Installing the FI interchiller on my Roushcharged Gen3 Coyote

[SH!FT]

Right, I noticed before that the boiling pressure/temp curve for yf1234 is extremely close to 134a, so they are likely interchangeable.

FI was able to provide me a charge weight for 134a.

The factory charge weight for my car is 1.19 lbs of YF. It's also the same for the I4 apparently.

Anyone have a 134a S550 that can share their factory charge weight spec? Sticker is under the hood.

Sponsored

 

[bankyf]

FI was able to provide me a charge weight for 134a.

The factory charge weight for my car is 1.19 lbs of YF. It's also the same for the I4 apparently.

Anyone have a 134a S550 that can share their factory charge weight spec? Sticker is under the hood.

A 2017 mustang took .75kg (roughly 26.5 ounces). It is my understanding and experience that YF systems typically take less refrigerant.

From what I understand, there is a point of diminishing returns when adding coolant capacity to these systems. I have heard of guys adding a trunk mount tank and actually seeing an increase in water temps.

 

[SH!FT]

Thanks @bankyf
Wow quite a bit less YF required. The YF system also has slightly more volume due to the suction line being increased from 12 to 14.

I had my local shop quote me for YF based on the 134a spec that FI provided.
This makes way more sense now why the tech thought I was nuts and the quote was $600-$800 for the recharge.

 

[smokescreens]

From what i understand cooling capacity would drop about 10% going from y1234yf to r134a. I would assume the txv valve along with a/c line ports will need changed.

 

[SH!FT]

From what I understand, there is a point of diminishing returns when adding coolant capacity to these systems. I have heard of guys adding a trunk mount tank and actually seeing an increase in water temps.

Same. I was specifically told no trunk reservoir with the chiller. The heater hoses running to and from the trunk will act as heat exchangers. Also the added fittings and hose length will add load on the pump reducing flow rate.

We want short insulated water lines and high gpm flow rates. Tanks should be insulated and gravity feed the pump.

Based on what I've learned, I think VMP's new ice tank would be an awesome solution as long as its well insulated and could hold over a gallon of liquid.


Findings for adding IC coolant capacity:
I've been researching and bothering the hell out of FI about coolant capacity and plumbing route. FI's install documents provide good stuff on how coolant capacity affects performance on specific applications and how to minimize passive temp gains.

I looked into adding heater hose length, keeping the heat exchanger, and trunk tanks. The heat gain and air/water flow restriction seems to out weigh the benefit of the added coolant for all three cases.

 

[RSKTAKR]

Same. I was specifically told no trunk reservoir with the chiller. The heater hoses running to and from the trunk will act as heat exchangers. Also the added fittings and hose length will add load on the pump reducing flow rate.

We want short insulated water lines and high gpm flow rates. Tanks should be insulated and gravity feed the pump.

Based on what I've learned, I think VMP's new ice tank would be an awesome solution as long as its well insulated and could hold over a gallon of liquid.


Findings for adding IC coolant capacity:
I've been researching and bothering the hell out of FI about coolant capacity and plumbing route. FI's install documents provide good stuff on how coolant capacity affects performance on specific applications and how to minimize passive temp gains.

I looked into adding heater hose length, keeping the heat exchanger, and trunk tanks. The heat gain and air/water flow restriction seems to out weigh the benefit of the added coolant for all three cases.

I was also told no trunk mount ice tank, no 1" ID hoses to and from the ice tank and no more triple pass heat exchanger will be needed. I knew most of this already because they would all defeat the purpose of cold coolant. I am buying a used VMP ice tank this weekend from a friend that isnt using it. I have a 13 Mustang GT so the VMP tank for that car is 2 gallons. I will be moving my EMP pump up front. I am looking around for an option to switch my after cooler (under my blower head unit) in/out hose barbs to AN fittings somehow so that I can just have AN fittings everywhere on the coolant side of things instead of the current 1" ID hose and hose clamps. Someone suggested I look into Autoplumb but I haven't had a chance to just yet.

