AC Delete

[AndyW]

I think it's time. Even with CSF Rad, track mode in MHD, and defrost on, i was hitting 240F+ at the track today. Figure AC delete = more airflow. Request advice from those who have done it. Preferred kits? DIYs? Pitfalls? TIA.

[Dieselboy]

I'm interested as well. Also curious of the weight savings up front.

[Grimm5698]

There's a belt kit for deleting the AC compressor but you can buy them by themselves and save a bit, uses the following parts
Belt # 7PK1660
Pulley # 11287556251
Apart from that it's as simple as recovering the freon and removing the lines/ condenser, you can also remove the evaporator but that's under behind the dash so not an easy job, not sure on weight but I'd say at least 30-40lbs roughly if you remove everything.
Also are you running any upgraded oil coolers?
Link to the kit
https://www.ecstuning.com/b-assemble...it/n54acdltkt/

[AndyW]

Originally Posted by Grimm5698

There's a belt kit for deleting the AC compressor but you can buy them by themselves and save a bit, uses the following parts
Belt # 7PK1660
Pulley # 11287556251
Apart from that it's as simple as recovering the freon and removing the lines/ condenser, you can also remove the evaporator but that's under behind the dash so not an easy job, not sure on weight but I'd say at least 30-40lbs roughly if you remove everything.
Also are you running any upgraded oil coolers?
Link to the kit
https://www.ecstuning.com/b-assemble...it/n54acdltkt/

Thx. My engine is N55 so I don't think that kit will work.

[amg6975]

You don't really need a kit, just replace the belt with a shorter one and pull out as much of the system as possible. I left the evaporator because it weighs almost nothing, I put rubber caps over the lines that go through the firewall.

I think there's a VO code for A/C you can delete and default program the IHKA module so you don't get an error when it tries to turn on the AC compressor. You may have to do the JBBF too, I can't remember exactly.

Everyone always says 30-40 lbs but the whole thing is actually less than 20. The compressor is the only thing that has any appreciable weight to it.

EDIT see picture, just remove the A/C compressor from the system and follow the green path.

[AndyW]

Originally Posted by amg6975

You don't really need a kit, just replace the belt with a shorter one and pull out as much of the system as possible. I left the evaporator because it weighs almost nothing, I put rubber caps over the lines that go through the firewall.

I think there's a VO code for A/C you can delete and default program the IHKA module so you don't get an error when it tries to turn on the AC compressor. You may have to do the JBBF too, I can't remember exactly.

Everyone always says 30-40 lbs but the whole thing is actually less than 20. The compressor is the only thing that has any appreciable weight to it.

EDIT see picture, just remove the A/C compressor from the system and follow the green path.

Thx for this. I presume the belt listed in the previous post would work? What belt do you use?

[amg6975]

Originally Posted by AndyW

Thx for this. I presume the belt listed in the previous post would work? What belt do you use?

I'm not sure if that belt will work, probably a good place to start. I'm also not totally sure why it comes with a new idler...

My car is an S65 so very different ball game: https://www.m3post.com/forums/showth...=198848&page=2

[AndyW]

Originally Posted by amg6975

I'm not sure if that belt will work, probably a good place to start. I'm also not totally sure why it comes with a new idler...

My car is an S65 so very different ball game: https://www.m3post.com/forums/showth...=198848&page=2

Nice. I've thought of doing that if/when my n55 blows up. How much does it shift the weight distribution?

[spidertri]

AndyW I can't remember from your threads, but do you have any hood vents installed? Getting those in and placed correctly would really help with air flow through the radiator.

[AndyW]

Originally Posted by spidertri

AndyW I can't remember from your threads, but do you have any hood vents installed? Getting those in and placed correctly would really help with air flow through the radiator.

Yes, I do. I opened the vents on my Seibon hood.

[amg6975]

Originally Posted by AndyW

Nice. I've thought of doing that if/when my n55 blows up. How much does it shift the weight distribution?

I don't have before numbers but I would suspect it'll move the weight bias rearward very, very slightly. It's amazing how much smaller the S65 is in almost every dimension, particularly how much lower and rearward it sits.

