i tink it should supply the same amount of fluid;
not sure about the wheel spacer; i aint using any.
yes i m currently still using the ek9 master cylinder.
caliper & rotor comparison (r32,r33 & ek9)
- Thread starter moon*
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not sure about the wheel spacer; i aint using any.
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Ok I did some sums, and the findings are interesting. Seems I had the wrong idea about MC size, as apparently you only take the inboard caliper size for calculation purposes, not both sides, so my mental calculations were over estimated by 50%! Quite why this is I do not know, I would assume all four pistons on each caliper would be counted but as far as my research and uni work states, we only take into consideration the inboard piston diameters.
This is what I did find however...
Front caliper piston area:
The standard EK9 7.36in²
The 4 pots 7.04in².
Assuming the EK9 MC is the same as the EK4 at 15/16” diameter, the pedal ratio is 5:1, and force from the drivers leg is 80lb... (and ignoring the booster for now)
Force at the MC is 400lb (Leg force * pedal ratio)
Thus MC pressure is 426lb/in² (MC Input Force / MC area).
Caliper clamping force is therefore 3135lbs (MC pressure * Piston area) on the OE Ek9 calipers, 3152 for the 4 pots.
So we can see that given that the supposed clamping force and rotor size is so similar for the two setups, and assuming pads of an identical Cf are used, it would seem that the four pots are going to perform only marginally better than the EK9 calipers!
I have eclipsed my point about the master cylinder, as it is clearly adequate for the calipers, but now I must ask, did you know about these figure before starting the project? If so, is there another motive for the install given that overall theoretical braking performance is not improved?
This is what I did find however...
Front caliper piston area:
The standard EK9 7.36in²
The 4 pots 7.04in².
Assuming the EK9 MC is the same as the EK4 at 15/16” diameter, the pedal ratio is 5:1, and force from the drivers leg is 80lb... (and ignoring the booster for now)
Force at the MC is 400lb (Leg force * pedal ratio)
Thus MC pressure is 426lb/in² (MC Input Force / MC area).
Caliper clamping force is therefore 3135lbs (MC pressure * Piston area) on the OE Ek9 calipers, 3152 for the 4 pots.
So we can see that given that the supposed clamping force and rotor size is so similar for the two setups, and assuming pads of an identical Cf are used, it would seem that the four pots are going to perform only marginally better than the EK9 calipers!
I have eclipsed my point about the master cylinder, as it is clearly adequate for the calipers, but now I must ask, did you know about these figure before starting the project? If so, is there another motive for the install given that overall theoretical braking performance is not improved?
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I think possibly the reason only the inboard calipers are counted is that including all four pistons will double overall brake pressure, but require double the fluid to feed the increased capacity, resulting in zero Net gain.
So perhaps you will need a bigger master cylinder after all, perhaps in length rather than diameter?
Anyone know what the piston sizes are in the Spoon calipers?
So perhaps you will need a bigger master cylinder after all, perhaps in length rather than diameter?
Anyone know what the piston sizes are in the Spoon calipers?
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RagingAngel
本田 Gearing Authority
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clamping power is one aspect to take into consideration - but this has NEVER been a deficiency of the EK9/DC2-R's stock braking system.
The reason why most people would upgrade to a 4 piston has to do with
1) weight (this is a bit of a non issue here with the R32 setup)
2) modulation - 4 piston calipers give the driver more feedback on what's going on at the limit
3) even pad wear - the stock single piston caliper wears the inside pad sooner than the outside and would require regular intervals of "flipping."
4) heat - 4 piston calipers generally cool faster by virtue of their materials and not necessarily their design
Largely, since the braking force (based on the above calculations) is similar, one can expect that the performance of this system to improve once brake pads have been changed to more aggressive compounds.
The displacement of fluid is not the issue here. I have seen large Brembo calipers on Hondas still using the 15/16ths master cylinder and it brakes just fine as well. The pedal might go a bit deeper, but some drivers prefer this for better modulation. It's a fine balance between sizing, pad compound and driver preference.
