Ford Mustang Forums banner
1 - 20 of 79 Posts

· Registered
Joined
·
333 Posts
Discussion Starter · #1 ·
got the compressor to finally cycle as intended. want some opinions on how the ac behaves. 90 degree ambient temps idling the vent temp is around 60-62 degrees (humidity in the 80% area). when I drive the car, with airflow moving through the condenser other than my fans running (high all the time 3600cfm derail fans with shroud covering entire rad) the vent temps will drop to about 55 degrees with your regular street traffic. coolant temps 195-200 with ac on. when the sun goes down the vent temps will be around 55 degrees (ambient temp 80 degrees) but when the car is cruising for long periods of time the vent temps will drop to the 50 degree range. I saw as low as 48 while going around 45 mph for a couple minutes straight. It sounds like there's an airflow issue across the condenser so I was thinking of putting in a pusher fan in front of it to assist with cooling in stop and go traffic. compressor and liquid line are brand new. does this seem normal? am I asking for too much given I live in south Florida? putting water on the condenser cools the vent temp as well given that the water is removing large amounts of heat from it. like I said this sounds like an airflow issue to me. what do you guys think.
 

· Registered
Joined
·
394 Posts
Most likely an airflow issue like you said. Though I would verify head pressures while you’re at it. I wouldn’t be surprised if it was a little low.

For reference, my 87 Grand Marquis with the stock mechanical fan and r134a will blow around 50-55 in the middle of the day at idle. It’ll get down into the low 40s while driving. And this is in southwest Florida in the summer.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #3 ·
Most likely an airflow issue like you said. Though I would verify head pressures while you’re at it. I wouldn’t be surprised if it was a little low.

For reference, my 87 Grand Marquis with the stock mechanical fan and r134a will blow around 50-55 in the middle of the day at idle. It’ll get down into the low 40s while driving. And this is in southwest Florida in the summer.
it'll be around 57 just driving 15 mph around my neighborhood so I think in a couple weeks im going to install either a single large or two small pusher fans spliced from my primary fan wiring to just come on whenever the derails come on.
 

· Registered
Joined
·
394 Posts
it'll be around 57 just driving 15 mph around my neighborhood so I think in a couple weeks im going to install either a single large or two small pusher fans spliced from my primary fan wiring to just come on whenever the derails come on.
Do you by chance have a fan shroud? I think a pusher fan will help but I think you should find the root cause.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #5 ·
Do you by chance have a fan shroud? I think a pusher fan will help but I think you should find the root cause.
yeah I have a fan shroud as well as a 3 core aluminum radiator which I think impedes airflow through the condenser. car cools off fine with the ac off and will get to around 200 with it on. for the pusher fan I was thinking of a single 16" spal that pulls and advertised 3000 cfm. I think that across the condenser would improve the temp at idle considerably
 

· Registered
Joined
·
394 Posts
yeah I have a fan shroud as well as a 3 core aluminum radiator which I think impedes airflow through the condenser. car cools off fine with the ac off and will get to around 200 with it on. for the pusher fan I was thinking of a single 16" spal that pulls and advertised 3000 cfm. I think that across the condenser would improve the temp at idle considerably
I’d still check head pressure first but the pusher fan will probably fix the issue.
 

· Registered
Joined
·
2,890 Posts
A pusher fan is going to restrict airflow while driving. A 3 core radiator is not helping either. 3 cores will have more restriction than a 2 core of the same thickness simple because of the fin breaks between cores. You get turbulence and air slows more each gap between fins A 2 core with 1 inch tubes would be better than a 3 core and give you more than enough cooling.

Have you put gauges on it? Gauges will tell you if your pressures are good. Low refrigerant will cause the vent temps to be higher than normal too.
 
  • Like
Reactions: 07gts197

· Registered
Joined
·
10,380 Posts
I would put gauges on it like stated and check pressures. You want to use a manifold set that displays high side and low side pressure.

