Increasing power to center AC vents

[stevedmc]

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.

To me the door vents never seemed to put out any air worth getting excited about. To me the door vents seem to be poorly designed. You have tubing running to each door and each tube has connectors on each end where air can leak.

The mod is really simply. I removed the tubing from each side and used the plastic duct that sits above the steering wheel as a template for cutting styrofoam to fit into the housing the ducts would normally connect too.

I cut the foam a little larger than needed and used it to plug the center vents. Now I have much stronger air coming from the center vents.

The mod was virtually free and now I don't have to sweat this summer.

[fnzen]

Steve
Did you use anything to keep it stuck in or is it a tight fit? About how thick was the styrofoam about like a cheapie ice chest?

[stevedmc]

The foam I used was about half an inch thick.

I cut the foam a little larger than necessary so it would be a tight fit. As long as you do this and semi force it in there you will not need to seal it with anything.

If you want to seal it you could probably use foam sealer. I don't see any need to seal it though. Foam sealer is messy and you could get that stuff on parts of your car where you don't want it.

Give it a try and see if you like it. Like I said, this mod is virtually free and can be reversed at any time.

[SBL]

A tennis ball fits perfectly, placed from the outside port.

steve

[Spittybug]

A Crystal Light drink mix can top (plastic disk) fits snugly in the end of the hose on either side of the dashboard. Quickly removable if desired. Works well.

[Bitsyncmaster]

I've always been thinking I would (someday) remove some of the plastic veins in the center vents to increase airflow and be able to direct the vents more (in my face).

[stevedmc]

Plugging the hose is fine but the reason I eliminate the hose completely is to limit the amount of cold air that leaks. It is 100 degrees down here and every bit counts.

The way I see it, if you leave the hose attached and plug the end of it you are allowing cold air to sit in a hose that isn't insulated. You are going to loose some cooling ability plus it is going to leak out the ends of the hose.

Removing the hoses and plugging their sources eliminates as much wasted air as possible.

[Bitsyncmaster]

Ever put your hand on the dash when it's in the sun (even with the AC on MAX)? You can burn your hand. We have got to get and "Eglass" windshield.

[stevedmc]

A tinted windshield would be nice. I have a DMCH grey dash and I've never had the desire to touch it when hot. In no way am a bragging about it, but I can imagine it isn't as hot as a stock black dash.

Anyway, now I am seriously considering getting my windows tinted. I know a guy/shop that does tint work who gets really excited when I bring the Delorean by. I wonder if he will cut me a deal.

[Bitsyncmaster]

The tint will help but there still is a coating that reflects the infrared to the outside surface of the glass. That is the type of windshield I would buy to replace mine just to keep it cooler in the summer. Yes I have black interior.

Even the window switches will get hot if the sun hits them.

[stevedmc]

This is a dumb question but do windshield covers help much to keep it cool in the car. I might get one for when I leave the car in parking lots if it will help.

[Bitsyncmaster]

This is a dumb question but do windshield covers help much to keep it cool in the car. I might get one for when I leave the car in parking lots if it will help.

Yes it keeps it cooler

[Chris 16409]

I've got the UVS100 Heat Shield from CoverCraft. I really like it, it's custom cut for the DeLorean. Here's one of the online sites you can order it from.

http://www.carcoverusa.com/Covercraft-Window-Sun-Shields.html

Here's a link to CoverCraft's own webpage about the windshield cover.

http://www.covercraft.com/windshield_heat_shield.htm

It has a bunch retailers that sell the UVS100. CoverCraft does not sell its products directly apparently. You have to go through one of their retailers. Honestly, just click through a bunch of them to find the best price with shipping (supercarcovers.com has free shipping). I even got the vinyl bag to store it in.

[Spittybug]

Dave is absolutely right about the Eglass. While screens really help when the car is parked, their use is frowned upon when driving :dunno: I have a light grey dash cover that helps reflect some of the sunlight/heat as I'm driving, but if you stick your hand under it, the black dash is still tooooo hot to touch. Just like the thin foil radiant barrier that goes in attics, I wonder if something comparable could be affixed to the underside of the dash cover? That way you'd reflect the non-visible spectrum of energy too? The air conditioning load that cooling that mass of hot vinyl must consume is probably very, very large.

[Farrar]

I like this idea -- and it will make placing my footwell lights easier. (I plan on re-doing it to make the light more even.) Good job, Steve!

