A/C Air Flow - See Pic
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
A/C Air Flow - See Pic
I recently upgraded to a C4 blower hoping to get some serious air flow out of the vents. I am getting practically no air flow as a result. 
After checking all of vent ductwork and vacuum doors (which seem fine), I took this picture of the fan blower as it faces the firewall (in the cowl area). I thought that it is kind of strange that the air from the blower does not immediatly go into some kind of duct or tunnel -- it is just an open area. So I am thinking that I might be missing something in my ductwork ??
Has anyone else been deep enough in there to know what I am talking about?
After checking all of vent ductwork and vacuum doors (which seem fine), I took this picture of the fan blower as it faces the firewall (in the cowl area). I thought that it is kind of strange that the air from the blower does not immediatly go into some kind of duct or tunnel -- it is just an open area. So I am thinking that I might be missing something in my ductwork ??
Has anyone else been deep enough in there to know what I am talking about?
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by 79vetter
I recently upgraded to a C4 blower hoping to get some serious air flow out of the vents. I am getting practically no air flow as a result.
After checking all of vent ductwork and vacuum doors (which seem fine), I took this picture of the fan blower as it faces the firewall (in the cowl area). I thought that it is kind of strange that the air from the blower does not immediatly go into some kind of duct or tunnel -- it is just an open area. So I am thinking that I might be missing something in my ductwork ??
Has anyone else been deep enough in there to know what I am talking about?
After checking all of vent ductwork and vacuum doors (which seem fine), I took this picture of the fan blower as it faces the firewall (in the cowl area). I thought that it is kind of strange that the air from the blower does not immediatly go into some kind of duct or tunnel -- it is just an open area. So I am thinking that I might be missing something in my ductwork ??
Has anyone else been deep enough in there to know what I am talking about?
Drifting
Joined: Jun 2005
Posts: 1,523
Likes: 1
From: grand prairie texas
Did you change to the c-4 blower motor because the original blower motor quit? I was wondering how the airflow was with the original motor? Does the new motor act like it is turning at max speed? Did you use the original squirrel cage? Does the new blower motor turn in the same direction? You could get a wire and go straight from the battery to the hot side of the blower motor and give it full 12 volts to see if your airflow increases.
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Pro
Joined: May 2005
Posts: 745
Likes: 0
From: Miami Florida
its a good thing it didnt suck your feet up through the floor vents. now that its done is there a significant difference? i mounted a larger hamster wheel and made the housing larger with some fiberglass work. its definately better but it still aint like a new car. i still have to tape all the ducts where they fit together. there is alot of loss there. i covered the entire plenum box and fan housing with both dynamat and 3/8" hot water heater insulation as well as double wrapping the headers where they come close. that little bit helped.
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
79Vettr
Most older Vettes have leaves and other assorted crud in the evaporator box that blocks air flow. Get a piece f 1" hose and duct tape to the end of your shop vac hose. Stick it slowly inot he cowl vent and suck out the leaves, etc.
Put the passenger side up on jack stands, run the blower with the engine off. feel around the evaporator box for leaks and caulk them closed. Check at the bottom of the evap box where the heater hoses enter. Replace the seals around the heater hoses for a good seal.
Then, if you are feeling cocky, open up your dash and seal all your ducts.
Also make sure that you have 12 volts to the fan and a very good ground.
Most older Vettes have leaves and other assorted crud in the evaporator box that blocks air flow. Get a piece f 1" hose and duct tape to the end of your shop vac hose. Stick it slowly inot he cowl vent and suck out the leaves, etc.
Put the passenger side up on jack stands, run the blower with the engine off. feel around the evaporator box for leaks and caulk them closed. Check at the bottom of the evap box where the heater hoses enter. Replace the seals around the heater hoses for a good seal.
Then, if you are feeling cocky, open up your dash and seal all your ducts.
Also make sure that you have 12 volts to the fan and a very good ground.
Pro
Joined: May 2002
Posts: 518
Likes: 17
A great mod is to run a Compressor Cut-Out Switch, and use the AC Norm position for fresh air with the AC Compressor off.
This will drastically increase the volume of outside air available through the system due to it's more direct path vs the Vent position.
Doug
This will drastically increase the volume of outside air available through the system due to it's more direct path vs the Vent position.
Doug
Originally Posted by flynhi
79Vettr
Most older Vettes have leaves and other assorted crud in the evaporator box that blocks air flow. Get a piece f 1" hose and duct tape to the end of your shop vac hose. Stick it slowly inot he cowl vent and suck out the leaves, etc.
Put the passenger side up on jack stands, run the blower with the engine off. feel around the evaporator box for leaks and caulk them closed. Check at the bottom of the evap box where the heater hoses enter. Replace the seals around the heater hoses for a good seal.
Then, if you are feeling cocky, open up your dash and seal all your ducts.
Also make sure that you have 12 volts to the fan and a very good ground.
Most older Vettes have leaves and other assorted crud in the evaporator box that blocks air flow. Get a piece f 1" hose and duct tape to the end of your shop vac hose. Stick it slowly inot he cowl vent and suck out the leaves, etc.
Put the passenger side up on jack stands, run the blower with the engine off. feel around the evaporator box for leaks and caulk them closed. Check at the bottom of the evap box where the heater hoses enter. Replace the seals around the heater hoses for a good seal.
Then, if you are feeling cocky, open up your dash and seal all your ducts.
Also make sure that you have 12 volts to the fan and a very good ground.