Brake proportion/bias thingy?

Brake proportion/bias thingy?

Author
Discussion

arhTVR

Original Poster:

226 posts

125 months

Monday 20th April 2015
quotequote all
My apologies for the flippant title but my brain hurts from reading all the brake upgrade posts on here. I still can't decide whether to leave well alone, put 260 on the front and 25x on the rear or even 257 on the front. Enough of that, lots said already!

What I am really after is a Sierra brake proportioning valve as mine is in a very poor condition. Does anybody know where I can get one from?
Tony

glenrobbo

35,251 posts

150 months

Monday 20th April 2015
quotequote all
www.sierrasrus.co.uk ?

Won't it clean up with a bit of tlc?

v8s4me

7,240 posts

219 months

Monday 20th April 2015
quotequote all
Have you tried your local main dealer or motor factors?

As for brake upgrades here's a starter for 10..

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

arhTVR

Original Poster:

226 posts

125 months

Monday 20th April 2015
quotequote all
glenrobbo said:
www.sierrasrus.co.uk ?

Won't it clean up with a bit of tlc?
Thanks Glen
I'll give them a try and see what they have. Mine is beyond repair unfortunately.
I'm considering a Chim/griff setup for the brakes which might mean that the available Griff (mondo) valve might work idea
Alternatively, perhaps just upgrade the front to Griff 260mm set up.
Cheers.
Tony.

v8s4me

7,240 posts

219 months

Monday 20th April 2015
quotequote all
Why muck about with a valve off another model which might not work when you can get an adjustable one?

http://www.carbuildersolutions.com/uk/brake-propor...

phillpot

17,115 posts

183 months

Tuesday 21st April 2015
quotequote all
v8s4me said:
when you can get an adjustable one?
Do they do the same thing?

I imagine those type to give a set bias depending how far down you screw the screw? Good for racing/rallying maybe, whereas the Sierra type vary braking force to the rear wheels depending how hard you brake (decelerate) scratchchin


Unless you have a stripped thread find it hard to see how yours is un-useable, it's just a lump of metal that can be cleaned up and painted, got a photo? Think I may have a spare somewhere but possibly no better looking than yours.

arhTVR

Original Poster:

226 posts

125 months

Tuesday 21st April 2015
quotequote all
I can make it look OK but one thread is no good. If push comes to shove I could try a helicoil fix. the outside is proper rusty and the bracket pretty much non existent, so I'm concerned that the the 'ball' and spring inside may not be OK - it has been stood for over 8 years. I thought it safer to get a new one but my mate Google was no help. I'm about to try the Guys in Glen's link. (Thanks again)

My (limited and amateur) understanding is that the kit car adjustable regulators reduce the overall pressure, in a 'static' sense.
The Sierra ones use inertia(?) to dynamically reduce the pressure under braking, and my assumption is that the Chim/Griff set up (which the larger rear discs and 260mm front emulate) use a regulator which reduces the pressure when the pedal is pushed very hard - again, more of a dynamic arrangement. I'm aware that I am messing with things I don't fully understand but the Chim bible suggests that its unconventional set up of larger rears works well in this particular case.

I'll update with some pics later - just making a few minor mods to the chassis repairs before getting it to the powder coaters.
Tony

Kitchski

6,515 posts

231 months

Tuesday 21st April 2015
quotequote all
I've got a good spare somewhere, as I fitted a Mondeo one when I fitted the Griffith brakes, if it helps?

phillpot

17,115 posts

183 months

Tuesday 21st April 2015
quotequote all


Helicoil on brakes = a big NO NO in my book !


This is what's used on the Chimaera.


Plough your way through this if you have five minutes.


A little while ago I think it was our friend Han in Holland had some stainless mounting brackets made, my guess is that because brake pipes have to be undone, braked bled etc. it is not a five minute job to fit one so there are probably a few "spare" ones around, bought but never fitted?

arhTVR

Original Poster:

226 posts

125 months

Tuesday 21st April 2015
quotequote all
OK. Those nice people at Sierras R Us had one, so no need for helicoils or any other worries I hope. If anybody still has a nice stainless bracket that would be great wink Thanks to Glen for a great link - they seem to have lots of second hand Sierra parts readily available.

I may just go for 260mm front discs and retain the rear drums, but as I have most of the parts for a 273mm rear disc set up that is also very tempting. This would be similar to the Griff 500 set up so fitting a Mondeo pressure regulator seems appropriate - I think that must be what Richard did (previous post). I now have both options and will make a final decision when I get to re-building the back end.

Thanks to everybody for their help.
Tony

joe-motion

123 posts

65 months

Wednesday 30th January 2019
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arhTVR said:
OK. Those nice people at Sierras R Us had one, so no need for helicoils or any other worries I hope. If anybody still has a nice stainless bracket that would be great wink Thanks to Glen for a great link - they seem to have lots of second hand Sierra parts readily available.
Ordered a new bias from Sierras R Us however didn't come with a bracket and mine has perished. What have people used to replace these? Preferably shiny as well!

phillpot

17,115 posts

183 months

Wednesday 30th January 2019
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Not the best photo but here's one I made earlier wink


phillpot

17,115 posts

183 months

Wednesday 30th January 2019
quotequote all
Its predecessor, a stainless steel copy of the original ..............


joe-motion

123 posts

65 months

Wednesday 30th January 2019
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I like them. You still got the predecessor Mike?

For a small fee of course smile

phillpot

17,115 posts

183 months

Wednesday 30th January 2019
quotequote all


Sorry but that's staying (for "just in case"), probably got an original rusty one somewhere!

joe-motion

123 posts

65 months

Wednesday 30th January 2019
quotequote all
No worries will try and get one made up.

HvdWeerden

1,736 posts

200 months

Thursday 31st January 2019
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This might help :





joe-motion

123 posts

65 months

Thursday 31st January 2019
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That's great, thanks.

What is the original off? Or is it TVR designed and now not available?

Kitchski

6,515 posts

231 months

Thursday 31st January 2019
quotequote all
I've got some kicking around somewhere.

joe-motion

123 posts

65 months

Thursday 31st January 2019
quotequote all
That's great if you have one in good nic, let me know what you want for it.smile