Give us the high/low pressure as well as the static (system off) pressure and the ambient conditions (temp/humidity).
 
  • Like
Reactions: 07gts197

· Registered
Joined
·
333 Posts
Discussion Starter · #9 ·
I would put gauges on it like stated and check pressures. You want to use a manifold set that displays high side and low side pressure.

Give us the high/low pressure as well as the static (system off) pressure and the ambient conditions (temp/humidity).
Static pressures resting at 70, with the compressor jumped it would stay at around 20-25 on the low side (can’t remember the high side but it was around 220). With the compressor cycling and coolant temps at around 175 it would drop it all the way to 20, kick off the compressor, rise to about 45-50 then kick back on. High side pressure would go to about 230 and back down as the compressor cycled. Took just shy of 3 cans of refrigerant (35 oz). At night temps at the vent are nice and cool at around 52-53 as the cabin cools down but during the day it really struggles at idle. It improves with air flowing through the condenser
 

· Registered
Joined
·
333 Posts
Discussion Starter · #10 ·
A pusher fan is going to restrict airflow while driving. A 3 core radiator is not helping either. 3 cores will have more restriction than a 2 core of the same thickness simple because of the fin breaks between cores. You get turbulence and air slows more each gap between fins A 2 core with 1 inch tubes would be better than a 3 core and give you more than enough cooling.

Have you put gauges on it? Gauges will tell you if your pressures are good. Low refrigerant will cause the vent temps to be higher than normal too.
I was thinking of a 14” pusher fan because the car cools off very well at speeds. Never had an issues cruising on the highway. I was gonna add the air damn underneath the car as well but for low speed cruising I don’t see why a pusher fan would hurt it. It would purely be to cool off the condenser. The car will maintain 180-185° Coolant temps with the ac off during the car when it’s 100+ degrees outside and with the ac on it’ll run around 20° hotter
 

· Registered
Joined
·
2,890 Posts
205 is the normal temp it should be running at with ac on. That's the normal operating temp for a SBF. When cruising down the highway your car gets most of it's cooling from the bottom of the radiator/condenser which is the part getting fresh air. With a shrouded fan over the condenser it is going to block that area off. You would be better off investing in a quality 2 core radiator and getting a less restrictive condenser available for your car. When cruising above 35mph youre getting a lot more air into the radiator than a fan can push which is why the fans turn off above 35mph. It becomes a restriction. In my car, i'm upgrading to a 97 condenser because my giant fmic + standard condenser blocks too much flow at low speeds causing my car to hit 225 on hot days. If i remove the condenser, it runs at normal temps.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #12 ·
205 is the normal temp it should be running at with ac on. That's the normal operating temp for a SBF. When cruising down the highway your car gets most of it's cooling from the bottom of the radiator/condenser which is the part getting fresh air. With a shrouded fan over the condenser it is going to block that area off. You would be better off investing in a quality 2 core radiator and seeing if there is possibly a less restrictive condenser available for your car. When cruising above 35mph your getting a lot more air into the radiator than a fan can push. It becomes a restriction. In my car, i'm upgrading to a 97 condenser because my giant fmic + standard condenser blocks too much flow at low speeds causing my car to hit 225 on hot days. If i remove the condenser, it runs at normal temps.
It won’t be a shrouded pusher fan otherwise I’d agree with being too much of a restriction. I’m considering biting The bullet and replacing the evaporator core as well. I compared the ac to my buddies 95 and his vents seem to blow much harder than mine in every setting. I replaced the blower motor and resistor so I think the evaporator could be clogged up with crap which isn’t helping my situation. The ac never worked fantastic when I bought the car with an HCI 302. I really wanna get it dialed in because it’s brutal in the summer.
 

