Packard Forum Index » V-8 (1955-56)

The hydro booster or any booster mc combo with careful planning and design will get the job done. the small packaging of the hd seems to be a better option for those with ac cars. All must realize this idea of keeping the orig pedal ant its ratio is the limiting factor. I ask again: what is the need to keep it!?

Here is the link for the common large pass car master bores and pedal ratios. again around 1 in is standard and these are non boosted. As stated drums will want to be in the 600-800 psi range and disc 800-1000 psi.

http://www.piratejack.net/index.php?option=com_content&view=article&id=14:calculating-the-correct-pedal-ratio&catid=12:tech-support&Itemid=21

Quote:

Not sure I understand the question on the need to keep the original but I believe the only reason most have tried keeping anything is to maintain the stock look of the car. Unfortunately none of the present options anyone has tried seems to be able to accommodate that wish with any great finesse..

Any of the replacement units other than maybe the ElectroBoost require a ratio change which means modifying the pedal in some very obvious way or moving the power unit somewhere higher into plain sight from the original out of the way location under the column. On the AC cars you don't even have the option of moving the booster to the firewall.

Getting back to the theory. The reasons to switch to frt disc from drum are heat dissipation and less maintenence. The calipers are self adj so they will not cause a pull due to mis adj and the wont fade on high speed stops or mountain descents as drums will. My clipper in 5 years of driving on weekends,to shows and cruise ins and on highways to the beach and NYC has not had fade or pull or failure as yet but I too am concerned about this btv failure issue.

Yes Howard. By " keep the original" I was talking about the pedal assm and ratio as I stated above. Is this a aaca thing? I dont get it because once modified, the car is not 100% orig so what is the big deal with the pedal. Let me restate I have no problems with retrofit if safety is involved. So is this about changing it to make it safe but show no visuals so certain judges not savy enough to know dont deduct 3 pts?

If a hydro setup will address "part 1" I will be happy to lend advice and info but beyond keeping the pedal pad and size of the pedal the same- get that "rod right under the pedal and 1:1 ratio" out of the equation for proper safe brake boost multiplication.
I too would prefer a small unit under the st shaft as out of sight as poss.

Until we know specifically what the bore and stroke is for the Gm hydro boost then no claim for pedal ratio can be made. IF the bore is in the range of 9/16" to no larger than 11/16" then the 1:1 stock oem Packard pedal can be used.

Then the stroke of the GM mc has to be close to that of the BTV.
Why change pedal ratio or the pedal at all if not necessary???

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It might be a judging thing but I expect most of the purists would be inclined to keep whatever was on the car untouched no matter what and wouldn't be interested in any mods. There are some in that class who might be won over if a safety mod was proven and virtually undetectable though.

I think you and I and most others are in some agreement with mods. I expect many wouldn't have problems seeing or modifying something for safety or reliability or even comfort if it is done neatly and discreetly. It is the in your face change that looks really tacky most object to.

I may be a bit different because I do tend to try and make anything I do look like something the factory would have done if the item had been available -- and I try to use the original pieces if I can hide or reverse the mods. That reversing part is only in case the car winds up in the hands of a purist after I'm done or tired of it. I respect their desire to want an original car as Packard made it. Anything I do usually can be undone relatively easily and leaves minimal if any scarring.

That is the main reason I am trying to keep as much original on mine as possible with no big holes or obvious changes. I think that if a bolt on brake mod that was relatively easy to do and still looked like it might have left Grand Ave was available it might even win over some purists. For those it didn't, if a screwdriver and a wrench would take care of the problem then so much the better.

For those not concerned about FACTORY Ac then lets make this as simple as possible ok???

Here ya go:
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=2686&forum=12&post_id=27924#forumpost27924

Remark: To avoid plumbing prop valves and residual pressure valves then use a 65-66 mustang master cylinder instead of the explorer mc.

About the only difficult part of the above conversion is about 4" of rather simple arc welding for the pedaal and i believe that can be overcome by a different method. I have an arc welder so not a big deal to me.