I have a litely modified S4 turbo. I was driving pretty hard when it was about 85 degrees outside. Car almost overheated. It looks like it has the stock radiator and fan along with an electric fan on the engine side that is bolted directly to the fins of the radiator. Fan turns on with a switch. Factory shroud is missing. Going to upgrade to a koyo from racing beat unless someone can recommend something better. As well as a new fan. My question is would puting the factory shroud back on (if I can find one) with an electric fan work best for cooling or an electric fan with a custom shroud work best. And can anyone recommend a prebuilt shroud that would work if that's the way to go. Also pull or push for the electric fan.

Thanks

 

I might have a really good answer for you tomorrow. I've got a Koyo N-flow radiator and a Flex-a-Lite fan in my garage. I did lots of searching and found an aftermarket shroud that I believe will work. It arrives tomorrow.

Either way, shrouded fan will always be better than an unshrouded fan. Almost everyone uses pullers for an electric fan on FCs. The stock system works fairly well for even modified vehicles, but we are all prone to wanting to upgrade.

 

I switched to a koyo rad and one of those all in one electric fan/shroud. It was great for daily driving and pushing the car on the street. On the track, however, it would still get pretty hot. It never got to the point where it overheated but would get close. It would cool down to normal temps after on the cool down lap though. For my new build I'm planning on running the koyo with a better fan and custom shroud hoping that will keep the temps down on the track.
+1 on the koyo rad can't really go wrong there
I'm going to try the mishimoto Race Line, High-Flow Fan, 10" + custom shroud

 

Thanks. Let me know how that shroud does and where you got it from

 

Just search for the Nissan Quest electic fan mod in the forum. Mohr's Garage has a recent youtube video that he did on the Nissan Quest fan mod. You can either pick them up in the junkyard or a new one from any auto parts store. I have an S4 with Koyo rad, and the Quest fan fits perfectly, you just need to trim for the rad hoses inlet/outlet. The fan and shroud are one piece so it's super convenient.

If you want to stick with OEM for now, you must have all the shrouds in place for the cooling system to work. You need the shroud the fan as well as the undertray. The undertray will be necessary for virtually all applications - it helps keep air flowing through the rad instead of around it and you will lose cooling capability if you don't have it. Pick one up used on Marketplace, they're about $80 right now.

 

You have to make sure you have the under tray in place. Without it a ton of airflow will bypass the rad.
The shroud on the engine side fan is also key even if electric or the stock.

The next is directing airflow into the rad and sealing up the gaps on air that can flow past it. either to the sides or bottom with foam. and on the top side with a duct panel that covers the over flow tank and all the relays etc in front.

With mine I an almost running too cool doing this.

the panel in front of the rad. if not having stock air intake system

foam on lower of oil cooler.

foam on lower of oil cooler & on the sides of the Rad.

Foam on the bottom panel. THIS IS Key to directing airflow through the rad.

 

I have the stock under tray and I bought the panel that goes in front of the radiator between the headlights. I see where you have foam. I'll stick some on there. Ordered the koyo and ordered a new fan and shroud assembly. Thanks for the advice.

 

Also, just a simple change is to run a lower concentration of coolant to water to aid in heat transfer and heat capacity. If you're somewhere that doesn't get that cold, 70/30 mix will gain you extra cooling capacity over the standard 50/50 mix. If you want even more cooling capacity, you can run straight water with only a corrosion inhibitor.

 

Ya that was my plan. Straight distilled water and a corrosion inhibitor. Live in so cal doesn't get that cold. Ordered a koyo, taurus fan, mishimoto thermostat, hks cap. Silicone hoses. Koyo won't ship untill Feb 7th.

 

I have the mishimoto thermostat too and it really runs the engine cooler.
So careful on Stock ECU and it will measure the engine as not warmed up and run richer.
I run stock fan and it almost works too well with Fluidyne Rad.

I am thinking of getting a higher Temp Thermostat . like 71C from japan. vs. the Mishimoto 68C