Classic Retrofit Blower force users check

[Nditiz1]

*Note - originally I started this thread as I was under the impression my blower was under performing compared to other users. This does not seem like the case. I feel I am within the variance of setups and test equipment.


I didn't want to clog my own thread nor the main CR thread with this air speed check. If you have the system install and own/can barrow an anemometer could you please post your Center Vent, Side Vent, lower foot vent speed as well as your car? I'm sorry to revisit this, but I believe there is some discrepancy.

***************UPDATE
To get a sense if you are within adequate variance, see the below setup

Top defroster vents not blowing, floor vents not blowing. Battery fully charged. Engine not running. Center vent pointing directly forward. Max blower speed. Tiny side vents. Blower driver port blocked as I do not have a lower center bow tie.

Fully blocked fresh air - Center vent - 10.1
Restricted fresh air - Center vent - 10.7
Fully open fresh air - Center vent - 11.0

***************

[Jonny H]

The readings you get will vary a great deal depending on:

1) the battery voltage E.g. whether the engine running.

2) size of vents. 3.2 large vents will record a lower speed than the smaller early vents.

3) whether you have the under dash snorkel tubes fitted or our swivel ducts.

4). anemometer. Most are cheap instruments rather than calibrated measurement equipment. The size of the propeller makes a difference too.

5. If you have the hood inlet gasket fully blocked.

[Nditiz1]

Jonny -

For the most part I am wanting to see what the center vent is pushing out. If someone is able to produce 12+mph out of the center vent (engine off) then I need to figure out what is going on and why I'm not getting those values.

While I realize anemometer can be inaccurate do you think from 1 version to the other it is off by more than 5%? I will glad send mine for a like to like comparison.

The center vent being blocked or not should not matter if the car is sitting, unless of course it is a windy day.

[Jonny H]

Originally Posted by Nditiz1

Jonny -

For the most part I am wanting to see what the center vent is pushing out. If someone is able to produce 12+mph out of the center vent (engine off) then I need to figure out what is going on and why I'm not getting those values.

While I realize anemometer can be inaccurate do you think from 1 version to the other it is off by more than 5%? I will glad send mine for a like to like comparison.

The center vent being blocked or not should not matter if the car is sitting, unless of course it is a windy day.

Battery resting voltage when engine off will be different depending on how long the car has sat there. Not a good test.

The anemometer head size and how you hold it onto the vent does affect the reading.

The centre inlet vent opening absolutely DOES affect the amount of air that can be drawn in to the blower, hence how much it can blow out too!

[timmy2]

I took the readings today as per Rocco’s request. On my 78 SC.
All vents open, fan on max, ignition on, Engine not running, battery fully charged.
I was using the anemometer Rocco sent me.
Results:
Top center dash vent - 12.5 to 13 mph
Small side dash vents - 8.5 mph each.
Center lower “bow tie” vents from old system - 6 mph
I was getting nothing from the 2 outside under dash vents, likely need to adjust the Bowden cables.
Front screen is not fully blocked, only has the restricted flow piece Johnny send out.

[Nditiz1]

Dennis,
Can you disconnect the blower bowden and close the flaps (lever goes towards passenger side). This should make it so only the center, side, and lower center vents get air. Then, read the center vent? If it comes out the same you are still 4-5 mph faster out of the center than me which is a huge difference. That's the difference between sitting back and feeling the center on your face and not.

[timmy2]

Actually that is how I tested it, the top slider was all the way to the left which closes those vents. Now I know how to get the lower outside ones to flow!

[timmy2]

Just tested again sliding things around.
I get 12 mph out the bottom vents with top slider in the middle, high speed.
The top vent dropped down to about 8-10 mph with full flow out the bottom.
Side dash vents were 7.5 mph
Center bow tie vents were 5 mph
If I restrict the lower output to about 5 mph with the slider, the top center vent goes back up to 12-13 mph

[timmy2]

One note of interest is by getting all the ports/vents open and flowing, the small white styrofoam bits from the old style packaging that was falling apart, and went into the blower unit flew out!

[Nditiz1]

Originally Posted by timmy2

One note of interest is by getting all the ports/vents open and flowing, the small white styrofoam bits from the old style packaging that was falling apart, and went into the blower unit flew out!

Hahahahaha!

Ok I have an update and will amend my original post.

Jonny WAS correct in stating that the blower top vents affect the blower speed at rest. I was under the impression the opening that pulls from the cabin was enough opening to pull in air. I tested fully open, restrictor plate, and full close.

I also had my vents directed towards me for the center. When I faced it forward I was able to get 10.1 out of the center. That is an increase from 8.9. While not Dennis's 12 - 13 this could be a result of the different anemometer's.

