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I did the 19 on a factory 89 with disk/drum, worked perfect. 22 might have been too much.
I have the 19 now in the same 3rd gen prop valve with an Astro master and Hydroboost, 4th gen front disks and big ford drums. Hitting the brakes is like slamming into a wall.
I did the 19 on a factory 89 with disk/drum, worked perfect. 22 might have been too much.
I have the 19 now in the same 3rd gen prop valve with an Astro master and Hydroboost, 4th gen front disks and big ford drums. Hitting the brakes is like slamming into a wall.
I've got an 82 rear drum proportioning valve and wanted to see if this mod would work not only on an 82 but also going from drum to disk. If so what spring should I use and where would it go on the 82 valve?
Anyone have a 1NCF2 19lb spring they want to sell? From what I've read on this thread I think that is what would be best to start with on my car. Its a 91 with disk/drum brakes and I want to install this spring when I convert to rear disk.
Anyone have a 1NCF2 19lb spring they want to sell? From what I've read on this thread I think that is what would be best to start with on my car. Its a 91 with disk/drum brakes and I want to install this spring when I convert to rear disk.
My 91 Camaro had disk/drum brakes from the factory. I installed a Strange 12 bolt rear with Wilwood disk brakes over the weekend. I change the proportioning valve spring to a 1NCR5 and the brakes work well. FYI for anyone doing a similar swap
I have (4) 1NCR5 springs left if anyone needs one. $5 shipped. PM your address.
To help contribute to the thread, and for those with a similar setup as mine, I have a 1991 Camaro RS. Came with Factory Disc front and Drum rear. I swapped out the rear end for a factory 3rd gen 10 bolt disc brake rear end. (Still had drum brake prop valve). The rear end was upgraded with Splicer axels, 3:72 gears, Auburn POSI, and cross drilled / slotted rotors. (I know only the rotors matter for this discussion, but...) I added the 1NCR5 to my prop valve and noticed a difference in braking power!
I also have a Wilwood Front brake kit on my car, so this was a pleasant surprise.
Remember... You MUST bleed the back brakes for sure, and its encouraged to do the front too... If you skip this, any gain you think you feel is in your head. They wont function to their potential without this being done.
I have (4) 1NCR5 springs left if anyone needs one. $5 shipped. PM your address.
To help contribute to the thread, and for those with a similar setup as mine, I have a 1991 Camaro RS. Came with Factory Disc front and Drum rear. I swapped out the rear end for a factory 3rd gen 10 bolt disc brake rear end. (Still had drum brake prop valve). The rear end was upgraded with Splicer axels, 3:72 gears, Auburn POSI, and cross drilled / slotted rotors. (I know only the rotors matter for this discussion, but...) I added the 1NCR5 to my prop valve and noticed a difference in braking power!
I also have a Wilwood Front brake kit on my car, so this was a pleasant surprise.
Remember... You MUST bleed the back brakes for sure, and its encouraged to do the front too... If you skip this, any gain you think you feel is in your head. They wont function to their potential without this being done.
Ok i have read the whole thread by now and have a question:
I have a 92 Firebird with factory Front Disc and Rear Drum brakes. And I don't wanna convert to rear discs since I have rebuilt all rear brake parts a few weeks ago.
Will the 1NCR5 spring improve my brake or will it not work with rear drums?
If it will work, is anyone here who can send this little spring to Germany in an envelope or small package? I can pay with PayPal.
I've never seen that yet, but id like to hear from someone that has. Concerned it might be just enough to lock the back brakes. I run a Upgraded spring (I believe I have the 22#) and it works great.
Originally Posted by RaceFace
Anybody tried this instead of spring inside of prop valve?
the 1ncr5 (19 lb) spring didn't do much for me. would not stop wheels when lifted off ground. bled the brakes multiple times. no improvements. put in an 1ncf2 (22 lb) spring today, didn't want to fit to well on the internal parts of prop valve. very hard to screw cap on. I can now stop the rear wheels without shifting into neutral. I haven't bled the brakes yet either and I can still tell a noticeable difference just in the driveway on gravel. I don't think you have to bleed the brakes after the spring swap as long as the prop valve is left on the car. fluid leaks out very slowly not letting air in. didn't lose much fluid removing the spring either. I'm not much of a mechanic, but the experts would still say bleed the brakes. so far I'm happy with the results.
the 1ncr5 (19 lb) spring didn't do much for me. would not stop wheels when lifted off ground. bled the brakes multiple times. no improvements. put in an 1ncf2 (22 lb) spring today, didn't want to fit to well on the internal parts of prop valve. very hard to screw cap on. I can now stop the rear wheels without shifting into neutral. I haven't bled the brakes yet either and I can still tell a noticeable difference just in the driveway on gravel. I don't think you have to bleed the brakes after the spring swap as long as the prop valve is left on the car. fluid leaks out very slowly not letting air in. didn't lose much fluid removing the spring either. I'm not much of a mechanic, but the experts would still say bleed the brakes. so far I'm happy with the results.
foxxtrot82 what kind of system do you have? LS1 fronts? PBR rears? rear drums?
I just ordered some 1NCR5's from Grainger they have a warehouse about 5 minutes from my work. I'll be putting in the LS1 fronts this summer and I have already converted to disk in the rear. I'm hoping this spring will keep me from sourcing an 1LE prop valve. If the 1NCR5 doesn't work i'll try the 1NCR2.
foxxtrot82 what kind of system do you have? LS1 fronts? PBR rears? rear drums?
