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Wilwood big brake setup


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#41 Maxzillian

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Posted 28 August 2011 - 08:56 PM

View PostTsTKl, on 28 August 2011 - 01:49 AM, said:

I was under the impression that the more simple proportioning valves just "turned down" your rear braking force by restricting flow to the rear. If your problem is too much front braking force you wouldn't be able to adjust it rearword at all. It depends on your set up though. I guess technically you could put one on both the front and the rear and then reduce pressure to the front. Either way though, your adjusting your brake bias at the cost of increasing pedal effort. I like the idea of a bias bar better because your mechanically changing the force going into each individual master cylinder. With a stock style master cylinder your line pressure will be the same in both lines unless you restrict flow in one.

The proportioning valve basically allows equal pressure front to rear up to a certain pressure before pressure to the rear is reduced at a linear rate. Under low braking where little weight transfer occurs, this is better than a bias bar where the braking force is linear and only set to provide the correct brake bias at full braking. For example, just to throw numbers around, a proportioning valve could distribute 60/40% braking at 20% power while a bias bar may be 70/30. Meanwhile at full braking, the proportioning valve could be set to meet 70/30 braking and be equal with the bias bar.

What this boils down to is that at moderate braking, a bias bar is actually giving too much front bias. You'd likely never see a problem on the race track, but on the street it can help reduce wear and tear on the front brakes and maybe make a difference in low traction situations.

View PostJamesR, on 28 August 2011 - 01:34 PM, said:

I think wilwoods are available in different widths depending on part numbers.  It's been awhile since I've looked at the catalog.  I could be wrong though.

They are, but I've got these 1.25" bore calipers sitting around and making spacers is much cheaper than buying another pair of calipers. ;)

Edited by Maxzillian, 28 August 2011 - 08:57 PM.

What's the fun in making something simple?

'87 TSI - StarOrion braided brake lines, StarOrion radiator, StarOrion alternator, StarOrion 2.5" stainless exhaust w/Magnaflow muffler, 1G MAS, Competition Clutch 15 lb flywheel, Competition Clutch Stage 4 clutch, Mookeh polyurethane bushings, ABS elimination, 8:1 Wiseco Pistons, TD05 14G turbocharger, Axiss ceramic rear brake pages, Hawk HP+ front pads, heat wrapped and ported exhaust manifold/turbine housing, Accusump oil accumulator, remote oil filter, NJV head, EVO intercooler, remote battery, D2 coil over struts, flatty front struts and control arms, 8" non-SHP wheels all four corners, 12.75"x1.25" front rotors with 4 pot Wilwood calipers, manual brakes using dual master cylinders and balance bar, gutted (deleted) brake proportioning valve and modified steering pump speed sensitive valve.





#42 TsTKl

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Posted 01 September 2011 - 01:57 PM

I hear ya, and thats all and good, but I can just turn the knob on my bias bar for street driving :)
proof it did run at one point...
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#43 Maxzillian

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Posted 01 September 2011 - 05:59 PM

I like to set it and forget it. :)
What's the fun in making something simple?

'87 TSI - StarOrion braided brake lines, StarOrion radiator, StarOrion alternator, StarOrion 2.5" stainless exhaust w/Magnaflow muffler, 1G MAS, Competition Clutch 15 lb flywheel, Competition Clutch Stage 4 clutch, Mookeh polyurethane bushings, ABS elimination, 8:1 Wiseco Pistons, TD05 14G turbocharger, Axiss ceramic rear brake pages, Hawk HP+ front pads, heat wrapped and ported exhaust manifold/turbine housing, Accusump oil accumulator, remote oil filter, NJV head, EVO intercooler, remote battery, D2 coil over struts, flatty front struts and control arms, 8" non-SHP wheels all four corners, 12.75"x1.25" front rotors with 4 pot Wilwood calipers, manual brakes using dual master cylinders and balance bar, gutted (deleted) brake proportioning valve and modified steering pump speed sensitive valve.

#44 TsTKl

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Posted 01 September 2011 - 11:38 PM

I'm putting my adjustment knob where the controls for the rear windsheild whiper used to be. It will be so close to my right hand it will be hard not to toy with it while driving. Plus keeps idiot passengers from turning it to see what it does. In my dsm my innovate LC-1 wideband calibration switch was next to the shifter. You'd be surprised how many people want to press a red button just to see what it does....
proof it did run at one point...
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#45 Maxzillian

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Posted 03 September 2011 - 03:45 PM

Heh, I can't say I've had that problem! Aside from people dicking with the radio controls in the back of my Malibu, but that was intentional. :lol:

I've got a LC-1 on my car, but the calibration button is at the top forward portion of the ECU cover and pretty difficult to tag with a foot.
What's the fun in making something simple?

