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Topic: 8.8 Swap proportioning valve? (Read 3369 times) previous topic - next topic

8.8 Swap proportioning valve?

I have the Coolcats walkthrough on the whole thing, but I'm running into a problem with the proportioning valve. I forgot to grab it when I bought the rearend from the guy I got it from out of his turbocoupe, and finding one of these things is impossible. I see one on Ebay for an SVO Mustang @ $150 for a used component, but that's pretty expensive and I still have a bunch of stuff I need to pay for (brake lines and such) to get everything ready to go. Might be my only way out, though.

Any ideas? The guys I'm working on this thing with won't even consider going with one of the adjustable valves because they all say they are too inconsistant. Considering I've never done a rearend swap, I'm at their preference and I need something that will be easy to work with (as far as "easy" gets, anyways).
88 Camaro RS - 355/TH350
87 Thunderbird Sport - 302 (351 going in)/AOD

8.8 Swap proportioning valve?

Reply #1
I see adjustable valves a lot cheaper.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

8.8 Swap proportioning valve?

Reply #2
Quote from: vinnietbird;362372
I see adjustable valves a lot cheaper.

I do also, but like I mentioned - this is my first time around, and they (the person helping me) did NOT like that idea.. and considering this is happening in his garage, I'm unfortunately going to need to do it his way unless I have positive evidence of that valve actually being effective. What did you do with your situation, and if you did use one of those - which one did you use? One from FMS?

Personally, I think he's just stuck in his ways as an oldtimer, or he bought a POS and didn't spend the money on a quality product. That's why I'm still all ears about this, I just need to be able to explain my reasoning for using one of these. I don't really see how you could screw things up outside of.. adjusting it too much in either which direction, in which case - understandably, the brakes will not work as intended because the amount of fluid needed is not what it should be. Am I right on this assumption?
88 Camaro RS - 355/TH350
87 Thunderbird Sport - 302 (351 going in)/AOD

8.8 Swap proportioning valve?

Reply #3
I'm still using the original valve and haven't had an issue although I don't really drive aggressively.
1986 Mercury Cougar - 2.3T/T5 swap, TC brakes and suspension and rearend, 3" exhaust, 255 lph fuel pump, Stinger BOV, Gillis MBC @ 18 psi
2003 Chevy Suburban Z71 - Daily driver
2015 Chevy Volt - Wife's daily driver

8.8 Swap proportioning valve?

Reply #4
I've also heard from people that the stock one works fine... others have problems.... it seemshiznit and miss for some reason.
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***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
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5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
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8.8 Swap proportioning valve?

Reply #5
That's really strange. You would think in something like this it would be a consistant is/is not basis, but I guess not.
88 Camaro RS - 355/TH350
87 Thunderbird Sport - 302 (351 going in)/AOD

8.8 Swap proportioning valve?

Reply #6
I think I have my TC proportioning valve left over from my SN95 vacuum booster swap.  If you want it.

8.8 Swap proportioning valve?

Reply #7
Plenty of racers out there with tons of experience running adj valves. Its not a 1.21 jiggawatt converter, Its a valve.

Me thinks said old timer doesnt understand how they work, and doesnt want to cut and flare the line.

That being said, I still have my original prop valve on my sn95 swap. Ive only driven it ten miles or so since. Ill put a plug in my original, and an adjustable valve one day down the road, but for now, its just not letting my rear discs do as much as they could. Thats low on the list for now.
87 Thunderbird LX
65mm tb, exploder intake, iron gt40 heads, 1.6 rr, a9l mass air swap, 9.5" Billet Dirty Dog TC, Built AOD, 4.10's, 31 spline TLoc, Superior Axles, full sn95 five lug swap.

8.8 Swap proportioning valve?

Reply #8
Ford even sold the Cobra brake conversion kit for the Fox Mustangs with an adjustable proportioning valve and instructions on how to modify the stock proportioning valve.  The guy doing your swap needs to open his eyes and ears to what hundreds if not thousands of guys have done on these cars.  I have the gutted stock proportioning valve/shuttle valve on both my cars with a Wilwood adjustable proportioning valve on the rear brakes and being able to dial in the rear bias to get the brakes to perform the way I like them is priceless.  I posted a diagram of the stock PV/SV assembly here (post #7):

http://www.foxtbirdcougarforums.com/showthread.php?31037-1987

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

8.8 Swap proportioning valve?

Reply #9
Just get an adjustable one.  The stock one is set to the stock balance of a stock 87-88TC, which you don't have.  Catch my drift? 

It takes a little bit to dial it in properly, but in the end, you have a brake bias that right for YOUR car.  There is nothing "inconsistent" about the adjustable ones.  You get it set, and you forget it.  If you change your engine, and change the balance of the car, you might have to readjust it, but it's not like they are always changing while they sit there.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

8.8 Swap proportioning valve?

Reply #10
I swapped in the TC brakes and rear into my Sport. I used the TC prop valve. But I have not been able to drive it yet since the swap. I am still waiting for my trans. I will let you know how it feels after I get my trans back and installed
1988 Thunderbird Sport. Work in Progress
5.8L swap w/fitech efi, 4R70W swap w/quick 4 controller, 2003 GT rear diff, 5 Lug swap

Bought this car back as an old project car.

:burnout:

 

8.8 Swap proportioning valve?

Reply #11
I always use an adjustable valve in every conversion i do. Weather its a 55 chevy or a 70 chivelle or a ford. They work excellent. I also use them to eliminate the RWA system from ford vans and pickups ETC
I spend money I don't have, To build  cars I don't need, To impress people I don't know

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