What if....

[mrvette]

What I was trying to do with this thread is to show that non assisted brakes using new material like Willwood brakes and master would be a great option for our cars...
I know the original system of the car could be good enough for street use and is used by a lot.

I am certainly considering it.

But I want to upgrade it and make it safer too at the same time,

While I'm at it...

The calipers perform the same, no matter how you assist them, hydraulic, pneumatic, nothing, a flux capacitor..... it is simply pressure inside the caliper times piston area..... simple physics....

non assisted brakes work just as good as anything, you just have to push the pedal harder.....

What everyone conveniently ignores is the fact that our stock sucky boosters have a spring between the input shaft to the pedal, and the output shaft to the m/cyl.....that spring is a problem child that allows way over excessive pedal travel, and it's worse on our cars with that early 4 wheel disc design from what? '65 was first year, and so you all ragging on me for making a simple improvement to the system without spending a grand on some aftermarket crap you can't tell in performance unless you racing....

:banghead::gurney:

 

[JPhil]

A big reason for cars switching from mechanicals to hydraulics was to keep the brakes balanced so there would be equal pressure on all wheels, almost impossible to maintain with mechanicals.

Would you mind explaining that, naively I don't see how boosting the brakeand would make the the pressure balancing better.

It's not the assist, it's the hydraulic fluid system which is self balancing & adjusting as opposed to mechanical levers & rods which wear causing uneven braking on the different wheels.

 

[68L71]

A big reason for cars switching from mechanicals to hydraulics was to keep the brakes balanced so there would be equal pressure on all wheels, almost impossible to maintain with mechanicals.

Would you mind explaining that, naively I don't see how boosting the brakeand would make the the pressure balancing better.

It's not the assist, it's the hydraulic fluid system which is self balancing & adjusting as opposed to mechanical levers & rods which wear causing uneven braking on the different wheels.

As in pre-1940

 

[BBShark]

What everyone conveniently ignores is the fact that our stock sucky boosters have a spring between the input shaft to the pedal, and the output shaft to the m/cyl.....that spring is a problem child that allows way over excessive pedal travel, ...................

:banghead::gurney:

Here is a Corvette booster. I can't find the spring that would cause lost motion. Maybe the valve return spring? I can't see that causing more than 1/8

 

[mrvette]

A big reason for cars switching from mechanicals to hydraulics was to keep the brakes balanced so there would be equal pressure on all wheels, almost impossible to maintain with mechanicals.

Would you mind explaining that, naively I don't see how boosting the brakeand would make the the pressure balancing better.

It's not the assist, it's the hydraulic fluid system which is self balancing & adjusting as opposed to mechanical levers & rods which wear causing uneven braking on the different wheels.

Which is way the V8 Ford club does not deduct point for a hydraulic conversion for the old mechanical brakes on early Ford cars.....this via a old friend with a converted '35? Ford rumble seat convertible....resto winner....

 

[mrvette]

What everyone conveniently ignores is the fact that our stock sucky boosters have a spring between the input shaft to the pedal, and the output shaft to the m/cyl.....that spring is a problem child that allows way over excessive pedal travel, ...................

:banghead::gurney:

Here is a Corvette booster. I can't find the spring that would cause lost motion. Maybe the valve return spring? I can't see that causing more than 1/8

Yes, that's the one I thinking of, now all I know is from the same diagram you show that's in my overhaul manual AND when finally giving up on it, and having a HB unit in hand, I tore it out of there, pulling the vac check valve supposedly told me it held vacuum, engine never lacked for vacuum, and pedal was always very soft and after ~4" of travel would stop the car, but after stopping the car, I could still force it to the floor, not a very confident feeling, but rather common for most GM cars with sucky boosters....

SO, not entirely trusting the Validity of the conversion, I installed the HB unit without ever breaking a BRAKE line, bolt on set booster rod length, and so slammed myself into the steering wheel on first drive....it was a 1 5/16 diameter truck m/cyl trying to get less pedal travel with the OEM booster....

so changing to a aftermarket aluminum m/cyl of stock dia pistons, solved THAT problem, and put the thing with a perfect pedal feel.....

that will NOT go to the floor no matter if I put one foot on the other with all my weight....gotta LOVE the confident feeling...and I can coast the car out of the garage by pulling outta gear also, so no significant drag on the brakes either, as has always been the case with any of my cars.....

