Cooling your m30

[ThatOneEuroE30]

Cooling your m30

Superior rad IMO is the mishimoto. You can use other fans but spals a good common brand there's really no high end fan.

[LagunaSecaBlue]

I want to stir some information on the following things.

Thermostats(80, 75 and 71)
Water Pumps(Metal Cast Impeller and Stamped Metal)
Radiators(E28 535i, M535iS South African, M5 Custom Aluminum and E36 M3 Aluminum)
Fan switches(80/88, 82, 91)
Electric Fans(Spal, Brushless)
Mechanical Fans(Audi and TD Clutch fans)

Does a lower thermostat opening temperature actually help in hotter environments?
Is the GMB Stamped Water pump a lot better?
Is there a definite superior radiator?
Which fan switches?(I ask because wouldn't a 80c thermostat and 80c fan switch be constantly activated)
I know Spal is a good fan but are there superior options?
Is there ANY documented cases of these fans being used?

I am approaching the build date on my M30 Swapped E30 with A/C, and the AZ Summer heat is in full effect. I only want the best possible cooling solution and will look at every option to ensure sufficient and reliable cooling.

[ThatOneEuroE30]

Yea and my car isn wired for AC so I don think I have a AC switch plus with the moshimoto I'll probably only need it on really hot days

[F34R]

What do you guys think about just hard wiring a spal fan with a switch on the dash to turn it on on hot days. I got put a low temp thermostat in it and I'm also running a mishimoto radiator.

This is what I am doing with mine, I like the option to turn it on and leave it on. No one forgets to turn the fan off when the car is turned off ;D

[ThatOneEuroE30]

What do you guys think about just hard wiring a spal fan with a switch on the dash to turn it on on hot days. I got put a low temp thermostat in it and I'm also running a mishimoto radiator.

[F34R]

Picked up the Spal fan and I am using a puller on the inside(no AC). I keep pissing coolant if I get stuck in traffic in 80+ degrees. I can grab one of those sensors from the local junkyard. Stand by for awesome cooling :D

[CorvallisBMW]

60amp fans? Jebus, I didn't know they came that big. You'd have custom wire it.

That 16" puller is pretty cool, I didn't know they made one. But I know that on my b35 with goodntight mounts there is no way even a 2" deep fan will fit. The nipple on the water pump is about 3/4" from the radiator.

[LagunaSecaBlue]

Thanks for the response,

I will be putting in an aftermarket gauge eventually so that should give me a more accurate reading of what's going on.

I was iffy about that 2.0 Bar, after I posted that I read up on some people using it on the E30 335i with good results because it boosts cooling capacity. It is still a toss up for me.

I have figured out my cooling solution which will cover the ENTIRE Radiator!(The pusher will be on the passenger side and the puller on the driver side covering 402 square inches.)

Alright, here is the final setup.

16" Spal Curved Blade Pusher Up Front set up on the A/C Relay using a 80/88c switch.

I am going to bite the bullet and try the 16" Low Profile Puller in place of the 10"(Same depth, I may have to do some trimming and cutting but it should work!) Set up on a Spal Relay and Harness using a 91c switch.

[CorvallisBMW]

CorvallisBMW,

I have compiled my part list based on your findings. Does my list look solid?

Radiator Behr 535i Manual Radiator
Aux Switch 80/88c and 90c Temp Switch
Radiator Cap E30 1.4 Bar Radiator Cap
Coolant vacuum bleeder
16" Spal Spal 30102048
10" Spal Spal 30100435
Zip tie Mounting Rod
Relay Spal FRH Fan relay

I have a few questions,

First off, how is the Cooling system with A/C holding up with the 10" puller?

What's the highest outside ambient temperature you have experienced while driving? How did the cooling system do? What was the gauge at?

What is the ideal idle and moving temperature for these engines in the E30?

Should I use a E30 1.4 Bar or M30B35 2.0 Bar Radiator Cap?(Only issue I see with this is the E30 Heater Core bursting above 1.4 Bar)

Would tapping off the 88c high temp wire(in the 80/88c Aux Fan Temp Switch) to feed the sender wire in the 10" relay work?
Would it be worth it or is the standalone 91c better?