Farrar

[jbreeden]

at one point i think caps for the a/c vents were available from one of the vendors. I thought DMC cali, but I'm not positive.

if you don't feel like forking over however much it costs for a custom cover, you can get one of the basic foil ones from autozone or wherever and cut it to size pretty easily. I've had good results with mine. Fits so well, actually, that I don't even need to use my sunshades to secure it in place.

[Ryan King]

at one point i think caps for the a/c vents were available from one of the vendors. I thought DMC cali, but I'm not positive.

DMC-CA did sell them for awhile. A customer of their's named Brian Brios was fabricating the Air Vent Caps. I don't know if they are in stock any longer or not.

[Chris 16409]

I tried the tennis balls and tried them, but I had some foam lying around so I cut two plugs that fit the air box. I wanted to eliminate the black plastic air duct on the drivers side so the tennis balls wouldn't work for that. I like the look foam better then the tennis ball anyway.

[Chris 16409]

at one point i think caps for the a/c vents were available from one of the vendors. I thought DMC cali, but I'm not positive.

DMCH sells them on their website. Here is the link:

https://www.delorean.com/store/p-10432-ac-vent-plugs-pair.aspx

DMC-CA must still have them in stock as well.

[dhaney]

at one point i think caps for the a/c vents were available from one of the vendors. I thought DMC cali, but I'm not positive.



It was DMCH and they are pretty nice with the DMC logo. I will take a pictures soon and post it.

I don't use them anymore because I fixed my AC and used spray foam to seal around the vents increasing the flow. But I do put them in place for car shows, so that nobody gets the idea that the vent hole is a trash receptical when the door is open.

A good running system will push out plenty of air from all of the vents. Of course my system is now essentially new after I blew one of my 28 year old hoses and shortly after that I blew the back off my compressor. The only old part left is the evaporator. I also decided to stay with R12, knowing it would run colder. It wasn't too expensive since one of our club members has all the correct AC equipment.

Dan

[Jacko]

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.

1134

[stevedmc]

Wow, I thought $30 was high but $50 is just crazy when you can use a piece of foam to do an even better job.

[Jacko]

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:dunno:

[dhaney]

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.

Dan

[stevedmc]

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.

[dmc6960]

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.

[stevedmc]

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?

[Bitsyncmaster]

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.

[dmc6960]

You remove the resistor so you dont break it when you reach your arm/shopvac into the fan opening.

[dhaney]

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.

Dan

[stevedmc]

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.

Dan

Not in the south and especially not in Baton Rouge. In fact, one guy reported it got so hot in Houston that his cup holder melted. He tried to blame it on DMCH for leaving his car in the sun.

[dhaney]

Not in the south and especially not in Baton Rouge. In fact, one guy reported it got so hot in Houston that his cup holder melted. He tried to blame it on DMCH for leaving his car in the sun.

That was me and it is true, the car was SITTING IN THE HOT SUN, on a concrete slab in the middle of a concrete jungle. It was not being driven around with the AC on. It was DMCH that left my car sitting all day every day in the hot sun for 7-9 weeks...

I can promise you that since 1985 that was the only time my car has spent more than one day in a row sitting in direct sunlight.... Hell even in Gettysburg I found a shade tree to park it under and in Vegas we were in a covered garage....

And yes the cup holder was brand spanking new when I took my car to them... But I do agee the true root of the problem with the cup holder lies with the manufacturer...

Back on topic... although I've never had my Delorean in Baton rouge or even anywhere in la, I've spent a lot of time in Louisiana in the Summer months all the way from NO to Morgan City, Lafayette (Yes I've eaten at the Blue Dog ;)) and New Iberia and even passed through Baton Rouge a few times and every rental car I've had has been nice and cool.... so I KNOW a good working AC system will certainly cool the entire inside of the car even in the "SOUTH"!

But as I tried to say... I understand the personal preference of having it blow in your face...

Dan

[stevedmc]

There is a huge difference between a short trip to the store and driving a car for several hours that has already had a chance to cool down. If you were simply driving through Louisiana your car already had the luxury of a cool interior.

My AC cools the whole car just fine as well but after baking in the sun it does take a few minutes longer to cool the whole car vs when it has been sitting in the shade. I would much rather the vents blast cold air in my face while I am waiting for the whole interior to cool down.

[dhaney]

There is a huge difference between a short trip to the store and driving a car for several hours that has already had a chance to cool down. If you were simply driving through Louisiana your car already had the luxury of a cool interior.

My AC cools the whole car just fine as well but after baking in the sun it does take a few minutes longer to cool the whole car vs when it has been sitting in the shade. I would much rather the vents blast cold air in my face while I am waiting for the whole interior to cool down.

