sbd16v

hi guys have some questions about master cylinder sizes and tarox calipers

first off the easy one

can you get brake pads for tarrox 6 pot calipers from any other manufatures than tarrox themselfs


and the second one is i am fitting a new brake system to my gte a twin master cylinder unit that replaces the master cylinder the master cylinder sizes at current are

.70
.625

go these sound like they are right for my astra

i am sorry but dont have the first idea what the numbers even mean

so any help would be much apreciated

sbd16v

bump

sbd16v

up for the day boys

xomeone must know something about brakes

dojj

iTrader: (3)

the numbers are the bore sizes for the cylinders

when i put the pedal box on my 3 door i had the same problems and even the people who were supposed to be selling them didn't help that much (mentioning no names because they have been faultless ever since)

if you are going for the adjustable pedal box assembly then you want the bigger one to do the fornts and the smaller one to do the rears

be warned that you will more than likely need to be plumbing in a set of servo's ebcause without them, you really do need legs like tom platz to be able to stop the same way you would before

after that it's trial and error to get the system set up to how you want it to behave, but make sure you don't go totaly loopy with it and send it the wrong way, you want the bias to be towards the front or you will be swwapping ends like torvel and dean

dojj

iTrader: (3)

also, when you set them up you will find that the bar goes across and, with no fluid in the system, you wil need to figure out which way to set it up so the biger cylinder get the front brakes and the smaller one gets the rears

from what i can remember (this is going back probably 10 or 12 years now) the shorter the bar the more effort you will be providing
so adjust it so that the shorter section of bar is on the .70 cylinder and the longer is on the 0.625

i'm sure you can get bigger ones but don't quote me on that

Micky

OK,when I fitted mine I was told by a reliable source who did rally preperation that the largest cylinder .7 was to work the front brakes and the smaller was for the backs.So thats the way I connected mine up.....................And the brakes where cr*p!! So I rings up my reliable source and tell him this,so he then tells me to swap the cylinders over,.625 for front and .7 for the back,and hey,the brakes where brillant!! Also,unless youre very weak (like those people who want to fit powering steering on a RST ) you will have no problem pushing the brake peddle.All the best,Micky

sbd16v

well thanks for the info lads atleast i have the right cylinders

i thought the .7 was for the front as they need more pressure so are bigger to send more to the front brakes :S

Micky

I agree,but thats not how it worked out for me.However if you dont get good brakes with the .7 for the fronts its no big deal to change over the cylinders so the .625 works the front like what I had to do.Let us know how you get on,all the best Micky

NUTS RuS

iTrader: (35)

Are you running a servo ?

The .7 one as mentioned above should be on the front, but that really depends on the lengths of the piston rods too.

You can change the characteristics within a bias box by adjusting the length on the piston rod, by altering the balance bar, or by using different sized cylinders. If you dont know what your doing you can easily mess it all up, but get it right and it will be superb.

As for the pads - yes you can

Micky sounds like your rod lengths were wrongly set up

ian sibbert

You'll get more pressure from the .625 814.87 psi compared to 649.61 psi for the .70 and that should be the front master cylinder....on all rally cars ive ever built we use .625 for the front and hand brake......70 or .75 for the rear....rod lengths should be equal in an ideal world but sometimes do need a tweek..

Regards

Ian

NUTS RuS

iTrader: (35)

Depends on what sort of pedal feel you want Ian

sbd16v

ok i am not running a servo and i also dont have a clue what i am doin with setting them up is there anywhere that can do this for me or does anyone fancy some laps at combe setting it up ???

where can i get teh pads from as tarrox's prices are a little special lol

89xr2

I would get someone who knows what they're doing to set up your initial brake balance etc or it could all go horribly wrong for you.

sbd16v

brilliant idea

can you tell me anyone that does this ???

89xr2

No But on the plus side i'm sure there must be someone who does know what they're doing! Somewhere that sets up rally cars or the like? I'm sure Martin at Reyland would be able to do it or someone similar?

There's some interesting stuff on here http://www.zetecinside.com/xr2/brakes.htm , might be able to help you understand it a bit more

sbd16v

i thought that might be the case as if you read 4 posts up i had already said i want it set up properly and how does it

89xr2

I should really start reading whole threads before i put in my ten pence

ian sibbert

Tony,

Rod length only determines how much travel is in the pedal, longer rod length (shorter travel) could make that cylinder operate before the other, so potentially the back brakes could lock before the fronts operate.....i'd always start with equal rod lengths and let the bias bar decide on bias front to back....and in my experience of competition cars ive never seen many that dont run a .625 on the front.....

At the end of the day its about personal preference but the majority of the braking effort wants to be on the front......

Ian

89xr2

In a fwd car it should only be about 10% of your braking on the rear

ian sibbert

If you were closer matey i'd do it FOC...its simple and as long as get the basics right the tweeking is down to you anyway......Tony would have more experience than me on a FWD car but i'd have the .625 on the front...the .70 on the rear and start with the bias bar at the half way point....wind it towards the front to the car brakes in a balanced manner (and it aint wantin to swap ends on you) we used to use an old industrial estate with plenty of room to get the base setting then you want to tweek it on track.....

Ian

sbd16v

thank you for the offer is there any good seting up insturtions for the basic's anywhere
or does anyone in the south fancie a go lol

NUTS RuS

iTrader: (35)

Equally so you can use that principal to get the fronts to work before the backs which can save fitting a pressure reducer in the back lines. By no means ideal but I have seen road / track cars with it set up that way.

As your running no servo then yes the .625 front will work better (I was presuming you was leaving it on). Again thats presuming you want a firm / no travel pedal feel.

Set it up, dry build with the rod lengths equal as Ian says, and with the bias wound about 80% on the front. Fill with fluid and bleed as normal then go find yourself a big open space and see how it performs. Be very careful at this point. If you have set it up wrongly the car will chuck you in all sorts of directions (which is fun) lol.

Dont expect to get it right first time - but do have a go yourself before calling on the experienced, that way if you need to adjust anything in future you will have half an idea what to do.

For pads take your existing pad somewhere like a motorfactors (when they are quiet) and ask them to match it up. They should have all the reference books to do this. That will give you a car and model where it comes from, then just order a competition pad for that vehicle.