Water pump flywheel?
Safety Car
Joined: Dec 2007
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From: Sandhills of North Carolina
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Indeed it's the "frisbee" that was installed to dampen out any vibration when the new (in '88) A/C compressor kicked on/off.
Toss it and use lock washers under the bolt heads; should be worth ~10 chp gain.
Toss it and use lock washers under the bolt heads; should be worth ~10 chp gain.
Thread Starter
Instructor
Joined: May 2007
Posts: 149
Likes: 7
From: Arkansas City Kansas
I took it off. My first trip to work without it I noticed the engine will buck at low rpm right before the downshift from 4th to 3rd. Engine was not fully warmed up yet never had this before? Didn't seem to do it after engine was up to temp.
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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Doesn't seem likely that the frisbee prevented bucking during a downshift but I suppose there's small possibility it was helping to mask a problem you might have with injectors or tuning/tune-up. Or...it was total coincidence. If it continues, simply reinstall and report if the problem disappears.
FWIW: Extra weight you add to a motor will create an interia that helps keep the motor running. That's why a heavier FW is easier to drive with a stick than a lightweight alum one. Considering they put that weight on the WPump vs the A/C, I'm more inclined to think that extra inertia keeps the engine RUNNING smooth when the A/C kicks in.
Any chance your A/C was running and the compressor happened to be kicking on JUST as you were downshifting?
FWIW: Extra weight you add to a motor will create an interia that helps keep the motor running. That's why a heavier FW is easier to drive with a stick than a lightweight alum one. Considering they put that weight on the WPump vs the A/C, I'm more inclined to think that extra inertia keeps the engine RUNNING smooth when the A/C kicks in.
Any chance your A/C was running and the compressor happened to be kicking on JUST as you were downshifting?
Last edited by GREGGPENN; Jul 23, 2010 at 06:40 PM.
