Thoughts on AC for M20 turbo project - keep, upgrade, or ditch?

[jc1000]

Hello, I am in the early stages of my first build: a 327i (eta bottom end + i 885 head) turbo. I am about to pull the engine to check on the health of the bottom end and am trying to decide what to do with the AC. Since this is my first build, I realize it is probably easiest to just drop the AC to give me more room for the turbo plumbing, intercooler, etc. However, I live in Utah where the summers can get really hot, so I would love to keep AC if possible. I am pretty positive the current AC system is original.

So, I believe my options are:
-Keep original AC (hopefully it works! The car doesn't run yet) and deal with less room for turbo setup
-Upgrade the AC to something newer, especially since I am pulling the engine anyway
-Ditch the AC, making more room for the turbo setup, and deal with the summer heat

What do you think would be best? Also, would it make sense to ditch the AC for now, build everything else, then consider adding it later? I would imagine this is a bad idea, but want to hear from those with experience.

Thanks!

[varg]

Big dose of IMO here but AC is crucial to a frequently driven street car, and deleting it is just taking the easy way out. If I can do it, you can too. Piping gets a little tight but I have the biggest possible FMIC without substantial sheet metal mods and I have AC. Compressor discharge goes down between the AC compressor and frame rail, down to the IC inlet, and then the cold side goes out on the other side of the core support and up past the power steering pump. If you have smaller power goals than me (or a spiffy garrett or bell intercooler core) you can run a smaller IC than my big ebay core and even keep a decent sized condenser fan instead of the 3 server fans I run

[Hoffbrohaus]

I am in the same boat. Early stages of my first M20 build. I live in Phoenix so you'd think AC is essential. The problem is I took the time to replace everything on my AC to go R134A, even the pain in the ass thing behind the center console. But for some reason it still isn't very cold once we hit 110F. I know it should be because my E46 is ice cold even when it's 120F out.

So on top of it not really cooling me that much I'm concerned about the engine overheating when you have an IC, and AC Condenser blocking the stock radiator. With my old SR20DE turbo build sitting still in 110 degree heat the AC was worthless and the engine started to overheat, granted the turbo was mounted directly behind the radiator in that car . Also my e30 is my secondary car, I dd my e46. So I'm thinking why not strip out all the AC stuff?. If I do I could sell it to you :)

but at this point I'm thinking I'll give it a try, if the car get's too hot and the AC is useless I'll strip it then.

What do you think would be best? Also, would it make sense to ditch the AC for now, build everything else, then consider adding it later? I would imagine this is a bad idea, but want to hear from those with experience.

I would say see if it performs well, if so keep it. If not ditch it and go all new later if you really need it.

[iansane]

Street car? Keep the a/c and upgrade the stuff you need to run 134. (I say that because I really doubt the og r12 system works, but it could!). Yes it's some extra work to make the a/c function but it'll mean you're that much more likely to drive and enjoy the car, as well as bring other people with you. I ditched a/c when I went m50 and regretted it. When I went v8 I put it all back in and it's so much nicer to drive.

[e30davie]

I don't have a turbo (yet..), but I put a modern Sanden sd5h09 compressor on my m20, significantly smaller than the oem one. So if you are light on room I would get one of them and if you make your own brakcet you can put it lower. I made my bracket quite low compare to oem, so there is alot more room around the exhaust area (I figured best to keep AC things away from the exhast...). and you can make new lines to really get things out of the way.

I made the mistake of removing the AC from my car for a few years, but I live in Australia so its always hot and therefore I started to avoid driving the car when hot....which defeats the purpose. But now that the AC is operating again i drive the car everywhere. I took it too a track day the other day, whole day in the sun, and then driving home on the highway with the AC on - delightful. AC is also good for clearing the windscreen in the rain..

[Hoffbrohaus]

OK so I drove the E30 home from work today and needed the AC. Car said it was 85 degrees out in Phoenix. The AC was nice. I'm going to do all I can to keep it. Imagine boosting with the windows up and cool air in your face. Sounds good to me 😎

e30davie how did you fab your sanden brackets? Can you make me some? Mine are crap.

[e30davie]

Couple of photos I found, bit of steel and I found a hot rod place that sold the mounting arms welded together and painted black. I could make you one but shipping from Australia might be a bit high?

[Hoffbrohaus]

Couple of photos I found, bit of steel and I found a hot rod place that sold the mounting arms welded together and painted black. I could make you one but shipping from Australia might be a bit high?

Yea probably not worth shipping from Australia. The pictures help, I think I might be able to fabricate that. If not I did find this in the US, for $170, just not sure the fitment would be good for turbo, looks like it mounts it high and the overhead bracket would get in the way. https://lcwylieco.bigcartel.com/prod...ersion-bracket

[varg]

With the appropriate CAD drawings, you could get a set of brackets like Davie's CNC cut and weld them up, it would probably be cheaper to have them cut than shipping from Australia. I do think those LC Wylie brackets might make things a little tight with a turbo setup.

[e30davie]

yer i saw the LC wylie brackets, and were somewhat of the inspiration for mine. with shipping and the exchange rate one LC wylie was not economically viable for me. These are the sliders I bought locally, and I just got a bit of 8mm plate for the backing. surely someone in America sells something like this? a hot rod place perhaps? or yer just cad it up. the radius of the adjustment slot just needs to match the dimension between the ears.

https://store.autofrost.com.au/index...roduct_id=2118

You just have to be careful of the crank sensor. I'm not going to lie i forgot to take it into account on my car, but by shear luck it fits...just. I should redo mine one day, but its been working fine for years.

I made another bracket for a guy here for the same compressor on an m20b27, and I just welded on the brackets ~30mm lower. But i don't have any photos of his I'm afraid. but access to the crank sensor wasn't an issue with how i made his.