Im starting my M30 Swap.

[Good & Tight]

Okay, Ill run an electric.
What are the exact benefits and disadvantages of Position 2 vs 3?
I am just pushing for position 3 mostly because of http://www.e30.de/335i/06.htm

You will have to beat the firewall in a good amount to get position III.

[navytapaul]

Finding a 5 speed m30 e32/34 will be hard, I'd pull a trans from an e28/24 if you can along with the clutch and flywheel from one too. If you can find a 533i flywheel that would be great as they are the lightest.

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[LagunaSecaBlue]

Still need help on a couple things. Installing 2 electric fans, push and pull.
What sizes? Replacing the Aux Fan and putting one behind the radiator.

[kronus]

You don't really need two.. a 16" pusher up front is big enough.

[LagunaSecaBlue]

You don't really need two.. a 16" pusher up front is big enough.

Even with A/C and Arizona summer heat?

[CorvallisBMW]

Even with A/C and Arizona summer heat?

ouch... ya that's a huge cooling load.

Are you running r12 or r134a?

Essentially you're facing 2 issues:
1) The high-side pressure of an r134a A/C system at 110F ambient is around 350psi. The saturation pressure or r134a at 350psi (i.e. the temp at which the gas condenses to a liquid) is 172F. If you're running an 80C/176F thermostat this results in a delta-T (temp difference) of 4F. Which means that you're doing essentially zero cooling. The air coming off your condenser is nearly the same temp as your coolant, and therefor cannot absorb any additional heat.

2)The standard e28 535i radiator has frontal (2-D) surface area of 408 square inches (575x558mm). A 16" fan has an area of 201 sq in, or less than half of that. And if it's mounted on your condenser it means that 100% or nearly 100% of your forced air will be hot as balls (technical term) when it hits the radiator.

You need to find a way of providing forced air to a larger area of the radiator, specifically the parts which are NOT behind the condenser. I don't know what the best way is because I'm still fighting that myself. You may want to look in to fitting a 324td mechanical fan and clutch; if you're running in 'position 3' it will supposedly fit: http://www.e30.de/335i/09.htm

Try using this diagram and overlaying fan options on to it. Many manufacturers make side-by-side setups out of 12" or 14" fans that would cover more area: http://images.esellerpro.com/2489/I/287/950/R1709.jpg

Just as a reference, I live in Portland and we rarely see temps over 100F. But even at 90-95F if I'm in stop-and-go traffic I cannot run my A/C without the temp creeping up past 3/4. And I'm running r12, which runs at lower temps/pressures than r134a.

I've been able to fit a 16" pusher up front and I'm currently fitting a Spal 10" puller on the back side, just above the alternator. There's about 3mm of clearance between it and the water pump pulley :shock:

Good luck!

[LagunaSecaBlue]

Thank you for the information!

Would an aftermarket radiator help?

I'm running R134a. Switch to Freeze-12?

Switch to a 75 or 71 degree thermostat in the Summer?

16" Spal Pusher up front and a side by side set up or the 324td Mech fan?

[CorvallisBMW]

Thank you for the information!

Would an aftermarket radiator help?

I doubt it, not unless you can get forced air to parts of the radiator that aren't directly behind the condenser. A thicker radiator may be able to reject more heat, but like I said if the air coming off the condenser is nearly the same temp it won't matter.

I'm running R134a. Switch to Freeze-12?

I am not familiar with Freeze-12 but it's not the same as r12, as r12 is now illegal to sell or mfr in the US (and most other countries), unless you have a license

Switch to a 75 or 71 degree thermostat in the Summer?

This won't work. 75C = 167F, so the air coming off of your condenser would actually be hotter than your thermostat temp. You would be adding heat :firehop:

16" Spal Pusher up front and a side by side set up or the 324td Mech fan?

I can't answer that, like I said you'll have to do some research and experiment. I would look for either a side-by-side setup, or a pusher fan in combination with the mech fan. Just make sure you have a good fan shroud for the mech fan, as you loose a tremendous amount of cooling capacity without one (This will probably mean making something custom. If you could measure it all out and draw it up I'm sure a sheet metal shop could fab it out of aluminum for a reasonable price).

One other very important note: make sure that whatever type of fan you put on the front of the car, you get it as close to (ideally directly on) the radiator as possible. If you mount a fan 1/2" off the radiator, 50% or more of the air will hit the rad and simply disperse around it, rather than going through it and removing heat. The rad essentially acts like a wall to the oncoming air; if it can find an easier path than going through the vanes, it will. It's absolutely critical to control the air and force it through the rad. A side-by-side fan would therefor sit 1" or more away from the rad because of the condenser, so you will need to build some kind of shroud/gasket to contain and force the air through the rad.

[navytapaul]

I'm running the stock aux fan on constant low and it's been fine here in texas heat. I'd still suggest running a auxillary fan that pushes more cfm than the stock one. I also have it mounted on the radiator so that may also help too.

[CorvallisBMW]

I'm running the stock aux fan on constant low and it's been fine here in texas heat. I'd still suggest running a auxillary fan that pushes more cfm than the stock one. I also have it mounted on the radiator so that may also help too.

If you're not running A/C then yes, the stock fan is just barely adequate. I'd still upgrade it in a place like AZ though.


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[navytapaul]

I am too, but for now its all I had available. I would definitely recommend anything better. Doesn't the 750i fan work?

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[CorvallisBMW]

No idea.

[LagunaSecaBlue]

I am running a 16" High Performance Spal pusher to replace the Aux fan for sure. I am still figuring out the puller set up.

[navytapaul]

Unless you're going to seriously massage the firewall, I'd give up on the puller idea, there just isn't enough space to squeeze one in there.

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[CorvallisBMW]

I'm using the good'n'tight mounts and there's no way I could squeze in the mech fan. Hence the 10" puller idea.