Does anyone know if there is a good Aftermarket rear Caliper that has a hand brake?
I\'m thinking about fitting big brakes to my fd but would like to keep it ballanced.
I have been looking at quite a few web sites and racers tend to use 4 pots on the back and use a Hydrolic hand brake if one is used at all.
Would be intrested to know what people do to ballance the back when big 6 pots and disks are fitted up front.
we have the HiSpec going up on our site, and we are putting a kit together as well.
http://www.rotaryart.uk.com/acatalog/Calipers.html
Dont know if it would be the same, but my bro used to have a rally preped Talbot Sunbeam Ti, and the previous owner converted to a hidrolic handbrake. when it was parked on the drive for about an hour after a run the handbrake would release and the car would slowly roll out on to the main road. used to supprise a few motorists, comeing around the corner to find a car parked nose to the curb!!!
Jono
thats because hydraulic systems dont hold pressure over time
a hydraulic handbrake is an MOT failure
Quote from: GrizzlyDoes anyone know if there is a good Aftermarket rear Caliper that has a hand brake?
I\'m thinking about fitting big brakes to my fd but would like to keep it ballanced.
I have been looking at quite a few web sites and racers tend to use 4 pots on the back and use a Hydrolic hand brake if one is used at all.
Would be intrested to know what people do to ballance the back when big 6 pots and disks are fitted up front.
Hi Chris,
For many years the big 2 pot or 4 pot calliper with hand brake has stumped big manufactures let alone small aftermarket companies, you only have to look at Evo\'s to see this many manufactures get around the problem by using the inside "hub part" of the disc as a brake drum and fit shoes inside leaving them to have a fully independent calliper with however many pistons they choose.
Mazda and others have got around things as best they can by fitting a single pot sliding calliper so when they push the piston out it pushes against a firm surface and not another piston that just pushes away and pushes fluid back up into the master cylinder reservoir that then needs the pedal to be pumped to get the pedal back to the height it should be!.
So having said all this I will be surprised if anyone comes up with a way of achieving a proper 4 pot calliper with a hand brake, so until then for home made brake kits it looks like your stuck with the mechanical "spot callipers" to keep your car legal with a hand brake that works on a separate system.
As you say one last alternative would be to fit an hydraulic hand brake kit as used in rally cars, however these are not legal for the road as the hand brake is supposed to be a totally separate "secondary" system so that it is independent of the main braking circuit in the event of total brake failure.
That said I am sure an enthusiastic MOT tester could be persuaded to put a test on the car as it would have a very good hand brake as your hand brake would have the same efficiency as your foot brake!
I too have worried again and again about people fitting huge callipers on the front and doing nothing with the back but even more than that what about the master cylinder.
Fitting huge front callipers at the front is fine for show but if you actually want the car to stop properly you need to address not only the back of the car but also the master cylinder or you will not only have a very hard pedal to push but you also will find you have just lost the gains you thought you made with your upgrade due to the master cylinder being too small.
When I decided to fit 4 pot Brembo callipers onto my car I carefully measured and worked out the piston sizes to make sure that the master cylinder was still adequate for the job by being able to displace enough fluid and then fitted soft pads in the back to compensate for the increased efficiency on the front keep the brake balance somewhere near correct.
I personally feel that any larger set brake up\'s than this requires a fully adjustable bias braking pedal box, and as you probably know this is where you have two master cylinders with an adjuster between the two that dictates the amount of push onto each master cylinder and thus gives more braking to either the front or rear of vehicle.
Also be careful of the make that you choose as many "Race" callipers are not able to cope with the U/K roads salt and muck due to either inadequate seals or the metal used to make the pistons.
If you want to make a proper real real good cheapish upgrade you need look no further than fitting the 4 pot Mazda callipers and disc\'s from the front, then finding a pair of Porsche front callipers on ebay or whatever then going to Rally Design in Faversham Kent for a pair of spot callipers for the hand bake and a proper bias pedal box that will only cost you around £120 pounds
I was thinking about this today at work (:() and a guy i know that has been rallying for years walked in and we had a chat about it. He had the same problem on a car he uses for Trackdays etc. What he did is kept the stock caliper and welded a mounting on the other side of the Hub, so he ran a 4 pot as well so all he used from the stock caliper was the Hand brake. But would having no fluid in the caliper make it stick?? and i don\'t think i fancy depending on two welds on a hub that\'s not supposed to take that load in that area?
The Hub idea does intrigues me as Ed rx7 has a set of Wilwoods that have been converted to hub handbrakes.
Out of Intrest do you remember the Brake set up Chris Wilson fitted to his FD? He went full hog with Twin Master cylinders etc, but i seem to remember he had 4 pots on the back? i wounder how he got round it with his knolage of tricks in the racing world....
Looking at the measurments at the Wilwodd spot caliper, it wont take a stock rear disc. They are designed for solid, not vented discs.
As for Chris Wilson\'s setup, he did NOT have to worry about a hand brake.
Fish
Well the next stop is the wrote of Vectra we have at work :) i\'m intrested in these hub hand brakes. If there compact i wounder if it can be moded to fit inside a bell? kind of like Ed\'s. I supose you could fit any make caliper as all the hand brake is taken care of?
The Cosmo uses a hub handbrake which is the same as a mazda 929. You may be luck and it may be a straight bolt up. As a lot of mazda bits are interchangable.
Kevin
Now that is interesting!!!!!!!!
