum temperature that your race pads require for proper braking.
(6) Rotor costs for most other kits is much higher, and pad availability is more restricted for the racing calipers used in other big brake kits compared to the wide availability for the Porsche calipers.
Those Porsche rotors crack at the holes just like any other drilled rotors...cup car guys hate them....
I was thinking of te guy at The Ultimate Garage - sells a plenty of the kits in Long Island NY - land of dudes w/ cash and no brains lol
wrxbrakes on ebay - noooooooo - say it isnt so......
I'm too f**** legit for ebay..
Definitely a Porsche 2 piece rotor - I can tell by the vane design.
AKAIK - he adapts it to other cars - he's good with teh mill/lathe
he hates all customers too - so it's even better..LOL
He was around before all these import BBK companies sprung up....made a kit fo r the 96 Impala SS - that kind of stuff.
I haven't looked at his site lately - but I doubt you'd see a chinese rotor on there....
From some site
Why not some other Brand Big Brake Kit
(1) The Movit kit is extremely street friendly due to sealed pistons in the Porsche caliper
(2) Readily available supply of spares, pads, rotors compared to other big brake kits. Rotor cost is less than with other big brake kits for example the Brembo kit.
(3) The Porsche Calipers – even though they are made by Brembo, have much larger bolts (12mm vs. 8mm for the Brembo) – thereby preventing any caliper flex – even under repeated heavy braking.
(4) Porsche Rotors are cross drilled (during casting) – not by actual drilling. This method prevents spider cracks around the vent holes in heavy heat conditions that causes other cross drilled rotors to start failing.
(5) The Porsche rotors have a phenomenal ability to shed heat, so much so, that if you use Race Pads with this kit, you have to monitor your brake temperature to see if you want to BLOCK your brake cooling duct. Otherwise you brakes will be running so cool, you will not achieve the optimum temperature that your race pads require for proper braking.
(6) Rotor costs for most other kits is much higher, and pad availability is more restricted for the racing calipers used in other big brake kits compared to the wide availability for the Porsche calipers.
Those Porsche rotors crack at the holes just like any other drilled rotors...cup car guys hate them....
I was thinking of te guy at The Ultimate Garage - sells a plenty of the kits in Long Island NY - land of dudes w/ cash and no brains lol
wrxbrakes on ebay - noooooooo - say it isnt so......
I'm too f**** legit for ebay..
Last edited by EVOBrakes; Aug 31, 2006 at 09:05 PM.
Sep 17, 2006 | 10:47 AM
#42
Your stock brakes can take a lot with race pads - they have plenty of torque. They will generate a LOT of heat though - so for lots of racing some ducts would help reduce maintenance costs considerably as the heat is pretty destructive.
(Buscher and AMS Time attack cars with 500 WHP run the stock brakes iirc)
Going to a 6 pot/4 pot is far from necessary - but you would likely get longer component life especially if you don't run ducts. Considering the cost at 4-5K I would think that money could be spent better elsewhere - it's not like a WRX wherer the stock brakes are pretty small.
my 2cents
(Buscher and AMS Time attack cars with 500 WHP run the stock brakes iirc)
Going to a 6 pot/4 pot is far from necessary - but you would likely get longer component life especially if you don't run ducts. Considering the cost at 4-5K I would think that money could be spent better elsewhere - it's not like a WRX wherer the stock brakes are pretty small.
my 2cents
Sep 17, 2006 | 11:48 AM
#43
Movits are very good, and quite a bit more popular across the pond.
With regards to Rotora, I'll just say i'm more of a fan of Stoptech and leave it at that.
I really want to see the PFC 4 piston caliper used at Le Mans.....that had 1 pad for each piston. The pics I've seen made me drooool.
- andrew
With regards to Rotora, I'll just say i'm more of a fan of Stoptech and leave it at that.
I really want to see the PFC 4 piston caliper used at Le Mans.....that had 1 pad for each piston
. The pics I've seen made me drooool.- andrew
Sep 17, 2006 | 12:06 PM
#44
Hey guys I have movit kit and to be honest they were cheaper than alcon, or ap- 6 pots but thats not what caused me to go for them. They cost me about 2700 USD.
The reason I went for them was I hadnt heard a bad thing about them there are alot of German and swiss guys using them and their seroius racers.
They are using the smaller disc and they have never ever got brake fade.
One of the members on here from Germany uses them and he does endurance racing in his evo6.
Actually one UK user said his mate with Ap 6-pot calipers has to be carful when behind him on the track as they brake so well.
I havnt actually got my set fitted yet as I was sent the wrong discs but a friend of mine has them on his VII and he has just finished bedding them in and he loves them he says they just keep getting better and better.
He needs good brakes his 7 has a ams gt35r and crower 2.4 stroker.
Another thing I noticed about the Movits is pad size I have never seen pads so big as in depth and pad surface area. The likes of Ap and Alcon may have 6-pots but the movits have a larger pad surface area.
The kit I have are 342x34 4pots.
With regards getting pads its easy you can either order direct from movit or you can use pagids or anypads made for a porsche 996 twin turbo.
Here are pictures of my brakes: https://www.evolutionm.net/forums/sh...ighlight=movit
And here is contact details for the movit dealer in scandinavia he looks after the US market as well.
http://www.movit-scandinavia.com email is info@alltombilen.com
The reason I went for them was I hadnt heard a bad thing about them there are alot of German and swiss guys using them and their seroius racers.
They are using the smaller disc and they have never ever got brake fade.
One of the members on here from Germany uses them and he does endurance racing in his evo6.
Actually one UK user said his mate with Ap 6-pot calipers has to be carful when behind him on the track as they brake so well.
I havnt actually got my set fitted yet as I was sent the wrong discs but a friend of mine has them on his VII and he has just finished bedding them in and he loves them he says they just keep getting better and better.
He needs good brakes his 7 has a ams gt35r and crower 2.4 stroker.
Another thing I noticed about the Movits is pad size I have never seen pads so big as in depth and pad surface area. The likes of Ap and Alcon may have 6-pots but the movits have a larger pad surface area.
The kit I have are 342x34 4pots.
With regards getting pads its easy you can either order direct from movit or you can use pagids or anypads made for a porsche 996 twin turbo.
Here are pictures of my brakes: https://www.evolutionm.net/forums/sh...ighlight=movit
And here is contact details for the movit dealer in scandinavia he looks after the US market as well.
http://www.movit-scandinavia.com email is info@alltombilen.com
Sep 17, 2006 | 12:13 PM
#45
Also my Mechanic looks after group N evos up until now they could only run stock brakes but they now use up rated brembos they are still 4-pot but a mono block caliper with bigger 2 piece discs.
When he seen my movits he said the calipers were very similar and wonders why they couldnt have used something like that as the brembo kit was about 12,500 dollars for the front and rear kit.
When he seen my movits he said the calipers were very similar and wonders why they couldnt have used something like that as the brembo kit was about 12,500 dollars for the front and rear kit.