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who is running 4wheel manual disc brakes #2986370
11/18/21 11:54 AM
11/18/21 11:54 AM
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wine country
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8urvette Offline OP
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8urvette  Offline OP
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wine country
Like the title asks,

ON your race car, who has 4 wheel manual disc brakes.

How well do they work and what are the parts, or kit you used?

my A body disc brakes (73 dart front), inline tube dana 60 rear disc conversion DR.diff master cylinder around 1" bore, and wilwood proporting valve. My brakes are flat out bad. They do work, but not well, I could never lock of the tires. NO MATTER HOW HARD I PRESS!

They bleed fine, both front and back, but when bleeding the back the brake pedal will not drop all the way to floor, like when bleeding the fronts.

Not sure what my problem is, I am not bove just replacing parts till it works.

Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986377
11/18/21 12:14 PM
11/18/21 12:14 PM
Joined: Aug 2003
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On the parachute mount
N
n20mstr Offline
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On the parachute mount

On my sons duster, we have stock 73 up discs. THe rear had an 8.8 rear with factory disc brakes. We used a 15/16 alum master, stock distribution block. car stops great , Maybe something that helped, we ran all steel braid instead of factory rubber lines. If you are using the factory rubber hose up front, that may be a problem....


....BAD A$$ STREET CAR.....
Re: who is running 4wheel manual disc brakes [Re: n20mstr] #2986381
11/18/21 12:24 PM
11/18/21 12:24 PM
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wine country
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8urvette Offline OP
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Thanks, but I have steel braded at all 4 corners as well.

Im thinking it may be in my proportioning valve. I have a generic GM 4 wheel disc brake proportining valve I may install to see what happens.

Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986387
11/18/21 12:31 PM
11/18/21 12:31 PM
Joined: Jul 2004
Posts: 1,145
Arizona, USA
gsmopar Offline
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Wilwood front, SVO rear. Dr. Diff supplied the master cylinder and rear brakes. Proportioning valve to bias rear (pro street car). I used the 1st turn out at the track (10.15 @133). Stopped fine, but smoked the front pads. I'll call this one a driver error on a new set up that has a lot more MPH than the old set up. tsk Car will go 9's and I will be using the second turn out (parachute if/when I use the nitrous).

[Linked Image]P4020004 by Greg Ault, on Flickr

[Linked Image]IMG_2203 by Greg Ault, on Flickr

Re: who is running 4wheel manual disc brakes [Re: gsmopar] #2986409
11/18/21 01:06 PM
11/18/21 01:06 PM
Joined: Jan 2003
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A shed in England
Tig Offline
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Tig  Offline
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Willwoods on all 4 for me. Stops great now I have the correct master cylinder (7/8" Bore ?) 145+ @ 4000lb + best. If I really stood on them I reckon I could make the first turn.


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986422
11/18/21 01:39 PM
11/18/21 01:39 PM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline
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Taxes & Virus's R-US, NY
Throw the factory prop valve out.....If its a big tire car with 4-wheel disk, all is good with a 50/50 split. My cars stop awesome with Willwoods on all four.


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986440
11/18/21 02:20 PM
11/18/21 02:20 PM
Joined: Oct 2003
Posts: 11,678
W. Kentucky
justinp61 Offline
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W. Kentucky
My Dart is a street/strip deal that runs 10.0's. I started with 73 disk on the front and Wilwoods on the rear, factory non power 7/8" (I think) mc through a 73 proportioning valve. The car stopped great, it was like the car sat down when the brakes were applied. Hemi Fred made me a good deal on a set of Strange fronts so I added them, the mc was leaking so I bought a 1 1/16" aluminum mc to replace it. The car would hardly stop and the pedal was hard as a rock. I installed an adjustable proportioning valve, had it in the front and rear, no help. I them bought a 15/16" mc from Dr Diff. Better but still not what I wanted, in the end I gutted the factory proportioning valve and just running the rear brakes through it. The fronts are on a T with the line directly from the mc.

