SNAFU; high performance 318is build that lives up to the name, Turbo M42 ➞ Turbo M20

[ak-]

Turbo blankets etc? Wrapped downpipe? Maybe ceramic coated housings

I have all that and I'm still battling to stay under 205F.
Stock clutch can though, so maybe an electric with a proper shroud would work. I'm also in SoCal and it's averaging 90's right now.

[varg]

Turbo blankets etc? Wrapped downpipe? Maybe ceramic coated housings

Not sure how much it would help. I have a turbo blanket and wrap for my downpipe which I have yet to apply. I still see over 200° with the hood off which shows that a lot of it has to do with lack of air flow through the radiator

[Schnitzer318is]

What temp thermostat are all of you guys running? I might have dropped mine down when I did the turbo... if I see over 200 I am overheating... or have forgotten to turn on the Efan.

[Dj Buttchug]

I run an OEM one.

[Schnitzer318is]

I run an OEM one.

Ahhh... realoem shows a temp of 88deg C on a stock one. I believe I am running a 75deg C version. The one shown below.

https://www.fcpeuro.com/products/bmw-engine-coolant-thermostat-11531721002-75

Keeps me right where I want to be during 95% of Texas seasons. In the "winter" I almost never run my electric fan and the car still gets up to operating temp okay.

[econti]

I have all that and I'm still battling to stay under 205F.
Stock clutch can though, so maybe an electric with a proper shroud would work. I'm also in SoCal and it's averaging 90's right now.

I reckon you'd find that with a good flowing leccy fan and a good shroud you'll have more success.

Oddly enough down here I sat in 50 degree C stopped for 45 minutes and the gauge never even moved. Granted, no A/C condenser in the way and no turbo, but I to be honest would doubt that a turbo pumps that much heat that it changes from stable temps to flat out overheating.

[varg]

The clutched fan with stock shroud will do a better job cooling than most of our E-fan setups, it moves a ton of air and is designed and tested to keep these cars cool in extreme heat, I'm not using it because there's no room and it will hit my radiator when the engine moves (BTDT). The turbo changes things a bit, it significantly heats the air in the engine bay. Air conditioning also makes a huge difference. Say it's 93°f here like it was yesterday, humidity ~%70, with the AC off (not happening) the air flowing through the radiator is 93°, with the AC on the air flowing through the radiator has been pre-heated by the AC condenser to over 120°f (I tested this). Add to that the fact that my intercooler is between my condenser and radiator hampering air flow and that's why I see temps over 200° with the AC on. I don't have room for a fan shroud or a bigger fan with the rad pushed back 3," something I'm hoping to change this weekend when I get the rest of the piping I need to move the IC (I hope). The thermostat isn't going to change anything here, a 75°C thermostat doesn't flow any more water than an 80°C or 88°C thermostat, it just opens earlier. Thermostat temp doesn't make a lick of difference once you're past it.

FWIW, 205°f is not overheating, even for these cars. Many cars are designed to keep coolant temps higher than that bone stock. 230°f is overheating.

[Schnitzer318is]

The thermostat isn't going to change anything here, a 75°C thermostat doesn't flow any more water than an 80°C or 88°C thermostat, it just opens earlier. Thermostat temp doesn't make a lick of difference once you're past it.

True, for some reason that never registered in my head. I remembered though I do run a mostly water/coolant mix. 90/10 maybe with a bottle of water wetter thrown in for good measure. I've actually been meaning to drain everything and throw in BMW's smurf piss to see if it makes a difference.

FWIW, 205°f is not overheating, even for these cars. Many cars are designed to keep coolant temps higher than that bone stock. 230°f is overheating.

Noted, I just don't like to be over center hash at all... that's what I meant by overheating, not actually overheating towards the red part of the gauge. I think 215deg puts me over the middle mark by more than I like if memory serves (I drove the car 2 times last year). With AC on and the high temps here I like mine 185-200deg.

At any rate, I think a good electric fan, along with the stock shroud produces excellent results. My temperature drops amazingly quickly if I let the car get hot and then switch on mine. Hopefully you get yours sorted with your plan to move the rad back.

[megu2ice]

I think you should consider redoing your intercooler setup to allow room for the stock clutch fan and shroud. On my turbo m20 the temperature is always right around the halfway mark, regardless of whether the ac system is on. As long as your willing to cut up the valence a bit, you can fit the radiator in its stock location, a condenser, slim spal and intercooler with the 2.5 inch pipes running below the headlights.

[econti]

Can you low mount the cooler behind the valance?
Alternatively be fucking sick and run a V mount setup and put the condenser in the boot or something

[Northern]

I must've missed someone already say this, but maybe it's time for a bigger rad?

[varg]

I think you should consider redoing your intercooler setup to allow room for the stock clutch fan and shroud. On my turbo m20 the temperature is always right around the halfway mark, regardless of whether the ac system is on. As long as your willing to cut up the valence a bit, you can fit the radiator in its stock location, a condenser, slim spal and intercooler with the 2.5 inch pipes running below the headlights.

Unfortunately it's probably impossible to run the stock fan with a setup like mine, even with the intercooler relocated. The IC is too large to mount with the piping routed under the headlights, I attempted to do that recently and it didn't work. With the IC mounted low the piping has to go somewhere, and that somewhere is space the mechanical fan and shroud would occupy. My "new" Volvo 940 E-fan will be adequate. They move air like nobody's business.

Can you low mount the cooler behind the valance?
Alternatively be fucking sick and run a V mount setup and put the condenser in the boot or something

Moving the IC behind the valance has been the plan all along. I just wrapped that job up today, in fact. Boy was it a huge pain in the ass.

I must've missed someone already say this, but maybe it's time for a bigger rad?

I doubt my problem has to do with the radiator's heat rejection capability. We'll soon find out since I've put the radiator back in its rightful place and upgraded my electric fan to the powerful Volvo radiator fan that I've had laying around.

[varg]

The intercooler is on and the car is put back together. It was one hell of a process.


Pipes too long.


Cut down and beaded.


My $6 bead forming tool.


I had to cut the bracket off of this AC condenser line and push it back in order to make the IC fit behind the valance, even with all of the cutting. The zip tie is to keep it from vibrating and eventually breaking.


The cut valance.


The cut I made in the bumper hoping for some more air flow to the top of the IC.


The old stack.


And finally, no more stack and a proper electric fan. This is off of a Volvo 940, it's a powerful two speed fan and with the end of the shroud cut off it fits the M42 radiator quite well. I shouldn't have any airflow troubles anymore.


It's a little conspicuous for my taste and even though I never needed them I really liked how the brake ducts looked so I'm bummed that they're gone. I do not like the look of the exposed piping. I also managed to break one of my fog lights, which miffed me. I'm going to get my hands on some fog light blanks and hopefully figure out a way to cleanly block the open hole where the brake ducts once went so I don't have to look at the piping.

[Schnitzer318is]

Okay... now I see why you were having a hard time. That intercooler is probably 4x larger than the one I'm running. :)

Nice work getting it to fit in there with the AC components though. I'm sure there was much cursing involved.

[Northern]

So much room for activities in an M42 engine bay... between the Z3M rad and the M52, I have zero room for a fan. I only have one because the 16" slim SPAL fits inside the rad support where my condenser used to be.