· Registered
Joined
·
2,890 Posts
It won’t be a shrouded pusher fan otherwise I’d agree with being too much of a restriction. I’m considering biting The bullet and replacing the evaporator core as well. I compared the ac to my buddies 95 and his vents seem to blow much harder than mine in every setting. I replaced the blower motor and resistor so I think the evaporator could be clogged up with crap which isn’t helping my situation. The ac never worked fantastic when I bought the car with an HCI 302. I really wanna get it dialed in because it’s brutal in the summer.
I hear you. I live in Colorado which normally is 100+days often although this year it's been cooler and rainy this whole summer. It rains almost every day for the last few months which is how it was in the 90s with i moved here. The biggest upgrade you could do is to put a 97-98 condenser in it. It will help allow your radiator to pull more fresh air through it. My ac blows really cold when it was installed but the problems i listed above have forced me to upgrade to condenser. For now i am running without a condenser. I verified with LMR 2 days ago, their condenser for 96-98 is the less dense 97+style. They sent me pictures of the fins so u know for sure it's the better sn95 version. It's worth doing if you're serious about having ac.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #14 ·
I hear you. I live in Colorado which normally is 100+days often although this year it's been cooler and rainy this whole summer. It rains almost every day for the last few months which is how it was in the 90s with i moved here. The biggest upgrade you could do is to put a 97-98 condenser in it. It will help allow your radiator to pull more fresh air through it. My ac blows really cold when it was installed but the problems i listed above have forced me to upgrade to condenser. For now i am running without a condenser. I verified with LMR 2 days ago, their condenser for 96-98 is the less dense 97+style. They sent me pictures of the fins so u know for sure it's the better sn95 version. It's worth doing if you're serious about having ac.
Is there any modification to be done or is it just a straight forward replacement?
 

· Registered
Joined
·
2,890 Posts
According to @fasterthangas it's a direct swap. Pictures look the same. Fasterthangas said he did it on a couple sbf sn95s. I'm ordering mine here in the next coupe days.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #16 ·
According to @fasterthangas it's a direct swap. Pictures look the same. Fasterthangas did he did it on a couple sbf sn95s. I'm ordering mine here in the next coupe days.
I’ll give it a look but I’m leaning towards adding that auxiliary fan just because in low speed situations I feel like it’ll help keep consistent airflow through the condenser. I think I’m gonna end up replacing the evaporator core in the car to eliminate that component as a possible source of leaks plus as mentioned earlier i noticed the lacking vent performance which makes me think it’s clogged up with crap
 

· Registered
Joined
·
2,890 Posts
Before you replace it, check your pressure levels. Fyi, you have to cut the ducting on sn cars to get the evaporator out. It's not removable like the fox. I did mine 2 years ago because mine was full of metal shavings because someone cut the metal hose instead of removing it at the coupler.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #18 ·
Before you replace it, check your pressure levels. Fyi, you have to cut the ducting on sn cars to get the evaporator out. It's not removable like the fox. I did mine 2 years ago because mine was full of metal shavings because someone cut the metal hose instead of removing it at the coupler.
I’m gonna check the pressures before I replace it when it’s static to see if I lost anything. If there’s no change then I knkw the system isn’t leaking and there’s most likely just an airflow problem. If it is leaking then the only place I can think of is the evaporator because I’ve already hit the system with some dye and a UV light and everything is clean under the hood. Might have a shop use one of those Freon wands to see if anything is coming out of the evaporator if it is leaking. Probably gonna replace it just to see if the vents blow any harder.
 

· Registered
Joined
·
2,890 Posts
some loss over time occurs if im not mistaken. it permeates through the hose very slowly from what i remember. im not 100% sure on that though so Im sure someone will correct me if I am wrong.
 

· Registered
Joined
·
333 Posts
Discussion Starter · #20 ·
some loss over time occurs if im not mistaken. it permeates through the hose very slowly from what i remember. im not 100% sure on that though so Im sure someone will correct me if I am wrong.
I’ve read about it too, I just see people boasting vent temps in the mid 40s to 50s and my car struggles to reach those temperatures at any given day which is frustrating hence why I feel like it’s an airflow issue or clogged evaporator.
 
1 - 20 of 79 Posts
Top