Bad brakes

The bore size of the master cylinder may be too small. Did you change that or is it stock?

No, it is the same size, they did work fine once. I have changed booster and seal but nothing effects the brake performance...

the power brake booster relies upon vacuum to operate. The bigger cam = less intake manifold vacuum.

If you haven't already done these things, optimizing ignition timing and replacing a single plane intake manifold with a dual plane intake manifold will restore a lot of the vacuum your motor has lost.

-G

Low engine vacuum? Now there's a thought. You need around 12 inches minimum at idle to have vacuum assist to the brakes.'

However, if you don't, don't panic. You can install a vacuum reservoir kit in the car. An electric vacuum pump is also an option.

Measure the engine idle vacuum and see what you have.

Wilwood calipers are available with different size pistons.
So it does depend on what you fitted.
If the combined area of the Wilwood caliper pistons are greater than the stock Pantera calipers you will have a pedal that is softer & has more travel.
With this setup you should have better braking, but its possible to run out of pedal travel before the brakes bite.
In this instance you need to go to a larger master cylinder.
Smaller caliper piston area than stock, the pedal will have less travel & be much harder to push.
And as others have stated, lack of vacuum could also be the issue.
I used a vacuum bottle on my car, it helped a bit, but not enough.
So now I'm installing a Hella brake vacuum pump, (you can get these from Summit racing).

regards,
Tony.

I installed a vacuum pump after I determined that I was getting only 3" of vacuum. It makes a big difference.

Mark

The system I have is sorted out by Pantera Performance Center. Intake is a efi weber style with a small vacum block for the ecu. Electric pump?! Could a hose with smaller diameter make a diference?

Ahhh, so your running a similar system to what I have.
Because your manifold is individual runners there needs to be a vacuum port tapped into more than one intake runner.
Have a look & see how many intake runners are feeding the vacuum hose that in turn supplies the brake booster.
I tried one on my setup, (has a moderate cam) & that was not enough vacuum.
Now I have the vacuum supplied from 4 intakes & it still really needs more.
Brakes are OK, but could be much better.
(Difficult & time consuming to tap into more intake runners with the intake installed on the engine).
Hence the need for the electric vacuum pump.

regards,
Tony.

quote:

Because your manifold is individual runners there needs to be a vacuum port tapped into more than one intake runner.

If a carb is on top, it usually has a large vacuum port, and then put a plug in the hole in the manifold?

quote:

Originally posted by No Quarter:

quote:

Because your manifold is individual runners there needs to be a vacuum port tapped into more than one intake runner.

If a carb is on top, it usually has a large vacuum port, and then put a plug in the hole in the manifold?

I think the point is that there is not one carb on top on this setup. There are individual runners with 8 stacks. (Edge's avatar)

Got it. Yeah, need to find some vacuum "in the middle" somehow.

There is no "middle" like on a carbie manifold.
The 8 throttle body setup has 8 individual runners.
regards,
Tony.

Got it (too high tech for me)

How is this sorted on all other cars out there with this set up, Panteras and all? They all need vacuum, right?

I was thinking maybe some tubing to each runner, looking like a Nitrous injection but being just vacuum, 8 lines into one tube 3/8". Could be made good looking.

I would think that most IR setups will use Hall Pantera Weber intake manifolds? They don't lend themselves well to plumbing vacuum or nitrous under the manifold.

The 48ida's don't have vacuum ports, TWM 48ida throttle bodies do. I don't know about others like Clasic, which may.

Actually there is no rule that says a Pantera has to have power assisted brakes. I doubt the race cars do.

Plumbing all runners together for vacuum or even nitrous is not an esthetic delite. There are not going to be a lot of possible variations.

You could use 48ida carb spacers and put the plumbing nipple in them. That would save butchering up the manifold itself.

If that is too high of an assembly, you could mill down the mounting flange for the carbs on the manifold.

The Hall manifold is very thick there. The DT manifold wasn't and had the tendency to warp as a result.

As far as what size tubing to use for the plumbing to work, I don't know that.

With the Webers if you go too large it will affect interaction of the carbs since at some point you start to create a single plenum manifold and depending on the overlap of the cam, you are presurizing the tubing.

The Webers actually make enough vacuum for the brakes to take vacuum off of one cylinder. That's the way Halls manifold was sold new originally, with a vacuum port off of #8.

quote:

Actually there is no rule that says a Pantera has to have power assisted brakes. I doubt the race cars do.

I am working on such a setup right now...

In this picture you can see I'm pulling vacuum from cylinders 1 & 4, as well as cylinders 5 & 8 on the left side, (not visable).
This only just supplies enough vacuum for the brakes, it's the absolute minimum.
I find it difficult to imagine Halls system supplies enough vacuum from just one cylinder.
I tried that & it was hardly noticable, no brakes at all.
Maybe Halls setup may work with a stock cam?

regards,
Tony.

quote:

Originally posted by Edge:
In this picture you can see I'm pulling vacuum from cylinders 1 & 4, as well as cylinders 5 & 8 on the left side, (not visable).
This only just supplies enough vacuum for the brakes, it's the absolute minimum.
I find it difficult to imagine Halls system supplies enough vacuum from just one cylinder.
I tried that & it was hardly noticable, no brakes at all.
Maybe Halls setup may work with a stock cam?

regards,
Tony.

It takes a -10 hose. I suppose it depends on how much vacuum assist you want? I don't see where 8 1/4" hoses will do it either? I think it is volume rather then pressure itself?

The brakes are on the firm side, yes. Not at all like you would get slamming on those marshmallows that they call breaks in a Lincoln. Ford does need to build cars for your great grandmother and worse?

The Pantera was a "Luxury GT" sold at Lincol-Mercury dealers. I'm surprised that it was only built as a manual transmission and not an automatic as it is?

It isn't a perfect world that we live in now is it?

Seems like this thread wandered off track a little. . . .

My Hotrod truck:
wilwood fronts (came with a front suspension kit) and it would only lock the rears in the gravel.
added wilwood rear discs: it would only lock the rears in the gravel.
New master cyls: it would only lock the rears no matter how hard I pushed on the pedal.

At this point I was out of ideas - and mentioned to my fab man that it needed vacuum boost. Fab man says no.

(here is your possible answer)
So: I went and re-measured everything and did the math. (this is where you should find YOUR answer - doing the math on what you actually have)

Turns out the original front calipers were REAR calipers and the problems were all fixed by installing the correct FRONT calipers on the FRONT.

Sorry I don't have pictures of a wonderful carb setup or half nekkid girl to illustrate. - - - - make sure you have the appropriate sized calipers everywhere.

Done the math yet? Know exactly what you have? I didn't and spend a lot of $$$ until I did.

all the best,

quote:

Originally posted by SF:
Wilwood superlite brakes with balance bar brake effect is weak.
First installed they was great, 280 cam, then a turbocamshaft and now a Crower 292 cam. I have to push harder then hard to stop the car. No air in system soft brake pads.
Any thoughts?
Anders

Has not wandered off topic at all.
Anders has poor brakes, looks to be vacuum related & he is running an IR injection setup.

Looks like he had good braking, then changed the cam & now has poor braking, so more vacuum supply would be the obvious route to go down.

Yes alot has to do with caliper/master cylinder matching which was what I originally posted on this thread.
That all needs to be correct before you start chasing more vacuum.

PanteraDoug.
The 4 x manifold hoses I'm running are -8 which then feed into the original vacuum pipe to the front.

regards,
Tony