After having the cooling system in for sometime, would you change anything? Fan Size, Fan Performance, Fan Activation Temperature, Dual Temperature Switch, Wiring?

Thanks, Got to be prepared for another 125 degree day out here this summer!

Honestly it hasn't gotten hot enough here for me to test the new 10" puller with A/C on and high ambient temps. The most I've tried was around 80F ambient, but I was on the highway and moving.

Ideal temps are regulated by your thermostat, which is 78C for the m30b35 IIRC. However the e30 temp gauge is calibrated for 88C (or whatever an m20 runs at) so you will notice that at crusing speeds the needle sits just above the 1/4 mrk, as the gauge "thinks" you're 10C cool. To remedy this you would need to swap in an e34 535i temp gauge.

I don't know about the radiator caps but 2bar is 29psi, which is a lot. I'd be worried about leaks at that point, not just from the heater core but from hose clamps and all kinds of places. 1.4bar seems more reasonable but I'm not an expert on this.

Yes you can use the same 88C trigger wire to trigger both fan relays; the amperage draw is negligible.

As far as changing anything, I wouldn't make any functional changes but I would have done my wiring more cleanly the first time around (I'm still learning...). So far though it's working pretty well. But if you're planning on running A/C in 125F ambient, I would get the biggest f**king fan I could, 16" may not be enough. As I said in post #1 it will only cover half of your radiator and only with hot air off the condenser. When in doubt, go big.

[LagunaSecaBlue]

CorvallisBMW,

I have compiled my part list based on your findings. Does my list look solid?

Radiator Behr 535i Manual Radiator
Aux Switch 80/88c and 90c Temp Switch
Radiator Cap E30 1.4 Bar Radiator Cap
Coolant vacuum bleeder
16" Spal Spal 30102048
10" Spal Spal 30100435
Zip tie Mounting Rod
Relay Spal FRH Fan relay

I have a few questions,

First off, how is the Cooling system with A/C holding up with the 10" puller?

What's the highest outside ambient temperature you have experienced while driving? How did the cooling system do? What was the gauge at?

What is the ideal idle and moving temperature for these engines in the E30?

Should I use a E30 1.4 Bar or M30B35 2.0 Bar Radiator Cap?(Only issue I see with this is the E30 Heater Core bursting above 1.4 Bar)

Would tapping off the 88c high temp wire(in the 80/88c Aux Fan Temp Switch) to feed the sender wire in the 10" relay work?
Would it be worth it or is the standalone 91c better?

After having the cooling system in for sometime, would you change anything? Fan Size, Fan Performance, Fan Activation Temperature, Dual Temperature Switch, Wiring?

Thanks, Got to be prepared for another 125 degree day out here this summer!

[CorvallisBMW]

If you go that route, post up some pictures. I'd like to see what the Audi fan looks like.

[lukeADE335i]

Thanks for the measurements.

I don't think you'll have problems with the engine moving around too much. I can barely get my fingers between the distributor cap & radiator, but it has never hit.

I've also been looking at the possibility of using an Audi A4 clutch fan (which is very slim due to the Audi's engine being so far forward in the chassis).

[CorvallisBMW]

Excellent work. I've been thinking about refitting AC to mine (after driving in up to 115F this summer & thinking I'm getting too old for this :) )

Looking forward to hearing how your setup goes on the hot weather.

Would you mind measuring the distance from the front face of the water pump pulley to the your radiator? I have a 40mm gap where my engine sits, wondering how tight a fan would be in there.

I measured it up, I've got about 40mm as well. I'm a bit worried that under heavy braking the engine may shift forward and allow the nipple on the water pump to hit the fan. I'm currently suing OEM m20 motor mounts, I may need to switch to 75D polyurethane if this ends up happening.

[uturn]

Looks great, I'm actually doing the same thing to mine but instead of thru core mounts I'm actually fabricating brackets using aluminum angles.

[lukeADE335i]

Excellent work. I've been thinking about refitting AC to mine (after driving in up to 115F this summer & thinking I'm getting too old for this :) )

Looking forward to hearing how your setup goes on the hot weather.

Would you mind measuring the distance from the front face of the water pump pulley to the your radiator? I have a 40mm gap where my engine sits, wondering how tight a fan would be in there.