Griffith's AC upgrade for '84 911 install thread

[pavegeno]

Skip1...let me know next time you are in Stuttgart. We'll stay "Keuhl" on a Black Forest run.

[wwest]

Originally Posted by Skip1

I did not, as I wouldn't know where to begin - as I said, I'm a newbie at AC systems. The console is all reassembled now, as is the evaporator.

When you get to the point wherein you have the time, or the NEED, let me know and I, or Charlie, can walk you through a procedure that will allow you to check the calibration without any disassembly. Then, if need be, mark the control with a "CW beyond this point is sub-freezing".

[Skip1]

Originally Posted by wwest

When you get to the point wherein you have the time, or the NEED, let me know and I, or Charlie, can walk you through a procedure that will allow you to check the calibration without any disassembly. Then, if need be, mark the control with a "CW beyond this point is sub-freezing".

Thanks, sounds like a plan.

[Skip1]

Originally Posted by pavegeno

Skip1...let me know next time you are in Stuttgart. We'll stay "Keuhl" on a Black Forest run.

Don't get down that way very often, but will do. Thanks.

[DaveMcKenz]

Originally Posted by homfkb

Thanks for the comments thus far. I will certainly try to answer the specific queries posed and include pictures for clarification as best I can.

I'm sure looking forward to your contribution.
Dave

[DaveMcKenz]

Originally Posted by homfkb

Thanks for the comments thus far. I will certainly try to answer the specific queries posed and include pictures for clarification as best I can.

I'm sure looking forward to your contribution.
Dave

[kuehl]

Originally Posted by wwest

Not so sure about Griffith's aftermarket front lip condenser but the factory one benefits so greatly from forward motion cooling airflow that the blower can be de-powered >20 MPH.

Willy,
1) The factory front condenser does not benefit anymore than any other
from under tub draft; and later model 911's have a rubber lip option that blocks any air flow directly.
2) The factory design relies on the blower motor.
3) The Kuehl serpentine design allows more air flow through the entire
unit vs. the factory. We know this because we tested the original prototype design
some 10 years ago as well as the latest design.
4) This thread is suppose to be about the OP car owners experience installing upgrades, not about your repetitive comments you post in every AC thread. At this point you have posted more comments than the OP. Why don't you sit back and wait to see how his project turns out rather than hijacking his thread.


Griffith's next generation front condenser is 75% thicker.

[zippy_gg]

Originally Posted by kuehl

willy,
1) the factory front condenser does not benefit anymore than any other
from under tub draft; and later model 911's have a rubber lip option that blocks any air flow directly.
2) the factory design relies on the blower motor.
3) the kuehl serpentine design allows more air flow through the entire
unit vs. The factory. We know this because we tested the original prototype design
some 10 years ago as well as the latest design.
4) this thread is suppose to be about the op car owners experience installing upgrades, not about your repetitive comments you post in every ac thread. At this point you have posted more comments than the op. Why don't you sit back and wait to see how his project turns out rather than hijacking his thread.


Griffith's next generation front condenser is 75% thicker.

+1

[wwest]

Originally Posted by kuehl

Willy,
1) The factory front condenser does not benefit anymore than any other
from under tub draft;

Charlie, any JUNIOR HVAC engineer, actually, anyone with just a bit of common sense would understand that the factory tube and fin design allows for cooling airflow from upward or forward, whereas yours and KelogGes' clearly present a FLAT surface to roadspeed airflow. What you both need is some method for creating differential air pressure either above or below your front lip condensers.


and later model 911's have a rubber lip option that blocks any air flow directly.

Point taken. But, if the rubber lip option on my '78 blocks any direct air flow how is it that the flat forward face of yours and KelogGes" does not..???


2) The factory design relies on the blower motor.

Yes, absolutely, but there is no evidence that it is any help at all except when roadspeed and engine RPM are consistently low. But simple logic indicates that the blower may not be required "at speed" with the factory condenser.

3) The Kuehl serpentine design allows more air flow through the entire
unit vs. the factory.

From the factory lower a big NO to that, more efficient use of the blower airflow, a YES just as big!

More roadspeed airflow, NOT, a bit of dreaming on yours and KelpgGes' part.

We know this because we tested the original prototype design
some 10 years ago as well as the latest design.

Then prove it. Since simple logic says otherwise then post the conditions and results both before and after.

4) This thread is suppose to be about the OP car owners experience installing upgrades, not about your repetitive comments you post in every AC thread. At this point you have posted more comments than the OP. Why don't you sit back and wait to see how his project turns out rather than hijacking his thread.

I work, diligently, to be sure my comments are productive.

[Ronnie's.930]

Originally Posted by kuehl

Why don't you sit back and wait to see how his project turns out rather than hijacking his thread.

Well Griff, it looks like you might have well asked a bear not to **** in the woods . . .

[uwanna]

Ya know, it kinda looks like embarrasing this Williard clown is much like "trying to give a fish a bath". He's too dense to understand.
Or better yet, it's like wrestling in the mud with a pig, all you do is get dirty and the pig loves it.
GO AWAY!!!

[carreradpt]

Skip, how's the upgrade coming along?

[Skip1]

OK, so after a two week sabbatical on holidays across Europe, this morning it was back at it. In accordance with Griffith's recommendations, my next step should be installing the condensers. I have a new front condenser, a new rear LH wheel well condenser, and need to reinstall the OEM decklid condenser. Then it'll be on the the hoses - oh joy :-).