They say the difference between an N55 and S65 is 40lbs but that doesn't include accessories like the intercooler or turbofold, etc. I think it's within tolerance the same weight but with the S65 weight being positioned much better.

With mild interior stripping, the completed [DCT] car weighed right around 3200lbs with 1/4 tank of gas. Wouldn't be hard to remove another 200lbs but I do drive it around every now and then.

[alindquist]

How much oil cooler do you have? I rather be trying to add another oil cooler to keep the temps down. Maby adding som extra holes in the bumper. I live in Sweden, but I still thinks AC is giving me more than the win of removing 20 lbs.

Have you tried water wetter?

[thisisluka]

I think ultimately you’ll be hurting yourself more than you’ll find use for removing the AC. The weight savings, and any sort of air blockage to the rad should be negligible to the clear head you’ll have on and to the track when you’re comfortable.

More importantly, have you upgraded your oil coolers? Granted I’m running an N54, which seem to have more heat problems than the N55’s and was a track day in with a single 34row oil cooler, 185° tstat, CSF Rad with distilled water and water wetter, and was still getting miserable temps - 242°f coolant (240 is where you’ll find our cars hit limp mode) and ~270°f oil. Oil limp won’t happen till 300°f. Upgraded to a dual 25 row, run in series, along with trimming my fender well guards to allow the air to properly pass through, and temps have been rock solid. Ultimately the hotter the oil gets, the hotter the coolant will follow. In my opinion they have to work together if you want stable temps.

Also consider inlets / intake, and what tune & fuel you’re running. Inlets / intakes will help lower the WGDC of the turbos making them work less hard = less heat, and any higher power tune over stock is going to introduce a lot more heat through the snails, so keep that in mind too. Running e85 mixtures will also help bring your temps down while also getting a boost in power, since the volume needed to burn e85 is higher which reduces chances for detonation and also whicks off more heat as a result.

[AndyW]

Originally Posted by llumo

...

All good advice. Already have two 25 row oil coolers. CSF Rad, but still stock coolant. 19 row dct cooler. Running a stg 2 tune(20#, 100 oct tune). Most things have been sorted and temps are ok unless it's above 80/85F. I don't get limp modes due to temp but car will torque limit below limp mode temps(you can tell because it limits boost to 8# or so on my car). About 235 for coolant, 270 for oil, 250ish for dct, as i recall. Only thing getting too high right now occasionally is coolant but I can mitigate that if I put the defrost on at 84F on the track. Just ready to maximize everything so AC delete seems logical. Goal is 90F ambient hot laps with no cooldown laps required... Will shift to water wetter next season, also.

[thisisluka]

Originally Posted by AndyW

All good advice. Already have two 25 row oil coolers. CSF Rad, but still stock coolant. 19 row dct cooler. Running a stg 2 tune(20#, 100 oct tune). Most things have been sorted and temps are ok unless it's above 80/85F. I don't get limp modes due to temp but car will torque limit below limp mode temps(you can tell because it limits boost to 8# or so on my car). About 235 for coolant, 270 for oil, 250ish for dct, as i recall. Only thing getting too high right now occasionally is coolant but I can mitigate that if I put the defrost on at 84F on the track. Just ready to maximize everything so AC delete seems logical. Goal is 90F ambient hot laps with no cooldown laps required... Will shift to water wetter next season, also.

Ahh yeah so you’ve got most of the right parts good to go. Did you by chance trim the fender well guards behind your oil coolers? I noticed a significant difference in temps once I did this. I’m sure with proper shrouding to and from the coolers it would help even further. Attached some pics of my setup for reference. Did this on both sides.

Yeah I think 2 bottles of water wetter and distilled water would help a bit as well.

Have you considered running meth at all just for IAT cooling? Something I’m considering if I ever begin to really push temps.

[AndyW]

Originally Posted by llumo

Ahh yeah so you’ve got most of the right parts good to go. Did you by chance trim the fender well guards behind your oil coolers? .

Yes, I have custom cutouts and screens similar to you. I also have custom shrouds that route the air in.