Learn something new everyday.

[Y-me]

Just found out the fun way A ZR-1 Does not (your experience may vary) necessarily need the Secondary vacuum pump as I was led to believe, you just gotta block off the vacuum line. Experience is the best teacher.

[Paul Workman]

Originally Posted by Y-me

Just found out the fun way A ZR-1 Does not (your experience may vary) necessarily need the Secondary vacuum pump as I was led to believe, you just gotta block off the vacuum line. Experience is the best teacher.

Well, not zackly true...

Except at WOT, you're right: the engine will provide vacuum, and "charge" the vacuum reservoir. However, at WOT, vacuum drops to near zero, and then the vacuum pump will replace vacuum for the secondaries as long as needed.

As for the vacuum reservoir, the purpose is to "boost" the initial opening of the secondary port throttle actuators, thus reducing the reaction time to opening, once the secondary vacuum solenoid is triggered "on". The pump then sustains the vacuum as long as needed, and to re-charge the reservoir.

[Y-me]

Originally Posted by Paul Workman

Well, not zackly true...

Except at WOT, you're right: the engine will provide vacuum, and "charge" the vacuum reservoir. However, at WOT, vacuum drops to near zero, and then the vacuum pump will replace vacuum for the secondaries as long as needed.

As for the vacuum reservoir, the purpose is to "boost" the initial opening of the secondary port throttle actuators, thus reducing the reaction time to opening, once the secondary vacuum solenoid is triggered "on". The pump then sustains the vacuum as long as needed, and to re-charge the reservoir.

All I know is with bad pump attached, car slow, with pump gone and line plugged, car fast.

[cvette98pacecar]

Paul, I can't believe you did not see that coming.

[Dynomite]

Originally Posted by Y-me

All I know is with bad pump attached, car slow, with pump gone and line plugged, car fast.

I like simple

With 87 Octane fuel and no chip, car slow, with chip and 91 octane, car fast.

With Stock Exhaust, car slow, with SW Headers and Exhaust, car fast.

With Stock Cams, car slow, with Pete's regrinds, car fast.

With Stock Radiator, car hot, with Ron Davis Radiator, car cool.

With No Top End Porting, car slow, with Top End Porting, car fast.

With No Powder Coating, car boring, with Powder Coating, car exciting.

With No Carter Bling, car dull, With Carter Bling, Car flashy.

With Secondaries in place, car complicated, with Secondaries Removed, car simple.

With no Oil Catch Can, car oily, with Oil Catch Can, car clean.

With TB coolant in place, car normal, with TB coolant Blocked, car better.

That is all I know.