Hydroboost Conversion
Well, As They Say, Vacuum Boosters Need Vacuum To Work. They Are Rated To Operate At 20" Of Vacuum. Tough To Find On This Type Of Car. My Guess Is That Gm Did Not Want To Revisit The Powermaster Again, In 1989. I Think They Only Built 1500 Tta's. Gm (bendix) Never Got Around To Designing Hydroboost Brackets For The F Bodies. It Wasn't Cost Effective For Them To Do It. We Do, However, Make Them. Buick Did Install Bendix Hydroboosts On Their 83-85 T Types. No One Here Ever Complains About Those Hydroboosts, 20 Years Later. Since 1995, Bosch Resumed Production Of The Hydroboost. Also, In 1989, There Were No More G.n.'s, But Maybe Gm Had Some Turbo Motors Left Over, And Gave Them To Pontiac. Pontiac Also Used A Few Corvette Engines In The Formula Firebirds. But, To Make This Vacuum Booster Work, They Installed A One-way Check Valve Between The Manifold And The Vacuum Booster, To Prevent Boost Pressure From Exploding The Plastic Check Valve At The Booster. For The Last 45 Years, Camshafts Have Had To Be Ground Conservatively, Just To Create Vacuum For The Brakes. Ask The Racing Cam Manufacturers. Those Tta's Also Had Rear Discs, And A Different Prop Valve. There Is Someone Here On This Forum That Has A Tta, And He Says The Brakes Suck. The Standard F Bodies With 4 Disc Have A Spongy Pedal, And Few People Like It. The 80's El Dorados Had A Similiar Brake, But With An 11" Vac Booster. Those Cars Have All Been Scrapped Now, Mostly Because They Couldn't Fix The Brakes. We Devised A 10lb Check Valve In The 80's To Deal With The Low Pedal. It Worked, But We Couldn't Fix Them All. The Only Time Enough Vacuum Is Created To Work The Booster Is When The Throttle Slaps Shut. Watch The Boost Guage On The Dash. It's Easy To Get Vacuum With A Carburator, But With F.i., The Idle Air Motor Maintains A Fast Idle, Even With The Throttle Shut. In Overdrive, And On A Fast Idle, It's Hard To Slam On Brakes. It's Even Harder To Build Vacuum When Spooling Up A Turbo At The Drags. There Were Some Cadillacs, Citations, And Other Gm Cars That Came With An Electric Vacuum Pump, From The Factory. It Was Still A Half-assed Approach To Real High Performance Braking. We Retro Fitted Many Of Those Pumps In The 80's And 90's. It Was Always Marginal Improvements. The Hydroboosts Beat Any Other Combination.
