Doug's A/C System, R&D/Build Thread Options

[Literati914]

In order to improve the airflow into the frunk mounted AC condenser, has anyone tried creating an air inlet by opening up the holes behind the front bumper that have the biground rubber plugs, like guys who run 914-6 engines do when building a front mounted oil cooler and ducting into the frunk floor?

GT opening for a condenser instead of oil cooler or radiator (Suby/v8 cars). Sounds like the way to go if you are serious about a/c. It’s the optimal location for airflow.

I like this idea the best.. would A GT opening (both bumper and Valance) be sufficient for air to the condenser? I suppose even at GT oil cooler shroud could be incorporated and may even help the flow? Thoughts?


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[technicalninja]

You're already in...

I wouldn't waste my time on that itsy bitsy core.

You live in HELL!

Design accordingly...

You're already there!

I'd get my tape measure out and figure out how big a core you can fit.

Depending on your hose set up a proper big single core might just fit.

The connections will be the same most likely...
#8 and #6.

[friethmiller]

You're already in...

I wouldn't waste my time on that itsy bitsy core.

You live in HELL!

Design accordingly...

You're already there!

I'd get my tape measure out and figure out how big a core you can fit.

Depending on your hose set up a proper big single core might just fit.

The connections will be the same most likely...
#8 and #6.

(IMG:style_emoticons/default/idea.gif) I think/know you're right. So, pull air from a new hole/intake from the valance/bumper area. Screw the bottom intake crap and use the entire area for the condenser and fan. This seems like a better way to go. I'm all for it!

[friethmiller]

@technicalninja - I called and talked with one of the techs at old air. He said parallel flow condensers should not be mounted flat - like I have. It must drain to the smaller, liquid side. Crap! More redesign. I may just put on a better 12” fan, increase the intake air, and see how it goes (IMG:style_emoticons/default/wacko.gif)

[technicalninja]

I disagree with him...

Read my previous posts.

I've covered the oiling issue already.

Lots of things have condensers and evaporators at not "textbook" angles.

Don't automatically believe every expert you speak with.

Most are FAR less expert than they think they are...

He is RIGHT about vertically mounted condensers needing the input at the top and the exit at that bottom. Do it backwards and the reaper awaits.

Laying the condenser flat is not a deal killer. I'm more worried about fan life myself...

[Chris914n6]

From what I can tell what you have now should work fine. The dealer options worked fine.

You need a PULLER fan. Pushers don't work worth a turd. If TN was right you can just reverse the wires on the fan you have and it will actually work as designed.

Skinny fans won't move much air, so it becomes a space issue. The Chinese don't do CFM measurements, they just copy and most of their fans under preform. If the current fan doesn't cut it buy a thick Spal fan.

The cardboard duct can be trashed.
It would be better to structure the opening further forward under the spoiler/bumper with it flowing wide and shallow to the cond inlet. The mouth can be as big as needed but really your limited to the area of the exit hole.

Pardon my crude drawing, but this should solve most of the problems by changing placement and maybe a new enclosure.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1713419868.1.jpg)

[friethmiller]

From what I can tell what you have now should work fine. The dealer options worked fine.

You need a PULLER fan. Pushers don't work worth a turd. If TN was right you can just reverse the wires on the fan you have and it will actually work as designed.

Skinny fans won't move much air, so it becomes a space issue. The Chinese don't do CFM measurements, they just copy and most of their fans under preform. If the current fan doesn't cut it buy a thick Spal fan.

The cardboard duct can be trashed.
It would be better to structure the opening further forward under the spoiler/bumper with it flowing wide and shallow to the cond inlet. The mouth can be as big as needed but really your limited to the area of the exit hole.

Pardon my crude drawing, but this should solve most of the problems by changing placement and maybe a new enclosure.

Thanks Chris. A few things I like about this design is that it trades exhaust for more intake space, which I need. Additionally, the puller fan set-up. That said, as you mentioned, the enclosure would likely need to be increased in height (at a minimum). The existing condenser is 14"x12"x1" and it sits inside a 16"x16"x4" box. Another issue I'm dealing with is the full-sized spare tire. It mounts to the top of the box and I have a factory style funk cover on top of that. I've customized this cover to work with everything. I guess I'm trying to find the optimal solution here based on my constraints.

Again, thanks for your input, TN's, and others. I'll keep this all in mind moving forward. Just based on expenses, I may implement something quick to improve the current situation then plan and execute on a better, more permanent fix later this year.

[914sgofast2]

I would change that design by having the outside air enter the front of the air box, instead of the bottom. That way it is similar to how many people mount front oil coolers for the 914-6 engines in the frunk when they collect the cooler outside air thru the front bumper cutout, instead of from under the frunk floor, and then exhaust the air under the car from the frunk floor, similar to how the original A/C systems exhausted their hot air under the car. This would require building some metal ducting from the front bumper area to the original A/C air box' front and opening up the front of that air box. Think of how Mike Cairo's Six Project is making a new front oil cooler housing.