I don't know why you want to fight with me but last I checked..... NO to Lafayette was almost 3 hours driving....Add to that the fact that I would spend several days there driving around the state for hours on end visiting various oil & gas equipment suppliers... Lafayette to Morgan City... more than an hour one way... Or you go to Houma from Morgan City and then drive from there back to Lafayette... 2 hours.... I agree short trips are different but don't you think I would get plenty of those as well?? From an office site to a resturant for lunch as an example... From the hotel to the airport... Trust me I have spent plenty of time in Louisiana and Houston humidity including a period of 1 year and 4 months where I literally commuted to Houston for work. I got on a plane on Monday morning... grabbed a rental car and went to work all week... and got back on a plane to Denver on Friday. Every night I drove the 4 miles from the office to my apartment and regularly took trips from there to Rice University to work out or to resturants and the like... Trust me I understand and really dislike hot and humid...

As I said TWICE already.... I certainly understand the personal preference of having the AC hit you in the face!

Dan

[Bitsyncmaster]

I still think the difference in AC in the D is due to the direct sun light heating up the dash. Maybe just the angle of the windshield or the fact the glass is not like todays car glass.

My daily driver (2005 Malibu) takes a good 10 minutes driving with it's AC on MAX to cool the car down after sitting in the 100 degree summer sun. The D may take a half hour to cool down.

Both are probably the same time on a cloudy day.

[stevedmc]

I don't know why you want to fight with me

Its not a fight. I just don't think it is fair to compare the design of a poorly designed 30 year old car to a modern car with years of development behind it. These cars suck and I do whatever I can to make mine better. Try driving a Delorean in 104 degree heat with a perfect AC (and no window tint) that has been sitting in the sun for hours and tell me how you like it.

I almost forgot to mention that most modern cars have windows that you can open for a few minutes to let some of the hot air out. We don't really have that luxury in Deloreans. The windows are so small that you practically have to be a basketball player to succeed in throwing trash out the window.

[dhaney]

I almost forgot to mention that most modern cars have windows that you can open for a few minutes to let some of the hot air out. We don't really have that luxury in Deloreans. The windows are so small that you practically have to be a basketball player to succeed in throwing trash out the window.

I personally feel my car with R12 gets colder quicker than my daily driver. Obviously the space in the Delorean is smaller...

But I conceed that generally you are right modern cars have better windows and are more efficent at moving air... But a bit of tint for the windows and a good working AC and that is the best you can do.

As far as letting the hot air out, we've got something even better than a big window to let the heat out, Gullwing doors!! Ever notice that when your car is closed up and you open the door how much hot air hits you in the face.... It escapes right away as you open the door.

Dan

[stevedmc]

As far as letting the hot air out, we've got something even better than a big window to let the heat out, Gullwing doors!! Ever notice that when your car is closed up and you open the door how much hot air hits you in the face.... It escapes right away as you open the door.

Dan

I have never noticed this. Maybe I will start driving on the highway with the doors open to see what happens.

[Ron]

Have you considered installing a solar powered ventilator?
I guess the window mounted ones are out of the question for a D, w/o making a custom mount to keep the rain out. But, if it's all that bad, you can always find a good place to add a vent hole...

[1batt4u]

How about after putting the foam in, then wrapping the holes with some cork tape??

[stevedmc]

I think I am going to just install a sun roof.

Btw, its really not that bad and at this point I am just joking since the purists dont like my little mod. Did I mention that I am carbureted as well? Now I know how Bill feels. I mentioned a simple mod that works for me and all of a sudden people are attacking it.

[Chris 16409]

As you can tell from my post on page 2, I think it's a great idea! Additionally, now that the black air duct on the driver's side it out of the car, that's one less step I have to do if I need to remove the binnacle.

[stevedmc]

As you can tell from my post on page 2, I think it's a great idea! Additionally, now that the black air duct on the driver's side it out of the car, that's one less step I have to do if I need to remove the binnacle.

Thanks. At least you and Farrar are on my side.

[stevedmc]

Today I drove the car to work and decided to leave a thermometer in it to check the parking lot temperature. After sitting in the parking lot all day it had a pleasant inside temperature of 155 degrees.

It was very nice to have cold air blasting in my face while I waited for the rest of the car to cool down. It took about 10 or 15 minutes for the cabin to get cool and I never made a drop of sweat while I was waiting.

[1batt4u]

Today I drove the car to work and decided to leave a thermometer in it to check the parking lot temperature. After sitting in the parking lot all day it had a pleasant inside temperature of 155 degrees.

