Which Hydroboost?

[keith1365]

Thinking about switching to hydroboost for my 68 camaro. Which unit is better to use? Mustang or Astro? I plan on making my own modifications. Both units look usable but just looking for some additional info before I jump in. Any personal preferences out there?

[Mike Holleman]

Keith, Try www.hydroboost.com. Paul is a site sponser and a great guy to do business with.

[keith1365]

I am pretty tight and prefer to dumpster dive. I like the challenge of making something out of nothing. The only problem is going to a parts store and remembering what pieces came off of what when I need new stuff. I hear he runs a great store if I was in the mood for retail bolt on and go. Winters in the Midwest can be long and TV reruns have already begun.

[CRead01]

I am doing this conversion too and I got a unit out of a full size van. From what I hear though the mustang unit is not much better than a regular vacume booster. I would go with the astro unit out of the two.

[CarlC]

I am doing this conversion too and I got a unit out of a full size van. From what I hear though the mustang unit is not much better than a regular vacume booster. I would go with the astro unit out of the two.

Not true. Any Hb system must be properly balanced to work correctly.

See my website for details.

[CRead01]

I am curious what part you are saying is not true? as per your website a stock vacume booster puts out about 900 psi and the mustang unit puts out about 1500 psi. I am not sure of the exact numbers but doesn't the gm unit put out around 2000 psi? I am not saying that the mustang unit is useless, but I dont beleive it puts out as much pressure as the gm unit. I am definately no expert and alot of my info is from other posts on the web from other people that have done this mod so I could be wrong but again I am curious about what part is not true. I am curious what unit hydratech uses but I know they are pretty tight lipped about that. I dont blame them though.

[CarlC]

It's not true that the Mustang unit is not much better than a vacuum unit. A 66% increase in line pressure is significantly better.

More line pressure than what the caliper is designed for will make for an almost undriveable braking system. The Mustang booster and master cylinder is made to be used with the C4/Mustang PBR caliper, the same one used by Baer. It is a well balanced system. Having a braking system where only 10# of pedal effort is needed to lock the brakes will result in nearly zero modulation and a real chance of wrecking the car. I had a Challenger in my earlier years that had a badly mis-matched booster and MC, and it was dangerous to drive since just laying a big toe on the pedal would just about throw me through the windshield.

Also, 1500 psi is what the system is capable of. It requires less to lock the brakes. How much? I don't know. 1500 psi is at full-leg, and I don't need nearly full-leg to lock the brakes.

So, would adding another 33% line pressure be worthwhile? What would be the benefits and drawbacks?

Also, it's not just the booster that needs to be evaluated. The MC is an integral part of the system. Just picking up a booster and attaching your current MC may not assure good results. Many GM junkyard HB's and MC's are designed to be used with a caliper with a piston area that is very much different than the aftermarket calipers (C4, C5, Wilwood, etc) that most of us adapt to our cars. You could still end up with poor braking performance if the HB and MC are not matched to the caliper.

Brakes need to be viewed as a system. More can be better, but too much is no fun at all.

[keith1365]

Carl, So I take it you recommend the mustang set up as that is the one you are using. I am running c5 fronts and LT1 rears currently in manual mode with a 7/8 master cylinder. Car stops but you need a leg. My wife is scared to death of it.

[CarlC]

Not necessarily the Mustang system. Hydratech makes great products, but part of Paul's customer service is to ask not only what the car is, but what the rest of the braking system consists of. This is so he can provide a booster and/or booster/MC that will work well when installed. Since the Mustang HB and MC are OE engineered to work with the PBR caliper it is a good referance point to start with when considering system components.

My intent is to get people thinking about what happens to the system and the possible results when unknown components are mixed together. If an incorrect engine camshaft is selected it's no big deal. If mis-matched braking components are used it can ruin your whole day.

There have been a few that have made your setup work in manual mode, but usually they even say that it takes a lot of leg. I've tried it with a friend using a 13/16" MC, and it was not fun. Here's the link http://www.geocities.com/torkerscamaro/torker.html

Though this is a C4 application the C5 should be OK as well.