 

[SH!FT]

If you haven't purchased the interchiller yet see if FI can include them. They seem to have good suppliers.

I just had to order a 14 refrigerant tee fitting through them.

 

[SH!FT]

From what i understand cooling capacity would drop about 10% going from y1234yf to r134a. I would assume the txv valve along with a/c line ports will need changed.

Feedback that I received for my 2020 HVAC system:
"R134a is 100% compatible, colder and cheaper.
You will require R1234yf couplings to plug into the fill ports.
You do not need to add any oil to the AC system unless oil was lost during the install."


TXV should have no issues. Here's the T/P comparison:

 

[smokescreens]

Feedback that I received for my 2020 HVAC system:
"R134a is 100% compatible, colder and cheaper.
You will require R1234yf couplings to plug into the fill ports.
You do not need to add any oil to the AC system unless oil was lost during the install."


TXV should have no issues. Here's the T/P comparison:

Was that from interchiller?

 

[bankyf]

Feedback that I received for my 2020 HVAC system:
"R134a is 100% compatible, colder and cheaper.
You will require R1234yf couplings to plug into the fill ports.
You do not need to add any oil to the AC system unless oil was lost during the install."


TXV should have no issues. Here's the T/P comparison:

If you had your system evacuated, it will always pull out some amount of oil with the refrigerant. The machine would have given a precise measurement of exactly what came out. You will need to put exactly that amount back in. I find it hard to believe that there would be no recommendation for additional oil for the additional capacity of the system. Though it will likely work, it is bad advice. As for how much to add, I'm not sure who could give us an accurate answer. I'll likely add an ounce or so because I know that won't be too much, but it's more than nothing.
It should also be noted for anyone else considering it that while many people do it, and I likely will myself, it is against federal law and considered tampering with emissions equipment to charge a vehicle originally equipped with 1234yf with 134a. Most importantly, if you do charge with 134a, be sure that you absolutely never let anyone unknowingly do any work on that system. Attempting to evacuate 134a into a 1234yf machine will cause the shop a giant headache.

 

[SH!FT]

@smokescreens
The feedback was. The graph is not.


@bankyf good info.
Are you saying some oil will vaporize during evac or that it will be visibly sucked out by the vacuum pump?

As for: "You do not need to add any oil to the AC system unless oil was lost during the install."
I'd consider the evac process as part of the install.

I trust FI and my local shop so I'm not concerned. I'll be changing the label under the hood to R134a and the new charge weight.

I've been attentive about oil loss during the disassembly and while I was "evacuating" the system. I'll be stopping at the dealer to pick up a can of OEM pag oil.

I found some oil trapped in the low point of the liquid line after I cut it. Will likely add at least a half oz into the suction line before installing the tee.

What's not ideal is the install is delayed a week due to not receiving the right size suction tee. This was unknown until I cut the hose on 7/24. The right one should be here on the 1st. I'll install it asap then vac down and seal the system until it's recharged. My recharge date got pushed to the 5th.

I've been religious about sealing open HVAC connections, but the system's been discharged since 7/22. I'll be transparent with the shop and have the system flushed if they recommend it.

Sh!t happens. It's still a fun project.

 

[bankyf]

@smokescreens
The feedback was. The graph is not.


@bankyf good info.
Are you saying some oil will vaporize during evac or that it will be visibly sucked out by the vacuum pump?

As for: "You do not need to add any oil to the AC system unless oil was lost during the install."
I'd consider the evac process as part of the install.

I trust FI and my local shop so I'm not concerned. I'll be changing the label under the hood to R134a and the new charge weight.

I've been attentive about oil loss during the disassembly and while I was "evacuating" the system. I'll be stopping at the dealer to pick up a can of OEM pag oil.

I found some oil trapped in the low point of the liquid line after I cut it. Will likely add at least a half oz into the suction line before installing the tee.