So this morning, I drove the car up onto my ramps to attack the front condenser replacement, which in principal is pretty simple, just pesky a little if you don't have the car very high (ramps don't give you too much clearance to move around - hope you're flexible :-)). I figured I could do this job without removing the crash bar, but during the process decided, for three bolts, it would save me some cursing thanks to my large sausage fingers and fiddling with the three 10mm bolts that hold the assembly up. Here are some before pics (I'd already R&R'd the crash bar a while ago, which made it simple to remove):




I had to spray some Liquid Wrench onto the bolts on the passenger side which have fixed nuts on the inside of the front trunk area as they were rusted in place and didn't want to break them off. Once loose, the assembly came down pretty easily, as did 31 years of dirt (be wary so you don't get it in the face). Once down just also be cautious of the four fan mounting self-tapping screws protruding downward into the area. While I didn't have any mishap, this could be quite a painful and rusty experience if you're not careful.





I first placed the new condenser on the three bolts slightly loose in order to ensure the fit and reduce the "holding it up while trying to secure the basket as well. It certainly would be possible to do it simultaneously, but as I didn't have much clearance, this seemed like a prudent move.



Once in place, I removed the passenger side basket bracket holding bolt (not sure what else to call it, in order to mount the protective basket. I had to put some newspaper into my 10mm socket in order to push the bolt out a little further to more easily catch the thread, as the cursing had started at this point. The addition of paper worked quite well. Once it caught the thread, I then slid the basket into place, and left the bolt a little loose while I worked the other side the same way. Once in place, I tightened all three bolts. You'll note that the support brackets are still a bit bent, but I don't have a vise locally, and wasn't quite sure on the angles to use (I think it should be two 90 degree angles based on what they look like, thoughts anyone?

As I haven't installed the hoses yet, I left the protective caps on the new condenser and packaged up the new o-rings that came with it for future install use. I then reinstalled the crash bar and tightened it up as well.





The last picture shows the location of the front condenser fan housing (I was able to remove it without taking the battery out, but will take the battery out for reinstall to ensure I don't break it. It has been removed at this point as replacing its motor is the next phase - you can see the new condenser through the hole in the tub.

[Skip1]

So, further today, I was able to change the motor in the front condenser fan housing. It's not particularly difficult, just takes time, as (again, in accordance with Griff's recommendation) I used a fair bit of liquid wrench on the set screw and motor shaft that holds the motor to the squirrel cage - it was on there tight.

The fan housing is pretty weak in its design I think, but then, I'm no engineer either .



The plastic body is pretty thin, so be careful when removing the metal clips holding the two sides together. Once the two halves were separated, I measured the clearance from the base of the squirrel cage to the plastic housing to ensure I put it back to the same point on the new motor shaft (don't ask me what it was cause I can't find where I wrote it down - sorry), I cleaned everything, and then set to work in slowly working the motor and squirrel cage out of the one side - it's pressure fit on three sides and simply pushes out, once you remove the single screw, and odd washer from the end of the cone.





Pushing the wiring slightly into the body was necessary, to get the requisite clearance to remove the male and female connectors off the motor - no need to worry where they go, as they have the male and female connector ends already attached.

This is where you have to be patient I think. in order to remove the squirrel cage from the motor shaft there is a 2mm allen set screw (covered in red paint in my case), which has to be loosened. Mine wouldn't budge, so liquid wrench and several hours were my friend. While likely obvious to some, there is a small hole in one the the fins of the squirrel cage for that little allen key to fit through (ingenious I thought).



Realignment was pretty simple IMHO using the measurement I had taken prior to pulling the motor out of the housing. Reassembling the housing was simple, except that there are actually two broken tabs and missing clips. I haven't figured out the best way to connect the two sides properly, but luckily the tub mounting screws hold the two sides together - will have to revisit this issue, once I figure out the best way to do it. Initially I thought of using a self-tapping screw, however the plastic isn't thick enough to drill through laterally and achieve a tight fit. Perhaps a very small bolt and washer might work, but that's for another day.

Next will be the rear wheel (driver side) condenser. May not get to that this week though, as I'm busy tomorrow for most of the day and back to work on Tuesday. I want to dedicate a day to the condenser. More to come.

[wwest]

I would have been certain that the new motor turns the squirrel cage blower wheel the same direction as the one being removed. It will still move air but at a much degraded level.

[Skip1]

Yes it does, same direction. Better speed with the new motor.

[wwest]

With squirrel cage blowers more "speed" does not necessarily mean more airflow volume.

Completely cover the inlet or outlet, for instance, and the motor will speed UP because it's doing less work.

[Ronnie's.930]

Originally Posted by wwest

Completely cover the inlet or outlet, for instance, and the motor will speed UP because it's doing less work.

Will, what would be the result if YOUR inlets and outlets were covered (say, with Gorilla Tape)?!?!?!

[wwest]

Originally Posted by Skip1

Yes it does, same direction. Better speed with the new motor.

You bought your Griffiths "kit" before April.?

For another $60 you could have avoided the squirrel cage blower wheel removal/re-install hassle.

Bosch (factory) motor + blower wheel.

New Porsche 911-930 Front Condenser Motor and Blower Wheel Assembly

[Skip1]

May 2014 actually :-)

Good to know however, thanks.