Hydroboost vs Powermaster

[lost2a6]

I'm thinking about converting my 87 GN over from the PowerMaster to the Hydroboost unit. What is the weight comparison between the two? Approx. how much extra HP will it rob from the engine due to putting more load on the power steering pump? Is there an aluminum master cylinder that will work properly with the Hydroboost unit? I'll more than likely use my 87 pump and "T" into the high-pressure line going to the steering gear box to supply the HB unit, and "T" into the steering gear box return line for the return of the HB unit. I would like to see some pics of the stock setup on the hot air cars if anyone has any. Do you guys think that this would work?
Thanks steve

 

[eviljoe]

i wouldnt t- into the high pressure lines, only the return lines, i am converting my 78 monte with a 454 to hydroboost, all of the hydroboost parts are still available. the master cylinder is a cast iron piece thats like the pre-plastic resivoirs. i bought a new reman hydroboost unit for $135 witha lifetime warranty, the master cylinder was $15 with lifetime, the 2 gn pressure hoses were like 29 & 35 each. since i have a bbc i had to get the hoses from the hydorboost equipped v8 diesel cutlass from i think 84 also, i am reusing the stock sbc power steering pump, all i did was drill a 1/2" hole into the side of the tank for the return line from the hydroboost unit.
the reason i am converting to hydroboost is my 454 makes low vacuum even with a vacuum tank i had only 14" of vacuum at idle in park and 12" in drive.

 

[turbofish38]

Some more information in this thread: http://www.turbobuick.com/forums/showthread.php?s=&threadid=138750

There is another thread floating around here somewhere and Nick Micale states there is another problem when converting. I'll be damned if I could find it.

I think an aluminum MC from a full size B,C,D-body GM will fit. I'm not 100% sure. The turbo Riv runs the HB and I remember putting one on back in the late 80's. I dont have the car anymore so I cant say if it was off a HB or vacuum car.

Your fluid routing is PS pump to HB to gearbox and back to the PS fluid reservior. You shouldn't have to tee into a pressure line.

 

[lost2a6]

Originally posted by turbofish38
Some more information in this thread: http://www.turbobuick.com/forums/showthread.php?s=&threadid=138750

There is another thread floating around here somewhere and Nick Micale states there is another problem when converting. I'll be damned if I could find it.

I think an aluminum MC from a full size B,C,D-body GM will fit. I'm not 100% sure. The turbo Riv runs the HB and I remember putting one on back in the late 80's. I dont have the car anymore so I cant say if it was off a HB or vacuum car.

Your fluid routing is PS pump to HB to gearbox and back to the PS fluid reservior. You shouldn't have to tee into a pressure line.

That sounds easy, you are sort of speaking tying the HB and gear box in series rather than in parallel so the return from the HB unit would still be under "high pressure" and should not effect the gear box function. Will the supply line to the HB screw directly into my 87 pump and also would the return from the HB screw directly into the gear box or will I need a special adapter? Could anyone give an educated guess as to how much extra HP it would rob from the engine, and how much heavier the HB unit is over the powermaster.
Thanks Steve

 

[eviljoe]

the way i am running the lines is
1-hipressure from hydro. to the gear box on frame
1-hipressure from hydro. to the power steering pump
1-3/8" braided steel fuel line from hydroboost to the power stering pump (low-pressure return line)
1-3/8" braided steel fuel line from power steering pump to gear box (low-pressure return line)

the pressure lines are still available for the 84 gn at autozone
i hope this helps

 

[turbofish38]

Eviljoe has it right. You can use your existing pump. You just need to use lines with the ISO/Saginaw style fittings which the 84 lines should be. I cant imagine it using anymore power than the stock set up as it doesn't need anymore pressure/volumn than the non-HB setup.

 

[lost2a6]

That makes sense, maybe if you were to start pumping your brake then it might rob some HP, but who would do that while racing? Thanks Guys

 

[lost2a6]

Well I just finished converting my 87 GN to the hydroboost system that I purchased from Michael at Muscle car salvage. All I can say is WOW!! The car brakes much better than the powermaster ever thought about. Last night I held the brake and brought the boost up to 13lbs with no problem at all. I could have gone even higher, but I didn't want to push it. With my PM, I could get 12 lbs but you could tell that it was about to start to roll. With the Vacc setup all I could get was about 3lbs. The installation was pretty easy and straightforward. With a little modification, I was able to use the aluminum master cylinder off of a 1980 regal. I would highly recommend going with the Hydroboost system.

 

[eviljoe]

What brake pedal did you use on the conversion, the stock power master one, or the vacuum brake one?

 

[lost2a6]

I used the orginal powermaster petal. The vac unit has a smaller hole in the push rod that fits on the petal. The hydroboost unit along with the powermaster have the larger hole in the push rod and uses the same petal.

 

[lost2a6]

Up Date: Just took it up to 16lbs with no problem, and this was with the max boost valve off! Wonder if it would pull the front tires, if it would hook, as a result of leaving the line with this much boost.

 

[turbofish38]

Originally posted by lost2a6
I used the orginal powermaster petal. The vac unit has a smaller hole in the push rod that fits on the petal. The hydroboost unit along with the powermaster have the larger hole in the push rod and uses the same petal.

Correct, the PM and HB use the same pedal which is different from the vacuum.

Hmm, I'm going to have to think about doing this. I have an 83 and an 84 HB setup gathering dust in the storage shed...


BTW, there is a 83 Cutlass with the HB sitting at the Pick-N-Save at Daytona Beach right now. Look for a brown 4 door with a diesel to gas conversion sitting in the middle of the GM cars.

 

[lost2a6]

Eric, just do it! The only drawback that I can see is if the engine was to die, you don't have a reserve power brake, but you can still stop the car if you put your foot into it a little, unlike the powermaster.

 

[GNVYUS 1]

How long did it take to set up?

Any pics of it installed?

How would you compare regular braking, better, the same?

 

[gofigr]

I'm lost2a6, for some reason I can't post anything under my old user name. The worst part was having to pull my vacuum brake petal assembly out and reinstall my original powermaster brake petal. I took my time and I was drinking a few beer sodas in the process and it still only took about 3 HRS. I don't have any pics at this time but I might can get you some in a couple of days. The normal breaking is great; I have a full petal, which is not spongy feeling. However it can be a little touchy as far as being able to lock up the tires with ease.

 

[Robbie-87plz]

Lost2a6

Any word on the pics? I'm thinking along the same lines of going Hydroboost. Put some sticky tires on that and I doubt you'll be able to lock them up...

 

[bruce]

Originally posted by lost2a6
Eric, just do it! The only drawback that I can see is if the engine was to die, you don't have a reserve power brake, but you can still stop the car if you put your foot into it a little, unlike the powermaster.

How's it act in a *FULL* Panic stop?.
Just a sudden brake application with all your leg effort posssible?.

Can you do any data logging to demonstrate how well it really stops the car?.

Just curious about the other side of the coin, is all.

 

[Robbie-87plz]

That would be interesting...nothing wrong with a lil flat spot...

 

[bruce]

Originally posted by Robbie-87plz
That would be interesting...nothing wrong with a lil flat spot...

IMO, properly sized components won't allow for that, at full *mash*, on a street car, there should only be a hint of locking of the tire, not enough to really flat spot it.

One of the problems with really getting brakes correct, is thinking one item can make up for other problems, IMO.