'87 TSI - StarOrion braided brake lines, StarOrion radiator, StarOrion alternator, StarOrion 2.5" stainless exhaust w/Magnaflow muffler, 1G MAS, Competition Clutch 15 lb flywheel, Competition Clutch Stage 4 clutch, Mookeh polyurethane bushings, ABS elimination, 8:1 Wiseco Pistons, TD05 14G turbocharger, Axiss ceramic rear brake pages, Hawk HP+ front pads, heat wrapped and ported exhaust manifold/turbine housing, Accusump oil accumulator, remote oil filter, NJV head, EVO intercooler, remote battery, D2 coil over struts, flatty front struts and control arms, 8" non-SHP wheels all four corners, 12.75"x1.25" front rotors with 4 pot Wilwood calipers, manual brakes using dual master cylinders and balance bar, gutted (deleted) brake proportioning valve and modified steering pump speed sensitive valve.

#46 ucw458

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Posted 05 September 2011 - 09:15 AM

View PostJamesR, on 27 August 2011 - 08:56 PM, said:


I bought Oscar's first original brake upgrade back in 2003 and had the same exact issue.  It also came with 1.75' bore wilwoods.  My fronts would sometimes lock up on the street and autocrossing was really bad.  I even had my adj. proportional valve set to mostly rear bias and still had issues.  After a few years (around 2006) of trying to find a master cylinder upgrade (me, Oscar, and Art tried for along time for a solution) I did the similar research and came up with the same solution and switched to a 1.38" bore caliper.  The guys at Precision Brakes which designed Oscar's kit said the 1.38" was too small and would not work and no one believed it would work.  BUT IT SOLVED MY BRAKE ISSUES!!!!!  And NO need for a bigger master cylinder.  My pedal feel is STIFFER THEN STOCK, but thats how it like it.  It's very similar to my RX-7 which is my normal autox car.  I haven't had an issue since.  Years ago when I last talked to Oscar, I believe he was switching to 1.65" bore which was a new size for wilwoods at the time.

Keep us updated on the 1.25" bore.


What size rotors are you using?  I have oscars kit with 1.75 calipers and 11 7/8" rotors.  Rotors are raybestos part # 96329.  Is yours the same?
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#47 JamesR

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Posted 07 September 2011 - 07:06 PM

View Postucw458, on 05 September 2011 - 09:15 AM, said:



What size rotors are you using?  I have oscars kit with 1.75 calipers and 11 7/8" rotors.  Rotors are raybestos part # 96329.  Is yours the same?

I bought oscars first group buy which came with 1.75" calipers.  I'm not sure what the rotor part number is, but they were for a BMW and where redrilled to the starquest bolt pattern.
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#48 ucw458

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Posted 07 September 2011 - 10:14 PM

View PostJamesR, on 07 September 2011 - 07:06 PM, said:


I bought oscars first group buy which came with 1.75" calipers.  I'm not sure what the rotor part number is, but they were for a BMW and where redrilled to the starquest bolt pattern.


Can you measure the diameter for me?  If they are 12" rotors then I may buy the smaller calipers and put my brake kit on.
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#49 Maxzillian

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Posted 24 March 2015 - 12:41 PM

A little late on this update, but ultimately I fixed the brake balance problem by doing to a dual master cylinder setup. By carefully selecting different bore sizes between the front and rear brakes as well as using a balance bar to fine tune it, I've managed to bring balance back to the brakes of the car. Typically I have them set to have as much rear bias as I can handle without the brakes throwing out the rear end on corners at autocrosses. On the street this balance seems to work well without problems. See the link below for details (last page for final photos).

http://www.starquest...howtopic=131151
What's the fun in making something simple?

'87 TSI - StarOrion braided brake lines, StarOrion radiator, StarOrion alternator, StarOrion 2.5" stainless exhaust w/Magnaflow muffler, 1G MAS, Competition Clutch 15 lb flywheel, Competition Clutch Stage 4 clutch, Mookeh polyurethane bushings, ABS elimination, 8:1 Wiseco Pistons, TD05 14G turbocharger, Axiss ceramic rear brake pages, Hawk HP+ front pads, heat wrapped and ported exhaust manifold/turbine housing, Accusump oil accumulator, remote oil filter, NJV head, EVO intercooler, remote battery, D2 coil over struts, flatty front struts and control arms, 8" non-SHP wheels all four corners, 12.75"x1.25" front rotors with 4 pot Wilwood calipers, manual brakes using dual master cylinders and balance bar, gutted (deleted) brake proportioning valve and modified steering pump speed sensitive valve.




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