If you want an immediate bite/pedal, regardless of compound (to a degree) then, yes, a larger master and/or even a larger booster may be required.
The reason why most people would upgrade to a 4 piston has to do with
1) weight (this is a bit of a non issue here with the R32 setup)
2) modulation - 4 piston calipers give the driver more feedback on what's going on at the limit
3) even pad wear - the stock single piston caliper wears the inside pad sooner than the outside and would require regular intervals of "flipping."
4) heat - 4 piston calipers generally cool faster by virtue of their materials and not necessarily their design
Largely, since the braking force (based on the above calculations) is similar, one can expect that the performance of this system to improve once brake pads have been changed to more aggressive compounds.
The displacement of fluid is not the issue here. I have seen large Brembo calipers on Hondas still using the 15/16ths master cylinder and it brakes just fine as well. The pedal might go a bit deeper, but some drivers prefer this for better modulation. It's a fine balance between sizing, pad compound and driver preference.
If you want an immediate bite/pedal, regardless of compound (to a degree) then, yes, a larger master and/or even a larger booster may be required.
HI kozy;
here's the spoon caliper details'
**spoon caliper weights 2.4kg; Piston size: 42.85 + 38.18
measurement; 240mm(W) x 135mm(D) x 95mm(H)
n wow; ur research above jst made me a little dizzy LUL.
ehmm.. well i m not aware of the above figures when i started the project; wat i had in mine was tat. i jst took the imagination of 1 big dude pushing u in the center and 4 mid size dude pushing u at all 4 corners.
BUT i mean if comparing the piston size of the SPOON n R32 ; one of the piston is ONLY slightly larger den the r32s BUT the stopping power is there.
well so far after driving its much better now
i believe its starting to run in already.
worst case scenario is its still not biting enuff i guess i gotta try a bigger MBC
but den again. ppl who upgrade to a 4pot spoon caliper doesnt required to upgrade their MBC, i might try the teflon tape vac bleeding and install a braided hose.
M i the first n only dude crazy enuff to do such a mod?? LUL =.="
here's the spoon caliper details'
**spoon caliper weights 2.4kg; Piston size: 42.85 + 38.18
measurement; 240mm(W) x 135mm(D) x 95mm(H)
n wow; ur research above jst made me a little dizzy LUL.
ehmm.. well i m not aware of the above figures when i started the project; wat i had in mine was tat. i jst took the imagination of 1 big dude pushing u in the center and 4 mid size dude pushing u at all 4 corners.
BUT i mean if comparing the piston size of the SPOON n R32 ; one of the piston is ONLY slightly larger den the r32s BUT the stopping power is there.
well so far after driving its much better now
i believe its starting to run in already.worst case scenario is its still not biting enuff i guess i gotta try a bigger MBC
but den again. ppl who upgrade to a 4pot spoon caliper doesnt required to upgrade their MBC, i might try the teflon tape vac bleeding and install a braided hose.
M i the first n only dude crazy enuff to do such a mod?? LUL =.="
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Fair enough RA, that makes sense, I did have a think about this as I was going to sleep last night and it made sense, I was just suprised that the gain in outright caliper clamping force was so small!
By no means the first to think of it, but you certainly got in there before me!
As I mentioned on Page 1, I would still like to have a go at Evo Brembo 4 pots on mine at some point, will have to work out the braking force when I find the piston sizes.
Was it quite easy overall? The pictures certainly suggest so!
(Oh and by the way, good job!)
By no means the first to think of it, but you certainly got in there before me!
As I mentioned on Page 1, I would still like to have a go at Evo Brembo 4 pots on mine at some point, will have to work out the braking force when I find the piston sizes.
Was it quite easy overall? The pictures certainly suggest so!
(Oh and by the way, good job!