I just ordered some 1NCR5's from Grainger they have a warehouse about 5 minutes from my work. I'll be putting in the LS1 fronts this summer and I have already converted to disk in the rear. I'm hoping this spring will keep me from sourcing an 1LE prop valve. If the 1NCR5 doesn't work i'll try the 1NCR2.
my setup is stock, rear disc, 91 z28 350.
Last edited by foxxtrot82; Apr 7, 2016 at 10:22 PM.
Reason: comma marks needed to be added for simplicity
OK, I gotta try this. I have a 1987 Trans Am with stock fronts and with what started out as drums in the back. I tossed on an axled that had disc. Not sure of year.
Any have a spring for sale? Not sure what Lbs. I'd need. Please advise as I'm close to having my LS Swap done and having extra braking force sounds kinda good.
OK, I gotta try this. I have a 1987 Trans Am with stock fronts and with what started out as drums in the back. I tossed on an axled that had disc. Not sure of year.
Any have a spring for sale? Not sure what Lbs. I'd need. Please advise as I'm close to having my LS Swap done and having extra braking force sounds kinda good.
Looking to do this upgrade. I assume this works with 4wheel disc breaks on 87 iroc. I was looking at the spring from McMaster-Carr part num. 9435k123. Any info/ help is greatly appreciated! Thanks!
I went with that 32.15 lbs. spring, and it locked up my rears in the wet last night when I barely had my foot on the brake pedal. The rear end coming around when one is trying to stop in certain conditions is not a good thing. I think I will drop it down to somewhere in the lower- to mid- 20 lbs. range.
Just got a notification about someone slipping in the wet trying this mod out. I tried this out a few years ago. My car ended up in a dirt field after an unintentional 360 degree spin. Luckily, my car and I were OK. After that, I gave up on this mod and bought an adjustable proportioning valve. No problems since then.
For the sake of safety, your lives, and cars, I recommend an adjustable proportioning valve.
Just got a notification about someone slipping in the wet trying this mod out. I tried this out a few years ago. My car ended up in a dirt field after an unintentional 360 degree spin. Luckily, my car and I were OK. After that, I gave up on this mod and bought an adjustable proportioning valve. No problems since then.
For the sake of safety, your lives, and cars, I recommend an adjustable proportioning valve.
There are many factor that come into play here regarding performance results from this mod.
I see a lot of guys doing the drum/disc swap but not bothering with the front brakes at all. Front brake hoses may be old and swelling. Pads may be those cheap Autozone "high performance ceramic" kind which dont work at all unless they are hot. All this things contribute to subpar front braking performance. Now, add in some 11"5" rear rotors, new rear pads, new rear hoses and you now have better brakes in the rear than the front. Add a few less than perfect road conditions and human error and the result can be loosing control of the car.
A LOT of people here have posted great results with this spring mod. I myself plan on doing this very mod in the next couple weeks. There is a spring that is a little less aggressive than the first one posted too.
The spring allows more fluid to the rear wheels before cutting it off. I have to push my pedal hard for the rear wheels to stop. I believe most of us are referring to the rear disc brakes not applying much force. Cleaning the sliding pins seamed to help, considering it was dry on the inside. My rears only slid a little on dry pavement when purposely dry to lock them down multiple times. The fronts got a little spongy when hot, so that allowed the rears more responsibility to slow the car down. Havent tried on wet pavement. Buy the 1ncr5 and 1ncf2 from grainger. Theyre not that expensive. Its a heck of a lot cheaper than trying a new set of rear calipers. Prices are a little steap compared to the fronts. If you don't like it, you can always put factory back in. Experience can go a long way. I'm still glad I'm not the only one out there who has had this problem. Brake safely!
I have an 87 Camaro that had drum rear brakes from the factory and I'm swapping in a disk brake rear with the aluminum calipers. Just to clarify I can swap the stock spring in the original proportioning valve with the 1ncr5 or 1ncf2 and it will work fine with the new rear disk brake setup? Picture is of the prop valve that's on my car now.
I have an 87 Camaro that had drum rear brakes from the factory and I'm swapping in a disk brake rear with the aluminum calipers. Just to clarify I can swap the stock spring in the original proportioning valve with the 1ncr5 or 1ncf2 and it will work fine with the new rear disk brake setup? Picture is of the prop valve that's on my car now.
Yes you are correct. Just to give you a idea of how it works I have LS1 brakes on all 4 corners and with the 1ncf2 spring
and the car is almost perfectly balanced on the track. have had only 1 turn in 8 track days over the last 2 years and 2 sets of pads and rotors that the rear wanted to lock up 1st. Using the brakemotive slotted and drilled rotors and pads I could out brake anyone short of anyone with the carbon rotors. I did however have 1 out of 4 front rotors develop a crack from the drilled holes to the OD of the rotor...
The brakemotive stuff is so cheap I just replace the rotors and pads every year.
Also I do have 3 of the springs left if you want to PM me $5 shipped to anywhere in the lower 48...
Looking for opinions here. I just did a drum to disc swap and used PBR calipers with stock Delco pads. I also used 13" Baer Eradispeed rotors. I have 3 options here for the proportioning valve.
1. swap in the 19lb spring (1ncr5) which I already have
or
2. swap in a complete valve from a disc/disc car of the same year as mine.
or
3. pull the spring and plunger out of the disc/disc valve and put it in my drum valve.
my original plan was to just do the srping mod but I found a disc/disc proportioning valve for under $50
just what I needed to hear 
