CHRIS GALE Posted January 27, 2002 Share Posted January 27, 2002 I have what i think is a common problem with the seven. On standard brakes when my size 12 hits the middle peddle (some times all three pedals)but in this instance the middle one, the rears lock up even in the dry. What are your oppinions on fitting a proportioning valve over uprated front brakes and do they actually improve all round stopping? I hope their are some positive answers to this one as i have the valve sat on bench ready for fitting.(i always seem to do everything ass about face.) Link to comment Share on other sites More sharing options...
Delberts Wallet Posted January 27, 2002 Share Posted January 27, 2002 I've fitted a brake bias valve to my seven and it improved the braking no-end. Now my fronts lock just before the rears under heavy braking and the car feels much more stable under "normal" braking. Worth doing Cheers Gareth Who Dares Twins bum.gif bum.gif Link to comment Share on other sites More sharing options...
Graham Perry Posted January 28, 2002 Share Posted January 28, 2002 Its worth the price of fitting one as they are not dear. You will have fewer 'oh my god' moments. Also they are compatible with front brake upgrades as you may find as I did that 4 pots didn't cure the rear first lock-up problem, and I ended fitting a valve anyway to cure the problem. Link to comment Share on other sites More sharing options...
Big Brother Posted January 28, 2002 Share Posted January 28, 2002 Out of interest...where is the proportoning valve fitted and how big is it? Also what sort of price would I expect to pay? The only ones I have previously seen, were the Tilton bias valves and they were not cheap! Steve www.Se7en-Up.co.uk id=limegreen> Link to comment Share on other sites More sharing options...
Delberts Wallet Posted January 28, 2002 Share Posted January 28, 2002 Steve, I paid around £50 for mine. I also had to by a pipe flaring kit for around £30. They not too big but I guess it depends on which one you get. I've fitted mine to the back of the pedal box next to the master cylinder. Gareth Link to comment Share on other sites More sharing options...
Graham Perry Posted January 28, 2002 Share Posted January 28, 2002 Same position for me. Again about £50 plus pipe Link to comment Share on other sites More sharing options...
Big Brother Posted January 28, 2002 Share Posted January 28, 2002 Please excuse my ignorancesmile.gif but how does the valve work. Does it just restrict the flow of fluid in the part of the braking system its installed or is it a bit more complex? Steve www.Se7en-Up.co.uk id=limegreen> Link to comment Share on other sites More sharing options...
Delberts Wallet Posted January 28, 2002 Share Posted January 28, 2002 I believe it just restricts the flow to which ever circuit you've installed it in. Could be wrong though! Gareth Who Dares Twins bum.gif bum.gif Link to comment Share on other sites More sharing options...
Graham Sewell Posted January 28, 2002 Share Posted January 28, 2002 Being equally stupid, where can you buy one? I have seen Dave A's description of modifying a Mini valve, but I don't have the kit to do the mods and I hate working on brakes - wimp I know, but I trust other (qualified) people with the more life threatening components. Would James Whiting do one??? Link to comment Share on other sites More sharing options...
CHRIS GALE Posted January 28, 2002 Author Share Posted January 28, 2002 Well I actually fitted it today, next to the heater pull knob. Had to re-position the immobiliser slightly, it's now easily adjustible from inside. Borrowed a friends flareing tool but had problems getting a good seal. Two attempts later, success. I used the Tilton 7 posn lever, I thought it would be better than the screw down type because you can remember the posns. I havn't had chance to try it yet, so can't pass comment. BUT IT WON'T BE LONG. C7 CJG Link to comment Share on other sites More sharing options...
David Hopkins Posted January 28, 2002 Share Posted January 28, 2002 Valve works by allowing full pressure to rears until a predetermined threshold pressure in the line is reached . At which point depending on the valve type it either shuts off the pressure to the rears ie any further increase in pedal effort only results in the front line pressure incresing from that point . OR if it is a reducing valve then the pressure is reduced by the ratio in areas of the piston in the valve as it 'cuts in ' then the rear line pressure only increases by half than that seen by the fronts if the ratio is say 2:1 . The cut in is set by a spring acting on the piston in the valve , adjustable ones function in the same way all you are doing is increasing or decreasing the preload on the piston . Performance Braking 01600 713117 can supply and give any expert advice required . Link to comment Share on other sites More sharing options...
New Barbie Posted January 29, 2002 Share Posted January 29, 2002 I bought one through Demon Tweeks - speak to Dave K direct. Dont't fit one to a new car you are building until after the SVA test - it will not pass with one in place. I've heard stories of people having to physically disable the valve permanently at the test in order to pass on the day and the test centre taking a photo to prove the device was inoperative. Also if you want to compete in certain series, you cannot have the valve able to be adjusted on the fly so it can't be positioned on the dashboard or close by where you can get to it, whether you'd actually get caught is another matter. Link to comment Share on other sites More sharing options...
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