fiestaturbo.com

[ChrisM]

ive got a set of focus rear discs an calipers to go on my si will i need to install a bias valve??? ive got mondeo setup from a 2L at the front end.
cheers

[Oranoco]

Yes or you will dissapear backwards off the road the first time you need to stamp on the anchors.

From experience rear disc conversions cause more problems than they solve. You really should ask yourself whether you really need them or not. In my mind fitting something like this for what is mainly an aesthetic point seems a bit daft.

[jimmyesh]

This subject ALWAYS seems to start a debate on this forum but from my own personal experience I can say YES GET A BIAS VALVE OR BALANCE-BAR SET-UP!!!

I had wilwood 4-Pots and 280mm discs on the front and a "Fiesta Centre" 240mm rear disc conversion set-up on my previous RS1800 and once, I had to stamp on the middle pedal coming over the crest of a hill on the A361 when there was pile-up on the other side

The back end was just snaking everywhere and I thought I was a gonner! I managed to hold it all together with a nifty bit of cadence-braking and a BIG helping of luck.

As soon as I got back to work I rang rally-design and ordered a Wilwood in-car bias adjuster and set it up on the roller-brake tester at work. NOT a gamble I'd be willing to take again! I wanna see my kids grow up

Basically it takes MORE pressure to operate drum-brakes as opposed to the disc equivalents, so your car's braking bias is factory-set for the operation of drums on the back, so when you swap them to discs they will be getting a dis-proportionate amount of pressure so will be applying too much stopping power to the back.

It pays to do this job properly if you're gonna do it at all...

Hope that helps mate

[Oranoco]

It pays to do this job properly if you're gonna do it at all...

That has to be in running for quote of the year

[Ollybee]

cadence-braking

This technique has saved my ass a few times as well. Why don't they teach this for the test?!

[jimmyesh]

cadence-braking

This technique has saved my ass a few times as well. Why don't they teach this for the test?!

Dunno But it meant I just got home with only cacky-pants instead of being crippled/dead so I'm glad I've mastered it!

[filtra]

cadence-braking

This technique has saved my ass a few times as well. Why don't they teach this for the test?!

My instructor showed me how to (he does it with all pupils but in his run around since the learner car has ABS).

TBH unless you have monster power most of the braking is done at the front of the car and is more asthetic and 'modernising' cars are still being produced with drums even now!

[ChrisM]

how does the focus setup work??? do they come with a bias valve, [ERRR] if i was to use the the brake cylinder from the focus would this work???
cheers

[jimmyesh]

Forget about using the Master cylinder from the focus, it's a little stubby thing which is completely different from the fiesta one and the Focus brake pedal set-up is laid out differently to the fiesta too in that there is no (crap) cross-linkage to put the servo over by the passenger side as there is in the fez.

The focus has the servo recessed into the bulkhead directly in line with the foot pedals so therefore has a much more positive brake pedal as there is less moving parts involved. I wanted to put that set-up complete into my fiesta when I did my ST170 transplant but there's just no room

You will have to source your own bias valve from Rally Design, they don't cost much and aren't rocket science to fit either just get a pipe cutter and pipe-flaring tool from Clarke or similar while you're at it and also a roll of 3/16" copper brake pipe too (loads of it on ebay).

Then when it's all fitted get the car to a garage with a Roller Brake Tester and get the bias set correctly, If you can't manage that just drive to a big empty space somewhere and keep hammering it/doing emergency stops and adjusting the brake bias until the car stops properly

[heeman10]

I took my car out for a good hard drive before deciding to fit a bias valve just for the sake of it. After some hard straight braking, and braking with some lock applied, I came to the conclusion that I was happy with the balance, so buying and fitting a bias valve would've been a waste of time and money for me. I have a fairly heavy car though, with a chunk of that weight coming in the form of full rear seats, a rear cage, 8kg parcel shelf and a lot of sound deadening throughout the car, including the boot floor, tailgate, rear turrets and rear quarter panels/under the seats also.

So, you can take two views:

1) Do it anyway, so if you DO need to adjust it, you can, straight away.
2) Try it all out (safely - even get it on the brake test rollers if you have access to some), and if all's well, you've just saved £50 odd.


Lots of people like sticking gizmos and gadgets on the car for show/wow factor anyway. I remember when people started learning about bias valves they appeared in every bloody car around, regardless of the braking system alterations!!