OEM Caliper Piston sizes
- Thread starter AdamB
- Start date
Thanks mate, good shout.
Checked DIY and the front and rear are the same part number. Although the Paseo didn't use disc brakes on the rear till 1999, but it's the same part number for a 95 GT and a 99 Paseo.
I'll try dig around on the net and see if I can find out the piston sizes
Checked DIY and the front and rear are the same part number. Although the Paseo didn't use disc brakes on the rear till 1999, but it's the same part number for a 95 GT and a 99 Paseo.
I'll try dig around on the net and see if I can find out the piston sizes
I think 48 is the bore not the piston.
I have some info but the sources often round off sizes so it takes a bit of work to check them exactly.
Just for interest I started investigation for piston areas vs disk size vs car weight vs power , this is how far I got -
___________________PISTON SIZE____PISTON/s AREA (sqmm)
MR2 AW11 1600cc piston 1x 51.05 dia____2046.82_____caliper 51-22 22x258disk
Celica st185 single 1x 57.17 dia piston____2567________caliper 57-25 25x258disk x5
Starlet standard starlet 1 x 46 piston ____1661.9_______ 135hp 116 ftlb
Sera piston 1x 51.05 dia 18mm disk_____2046.82_____caliper 51-18 970 kg 108.6 HP 96.4 ftlb
Celica Twin pods 2x 42.74 dia _________ 2869.38_____all trac 88-90 1483 kg gt4
mr2 twins is 2x 36.47 dia______________2089.42_____MR2 1991 late 1,262 kg 200hp 200ft lb
PS. STARLET front and rear are listed on Camskill but I cant see any sizes .
I have some info but the sources often round off sizes so it takes a bit of work to check them exactly.
Just for interest I started investigation for piston areas vs disk size vs car weight vs power , this is how far I got -
___________________PISTON SIZE____PISTON/s AREA (sqmm)
MR2 AW11 1600cc piston 1x 51.05 dia____2046.82_____caliper 51-22 22x258disk
Celica st185 single 1x 57.17 dia piston____2567________caliper 57-25 25x258disk x5
Starlet standard starlet 1 x 46 piston ____1661.9_______ 135hp 116 ftlb
Sera piston 1x 51.05 dia 18mm disk_____2046.82_____caliper 51-18 970 kg 108.6 HP 96.4 ftlb
Celica Twin pods 2x 42.74 dia _________ 2869.38_____all trac 88-90 1483 kg gt4
mr2 twins is 2x 36.47 dia______________2089.42_____MR2 1991 late 1,262 kg 200hp 200ft lb
PS. STARLET front and rear are listed on Camskill but I cant see any sizes .
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I found this which says the piston diameter is 48mm?
http://www.amazon.co.uk/Front-Brake-Caliper-Toyota-Paseo/dp/B00A3QFHVI
And here for the rear piston
http://au.toyotaownersclub.com/forums/topic/39080-rear-disc-conversion-on-el44-paseo/#
That's good info there mate, I'm trying to work out what caliper and piston size to go for as I'm looking to run adjustable brake bias to 2 separate master cylinders.
I did also check camskill but the same problem as you the size wasn't listed.
http://www.amazon.co.uk/Front-Brake-Caliper-Toyota-Paseo/dp/B00A3QFHVI
And here for the rear piston
http://au.toyotaownersclub.com/forums/topic/39080-rear-disc-conversion-on-el44-paseo/#
That's good info there mate, I'm trying to work out what caliper and piston size to go for as I'm looking to run adjustable brake bias to 2 separate master cylinders.
I did also check camskill but the same problem as you the size wasn't listed.
I thought you would appreciate that info. I had got info before from a site brakepartssuprestore.org.uk but the url isnt working.
Brakeparts.co.uk has detailed info but it lists starlet as 51.1 piston which is sera and mr2 mk1 so it may be dodgy although paseo is listed closer to what you have.
That sounds very flexible arrangement you are proposing.