:drink:

 

[racervette69]

I just remembered that I have used the HB system to slow my corvette down for a number of years.


When it was on the trailer being towed by my chevy van..

 

[mrvette]

I just remembered that I have used the HB system to slow my corvette down for a number of years.


When it was on the trailer being towed by my chevy van..

:loveletter::thankyou::gurney:

 

[clutchdust]

I have owned several diesel trucks over the years. And they all had HB brakes. I don't like them. I think the vac brakes work better and feel better.

Fkn hate mine too. On both of my diesels I had to replace that godawful POS because it leaked all over every thing. Now on my 1-ton gasser as soon as I get the chance, I'm putting a vacuum booster on it (I just wish I could see GENE's head explode).

 

[denpo]

What about an EVO valve?


Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

 

[kwplot34]

I have owned several diesel trucks over the years. And they all had HB brakes. I don't like them. I think the vac brakes work better and feel better.

Fkn hate mine too. On both of my diesels I had to replace that godawful POS because it leaked all over every thing. Now on my 1-ton gasser as soon as I get the chance, I'm putting a vacuum booster on it (I just wish I could see GENE's head explode).

:crylol: that would be something to see.

 

[BBShark]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

 

[mrvette]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

CRS sets in, I seen/heard of these controllers, but what sort of problems it cures?? my serp conversion, I fit the stock '72 brass valves into the back of the '88 vette pump, just to hook up the line, then when doing the rack some ten years ago, I cut the ends and spliced them, right off the pump, same valving setup......same trick for adding the HB setup, not a issue in the world with any of it.......what can that valve do for me???

:crutches:

 

[BBShark]

CRS sets in, I seen/heard of these controllers, but what sort of problems it cures?? my serp conversion, I fit the stock '72 brass valves into the back of the '88 vette pump, just to hook up the line, then when doing the rack some ten years ago, I cut the ends and spliced them, right off the pump, same valving setup......same trick for adding the HB setup, not a issue in the world with any of it.......what can that valve do for me???

:crutches:

The EVO valve is is a solenoid that pulses at higher speeds to reduce steering assist at speed. So your steering goes from full hydraulic assist at low speeds like parking to little or no assist when you reach a certain speed.

There is a Ford system that is essentially the same that uses a stand alone controller but I think it might be easier to make a controller that uses an accelerometer for speed sensing.

 

[denpo]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

Cool, the PDF explain between which speeds to interpolate.
From what I could read here and there, EVO take a PWN signal to modulate and I know at some point I'll have a dedicated microcontroller to deal with those kind of things.
Anyone know from which car I you could pick a EVO valve that would fit the Corvette ps pump?

 

[denpo]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

CRS sets in, I seen/heard of these controllers, but what sort of problems it cures?? my serp conversion, I fit the stock '72 brass valves into the back of the '88 vette pump, just to hook up the line, then when doing the rack some ten years ago, I cut the ends and spliced them, right off the pump, same valving setup......same trick for adding the HB setup, not a issue in the world with any of it.......what can that valve do for me???

:crutches:

It gives plenty of assisting at low speed, nothing at high speed. So no more risk of locking brakes or steering too quick when on the highway.

For you, it's the only device that could save your hydrobooster soul and
pride.

 

[mrvette]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

CRS sets in, I seen/heard of these controllers, but what sort of problems it cures?? my serp conversion, I fit the stock '72 brass valves into the back of the '88 vette pump, just to hook up the line, then when doing the rack some ten years ago, I cut the ends and spliced them, right off the pump, same valving setup......same trick for adding the HB setup, not a issue in the world with any of it.......what can that valve do for me???

:crutches:

It gives plenty of assisting at low speed, nothing at high speed. So no more risk of locking brakes or steering too quick when on the highway.

