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View Full Version : Rear Discs + Bias Valve = Must Have



Dod
03-07-10, 06:58 PM
Believe me.

craig green
03-07-10, 07:14 PM
Its common knowledge just banging them on in place of a drummed beam = FAIL.

Dod
03-07-10, 07:16 PM
Following a thread I started in here it was 50/50 as to fit one or not.

General Baxter
03-07-10, 07:16 PM
lmao, this is why i made my own valves,

lowest vauxhall ones are 4.7 bar, and still lock up, i had 4bar,

Dod
03-07-10, 07:17 PM
/\ How?

General Baxter
03-07-10, 07:19 PM
i work with hydraulics lol

Stuart
03-07-10, 08:07 PM
Most of the 'bias' valves dont restrict till a certain pressure anyway and the adjuster only alters the rate of limiting rather than the point of limit.

Dod
03-07-10, 08:11 PM
Whats the solution so?

Stuart
03-07-10, 08:58 PM
drums

craig green
03-07-10, 09:01 PM
Wilwood bias valve was fine on mine. Never had any concerns with locking or over braking. Have to agree that discs are for looks only. I'll openly admit thats the reason I put them on tbh.

Benn
03-07-10, 09:16 PM
Same here Craig.

Wouldn't do it again tho. I've never had it lock up, but since having discs on the rear the braking has always been crap, till i fitted 4pots.

Dod
03-07-10, 09:22 PM
For me, its just something to add to the spec sheet, but they're on now and extremely dangerous.

Be warned kids!

craig green
03-07-10, 09:23 PM
Same here, spec sheet addition + crooze points when in the company of Saxo's & Golf GTi's etc.

Benn
03-07-10, 09:29 PM
haha same. Dod, do you run both lines to the rear?

Maybe gently crimp the line that screws in to the calipar. Bit pikey i know but it will work.

bazil
03-07-10, 09:29 PM
pedal box? thats what i done.

Dod
03-07-10, 10:10 PM
I dunno, I've plenty of time to sort it anyway. The car was going for sale but its rebuild time now and its going no where for the foreseeable.

What Bias valves are every using?

Bazil, are the Pedel Boxes expensive?

Benn
03-07-10, 10:10 PM
What ones come in the 1.4 Sr mc? lol

bazil
03-07-10, 10:11 PM
second hand no, i link you in a second to new ones

http://compbrake.co.uk/shop/product_info.php?cPath=6&products_id=345

i might, most probably will be changing mine.

craig green
03-07-10, 10:29 PM
I have a Wilwood rotary jobbie.

wwmnw
03-07-10, 11:57 PM
Gareth_C needs to see this thread, he's adamant about putting discs on the back of his (already has the rear beam and bits), I keep telling him drums will do fine when he has wilwood 4 pots on the front.

General Baxter
03-07-10, 11:58 PM
ill NEVER fit them again lol

bazil
04-07-10, 12:16 AM
I find the handbrake piss poor on the disc setup tbh

Mark Sparks
04-07-10, 01:01 AM
I hate to disagree but i have to i got discs on the rear and the handbrake is bloody brilliant.
I am an mot tester so when i tested my brakes in the rolers i was shocked to find i could not lock the rear brakes i have v6 front and braided hoses all round.

nova_saloon
04-07-10, 03:47 AM
I hate to disagree but i have to i got discs on the rear and the handbrake is bloody brilliant.
I am an mot tester so when i tested my brakes in the rolers i was shocked to find i could not lock the rear brakes i have v6 front and braided hoses all round.

good to hear they have done some good for someone. mayb theyt just need proper setting up. how is normal braking and what are you using in the line to restrict it?>

Dod
04-07-10, 07:56 AM
No, my Handbrake is A1, it couldn't be better. Its just the end swapping that causes me grief. Bazil, if you are changing your set up, and you're selling your current item, pm me with the price please!

