I called willwood today. The tech there said they do provide proportional pressure control down low, but I'm not sure the guy I spoke to was the "lead" engineer at the place. Do some research and see what you find. I suggest doing anything besides gluing sleeving into the caliper bores. New master?
I had a call with them as well, the guy explained me that the rears wouldn't do much upwards to 100psi brake fluid pressure, and then gradually increase proportionally. It works with some sort of chamber with a piston that closes a needle valve. Not yet convinced of the operation and suitability. I like to have braking force on the rear as well, at lower brake forces. When there is snow or ice for instance.
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Funny, Tein apparently sells or sold the same technology I want to produce; twin tube damper with external reservoirs. Gathering parts atm.
http://www.rallyxd.com/parts/tein/index.html
Just ordered 4 internal floating piston reservoirs made by Fox from Evan @ http://www.schmidtyracing.com/ who was really super helpfull!
They have a 2" x 6" steel body with a Schrader valve on one end for the nitrogen filling. On the other end is an O-ring boss thread female fitting.
It will look somewhat like these, albeit much shorter:
and I will have to decide on mounting location, which will determine what kind of hose/connection/piping I will use. When on the shock I could use piping or a short hose with normal hose ends, when on the car, depending on where maybe with swiveling banjo's made by Goodridge, like on these pictures:
But then only on the shock body. They are quite expensive at around 80 USD each so...
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Got a fitting tool
Time to stirr things up a bit... and tame down the generally accepted awesomeness.
Because...
...
...
...
Damper reservoirs came in:
Now I need to figure out, with the large wheels and calipers mounted, if there is place to attach them to the damper bodies or if I need to remote mount them (with a piece of dash 5 hose)
Are you still doing those shenanigans instead of getting the proper master...?
1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
so you are going to sleeve the cylinder and make a smaller piston? dry ice and heat.
I'll use original brembo pistons. Im just scared that a strong enough press/interference fit (will be after they get delta T = 0 )sleeve could potentially crack the caliper. I have no clue what material it is etc...
And I think that even a press fit could potentially slide out with brake pressure. The surface area of the sleeve is basically the same as the piston it surrounds...
This can only be overcome by sealing the void between sleeve and chamber floor...
Last edited by daandaman; 08-22-2014 at 11:14 AM.
instead of a sleeve make it a piston. pressure chamber between the the 2 pistons. force expands in both directions. one applying the brakes and the other driving the (sleeve/piston) deeper into the caliper bore.
Daan I'm sure someone makes one. Have you called anyone?
1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
Wilwood ap brembo stoptech and then some...
The problem is that a tandem cylinder operates at same PRESSURE front and back circuit, regardless bore diameter. The difference in bore is just to make sure the stroke of the plungers is the same even though DISPLACEMENT of fluid is different front/back due to caliper piston surface difference. This is important because when a circuit fails the tandems internals make a mechanical coincident after some difference in stroke length and thus braking still works on the other circuit without loss of fluid in the other.
The only thing that would work in that config is a 'twin' master that looks like a tandem but doesnt have the middle divider piston acting as a membrane but rather a fixed connection. Youll get all sorts of other problems then; the one (piston) for the rear must have a larger surface area because only then hydraulic pressure drops to the rear calipers. However the stroke would be REALLY short due to the large volume displaced per stroke travel. Because it is mechanically lineairy connected to the front pump piston, this will only travel a short distance. Being smaller than the rear pump piston, the displacement is very little. So even though you then hydraulically have the right pressure differential built in, you wont have equal caliper piston travel going on. Problem.
Haha I understand them but thanks for the refresh :p it's just crazy to believe there isn't a solution you know?
1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
And i havent got enough place for twin parallel masters on top of the booster
Because rms inlet manifold/chargecooler
Reason number 83? To go turbo.
1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
You should build a new engine for turbo. I accept donations
Last edited by vollosso; 08-22-2014 at 12:31 PM.
1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
your sleeve idea: make it a cup idea. everything else as you described. port fluid into the cup rather than around it. the cup is just extra insurance that it wont come out but probably not necessary. the cup just ensures that pressure driving the piston out will also drive the cup in. the pressure drives the piston out, and at the same time it puts force on the cup which is fixed in the caliper bore anyways. but if its not it will be driven back into the bore because the piston cannot push the pad further out.
we sleeve hydraulic cylinders all the time and a captured sleeve should be fine (your idea). hydraulic pressure will not drive the sleeve out unless the piston mechanically locks to the sleeve. but you will notice the bias towards the rear returns. use the sleeve, its fine but the cup has been done too.
I assume you are trying to decrease bore diameter to decrease force correct? you know that for 1 inch of master cylinder stroke you get 1 inch of stroke at the slave with 100lbs of force. so the fundamental you are working with is decrease the bore diameter which will decrease force? but you still displace the same amount of fluid from the master so the slave will stroke twice twice the length (just an example). so 50lbs at 2 inches of stroke. correct? it should still get you less pressure on the rear. however the rear pads will touch the rotor sooner than the front.
another option is to just convert pressure to stroke external to the caliper. leave everything oem in the caliper.
Well the problem is that the oil feed of the caliper is all the way at the bottom of the bore. Exactly in the radius where the bore becomes bottomed out. So preventing fluid from getting underneath the piston is not possible as you described
you can cap the feed and put a new one in but really the sleeve is the simplest. for that matter the caliper could really just be a housing to hold a little self contained hydraulic power pack (bore, cylinder, porting) that you can easily change for different bias. the only word of caution would be that you will have to make up for lost thermal absorption capability with something. (heat sink, heat pipe, .....sounds like more cool options you could play with).
It is not physically possible to make a full hydraulic cilinder within the bore and then feeding to it in a different way than with the routing as is.
A sleeve with the desired thickness will have the same projected surface area thus trying to break loose out of the caliper bore with a force equal to that of the piston pressing the pad against the disc which is a lot of force.
A piston acting as a sleeve will want to break free with double that force.
Ive figured out a solution that is reliable and doesnt depend on retaining the hydraulic forces or bonding
Will 3d cad tomorrow
with all the craziness going on in this thread, I have to comment on your floor ha not sure why I never thought of using laminate in the garage. it looks rich lol
also im blown away by the work put into this car
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