The car stops fine, just not as good as the original set up. If I ever need to replace the mc I will use a 7/8" bore.

Last edited by justinp61; 11/18/21 02:22 PM.
Re: who is running 4wheel manual disc brakes [Re: justinp61] #2986456
11/18/21 03:22 PM
11/18/21 03:22 PM
Joined: Oct 2005
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Ringtown, Pa.
Dartsport540 Offline
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I have Wilwood 4 wheel discs on mine, with an adjustable proportioning valve. . Stops great. I also have a used front Wilwood brake setup for sale, hubs, rotors, calipers, caliper mounting bracket, Needs 1 hub, hub is cracked. . But it is for a Mustang II/Pinto spindle setup.

tn_IMG_0844.JPGtn_IMG_0838.JPGtn_IMG_0840.JPG
Last edited by Dartsport540; 11/18/21 03:27 PM.

548 cu. in., Bill Mitchell Aluminum Block, CRT 727 auto trans, Alston Chassis. 8.981et at 149.46 mph. 1.204et - 60 foot, So Far....
Re: who is running 4wheel manual disc brakes [Re: justinp61] #2986468
11/18/21 03:50 PM
11/18/21 03:50 PM
Joined: Jan 2003
Posts: 8,005
Tulsa OK
Bad340fish Offline
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my 68 Barracuda weighs 3550 with me in and runs 10.40s. I have Willwood disc brakes all around with a dr diff master and no prop valve. The car stops great, I occasionally race on a track with a very short shutdown and I don't sweat it one bit. They work fine in the street as well, I have vented discs in front and drilled non vented in the rear.


68 Barracuda Formula S 340
87 "Chrysler" Conquest
Re: who is running 4wheel manual disc brakes [Re: Dartsport540] #2986469
11/18/21 03:50 PM
11/18/21 03:50 PM
Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
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'72CudaRacer Offline
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Mooresburg, Tn
I have Strange 4 piston calipers, front & rear, with Strange alum hubs on front. Stock spindles, Dana 60 out back. 1-1/32" bore (I think) master cylinder (cast iron Wagner from a pick up), adjustable proportioning valve, braided steel line at the corners. Car is 3250 lbs w/driver. I run mostly 1/4 mile, 128 mph. The only problem I've had is a caliper bolt backed out. Safety wire took care of that. With big rear tires & narrow tires up front, 50/50 is very close to correct. Sorry, no pictures.

Brian

Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986471
11/18/21 03:57 PM
11/18/21 03:57 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
Try a smaller diameter master cylinder first to help it stop better, 7/8 or smaller scope twocents
My S/P car has dual Wilwood calipers on the rear with the same size single Wilwoods on the front, dual 7/8 Wilwood master cylinders with a balance bar, stops fine at 150+ MPH weighing 2850 Lb. with me in it, stops fine on a short 1/8 mile track at 125.+ MPH.
I took the parachute off do to it not running above 150.+ MPH in the 1/4 mile so it would fit in my enclosed 24 Ft .race trailer better with more room in front of the car up
Keep the hoses as short as possible also twocents

Last edited by Cab_Burge; 11/18/21 03:58 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: who is running 4wheel manual disc brakes [Re: Cab_Burge] #2986486
11/18/21 05:07 PM
11/18/21 05:07 PM
Joined: Mar 2009
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Sydney,Australia
tex013 Offline
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go from rear caliper towards mcyl . with someone holding a little pressure on brake pedal. crack /then shut, bleeder and each line fitting one after the other till pedal goes to floor . that will show where potential restriction/blockage is .
i have SSBC front brakes , metric rear GM calipers and a 1 1/32(?) master , works fine street and strip .