Dan
04-07-10, 08:52 AM
i think i'm going to bin the rear beam on mine. It came with the discs fitted so i just left it. As seen on my combe thread my brakes are aweful, i have the rears so they hardly work (correct regulator on mc + bias valve) but even with that the whole system just seems spongy/non responsive when it comes to caning round a track on inters

Dod
04-07-10, 09:29 AM
Have you thought about changing the MC for something like a GSi Cav item? I've done this with non disc'd rear Novas and there is a nice difference, that said, I've not done it with my current disc'd rear set up and I must agree, its spongey and feels really non effective until it throws you the wrong way around!

Stuart
04-07-10, 09:34 AM
thats the thing, it dosent take much to lock the back end of a nova up, so its like a switch lol I think we got away with it on Dans as the rear tyres are so epic they cant really be locked with the discs lol

bazil
04-07-10, 09:39 AM
im thinking about going for this servo assisted bias pedal box, the enging is staying a 1.6 so it should fit, wont be for a while tho, more details are required before ordering, but opinions welcome..

http://compbrake.co.uk/shop/popup_image.php?pID=3716

Dan
04-07-10, 09:42 AM
Dod you need to pm me a list of what you got and work you did for that cav gsi idea :thumb:.

Stuart the rears on mine are not very strong lol, with the pedal fully stamped a wheel brace can still turn a rear wheel when jacked up. thats why the wheels lightly dust when on track but thats it, as they are only just working. Once the pedal feel is sorted and i improve the front we may be good. But the drums are defo going on if dods idea only partially helps it

Dod
04-07-10, 09:49 AM
PM on Route.

Honestly, I'm glad the set up went the way they did where and when they did otherwise it could have been a lot worse.

Benn
04-07-10, 11:11 AM
Cav stuff is all wrong, the bolt on is a square patton, where as the nova has one bolt off set...

Spudly
04-07-10, 12:01 PM
I am an mot tester so when i tested my brakes in the rolers i was shocked to find i could not lock the rear brakes i have v6 front and braided hoses all round.




Thing is testing the brakes on a brake roller wont lock them as the weight of the car is acting against the braking force, as you brake hard on the road the back end unweights as the weight of the car is thrown forward by the braking forces, this allows the rear end to lock and throw you into a skid as my mate found out when he fitted a non-biased rear beam lol

My old XE nova had a wilwood bias valve in the drivers footwell and was set up perfectly, the handbrake was perfect and i never managed to lock the rear wheels under braking:thumb:

Mark Sparks
04-07-10, 12:30 PM
Maybe its just because i dont rally the crap out of it and drive it half sensible.:)

As for in line valves none its standard.

Spudly your correct but i do test a 100 cars a week and the ones with compensator valves never lock unless its loaded up or the valve is siezed open and the the ones without do lock 90% of the time. When you brake in the rollers it forces it down because you are only braking on that axel therfore more weight thats why they should lock in the rollers even on drums. hence why i was shocked.:thumb:

mayhem
04-07-10, 01:50 PM
over here they all use restrictors from a volvo 440.

Dod
04-07-10, 02:09 PM
How effective are they Mayhem?

mayhem
04-07-10, 02:10 PM
iirc there are 2 types used (full interiour and stripped out)

there ok'ish, but when braking hard in a corner, the still tend to lock up the rear.

Dod
04-07-10, 02:14 PM
Yeah so basically there is no "Cheap way" to do this, you do it right or end up in a LOT of trouble.

Dan
04-07-10, 02:53 PM
ive just checked my old posts to find what i fitted, most regulators on the nova's read 3/35 or 3/40. The one i run is 3/25 found on some vans which cuts it down alot. I think i got more than needed at the time

SR-Rally
04-07-10, 02:58 PM
im thinking about going for this servo assisted bias pedal box, the enging is staying a 1.6 so it should fit, wont be for a while tho, more details are required before ordering, but opinions welcome..

http://compbrake.co.uk/shop/popup_image.php?pID=3716

I use to have servo assisted pedal box, it was one hockley made as a one off apparently. It seemed to work well for mr but i've changed to a non assisted one now. Only difference is the pedal is solid.

