Has anyone replaced the master cylinder and booster with only a master cylinder unit with any sucess?? On my FP 85 Civic, in order to make extra clearance for dual sidedraft carbs, I tried a Wilwood unit (5/8 and 3/8 bores). The units bolted directly to the firewall mount and came with resevoir. I only had to do a line adaptor.
Sounds ideal but, but braking felt like I was standing on a brick!! I even tried removing the stock prop valve and running a singel rear line through an adjustable proportioning valve. Still standing on brick (no lock up though)
Before I spend more time/money I was hoping someone else may have found an answer.
Thanks
0
Brake Booster Elimination
Started by racers10, Nov 02 2004 10:11 AM
11 replies to this topic
#1
Posted 02 November 2004 - 10:11 AM
#2
Posted 02 November 2004 - 10:31 AM
Mine work the same as well everyone else' that I know that run them this way. Hi pedal effort with little braking effect. You'll need two things here:
1) bigger leg muscles
2) better brake pads
1) bigger leg muscles
2) better brake pads
Outside of a dog, a book is man's best friend. Inside of a dog it's too
dark to read. -Groucho Marx
dark to read. -Groucho Marx
#3
Posted 02 November 2004 - 10:45 AM
You can also use that 3/8 bore and try to find some larger calipers. The increase in ratio will allow more clamping force. You'll have to find a way to reposition the brake pedal to compensate for the increased travel...or cut a hole in the firewall.
#4
Posted 02 November 2004 - 11:21 AM
my CSP cars have no boosters. Takes a little getting used to but pad combo has a lot to do with how it works.
Victor
86 K24 Powered CRX SI (HPDE-4 NASA & TA-AB Time Attack)
85 CRX DX totally original
07 Harley FXST Softail
2021 Tacoma Tow/Daily
#5
Posted 02 November 2004 - 11:47 AM
Why not convert it to dual Master Cylinders and use short Tilton Master Cylinders? I converted my stock pedal assembly to use the Tilton Bias Bar and made an adapter plate that holds the Master Cylinders.
kirk
kirk
#6
Posted 02 November 2004 - 12:38 PM
There is a math formula used to determine proper master cyl size. You need to know the diameter and number of pistons in each caliper. From that you can get to the 1st guess on master cly size.
It is pretty darn close doing it this way. The best method is to use the mentioned Tilton pedal assembly. Hope this helps.
Bob
It is pretty darn close doing it this way. The best method is to use the mentioned Tilton pedal assembly. Hope this helps.
Bob
#7
Posted 02 November 2004 - 03:23 PM
I like Kirks dual Tilton setup also but to date I've been able to get my stock M/C to work quite well.
I have had my booster gutted for a few years now and I really haven't noticed a big difference in pedal effort on the track wittout it. I tried a larger M/C, from a Prelude I think, last year and did have a hard pedal but like you mention it took a huge pedal effort. Took it out after one session.
I just this summer finally got around to removing the booster and mounting the stock M/C to the firewall. I also mounted a Tilton bias adjuster inline to the rear brakes.
The front output of the master cylinder was routed to the front brakes and the rear one to the rear brakes. I dissasembled the stock prop. valve and gutted it. Then I made sure all the inputs and outputs (3 each) had the same orifice size. In other words, I drilled some of them. Then I plugged the bottom of it with a pipe plug and used them to split the master cylinder output lines to each front wheel and each rear wheel.
It worked great. I have better pedal feel than I had before and I can adjust the pressure to the rear brakes whenever I want.
Jay
I have had my booster gutted for a few years now and I really haven't noticed a big difference in pedal effort on the track wittout it. I tried a larger M/C, from a Prelude I think, last year and did have a hard pedal but like you mention it took a huge pedal effort. Took it out after one session.
I just this summer finally got around to removing the booster and mounting the stock M/C to the firewall. I also mounted a Tilton bias adjuster inline to the rear brakes.
The front output of the master cylinder was routed to the front brakes and the rear one to the rear brakes. I dissasembled the stock prop. valve and gutted it. Then I made sure all the inputs and outputs (3 each) had the same orifice size. In other words, I drilled some of them. Then I plugged the bottom of it with a pipe plug and used them to split the master cylinder output lines to each front wheel and each rear wheel.
It worked great. I have better pedal feel than I had before and I can adjust the pressure to the rear brakes whenever I want.
Jay
If you love the Elise, drive a Se7en - Caterham or whatever...
It has even less content than the Elise, is less graceful looking
...and changes direction like a ping pong ball whacked by Thor.
#8
Posted 03 November 2004 - 01:30 AM
#9
Posted 03 November 2004 - 02:14 AM
#10
Posted 03 November 2004 - 09:17 AM
Thanks!!!! I had a feeling that I was overcomplicating the problem.
Not a new concept for racers. I will have to try running just the master, as I already have the adjustable rear bias conrol plumbed in.
Not a new concept for racers. I will have to try running just the master, as I already have the adjustable rear bias conrol plumbed in.
#11
Posted 04 November 2004 - 08:26 AM
I have not tried it, but "I have heard" that if the pedal takes too much effort, get a smaller MC. It makes sense to me, considering things I've done and heard about the different stock vs. teg vs. prelude brake parts used on CRXs...
"If Honda does not race there is no Honda." -Soichiro Honda
#12
Posted 04 November 2004 - 12:05 PM
i like the tilton pedalbox setup.. with the dual masterbrake cylinders inside the car.. and the clutch adjuster inside the car etc.. thats one of the first things im going to buy next year.. when the new motor and turbo drops in.
Greetz Erwin.
Greetz Erwin.
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive