Anyone figured out how to use aftermarket RAD fan?

[scratchgolf135]

Would like to retain the stock PWM functionality. Co side ring trying a fan module from the e46 since it’s not integrated into the fan motor. Yes, I know the stock fan moves a ton of air, but I want to delete the AC and move the Rad forward and I can’t do that with the stock fan. This will give me more room in the bay with the rad in the condenser’s spot and a slim aftermarket fan for oil cooler lines and possibly some radiator outlet ducting to hood vents. Nope, not needed but would be a fun project and would make for a nice looking engine bay while guaranteeing good cooling.

[PRTSB1M]

Originally Posted by scratchgolf135

Would like to retain the stock PWM functionality. Co side ring trying a fan module from the e46 since it’s not integrated into the fan motor. Yes, I know the stock fan moves a ton of air, but I want to delete the AC and move the Rad forward and I can’t do that with the stock fan. This will give me more room in the bay with the rad in the condenser’s spot and a slim aftermarket fan for oil cooler lines and possibly some radiator outlet ducting to hood vents. Nope, not needed but would be a fun project and would make for a nice looking engine bay while guaranteeing good cooling.

You might want to evaluate cooling system(s) from S55, since it is closer to your current setup than E46 system(s).

[scratchgolf135]

Originally Posted by PRTSB1M

You might want to evaluate cooling system(s) from S55, since it is closer to your current setup than E46 system(s).

Not an option. Reason for the e46 module is it’s not built into the fan motor. Starting with the n54 and all motors moving forward, the Can to PWM co troller is literally built into the fan motor. I’ve torn mine apart though and am going to attempt to dissect in a way that allows me to solder leads for a new fan. I’ll just have to make a case for it.



I’ll likely fail at this so if someone has a broken fan shroud they’ve replaced and wants to sell me the motor I’ll likely end up needing one lol.

[PRTSB1M]

It sounds like you want more engine bay room and decent cooling. Sacrificing A/C might get you there. I assume you already evaluated the fan from BMW's PPK for N55?

[scratchgolf135]

Originally Posted by PRTSB1M

It sounds like you want more engine bay room and decent cooling. Sacrificing A/C might get you there. I assume you already evaluated the fan from BMW's PPK for N55?

Cooling is not an issue but will benefit. The crux of it is that the CSF rad doesn’t fit well with the VRSF 7” IC (I have another thread showing this). If I can remove the condenser and move the rad forward it’ll fit miles better. Problem with this is the oem shrouds, including ppk, extend all the way down to the intercooler which means it can’t move forward with the rad. The shaded area below illustrates this. By going to a custom shroud that is only the size of the actual rad it’ll sit atop the IC as in the second image.

[scratchgolf135]

I have more concrete verification that the e46 module works. It uses the same 100hz Pwm frequency and has the exact same logic as our module despite the different form factor. I can get one from China to test with for $40 so I’ve pulled the trigger on it.

[PRTSB1M]

Originally Posted by scratchgolf135

I have more concrete verification that the e46 module works. It uses the same 100hz Pwm frequency and has the exact same logic as our module despite the different form factor. I can get one from China to test with for $40 so I’ve pulled the trigger on it.

Interested to see how this turns out. It certainly seems simpler than a full S55 cooling swap; since you would need to adapt the H2O IC setup. BMW did address some of your concerns with the S55 by putting oil cooler where N5x cars' IC is. When looking at cooling for my N54, I decided to stick with 5" IC and will use meth to handle IATs it can't. Also have CSF rad and twin oil coolers for my build.

[scratchgolf135]

Originally Posted by PRTSB1M

Interested to see how this turns out. It certainly seems simpler than a full S55 cooling swap; since you would need to adapt the H2O IC setup. BMW did address some of your concerns with the S55 by putting oil cooler where N5x cars' IC is. When looking at cooling for my N54, I decided to stick with 5" IC and will use meth to handle IATs it can't. Also have CSF rad and twin oil coolers for my build.

A 5” IC wouldn’t change anything in this situation since the only thing that eliminates is the 2” height in the front the extends up in front of the rad and condenser. Even then I’ll still be spraying e85 via charge pipe injector for extra fuel and lower IAT. I’m also running dual setrab oil coolers with an Improved Racing tstat so cooling should be no issue on this build. A couple 10” fans in a diy shroud should be plenty anyways since it’s not a daily it won’t see much traffic if ever. Only night drives and hopefully some track days. Hood vents will go in as well once Trackspec finally gets around to producing the templates I sent them a year ago…

[PRTSB1M]

Originally Posted by scratchgolf135

A 5” IC wouldn’t change anything in this situation since the only thing that eliminates is the 2” height in the front the extends up in front of the rad and condenser. Even then I’ll still be spraying e85 via charge pipe injector for extra fuel and lower IAT. I’m also running dual setrab oil coolers with an Improved Racing tstat so cooling should be no issue on this build. A couple 10” fans in a diy shroud should be plenty anyways since it’s not a daily it won’t see much traffic if ever. Only night drives and hopefully some track days. Hood vents will go in as well once Trackspec finally gets around to producing the templates I sent them a year ago…

Are you planning to use an existing hood vent setup or something custom?

[scratchgolf135]

Originally Posted by PRTSB1M

Are you planning to use an existing hood vent setup or something custom?

I created templates from my hood based on the ideal position and lines and sent them to Trackspec. They’re working on getting them put into production and will eventually sell them specifically for the 135i. The front of the center vent lines up right at the back of the Rad for ideal extraction. The two on the sides won’t have as big of an effect but will help to pull heat from the hot side of the motor for sure. I’m running a Slek 1m splitter (this is a fully 1m converted car) and plan to try to 3d print a connection on the passenger “tunnel” on the splitter and a short run of 3” silicone tube up to the filter of my bottom mount turbo. Probably not needed (turbo heats up the air anyways, all that, blah blah) but the splitter has a perfectly good hole that’s screaming to give fresh air to something and I’m not planning to run brake ducts so I’ll give the turbo some extra air to counteract the air being extracted from the vents. I like messing with shit, even if there’s not real benefit or no problem to be solved, it’s just fun to do.