Vacuum brakes and Launching

[87we410877]

If i convert to vacuum brakes which i very well may, will they still work at the line when im trying to build 10 lbs of boost? My powermaster is shot and wouldnt hold the car at 0 lbs.

 

[mikestertwo]

You should have no problems. I have a 1984 Hurst Olds with an 87' turbo motor and vacuum brakes and I launch at 13 psi boost with no problems.

 

[QUIP'6']

If i convert to vacuum brakes which i very well may, will they still work at the line when im trying to build 10 lbs of boost? My powermaster is shot and wouldnt hold the car at 0 lbs.

i could hold 17 psi off the foot break and the car wont even try to creep forward

 

[87we410877]

How about my cam? Will it make eneough vacuum?

 

[QUIP'6']

How about my cam? Will it make eneough vacuum?

dont know but not likely throw a vacuum gauge on it and report back park and in gear

 

[BadAssGN]

Wait one second....


17lbs of boost on a stocker is quite a bit different then your build.

I doubt you will even see 5 lbs with your setup.
I know with a low 11 second car it's very hard to hold that much HP on the line.

a transbrake may be the way to go. are you looking to run 10?

p.s. if intrerested I have a complete Vaccum brake set up complete with a vaccum block that goes on the throttle body.
it's real nice I painted it for my own car but I don't need it.

PM if interested.

 

[Dreamcar86]

If i convert to vacuum brakes which i very well may, will they still work at the line when im trying to build 10 lbs of boost? My powermaster is shot and wouldnt hold the car at 0 lbs.

Assuming you install it correctly LOL. When I purchased my GN it came with vacuum brakes and they were not installed correctly. After speaking with members who knew what they were doing it is perfect now. I might add that I installed S10 rear cylinders and upgraded to a brass combination valve vs. the stock cast one. Now back to the answer to your question........YES.

 

[87we410877]

Assuming you install it correctly LOL. When I purchased my GN it came with vacuum brakes and they were not installed correctly. After speaking with members who knew what they were doing it is perfect now. I might add that I installed S10 rear cylinders and upgraded to a brass combination valve vs. the stock cast one. Now back to the answer to your question........YES.

I have s-10 drums as well in the rear. Not sure about the combination valve though. I am going to look at a unit today that a guy localy has and he used to hold his car which was a 9.70 stage car.

 

[TurboDave]

Wait a minute, you know someone that runs 9.70's on a foot brake??? Are you sure he wasn't leaving off a trans brake.

 

[87we410877]

Wait a minute, you know someone that runs 9.70's on a foot brake??? Are you sure he wasn't leaving off a trans brake.

Yea he had a trans brake in the car as well. This is exactly what he said to me. " I had to change my PM out to vacuum also because they wouldnt hold the car ". " I still have the system if you want it". Im not going to be at the track every weekend so a tranny brake is out of the question especially on a 200R4. Im thinking some kind of check valve for the vacuum line.

 

[87we410877]

turns out he didt have them. Must have gotten rid of it already.

 

[STG2LTD]

Go for it !

I just installed a vacuum kit that I purchased thru Red Regal T. My main concern of ditching the PM was that I wouldn't be able to hold boost at the line. I finished the install on Saturday and pulled the car out in front of my house. I brought the boost up and it started to creep at about 3-5 psi on my bald street tires.

I did a little research and saw a reply to a post about this from Bill Anderson. He suggested dropping the car into neutral and rev it a few times. Well I tried this today and sure enuff I was able to hold 10psi fairly easy....more than enuff for what I do. I'm sure it will hold more with some sticky slicks.

I'm real happy with the change over, great feeling breaks. I've had 2 PM fail on me in the past 6 months, both times exiting my garage...lucky me.

The only thing I had to relocate was the black ground wire that goes to the center of the firewall. I just moved it over to the drivers side fenderwell.

 

[87we410877]

I just installed a vacuum kit that I purchased thru Red Regal T. My main concern of ditching the PM was that I wouldn't be able to hold boost at the line. I finished the install on Saturday and pulled the car out in front of my house. I brought the boost up and it started to creep at about 3-5 psi on my bald street tires.

I did a little research and saw a reply to a post about this from Bill Anderson. He suggested dropping the car into neutral and rev it a few times. Well I tried this today and sure enuff I was able to hold 10psi fairly easy....more than enuff for what I do. I'm sure it will hold more with some sticky slicks.

I'm real happy with the change over, great feeling breaks. I've had 2 PM fail on me in the past 6 months, both times exiting my garage...lucky me.

The only thing I had to relocate was the black ground wire that goes to the center of the firewall. I just moved it over to the drivers side fenderwell.

I think im gonna go for it.

 

[six is enough]

You should go for it. The vacuum brakes work well. I have had a best sixty foot of 1.34 off of the foot brake with my car. This run was 9.33 at 146.60. If you have a line lock on the car you can hold the button and pump the brakes and this helps to put more pressure on the brakes. I also put a canister on the car for a little more vacuum reserve.

 

[GNVYUS 1]

The neutral blip works wonders on my Talon, 13" in gear, 24" when you blip it in neutral and slam the brake.

I am not sure why more vacuum guys kill the claim that, "vacuum brakes suck at holding boost" myth to shreds with that technique, it really works.

 

[Dreamcar86]

I just installed a vacuum kit that I purchased thru Red Regal T. My main concern of ditching the PM was that I wouldn't be able to hold boost at the line. I finished the install on Saturday and pulled the car out in front of my house. I brought the boost up and it started to creep at about 3-5 psi on my bald street tires.

I did a little research and saw a reply to a post about this from Bill Anderson. He suggested dropping the car into neutral and rev it a few times. Well I tried this today and sure enuff I was able to hold 10psi fairly easy....more than enuff for what I do. I'm sure it will hold more with some sticky slicks.

I'm real happy with the change over, great feeling breaks. I've had 2 PM fail on me in the past 6 months, both times exiting my garage...lucky me.

The only thing I had to relocate was the black ground wire that goes to the center of the firewall. I just moved it over to the drivers side fenderwell.

Do you have a line lock? If so, engage the line lock let off the pedal and then step on the pedal again and see if you can hold boost. Works for me.

 

[turbofish38]

Its all in the technique. BTW its the brakes and not the tires that determine how much you can hold on the line. Get your drums sorted out and 10 pounds should be easy.

 

[Dreamcar86]

Its all in the technique. BTW its the brakes and not the tires that determine how much you can hold on the line. Get your drums sorted out and 10 pounds should be easy.

This is correct, I should have mentioned that I have S10 rear wheel cylinders.

 

[8AV8]

You should go for it. The vacuum brakes work well. I have had a best sixty foot of 1.34 off of the foot brake with my car. This run was 9.33 at 146.60. If you have a line lock on the car you can hold the button and pump the brakes and this helps to put more pressure on the brakes. I also put a canister on the car for a little more vacuum reserve.

How did you plumb the cannister in and where did you mount it? Pics?

thanks,chris

 

[Dreamcar86]

How did you plumb the cannister in and where did you mount it? Pics?

thanks,chris

Pics, pics, we need pics! I'm liking the sounds of this. Can you give us the full scoop on this setup?