For you, it's the only device that could save your hydrobooster soul and
pride.

Ummm hummm....my car drives just fine, thank you very much....:smash:

 

[BBShark]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

Cool, the PDF explain between which speeds to interpolate.
From what I could read here and there, EVO take a PWN signal to modulate and I know at some point I'll have a dedicated microcontroller to deal with those kind of things.
Anyone know from which car I you could pick a EVO valve that would fit the Corvette ps pump?

Below is a picture of the EVO valve (w/ Standard valve on top).

What car are they from? I see them on pumps from mid 90's GM products like Olds Acheva, Grand AM etc. Some Saturns.

Also, as far as hydroboost, the EVO valve wouldn't have any effect on that.

Here is the catch with the EVO controller. You don't want to reduce pump pressure, at speed, while turning the steering wheel quickly. You will get what is called pump "catch up" where the wheel feels like it hits a stop. All of these systems use a steering wheel rotation sensor to detect that. Thats why I thought a 2-axis acelerometer would be the best choice for the controller.

I have a ton of information on this if you would like to pursue this. I talked to a retired Ford engineer about this and a Delphi steering engineer. They gave me lots of info.

 

[mrvette]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

Cool, the PDF explain between which speeds to interpolate.
From what I could read here and there, EVO take a PWN signal to modulate and I know at some point I'll have a dedicated microcontroller to deal with those kind of things.
Anyone know from which car I you could pick a EVO valve that would fit the Corvette ps pump?

Below is a picture of the EVO valve (w/ Standard valve on top).

What car are they from? I see them on pumps from mid 90's GM products like Olds Acheva, Grand AM etc. Some Saturns.

Also, as far as hydroboost, the EVO valve wouldn't have any effect on that.

Here is the catch with the EVO controller. You don't want to reduce pump pressure, at speed, while turning the steering wheel quickly. You will get what is called pump "catch up" where the wheel feels like it hits a stop. All of these systems use a steering wheel rotation sensor to detect that. Thats why I thought a 2-axis acelerometer would be the best choice for the controller.

I have a ton of information on this if you would like to pursue this. I talked to a retired Ford engineer about this and a Delphi steering engineer. They gave me lots of info.

Other than a possible MPG increase measured in the .1% region, I really can't see anything there....damned if I know WHY, but I LOVE the feel of my car at speed or in a parking lot, I guess maybe someone on a autocross maybe able to point out deficiencies....but seriously, I a reasonably quick street driver, never a over reaction at speed, never a problem with wheel tug or braking.....and besides, the overall steering ratio is the same no matter the boost, so I fail to see how that affects anything....except 'road feel' which to me is fine....

 

[denpo]

Also, as far as hydroboost, the EVO valve wouldn't have any effect on that.

I was about to ask why, but I rather did my homework.
http://forums.corvetteforum.com/c3-...wer-steering-flow-control-jim-shea-alert.html
http://forums.corvetteforum.com/c3-...e-know-how-a-hydroboost-works-internally.html
Looks like you had the same questioning 6 years ago and looks like you didn't pursue the idea, should I understand it's a dead end?

According to Jim the great, EVO valve modulate the flow and not the pressure to achieve its role.
Now I bought this things in the hope I would get better feeling in my steering and braking :
http://www.borgeson.com/xcart/catal...re_Reducing_Shim_Kit-orderby_0-p-1-c-133.html
Is this kit mis-labelled and should be called "flow reducing kit" or is it acting on the system in another way.
May reducing steering and braking assist level like pulling the rope from both ends?
Frankly I'm lost here.

PS: Michel, you don't mind I derail further the thread, it's for the good :sweat:

 

[MYBAD79]

this is turning into a great discussion on evo valves and pressure reduction at speed.... let's see where this goes and maybe we need to re-arrange the thread, it sure isn't searchable with the title "what if"
:friends:

 

[1Michel]

PS: Michel, you don't mind I derail further the thread, it's for the good :sweat:

I dont mind at all, I started this thread to start a "good discussion" about manual brakes.

I'm not convinced at all that HB is the only way to equip or modernise our C3.