What's not ideal is the install is delayed a week due to not receiving the right size suction tee. This was unknown until I cut the hose on 7/24. The right one should be here on the 1st. I'll install it asap then vac down and seal the system until it's recharged. My recharge date got pushed to the 5th.

I've been religious about sealing open HVAC connections, but the system's been discharged since 7/22. I'll be transparent with the shop and have the system flushed if they recommend it.

Sh!t happens. It's still a fun project.

Correct. When I recover refrigerant on my machines, there is always a measurable amount of oil pulled out. While I can’t see it as it’s coming out, I believe at least some may be vapor. The AC machine will separate it into a translucent container which has markings to show quantity and is also weighed by an internal scale. It is pretty typical to pull an ounce or two out durning the process. The oil is constantly circulating through the system with refrigerant and will coat the lines and somewhat pool in things like the chiller core, hence the need for a slightly larger oil capacity to accommodate the additional hoses/device. Too much oil and you hinder the ability to cool. Too little and you damage the compressor. The good news is that there is a decent sized margin of error here.
As for the system being open, I haven’t paid much attention, but do we have a dryer or a desiccant bag in the condenser? If there is a replaceable dryer or desiccant bag, I would consider doing it. If it’s a non serviceable desiccant bag in the condenser, I would do a longer vacuum with a good quality pump containing fresh oil. I’ll try to determine which it has when I get to work. I haven’t paid attention in shop manuals for many years, but in the past it was always mentioned in a service manual that any time a system was opened for any reason the dryer/desiccant should be replaced. In practice this rarely happens unless there was an internal failure or the system has been open for an extended amount of time.

 

[SH!FT]

Pretty sure there's a canister mounted on the driver side of the condenser. I'll take a look tomorrow. Likely won't open or disconnect it. Trying to break the least amount of seals as possible.

 

[SH!FT]

Update: The chiller is installed and ready for refrigerant. The Roush IC system is filled with ~1.75 gallons of Motorcraft yellow 50/50 coolant. I lost ~1 quart of coolant capacity by deleting the LTR.

I'll post my full install details once I confirm everything is performing correctly.


Delay #1 (7 days)
Morning of the 25th I found that my kit had the wrong size suction tee fitting for the R1234yf HVAC system. FI was apologetic and spent a small fortune shipping the parts fast.

First downside I've run into for this kit is that some components aren't available in the US.

I received the correct 14AN hose and fittings on Aug 1. Installed them immediately to finally get the system under vacuum that night. No leaks found after a 24 hour vac leak test. The plumbing included with the interchiller kit is top quality.


Delay #2 (3 days)
Today I took the day off from work to drive to the shop for the R134a charge on my R1234yf system. It was a no-go.

We were unable to swap the YF and 134a charge port connectors on the shop's machine. These R134a to R1234yf adaptors should be here tomorrow. I'll test them for fitment and leaks. Rescheduled the charge for Monday morning. Charge will cost $200-$250. I've added 1.5 oz of Motorcraft YN-12-D pag oil the system.

 

[SH!FT]

Had the AC system professionally charged with R134a today. The charge weight that FI provided seems to be spot on and made the process easy. These R134a to R1234yf adaptors worked fine. The charge cost me $250. I don't know what the cost for YF would have been.

Minor issue: The car decided to turn off accessory power to save battery. This closed the cabin solenoid valve unexpectedly. I made a jumper harness to my battery tender port to fix this issue.


I only had a 5 minute drive home from the shop with the system charged. Took it slow because I had the front bumper off in case we needed to troubleshoot. IAT2 temps looked to be ~30F cooler and still dropping when I got home. I'm still working with Roush and AeroForce to get the pre and post water temp readings to display on the interceptor gauge.

I'm impressed. Those IAT2 improvements were with the cabin AC on full blast and I have absolutely nothing insulated yet.

Sweating like a hooker in church..

Sponsored