It was very nice to have cold air blasting in my face while I waited for the rest of the car to cool down. It took about 10 or 15 minutes for the cabin to get cool and I never made a drop of sweat while I was waiting.

155 degrees, huh? Perfect temperature to put some leatherique all over!!

I think I will probably do the same thing, disable the door vents in order to increase airflow to the center vents!!

[jmrydholm]

My favorite quote in the BTTF game they recently made is when Marty complains in Episode 3 about the "stupid design" of the DeLorean's windows. In the summer, I feel his pain! I think I may have to vacuum out one of my center vents; the passenger side blows air full strength, but the driver's side is about half that, even with the fan on full. Maybe my seal broke on the duct work.

[Grover]

My favorite quote in the BTTF game they recently made is when Marty complains in Episode 3 about the "stupid design" of the DeLorean's windows. In the summer, I feel his pain! I think I may have to vacuum out one of my center vents; the passenger side blows air full strength, but the driver's side is about half that, even with the fan on full. Maybe my seal broke on the duct work.

That is normal. The driver side center vent blows a lot less than the passenger center vent.

[jmrydholm]

Ah, I never realized that! I assumed I just had more broken, decaying stuff to fix. My driver's side door pipe came off where the duct meets the flexible hose under the dash. Sigh...poor #10715. Always something. :) So worth it, though.

[Ryan King]

How do you get into the evaporator box?

[Jacko]

I have to agree that the center vents directed at my face certainly feels good on a hot day in the D.
A few years ago when I drove the Delorean a lot it was common for me to be behind the wheel for hours at a time with that cold air hitting me in the face ... felt good ... but I finally realised that cold air in my face was causing sinus inflammation and incessant summer colds. I did it for years before figuring it out. I stopped the air in my face and the colds went away. :biggrin:

[Farrar]

How do you get into the evaporator box?

Remove the passenger knee pad, center console and radio/HVAC bracket, blower motor, ducting, etc. to get to the box. Drain coolant, disconnect hoses from evaporator and heater core. Remove the box, hoping you don't break it.

All of these steps are interspersed with various ancient and modern oaths, from what I understand.

Farrar

[Bitsyncmaster]

Remove the passenger knee pad, center console and radio/HVAC bracket, blower motor, ducting, etc. to get to the box. Drain coolant, disconnect hoses from evaporator and heater core. Remove the box, hoping you don't break it.

All of these steps are interspersed with various ancient and modern oaths, from what I understand.

Farrar

You pretty much got it. But you have to remove the passenger seat and I recommend you remove the passenger carpet.

[dhaney]

Remove the passenger knee pad, center console and radio/HVAC bracket, blower motor, ducting, etc. to get to the box. Drain coolant, disconnect hoses from evaporator and heater core. Remove the box, hoping you don't break it.

All of these steps are interspersed with various ancient and modern oaths, from what I understand.

Farrar

It's really not too bad, especially after you remove all of the above, I'd take out the passanger side seat as well. It will give you more room to work in. Took me about 2 hours to get it all out.

When I did this job my only mistake was forgetting to line up the drain my OEM drain was in really good shape but when I put things back together I broke it and had to use the coil boot method instead.

Tinkering with wiring tightening things up and sealing the cooling/heater box with sealant made putting things back together a couple of day job but that was a labor of love and I couldn't be happier with the end result.

Dan

[A Van]

Remove the passenger knee pad, center console and radio/HVAC bracket, blower motor, ducting, etc. to get to the box. Drain coolant, disconnect hoses from evaporator and heater core. Remove the box, hoping you don't break it.

All of these steps are interspersed with various ancient and modern oaths, from what I understand.

Farrar

I would replace interspersed with "constant stream" or "continuous"

[Ryan King]

Remove the passenger knee pad, center console and radio/HVAC bracket, blower motor, ducting, etc. to get to the box. Drain coolant, disconnect hoses from evaporator and heater core. Remove the box, hoping you don't break it.

All of these steps are interspersed with various ancient and modern oaths, from what I understand.

Farrar

Drain the engine coolant you mean? Yikes. All just to get into the evaporator? Which box do you speak of? I'm just a little lost...I have never done it before.

My other question is what all gets into the evaporator? Is there anything I should change while I take on a big project like this?

[Bitsyncmaster]

The heater, AC and all the duct doors and package are all in a large box. That box need to be removed to get access to any component in it.

So yes, you must drain the coolant and the AC is disconnected.