)ehehe thanks kozy
ehhm.. only the bracket part the rest jst gotta check if the caliper condition. well since the caliper is already out, probably u wanna serviced it??
and about the bracket issue; if u'r lucky and the space is there. u can fabricated the bracket without having to saw the original off like wat i did >.<"
but.. its worth while.
HEY RA; one question. even when i upgrade the master cylinder or booster; it certainly depends on how much vacuum the engine is producing right?
oooo.. i tink i found a interesting article.
http://www.autoshop101.com/forms/brake05.pdf
ehhm.. only the bracket part the rest jst gotta check if the caliper condition. well since the caliper is already out, probably u wanna serviced it??
and about the bracket issue; if u'r lucky and the space is there. u can fabricated the bracket without having to saw the original off like wat i did >.<"
but.. its worth while.
HEY RA; one question. even when i upgrade the master cylinder or booster; it certainly depends on how much vacuum the engine is producing right?
oooo.. i tink i found a interesting article.
http://www.autoshop101.com/forms/brake05.pdf
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after washing my ride; clean rims & caliper
n usually after u wash your car; the rotor tends to get a little rusty; here's where i can check which side havnt been fully run in yet;
the right side; if u see carefully; u notice the brownish color on the right rotor; thats the area where the pads aint biting yet. a little more running in to do; m i m done
left rotor
right rotor
n usually after u wash your car; the rotor tends to get a little rusty; here's where i can check which side havnt been fully run in yet;
the right side; if u see carefully; u notice the brownish color on the right rotor; thats the area where the pads aint biting yet. a little more running in to do; m i m done
left rotor
right rotor
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some great info shared by jugbugz 
bleeding method and position for Right Hand Drive / FWD.
FWD is closest side to master cylinder, which is:-
front right
then left rear
then front left
then right rear
this is for right hand drive cars
bleeding method and position for Right Hand Drive / FWD.
FWD is closest side to master cylinder, which is:-
front right
then left rear
then front left
then right rear
this is for right hand drive cars
jugbugz said:make sure u read my post on brake bleeding
ur even though ur using a vacumme system, u may stil have leaks that would make it useless
if u have a handpump type vacumm system, when u build the pressure up make sure the pressure gauge shows that it's maintaining it's pressure, if it's not, means the tubes might be too big for the nipples. When u crack open the nipple valve, fluid will come out BUT... Ur pressure gauge should still be still with no loss of pressure. If there's loss, then this is your problem so listen up...
Your nipple valves are leaking, u need to buy some plumbing tape(Teflon tape) preferbly the one for gas. There are 2 types, 1 for water plumbing, the other for gas.
Remove the nipple valve, dry it with cloth, apply about 3 rounds of gas Teflon tape(5 rounds for water Teflon tape). Screw it back in. Apply the vacumme tube, build the pressure up to max, then crack open the valve 180degrees, the pressure on gauge should not move at all, if it does then reapply the Teflon tape as u might have done it wrong, or might just need more.
Once you dont see anymore bubbles, close the valve and your done. You need to remember the order for FWD cars are diff from RWD.
FWD is closest side to master cylinder, which is front right
then left rear
then front left
then right rear
this is for right hand drive cars
All my cars have some seriously short pedal travel b4 the pads bite, the pedal only travels an inch b4 biting hard. Super braking response I would say.
1 important thing I forgot to mention is, before u crack open the valve for each corner, jump into the drivers seat, step on the brake pedal a few times until the pressure is built up, then hop down and presume with the bleed. Do this for each corner.
Goodluck, some others will tell u differently, but I know what my brake pedal feels like. And even my gf was shocked at how little pedal travel it takes to slow the car down
enjoy
Eric
p.s I don't mind if u post this info on the forums to help others
p.s
ehm.. its the running in process.. earlier i had signs of the pads not biting on certain area of the rotor cos the rust was still there everytime i check..
i m still using the ek9 master cylinder, stock rubber hose, used pads and havnt re-vac bleed yet.
but its biting harder n much better den my first time.
it's also braking much better den my stock ek9 caliper.