Next question is do you know where i may get hold of a hub assembly?
Quote from: CraigNthats because hydraulic systems dont hold pressure over time
a hydraulic handbrake is an MOT failure
It is not.
not having a mechanical handbrake is an MOT fail, you can run both with zero problems.
Can you take all the covers of a stock hand brake and put them over a Hydraulic one (to make it look stock) :)
you can fit a cylinder onto the back of the existing handbrake lever, I managed to get all of that to fit under 90% of the original trim in my rally car (not saying it is possible on another car, but it can be done discretly on some) plenty of places do a kit of parts to convert to hydraulic.
Mine retains ALL the original handbrake components as well so I have both an hydraulic handbrake + the cables which are don\'t come into play unless I loose the hydraulics. All perfectly legal for an MOT (other regs are more complicated, say for an SVA)
So for a weekend warrior car and a bit dippy MOT tester it could be done??
Whilst we\'re on hydrolic Handbrakes, How do they work? if you just use a cylinder that pressurises the brace system won\'t it just overflow the master cyliner? and does it put on just the rears or the front as well?
LOL, No
They would have to forget to check the condition of the hand brake cables...
the MOT aint going to get any easier to pass in the future either ... quite the opposite I guess.
I\'d fit a pair of spot calipers if I were you, AP and Willwood do ones to suit different discs and it\'s perfectly legal and a nice simple setup. a hydraulic handbrake is a big compromise and is only really of use if you wish to use the handbrake to reliably lock the rear wheels when moving. If it is simply to hold the car when parked and satisfy the MOT man its got to be a cable setup.
To answer your question on how they work ... The rear brake lines need be reduced to a single brake line, this then loops into a handbrake mastercylinder and then back out again and back onto the rear brakes, when you pull the lever it moves the piston and operates the rear brakes idependent of the fronts.
You could always get a bit radical and mount a park brake assembly inboard of the rear hubs on the drive shafts.
Kevin
if you mount one the input flange to the diff you only need one caliper too ;)
Would he get high enough figures with a single setup though mike?
Kevin
I would expect it to be OK, you get a mechanical advantage due to the diff,
I\'m sure I\'ve seen the setup somewhere before.
Quote from: MikeLMRI would expect it to be OK, you get a mechanical advantage due to the diff,
I\'m sure I\'ve seen the setup somewhere before.
Good point Mike. There\'s every possibility of using a nice lightweight disc/ caliper set up and leaving the rear hub area free to mod anyway Grizzly wants.
Kevin
If its not a daft question why don\'t manufactures do this?
if you look under jag e-type or other jag with the old IRS you will find that they have been doing for a long time. NSU RO80\'s even have inboard front brakes
I think the answer is cost, it\'s cheaper to have a mass produced caliper with it all one package. secondary reasons are, cooling is probably better if it the brakes are at the wheel hub and ease of service.
I\'m guessing this is basicly what they did with Ed_rx7\'s brakes but proberly more made for the car rather than cut and tweeked to fit??....
Buy a kit like this http://www.streetrodstuff.com/Products/2058/
Then cut the lip of the Back plate so its flat and will take larger disks, then have the disk machined into a Bell so a Big aftermarket Disk can be fixed? You\'d only realy need the Backplate,Handbrake assembley and a disk to get the hand brake working? but the hole kit is only abotu £200??
So whats wrong with the calipers I pointed to earlier, they have a self adjusting handbrake mechanism.
Been told they will pass MOT when I questioned this today.
http://www.rotaryart.uk.com/acatalog/Monster-Handbrake.pdf
http://www.rotaryart.uk.com/acatalog/Billet-Handbrake.pdf
http://www.rotaryart.uk.com/acatalog/Road_calipers.html
Think I would rather trust my car and life in the hands of AP/Brembo and a spot caliper.
Fish
Sorry i did\'nt notice they had handbrakes.(apart from they say Handbrake in big letters... Doh!!!) Have you put a rear kit together?
Clive,
How\'s tricks? Could you clarify the bit you mentioned about the brake pedal being much harder with larger front calipers? I thought it\'d be the opposite, soft and spongey. Happy to stand corrected.
Cheers, Jode
Quote from: GerbilStuntFarmClive,
How\'s tricks? Could you clarify the bit you mentioned about the brake pedal being much harder with larger front calipers? I thought it\'d be the opposite, soft and spongey. Happy to stand corrected.
Cheers, Jode
Hi Jode, good thanks.
If you have to stock master trying to push more fluid than it was designed to trying to operate larger pistons then I would have said you will have a hard pedal as the poor little thing is working harder to displace more fluid and would show by requireing more pedal pressure than normal to make em work properly.
I found this years ago on a racer of mine when I fitted big AP callipers with a stock master.
The reverse would happen if you fitted a large master, i.e. soft and spongey
Hi Clive,
That makes sense now thanks, I won\'t be making any changes until we have a 929 master cylinder over here anyway. However I have seen lots of different ones at car shows for sale, so presumably there are alternatives that could be used for the same result?
The car is back in my hands tomorrow, will give you a call regarding the seat(s) as soon as possible.
Cheers, Jode
I\'ve got a 929 on mine and i tell you if i didn\'t have it..i would be fduked. my pedal now moves only 1 inch and its as hard as a rock (and i have 6pots and 4 pots!!). If you do upgrade your brakes be prepared for more travel if you don\'t upgrade the M/C...(from my experience)