Also, I think that the blocking off of the driver blower port is hindering the performance of my system. I might cut a hole and install the bow tie vent.

I would like to perform some more testing with the heat and the center outside fresh air unblocked.

Fully blocked fresh air - Center vent - 10.1
Restricted fresh air - Center vent - 10.7
Fully open fresh air - Center vent - 11.0

[targa80]

First off thanks to Nick (nditiz1) for creating this post.

Ok, I am a little confused on what is what on some of the vents terminology. We all know what it was like to make adjustments to the 3 or 4 slider vent control system for the first time. (say what!) My car was an 80SC with factory AC And the owners manual has the following pages:

Ventilation and heating page:

I do not have this slider configuration since I had factory air that changes the top two levers to one lever for ventilation and fan speed. So, I understand that to mean when I move my one top lever to the right I get fresh air and fan speed for the lower blend footwell vent and or the upper blend window defrost vent based on the location of the middle slider. The upper slider was not used with the Factory AC if you wanted max cooling. Also, the factory evaporator/blower pulled it’s own recirculating air from the passenger footwell when the AC was on.



Lower blend footwell vent:

This vent has several functions, it provides fresh air (top slider to right and center slider to the left) or heat (if bottom red slider is moved to the right). This lower blend footwell vent also draws in recirculating air from cabin.



Upper blend window defrost vent:

This vent has several functions, it provides fresh air (top slider to right the center slider must be to the right) or heat (if bottom red slider is moved to the right).





Air Conditioning page:

This shows the slider configuration in my car with AC. The AC was controlled by a fan speed and temp control in the center shifter console. It states max cooling requires the fresh air vents be closed. So I would NOT have used my upper slide lever with the factory air unless I wanted to add warm fresh air to the car. (Why would I do that?)




In factory AC cars, the center, side, bow tie and passenger side foot well vent only supply AC air.

Center vents:





Side vents/side window defrost vents:





Bow tie vent:



Passenger foot well vent:





With the CR system installed, I used all of the blower AC output ducts to feed all of the vents, center, side, bow tie, passenger side footwell and blend valve vents. The window defrost vent will also supply AC when the center slider is moved to the right. The amount of fresh air supplied to the system is based on how much of the front outside intake vent is closed off. The CR gasket I believe allows 25% of fresh air into the system. I have tried different levels of allowed fresh air and eliminating all fresh air provides lower evaporator/blower vent temps but at a reduced air flow speed. Also, using all of the output lines from the evaporator/blower lowers the speed at each of the vents. It is most noticeable at the center dash vents because you can not feel the air hit your face when it is pointed at you. I do not have a anemometer and have no plans of buying one so I am going with the in your face method and tissue paper taped to the center vent.

I am in the process of I hate to say it jeri-rigging up a booster fan for just the center dash vents (using the old fresh air blower motor and a different intake case. It won’t be pretty but so far it adds more air movement in the center vents that you can feel it hit your face when driving. It will take up additional space in the frunk but I can live with that if it works. Also, it would be tied into the the top slider 3 speed control and would provide added boost at each of the three speeds.

[targa80]

With all of the inputs and outputs of CR evaporator/blower being used on my car it did not provide the volume of moving air you would expect especially on the high setting. The two small side vents, bow tie vent and the blend outlet vents are ok but the output of the center vent was not strong as you would expect. I did not feel the air hitting my face when driving. so I decided to try something else.

This afternoon I tested out my jeri-rigged booster fan that was made out of the old fresh air blower and a few items from the Home Depot plumbing dept. I removed the rod and the two valves from both output ports since they are no longer needed. The booster fan was then installed between the evaporator/blower output and the center vent input. Also, I temporarily Jumpered the high speed setting of the fan to power and ground. The center vent now has enough movement of air that you can feel it on your face. Next I will wire up a jumper cable so it will be controlled by the three speed slider switch.



Hopefully, someone with a 3D printer can design a new case for the old blower fan that reduces the overall size of the unit compared to my jeri-rig HD plumbing setup. I don’t have an issue with installing it in the frunk on the passenger side.

[Nditiz1]

Pat great work! I am going to replicate this setup and do some heat soak testing.

[targa80]

The power connector is as follows:

Notch is on top of connector
Pin 1 = 12 volts
Pin 3 = low speed to ground
Pin 2 = med speed to ground
Pin 4 = high speed to ground



The following parts were used minus the “T” fitting, instead I went with a 2” 90 degree street elbow for the input.



I used a sticky foam strip to mate the fan to the plumbing fixture. Also, there are two screw holders inside the bowl that I cut away. I also filed a notch for where the power cable enters the shroud.