Like I said earlier, I had a few cars with unassisted braked and I recall having no problems stopping with them.

Sooo now, in 2012 I'm wondering if having a set of good lighter binders and a manual new master wouldnt be a better deal for me.

A few answered about what they felt about unassisted brakes and I'm happy with the answers.


And by the way, it's turning into constructive discussion about HB.
Your right Karsten, the tittle dont lead to brakes.... my fault, I'll try harder next time LOL

 

[denpo]

PS: Michel, you don't mind I derail further the thread, it's for the good :sweat:

I dont mind at all, I started this thread to start a "good discussion" about manual brakes.

Well, we're just a couple of post deep into the subject, we could start another thread without too much hassle, I could compile the existing discussions in the first post.

 

[1Michel]

Well, we're just a couple of post deep into the subject, we could start another thread without too much hassle, I could compile the existing discussions in the first post.

Thats a good idea, like you guys said, it's turning into a great discussion about the EVO valve and HB.

 

[010752]

What about an EVO valve?

Make it work past 25mph and you got best of both world. no?
Well, weight saving put aside, of course.

Someone needs to make a controller for the EVO valve. Certainly would cure a lot of steering problems. This is a Delphi document that explains pretty well how it works.

CRS sets in, I seen/heard of these controllers, but what sort of problems it cures?? my serp conversion, I fit the stock '72 brass valves into the back of the '88 vette pump, just to hook up the line, then when doing the rack some ten years ago, I cut the ends and spliced them, right off the pump, same valving setup......same trick for adding the HB setup, not a issue in the world with any of it.......what can that valve do for me???

:crutches:

It gives plenty of assisting at low speed, nothing at high speed. So no more risk of locking brakes or steering too quick when on the highway.

For you, it's the only device that could save your hydrobooster soul and
pride.

Ummm hummm....my car drives just fine, thank you very much....:smash:

I'm with Gene on this one. KISS method

 

[TimAT]

I just looked at Rock Auto's catalog-
They list 2 master cylinders for 1969- the NO power brakes m/c lists a 1" bore, while the WITH power bore size is listed at 1-1/8".

From that, the math is pretty easy- 500psi x 1"= 500psi. 1-1/8 x 500psi = 562.5psi (500psi is an arbitrary number, but hydraulics is hydraulics)

Not a whole lot of difference. And in those days, power brakes WERE optional. And past the master cylinder, nothing else cares. Proportioning valve, lines, calipers, and pads are the same.

The old real rod operated mechanical brakes- adjust them, go for a drive and stomp the pedal- if it takes off left or right, or swaps ends, keep adjusting.

 

[BBShark]

Something else to consider. The pedal lever ratio for power and manual are different
Manual 1" master dia. 5.5:1 pedal ratio
Power 1.125" master dia 3.5:1 pedal ratio

 

[69427]

I just looked at Rock Auto's catalog-
They list 2 master cylinders for 1969- the NO power brakes m/c lists a 1" bore, while the WITH power bore size is listed at 1-1/8".

From that, the math is pretty easy- 500psi x 1"= 500psi. 1-1/8 x 500psi = 562.5psi (500psi is an arbitrary number, but hydraulics is hydraulics)

Not a whole lot of difference. And in those days, power brakes WERE optional. And past the master cylinder, nothing else cares. Proportioning valve, lines, calipers, and pads are the same.

The old real rod operated mechanical brakes- adjust them, go for a drive and stomp the pedal- if it takes off left or right, or swaps ends, keep adjusting.

Remember, those m/c numbers are bore diameters, not bore area. The area ratio between them is 1.27x.

 

[rtj]

My 68 BB (sold) had factory manual/unassisted brakes. It would lock up all four tires in an emergency, no problem. I have been thinking of going unassisted on my current c3.

 

[rtj]

Something else to consider. The pedal lever ratio for power and manual are different
Manual 1" master dia. 5.5:1 pedal ratio
Power 1.125" master dia 3.5:1 pedal ratio

Thanks. Is the factory pedal drilled for both?