Tex


New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive
Re: who is running 4wheel manual disc brakes [Re: 8urvette] #2986504
11/18/21 06:28 PM
11/18/21 06:28 PM
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Bend,OR USA
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[quote=8urvette]Like the title asks,



They bleed fine, both front and back, but when bleeding the back the brake pedal will not drop all the way to floor, like when bleeding the fronts. /quote]
That tells me that the back brakes are working good, their stopping the pedal like they should when they doing all the stopping work scope twocents
I've had the back part on a dual master cylinder go bad due to heat from the Hooker fenderwell headers getting to it after years of use. It ended up having a soft pedal on the rear part for the stock A body front brakes, it didn't stop worth a hoot either above 30 MPH using the stock A body rear drum brakes whineyshock
I replaced it as I couldn't find a rebuild kit for it in SO CA based off of the Mopar casting number on it confused shruggy

Last edited by Cab_Burge; 11/18/21 06:28 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: who is running 4wheel manual disc brakes [Re: Cab_Burge] #2986569
11/18/21 08:23 PM
11/18/21 08:23 PM
Joined: Mar 2006
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MI, usa
dvw Offline
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64 Belvedere 3335lb using 4 wheel Will Woods. Runs 145-150. Stops great. Sons 62 Savoy has FMJ factory style front disc , Ford Explorer rear disc. 3750 stops from 135-140 very nice.
Doug

Re: who is running 4wheel manual disc brakes [Re: dvw] #2986581
11/18/21 08:42 PM
11/18/21 08:42 PM
Joined: Mar 2005
Posts: 1,402
Chesterfield Twp. Mi.
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John Burdine Offline
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Chesterfield Twp. Mi.
Wilwood front/rear no prop valve @ 3400. Great on the street as well as 148 mph at the track.

Re: who is running 4wheel manual disc brakes [Re: Tig] #2986603
11/18/21 10:01 PM
11/18/21 10:01 PM
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Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
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Originally Posted by Tig
Willwoods on all 4 for me. Stops great now I have the correct master cylinder (7/8" Bore ?) 145+ @ 4000lb + best. If I really stood on them I reckon I could make the first turn.

Same Wildwood on all four. 7-8 bore mc. The only thing I need is a proportioning valve to add brake force to the rear. Locks up the front too easy. 3015 lbs, 154 mph no problem.

Last edited by gregsdart; 11/18/21 10:04 PM.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: who is running 4wheel manual disc brakes [Re: gregsdart] #2986605
11/18/21 10:04 PM
11/18/21 10:04 PM
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Oregon
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AndyF Offline
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Oregon
Originally Posted by gregsdart
Originally Posted by Tig
Willwoods on all 4 for me. Stops great now I have the correct master cylinder (7/8" Bore ?) 145+ @ 4000lb + best. If I really stood on them I reckon I could make the first turn.

Same Wildwood on all four. 7-8 bore mc. The only thing I need is a proportioning valve to add brake force to the rear. Locks up the front too easy.


A prop valve reduces the force to the rears so that won't work for you. You could put a prop valve on the front to kill some of the front pressure but that typically isn't a good idea. Increasing the rear brake force might be a better bet. Use a bigger caliper piston on the rear or a bigger rotor in the rear or maybe even both.

Re: who is running 4wheel manual disc brakes [Re: AndyF] #2986628
11/18/21 11:08 PM
11/18/21 11:08 PM
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Posts: 5,762
Hot Rod Ridge
FastmOp Offline
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Hot Rod Ridge
Ka-Blue-E has 4 wheel wilwoods, strange mc, 2 residential valves and a wilwood adjustable proportion valve. Stops great from 160 mph .

Re: who is running 4wheel manual disc brakes [Re: FastmOp] #2986672
11/19/21 08:13 AM
11/19/21 08:13 AM
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Wichita Kansas
B Dartman Offline
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When I went 4 wheel Wilwood manual disks on 71 Dart Swinger, I installed the Wilwood proportioning valve. May be wrong, but was of the impression what some are referring to as the stock "proportioning valve" is actually a "distribution block" - equal fluid in all directions. shruggy

[Linked Image]

Last edited by B Dartman; 11/19/21 08:15 AM.

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B Dartman's 71 Dart Swinger in Dodge Garage (Sold Dec 2021): https://www.dodgegarage.com/news/article/showcase/2019/04/destiny-determination.html
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