Manual radiator fan

[steved0x]

These fans are a popular mod lately, I am just about to finish up a similar mod:



My switch has 2 positions and just turns on the high speed fan mode.

I've got an event at Carolina Motorsports Park in 2 weeks so I will be curious to see how much this helps there.

[AZ986S]

Originally Posted by steved0x

These fans are a popular mod lately, I am just about to finish up a similar mod:



My switch has 2 positions and just turns on the high speed fan mode.

I've got an event at Carolina Motorsports Park in 2 weeks so I will be curious to see how much this helps there.

Steve, I'll be curious too. For me, the benefit of the fans was on grid, and cool down. It might help some in low speed corners. I should do a run with then without to see the difference.

[BoxsterSteve]

Don't know how much this helps... it's a copy and paste from Rennlist a few years ago.


Radiator Fans

The mod consists of installing a switch that will allow you to turn on the high speed radiator fans at any time, while maintaining the automatic operation of the fans. The same thing can be done for the engine compartment fan.

Connect a wire to the ground of the 2 high speed fan relays located on the relay carrier located in the driver’s side foot well. The relays are #20 and #22. Feed this wire to where your switch will be located. Connect the wire to one side of the switch. Connect another wire from the other contact on the switch and then connect the other end of this wire to a chassis ground point.

With key on, this switch will now immediately turn on both radiator fans providing maximum cooling. When you turn the key off, the fans will continue to run for about 5 seconds until the relay shuts down. Your fan operation remains normal when the switch is off.

If you are adventurous, you can automate the operation of this switches so it will switch off at a specific speed, or operate when vacuum is present only, etc.

You can choose any style switch you want and even use Porsche switches. I simply used a toggle switch that I installed in the batwing.

[steved0x]

Originally Posted by AZ986S

Steve, I'll be curious too. For me, the benefit of the fans was on grid, and cool down. It might help some in low speed corners. I should do a run with then without to see the difference.

For sure on grid and cool down - right now (before installing this) my driver side fan is wired to run on high all the time (I bypassed the failed ballast resistor) and when I turn on the AC on low which kicks the fan on, the temp really comes down fast when I hit a cool down lap. I have a replacement resistor that I will wire in soon because I don't want it running on high every time the AC is on.

On a track like Roebling, where there is a decent amount of WOT, but it is very smooth and flowing, I think it will help some, but I think it will really have a bigger impact on tighter more technical tracks like The FIRM, which is mostly a 3rd gear track with a lot of tight lower speed corners. I think running the fans during the session there should help out. Except for one sweeper, and a hairpin, this track mirrors my ex wife's driving style - floor it until it is time to slam on the brakes. The car heats up pretty quick at this track especially when it is warm or hot outside.

[steved0x]

Got it wired up and it works I did a little drive around town, lots of stop and go, water temp started going up (not bad, just normal.in town driving, 85'ish F oat). Turned on the fans, within 3-4 minutes it was back on the 180 line (I have the low temp thermostat)