I got tired of not having much air coming out of my vents so I decided to disable my door vents in order to increase airflow to the center vents.
Steve, your method to stop the wasted airflow to the door vents is more efficient than simply plugging the holes ... which is what I did. Purchased the plugs from DMCca for about $30 for the pair IIRC. HUGE improvement in airflow to the center vents.
While we're on the subject I've always been intimidated by A/C systems and had that work done by others. The A/C on 4915 has been less than desired for a couple of years. This year, and I'm sure you'll agree with me Steve, it's gotten hotter sooner than in the recent past.
So, I decided to take the plunge and buy the gauges, the vacuum pump and a leak detector ... I was ready. Since the system was empty I replaced the 30 year old schrader valves. Interestingly the valve in the high side came out in pieces ... thats where the leak was. It then held 29" of vacuum for over an hour. I charged it up with R134a (held about 20 ozs). Buttoned it up, cranked it up and the A/C is killer! I went for a 30 minute drive around town today ... just tooling around, stopping at traffic lights etc. It was right around 100 degrees today and the A/C never faltered ... I am so proud of myself.
Steve, I agree the $50 was crazy. See edit.
BTW, I'm getting her ready for a car show and during my little drive around town I did not have the plugs in ... with the A/C operating properly the center vents were pretty strong and the door vents felt good. Don't need plugs with a working A/C I guess
It was DMCH and they are pretty nice with the DMC logo. I will take a pictures soon and post it.
Here are the pictures... However as Steve said witha good working AC system both the center and door vents will put out plenty of air. I know they were pricy but I like the look when I leave the doors open for car shows.
Well, we have summers here in excess of 100 degrees. I like to have as much concentrated air blowing in my face as possible. When I don't have a passenger I even turn off the passenger vent just to increase airflow in one vent.
Perhaps something you should consider is putting a small hole, perhaps an 1" diameter in the middle of your Styrofoam plugs. That will still significantly increase the center air vent pressure but still allow some air to flow through the side vents. That perimeter cooling does help the overall air temp of the cabin.
Another thing to consider, all things equal, the passenger side center vent has more airflow then the drivers side. When there is no passenger I'll have both center vents pointed in my direction. I'm relatively small so I sit further forward than most people and I still get good flow directed on me like that. If you completely close off your side vents AND the passenger side center vent you are no longer cooling efficiently, as the one vent is not enough area to maximize the air volume at fan speed 4. I also question the ability for just the two center vents at speed 4, which is another reason why I suggest the small hole in the middle.
You should also consider removing your blower motor/resistors, then reaching into the evaporator box and removing and junk/gunk in there that may be blocking the evaporator. Be careful not to bend the fins on it. A shop-vac with small flexible extension hose is also great for this. I did that a year after I got my car, it was FULL of crap. A/C saw a 25% improvement right there. (fan speed requirements dropped 1 speed on equal condition days to remain comfortable).
Other things to check are for the proper orientation of the squirrel-cage blades, and proper rotation of the motor. There are identical GM units that have both backwards blade direction and backwards rotation from the design of our airbox.
Don't forget its also worth the effort to remove the door trim and seal up the door vents to stop leakage into the door.
You should also consider removing your blower motor/resistors, then reaching into the evaporator box and removing and junk/gunk in there that may be blocking the evaporator.
Pardon the dumb question but what does removing the resistor do? Does it allow the fan to blower to operate at a higher speed?
Pardon the dumb question but what does removing the resistor do? Does it allow the fan to blower to operate at a higher speed?
The resistor is only used for speed 1, 2 and 3. On speed 4 the power is applied directly to the blower motor.
If you want more motor power you would need to find a more efficient motor to keep the current about the same (23 amps) on speed 4. I've thought about using an ASTRO cobalt motor used on RC airplanes. But I think modifying the center vents is something I would do first.
Well, we have summers here in excess of 100 degrees. I like to have as much concentrated air blowing in my face as possible. When I don't have a passenger I even turn off the passenger vent just to increase airflow in one vent.
Understood and that is personal preference... but a good quality functional AC will cool the entire passenger compartment in a matter of minutes and keep it that way, so there is no need to block off any of the vents.
Originally Posted by stevedmc
Reply With Quote
Dave M vin 03572