Air Pump
Gearhead406350
11-02-2007, 04:40 PM
I am putting headers on my 350 motor in my 1991 wagon and i want to get rid of the air pump. Since the belt can't be routed to spin the waterpump the correct direction i was wondering if anyone knows of an aftermarket pulley like an idler to take the place of the air pump so i can route the belt. Let me know
Jeremy
Jeremy
PeteA216
11-02-2007, 06:02 PM
They make an "air pump delete pulley" commonly sold on eBay. Your car may not pass inspection without the pump however. Personally I don't see what good the pump does aside from dullute the exhaust a bit, because the engine will still push out the same amount of emissions.
silicon212
11-02-2007, 07:46 PM
The air flows into the converter to activate second stage of the tri-cat. The first stage contains rhodium and works against the NOx pollutant, then air is injected behind (due to the rhodium using the available oxygen) to allow the catalyst to convert the HC and CO into H20 and CO2.
j cAT
11-03-2007, 01:13 PM
I am putting headers on my 350 motor in my 1991 wagon and i want to get rid of the air pump. Since the belt can't be routed to spin the waterpump the correct direction i was wondering if anyone knows of an aftermarket pulley like an idler to take the place of the air pump so i can route the belt. Let me know
Jeremy
I believe that if you delete the air pump on that vehicle the check engine light will come on. this will then cause you to fail emisson test.the air pumped into the exhaust aids the cat to remove unburned gases especially when engine is cold. On the 1996 impala there is an air pump delete mod GM approved this takes out the electrically operated pump, but computer must be reprogramed. But I guess that this emission test issue is not a concern because you will not put headers on a vehicle that has a cat in the exhaust.That just don't make sense to me.
Jeremy
I believe that if you delete the air pump on that vehicle the check engine light will come on. this will then cause you to fail emisson test.the air pumped into the exhaust aids the cat to remove unburned gases especially when engine is cold. On the 1996 impala there is an air pump delete mod GM approved this takes out the electrically operated pump, but computer must be reprogramed. But I guess that this emission test issue is not a concern because you will not put headers on a vehicle that has a cat in the exhaust.That just don't make sense to me.
silicon212
11-03-2007, 03:03 PM
The method j cAT describes above is OBDII behavior and occurs on 1996-up cars. You won't have a MIL on a '91 due to there not being a downstream oxygen sensor.
j cAT - it seems to me that you're stuck in a timewarp, when catalytic converters were a drag on performance. That isn't the case today, and hasn't been for much of the 80s and beyond. Technology has come a long way. I know you said that on your '83, removing the cat and going with dual gave you a huge performance increase. That tells me that you probably had a bad cat to begin with - today's monolithic honeycomb cats only take about 2-3hp away (from 300). You still gain more with headers and cats than you do with no cats and stock manifolds on duals.
Besides, headers and cats are legal - cat deletes are not.
j cAT - it seems to me that you're stuck in a timewarp, when catalytic converters were a drag on performance. That isn't the case today, and hasn't been for much of the 80s and beyond. Technology has come a long way. I know you said that on your '83, removing the cat and going with dual gave you a huge performance increase. That tells me that you probably had a bad cat to begin with - today's monolithic honeycomb cats only take about 2-3hp away (from 300). You still gain more with headers and cats than you do with no cats and stock manifolds on duals.
Besides, headers and cats are legal - cat deletes are not.
Gearhead406350
11-06-2007, 10:30 AM
Hey thanks everyone. I found a air pump delete pulley at my GM dealer so i bought it. My car is registered in a county that doesn't have emisions testing so i have the cat deleted already. I decided i am putting the headers on putting cutouts on after that for when i take it drag racing i can undo them so it doesn't go through the complete exhaust. I am also going to finish the duals. From what i know being a 91 the air pump is just an output which won't put on a check engine light. Thanks again.
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