I used a small angle bracket and a large small holed washer with a screw and cinch nut in two locations 180 degrees apart to hold the two half’s together.

[targa80]

The testing I did yesterday involved driving the car for 10 minute intervals and changing the Cabin Temp Set (CTS) point each time. The outside temp was at ~85F and humidity was ~73%. I am using two digital temp probes. Cabin probe is mounted just below the clock. The vent temp is located in the passenger foot well vent. I am driving on two/four lane roads with traffic lights, average speed between 35 - 45 mph.

Started with CR recommended CTS = 21
CTS = 21
Cabin Temp = 88
Vent Temp = 80

After 10 minutes:
CTS =21
Cabin Temp = 84
Vent Temp = 56

After 10 minutes:
Changed CTS =15
Cabin Temp = 80
Vent Temp = 48

After 10 minutes:
Changed CTS = 10
Cabin Temp = 79
Vent Temp = 47

Today, I will run the AC at a CTS = 15 over a longer period of time.

[Nditiz1]

Last night I took a brief video of Pat's setup and the differences in air flow. The real test will be to see if temps go down faster.

https://youtu.be/5ko9lGTBmQ4

Center vent speed CR setup - 8.0 mph
Center vent speed with stock blower added between CR blower and Center vent (blower off) - 5.4 mph
Center vent speed with stock blower on - 12.5 mph

[targa80]

The original slider fresh air blower motor circuit is tied to fuse 12 (25A) along with the rear window defogger switch/relay coil. The power for the rear window heating element is on fuse 24 (25A). This is good because the fresh air blower circuit can handle both the CR evaporator/blower motor and the added original fresh air blower used as as a booster fan. I checked the current draw on both fans at each speed.

CR evaporator/blower:
Low = 3.8 amps
Med = 4.5 amps
High = 5.7 amps

Original fresh air blower as a booster fan:
Low = 2.5 amps
Med = 4.0 amps
High = 7.0 amps

Combined current draw with both fans on slider fresh air blower circuit:
Low = 6.3 amps
Med = 8.5 amps
High = 12.7 amps

[targa80]

Originally Posted by Nditiz1

Last night I took a brief video of Pat's setup and the differences in air flow. The real test will be to see if temps go down faster.

https://youtu.be/5ko9lGTBmQ4

Center vent speed CR setup - 8.0 mph
Center vent speed with stock blower added between CR blower and Center vent (blower off) - 5.4 mph
Center vent speed with stock blower on - 12.5 mph

Nick,

You are fast, from what I can see you still have the rod and the two flaps on the original blower. You will want to remove at least the flap on the output side of the blower. Also, you might want to try a 2” 90 degree street elbow on the input. As you can see from my other post that the setting of the CTS is critical in lowering the vent temps. It will be an individual choice on how low to set the CTS. The lower the CTS the lower vent temps, but that causes higher current draw, higher duty cycle and lower voltage output. Hopefully later today, I will wire in the second fan and test the system on each of the three speeds. I thought I had the old evaporator and the harness but the plug on the harness was damaged and I already trashed the evaporator along with the other old AC parts. Don’t know what the added harness will look like yet, need to figure that out.

[PorterF]

Great work guys!

If Spal does indeed make a higher CFM blower that fits in the CR evap housing that would seem like the way to go. I have the Griffiths high output evap blower in my '82 and I use the 2 speed most of the time, but it really helps to be able to crank it up to 3 if needed.

Targa80 that was interesting to see the CTS changes. Was there any cloud cover that day? That could skew the results.

Since opening the fresh air vent yielded a 10% increase in Nditiz's airflow. Another experiment would be to have more return air from the cabin. I know there is the trapezoid shaped hole in the firewall connecting to the smuggler's box.

Not sure how hard it would be to duct that to the CR evap/blower unit, a quicker test would be to just open the hole in the firewall and one into the intake side of the CR blower, use the whole frunk as a return plenum. The return air from the frunk could be spliced in to the CR unit with a Y fitting.

Perhaps not a long term solution since you are now cooling all that area, but should be better than completely unconditioned air. At least will give us an idea about the return side being a bottleneck. (This could also solve the condensation issues Pat is having)

[targa80]

PorterF,

Presently, I have the front fresh air vent closed off completely. Recirculating air from the cabin is going into both lower blend valves and into both sides of the evaporator/blower. The airflow speed drops when you completely close off the fresh air source. The benefit is lower evaporator temps since all the air is recirculated. I cannot rave about the center vent output I was getting with all of the outputs on the evaporator/blower being used. Hence, the reason for the added booster blower on the center vent line. Now I can feel the air from the center vent in my face while I’m driving. It will be a while before I figure out all the settings to give me the best cooling without overtaxing the charger/battery system.