HydraBoost?!

[mazspeed]

Ok drove the car yesterday, and it felt like it didn't have any assist at all. The 7 inch vacuum didn't seem to be doing it's job. It's a CCP piece, but was wondering if it's enough? I have the zz430 and it makes plenty of vacuum for it, but I'm really thinking about the Hydraboost system? Any thoughts?

Thanks in advance

[mazspeed]

Also is there different kinds of hydroboosts? And if so, which one should I get?

[Blown353]

Small boosters inherently have less assisting power because the internal diaphragm area is signifantly smaller than a larger diameter booster. Often they try to compensate for this by running dual diaphragms but they still don't have the effective diaphragm area of a larger single diaphragm booster; even using grossly simplified math (i.e. throwing out the lost area to the center plunger and spring assy) a 7" dual diaphragm booster has only 80% of the surface area of a single 11" booster. Thus it will need more vacuum to provide as much assist as the single 11". This is why I don't like small diameter boosters. If your situation has major clearance issues my preference is either to run manual brakes (which is doable if you properly size your caliper piston area to the MC bore size, but some calipers like PBR's don't lend themselves to manual use) or run a Hydroboost. I've never been a big fan of supplemental electric vacuum pumps either.

A hydroboost will cure all your weak brake issues and then some, TONS of assist power available. I got mine from Paul at Hydratech and would buy from him again without a second thought. Great guy and great product.

How much vacuum are you making? Small diameter boosters typically don't like under 16-17 in/Hg because of their reduced surface area. I've had mixed luck with large diameter boosters (11") working decently all the way down to 11-12 in/Hg.

[mazspeed]

I'm pretty sure that's what we are going to do. I asked my shop to have one shipped to him overnight. I have heard pretty good things about hydroboost. Yeah the 7 inch is a duel diaphragm unit, but it feels as if it did when I had 4 wheel drums on it. Very odd. Just when you really stepped on it, is when you could feel the difference. Is there a different unit, or units to get, or is it one serves all? Thanks for the help by the way :thumbsup:

[mazspeed]

Also I might as well get a new master cylinder as well since the CCP one leaks. Which is the best one to get? Looks and performance and that will work with my Baer brake setup and a hydroboost system?

[Blown353]

What Baer's are you running? If you're running the Track setup with standard PBR 2-pistons up front and single pistons out back a MC with a 15/16" bore size works quite well. The Baer provided MC for this setup is sourced from a '77 Malibu with manual brakes, 15/16" bore size. That's what I'm currently using and am quite happy with the setup in terms of pedal feel and travel. About $50 at your local auto store, NAPA being my preference.

If you want something that looks a little snazzier a Wilwood Tandem in 1" bore size will also work well; pedal effort will be slightly higher (not an issue with the Hydroboost) and pedal stroke will be slightly shorter than the 15/16" MC.

http://www.wilwood.com/Products/006-MasterCylinders/009-ATCMC/index.asp

[mazspeed]

That is exactly what we will go with. Thanks again.