I remember 3 things that have guided me. WeeJohn said for track all you needed was 25mm thick disks with about stock disc height to eliminate the usual fade with 2 pods I think the 36.47 ones?
The second was some one finding the single piston too powerful 57.17 dia causing lock ups in the wet because Starlet is so light.
Similarly there was a post about how the original MR2 single piston was too difficult for some drivers thats why they then went 2 pods the brake application is smoother and less demanding for most drivers. However the post said a higher skilled driver could make it through the ss a lot faster with the single pod.
It also had to do with the mr2 having more weight in the back and it was designed to compensate for that unusual bias.
Bigger is not necesssarily better in several ways ... and bigger surface are may not always mean harder braking for example you will notice the twin has bigger surface area but they said it stopped slightly slower, well I read that's because the first piston heats the disk so much the second piston cant stop as well. Where as the single piston gets all is stopping power on a cooler part of the disk. Maybe with a thicker disk to disipate the heat and a light car like a Starlet this is less of a problem.
That link for rear pistons says measured as 2.7cm ( 27mm ) dia if you look in the photo you can see 27m ( for metric ) stamperd on the cylinder unit so that seems ok.
Brakeparts.co.uk has detailed info but it lists starlet as 51.1 piston which is sera and mr2 mk1 so it may be dodgy although paseo is listed closer to what you have.
That sounds very flexible arrangement you are proposing.
I remember 3 things that have guided me. WeeJohn said for track all you needed was 25mm thick disks with about stock disc height to eliminate the usual fade with 2 pods I think the 36.47 ones?
The second was some one finding the single piston too powerful 57.17 dia causing lock ups in the wet because Starlet is so light.
Similarly there was a post about how the original MR2 single piston was too difficult for some drivers thats why they then went 2 pods the brake application is smoother and less demanding for most drivers. However the post said a higher skilled driver could make it through the ss a lot faster with the single pod.
It also had to do with the mr2 having more weight in the back and it was designed to compensate for that unusual bias.
Bigger is not necesssarily better in several ways ... and bigger surface are may not always mean harder braking for example you will notice the twin has bigger surface area but they said it stopped slightly slower, well I read that's because the first piston heats the disk so much the second piston cant stop as well. Where as the single piston gets all is stopping power on a cooler part of the disk. Maybe with a thicker disk to disipate the heat and a light car like a Starlet this is less of a problem.
That link for rear pistons says measured as 2.7cm ( 27mm ) dia if you look in the photo you can see 27m ( for metric ) stamperd on the cylinder unit so that seems ok.
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That's kinda the info I'm looking for as well really, although I can get 4 pot calipers very cheap so it would be a waste to not take advantage of that, not to mention the weight savings compared with retro fitting from another car.
I'm looking at running a 25mm disc, between 280-285mm diameter, but at the moment this isn't much of a concern because the 4 pot calipers I'm looking at (AP Racing, Alcon and even Wilwood) allow me to run anything from 250-310mm disc diameter) The only doubt I have with running the 25mm disc is that the car will be used on the road as well, so keeping heat in the brakes might be tricky and leading to running a lot of front bias. Although this could probably be sorted by running a street type pad, then swapping the pads out for something more orientated for racing.
Hmm talking about the 57.17mm diameter single piston, that makes me wonder what size the master cylinder is for the starlet if it's easy to lock up. Because that's ultimately what I'm trying to achieve is to balance caliper piston area with master cylinder size.
I've been working out piston area sizes for a lot of aftermarket calipers, I know greater isn't always better as you lose the feel in the pedal, and if you go too small you get shorter pedal movement but obviously not enough power. I think I'm going to send my findings off to someone like AP Racing and see what caliper/piston size and master cylinder size they recommend for the mass of the starlet, power etc.
I'm looking at running a 25mm disc, between 280-285mm diameter, but at the moment this isn't much of a concern because the 4 pot calipers I'm looking at (AP Racing, Alcon and even Wilwood) allow me to run anything from 250-310mm disc diameter) The only doubt I have with running the 25mm disc is that the car will be used on the road as well, so keeping heat in the brakes might be tricky and leading to running a lot of front bias. Although this could probably be sorted by running a street type pad, then swapping the pads out for something more orientated for racing.