Let me know if you want pics or info of servo assisted pedal box as I still have it in the shed

MattBrown
04-07-10, 03:01 PM
ive just checked my old posts to find what i fitted, most regulators on the nova's read 3/35 or 3/40. The one i run is 3/25 found on some vans which cuts it down alot. I think i got more than needed at the time

I have 3/27 ones sat here, will these be ok?

General Baxter
04-07-10, 03:49 PM
no as there just normal vuaxhall ones, vauxhall dont make a low enough one for you to safely fit disks to a nova, this is why i made my own lol

Big_Chap
04-07-10, 04:16 PM
no problems here except my drivers side locks in "emergency stop" mode but its only a slight twitch and easily countered (15degs max) with slight opposite lock, cetainly not handbrake turn sort of locking, possibly in the wet would be different.

*edit* i have 4pots up front but it was the same on the 256's

mayhem
04-07-10, 05:07 PM
ive just checked my old posts to find what i fitted, most regulators on the nova's read 3/35 or 3/40. The one i run is 3/25 found on some vans which cuts it down alot. I think i got more than needed at the time

3/20 and 3/25 can be found on volvo's aswell, and there a direct fit iirc.

Benn
04-07-10, 06:01 PM
A Wilwood bias valve is only about £30, i couldn't get mine too seal that as you have to use a imperial to metric fitting and it wouldn't stop leaking. Even doing it sh*t or bust tight. So i binned it. Lucky i had some fitting i could bridge the pipe with.

Mike
04-07-10, 06:53 PM
Tilton FTW

Benn
04-07-10, 07:36 PM
^?

Mike
04-07-10, 07:37 PM
^?

Tilton Bias valves :)

http://www.rorty-design.com/images/Tilton_proportioning_valve_01.jpg

Benn
04-07-10, 08:29 PM
Ah metric fitting?

Dod
04-07-10, 09:48 PM
I'm going for 280s on the front of my Corsa with rear discs, its stripped out and rear caged, but after yesterdays incident, I'll still go for the Bias Valve.

Benn, sell me your Wilwood.

simonm
04-07-10, 09:56 PM
i used the same tilton one on my nova was scary with out it dod like pulling the hand brake every time to stop but the tilton one sorted it

Dod
04-07-10, 10:10 PM
Simon, believe me, after testing it yesterday I am very very very aware of it. lol

simonm
04-07-10, 10:17 PM
i no i didnt bother with the bias valve for a while thaught it would be alrite untill a bus pulled up in front of me scared the livin sh1t out of me ordered one up straight away

Dod
04-07-10, 10:19 PM
Where'd you order it from mate? Mind how much it cost you?

simonm
04-07-10, 10:21 PM
ordered it from broad side motorsport but there gone now cost me about 130euro and fairly handy to fit

Dod
04-07-10, 10:23 PM
Mmmmmm, must get a look into it but at the minute, theres plenty of time.

blue_peg_16v
04-07-10, 10:42 PM
with ate bias valve is a must with wilwood 4 pots normal balance is spot on

craig green
04-07-10, 10:46 PM
Simon, believe me, after testing it yesterday I am very very very aware of it. lol

That pretty much confirms my feelings about my setup, it was never even slightly twitchy. I played with it allowing more rear bias steadily. I 1st ran it maxed in favour of the front & thats where it was best if I'm honest. But introducing more rear wasnt an issue until nearly 2 or so turns in.

The valve I have.

http://i30.photobucket.com/albums/c323/turbocraig/NovaGSi-WIP_pics/work_in_progress026.jpg

Benn
04-07-10, 10:50 PM
Dude i sold it to a guy on here, after launching it in my garage...

Dod
04-07-10, 11:07 PM
Well, seems like the way to go then. Always good to get a bit more backround on it all.