Hmm talking about the 57.17mm diameter single piston, that makes me wonder what size the master cylinder is for the starlet if it's easy to lock up. Because that's ultimately what I'm trying to achieve is to balance caliper piston area with master cylinder size.
I've been working out piston area sizes for a lot of aftermarket calipers, I know greater isn't always better as you lose the feel in the pedal, and if you go too small you get shorter pedal movement but obviously not enough power. I think I'm going to send my findings off to someone like AP Racing and see what caliper/piston size and master cylinder size they recommend for the mass of the starlet, power etc.
Expert advice is always worth having in oz we have a testing center that will test the car let you know the brake bias as mods can change the original weight balance.
Reading some posts now makes me think some Starlets do have 51.05mm piston I guess maybe when they got heavier.
I like a car to oversteer in the wet so personal taste can come into this also 4 pots sound great but how they perform I am not sure maybe they put more heat in the disk to heat racing pads?.
I am not keen on adding a lot of unsprung weight with huge disks etc. if unneccessary esp with wider low profile tyres unless you are setup for it.
I would like to stop very fast but wonder a what point people start to run into the back of you on a regular basis.
Thats an interesting point about disk size ( thickness) and heat in the pads. I think car weight and rim weight would effect this as do bias , piston size and braking style. eg the 25mm seems to take all the heat of a Starlet where as the light MR2 had a 22mm disk presumably this would hold some heat but as the bias is more central there is less heat going to the fronts so a thinner disk can be used.
Reading some posts now makes me think some Starlets do have 51.05mm piston I guess maybe when they got heavier.
I like a car to oversteer in the wet so personal taste can come into this also 4 pots sound great but how they perform I am not sure maybe they put more heat in the disk to heat racing pads?.
I am not keen on adding a lot of unsprung weight with huge disks etc. if unneccessary esp with wider low profile tyres unless you are setup for it.
I would like to stop very fast but wonder a what point people start to run into the back of you on a regular basis.
Thats an interesting point about disk size ( thickness) and heat in the pads. I think car weight and rim weight would effect this as do bias , piston size and braking style. eg the 25mm seems to take all the heat of a Starlet where as the light MR2 had a 22mm disk presumably this would hold some heat but as the bias is more central there is less heat going to the fronts so a thinner disk can be used.
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That sounds like a good thing to have, only problem is the car obviously needs to be rolling to get there, and I wanna find out as much info as possible before splashing out on parts that may not make any difference.
Hmm am sure all starlet calipers are the same though? I've got a set of rears I can look at, although they are on the car, but I don't have a set of fronts I can measure so just have to assume that 48mm is the right size or there abouts.
The 4 pots just allow a more even spread of power across the pad resulting in even wear, also with a larger piston area you get more power as well, but if your master cylinder is too small you get an increase in power but a longer pedal and vice versa.
That's the thing there's no need to have such a large disc as it just adds weight, but like I say I can choose a disc at a later date as I have quite a wide range to choose from that will fit the caliper correctly.
I'm going to email a few brake companies and see what sizes they recommend for the car taking into account that they only weigh around 820kg.
Hmm am sure all starlet calipers are the same though? I've got a set of rears I can look at, although they are on the car, but I don't have a set of fronts I can measure so just have to assume that 48mm is the right size or there abouts.
The 4 pots just allow a more even spread of power across the pad resulting in even wear, also with a larger piston area you get more power as well, but if your master cylinder is too small you get an increase in power but a longer pedal and vice versa.
That's the thing there's no need to have such a large disc as it just adds weight, but like I say I can choose a disc at a later date as I have quite a wide range to choose from that will fit the caliper correctly.
I'm going to email a few brake companies and see what sizes they recommend for the car taking into account that they only weigh around 820kg.