Besides DaveO, is there anyone else out there attempting to tackle the electric fans for the sedan question?

What have you come up with? Any success or road blocks?

thx - Ted

'03 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
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This only affects the 5AT sedan, right? My understanding is that the 6MT sedan has the same fan as the coupe.

--Steve

 

Well, this is my opinion only, but if it's not electric, then it must be crank driven right..? So if you did derive at some sort of electric fan you would have to somehow remove the crank driven one... Is it on it's own seperate pully or directly driven..?

04' G35 / 6MT / Tein Basic Coilovers
Volk 19" GT-7 Gunmetal

 

Try looking here. http://www.jegs.com/cgi-bin/ncommerc...75&prmenbr=361

These aftermarkets are easy to install and thermally actuated.

 

it's just not the fans, its the harness and relays. Sedans are diff than coupes in that respect.

-T

'03 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS or Vote at Online Showoff

 

You wire these aftermarket fans in yourself. They're made as an add on or retrofit.

 

when is this helping - aux fan or normal fan?

 

These can be the primary fans on a sedan. Don't need external controls since they have their own thermostatic control. Just supply power. Some can hook up to the car's control system.

 

I thought I'd post this in order to provide a little history and the current status of our project.

Gurgen and I started brainstorming how to replace the engine driven "mechanical" fan about six weeks ago. Various sources, including Flex-a-Lite, said up to a 15hp improvement is not uncommon. We felt a 6 to 8 hp payback would make it cost effective.

Our goals from day one;
1 - A quailty, professional looking conversion.
2 - Equal or better cooling capacity.
3 - And it should be cost effective. $/ft-lb torque - $/HP

We discussed many options. The top three are described below.

Option 1 - Complete a traditional mechanical fan replacement. Incorporate a Flex-a-Lite 12" to 14" S-Blade fan (or other) mounted directly to the back of the radiator core. Use Flex-a-Lite's new VSC (Variable Speed Controller) for control and leave the stock shroud and aux fan in place.
Advantages - Low cost ($200 for parts). S-Blade fan is hidden by the stock shroud.
Disadvantages - Neither of us like mounting the fan directly to the radiator core. And finding a cool (temperature), "stealthy" location to mount the VSC that's easy to get to for thermostat adjustments.

Option 2 - Use a stock Coupe/350Z shroud to mount the Flex-a-Lite Fan and modify part of the AT Sedan's shroud to properly direct aux fan air flow.
Advantages - Stock looking conversion with a shroud mounted fan.
Disadvantages - 1/3 higher cost. The unknown. Will the Felx-a-Lite fan's bolt pattern mount directly to the shroud without modifications? What's the maximum fan blade diameter that will fit the shroud. (It may be 12").

Option 3 - Install a complete Coupe/350Z dual fan assembly.
Advantages - A direct fit mechanically.
Disadvantages - Most costly. The unknown. Fan control circuit and wiring differences are substantial.

So here's where we stand as of today. I have a Flex-a-Lite S-Blade Fan and VSC. Option #1 could be completed at any time.

Right now I'm holding off for two reasons. The radiator will need to be drained and removed to properly mount the fan to the radiator core and the cooling system will need to be drained in order to install the new 170 F 350Z thermostat assembly. The t-stat isn't here yet and I only want to drain the system once. And there's a small chance that I may end up with a low/no Coupe shroud.

If anyone needs more details, please PM me.

DaveO

 

so there are a few options for your predicament . . .

a.) basically, flex-a-lite won't be a bolt on kit, they're really for american cars, but are the best aftermarket electric fans currently on the market (i've got a set of dual 210's on my supra) - in order to mount it there are two options (1.) custom brackets - which can be made with aluminum or steel then chromed or powdercoated for the eye's sake (2.) there are plastic - lets call them zip ties - with washers on them that are designed to hold fans to radiator cores - there's a plastic 'bolt' on one side that goes through the fan bracket then through the radiator fins and zips up to hold the fan securely to the radiator - the cleaner much much easier option, that i used on the supra

b.) (1.) with a single fan, you can control it at two speeds with a fan controller (HKS makes one) - goes of the oem temp sensor reading and you can set it so that it kicks up the speed when it reaches a certain temperature, (2.) with a dual setup you can control them independently at a single speed - (3.)the other option is to wire them on a temp switch with a relay - so when the switch reaches the temp it either grounds or un-grounds and throws the relay so the fans go on (4.) the last option is to just have those bad boys running full bore at all times

c.) i don't quite understand the 'thermostatic switch' - cause the thermostat stays closed until it reaches a certain temp then opens to allow flow through the radiator. So a thermostatic switch would just mean the thermostat would open earlier? Or i'm taking it too far, and you're describing a temperature switch? In any case, why not just remove the thermostat completely? car will definitely run about 10deg. (C) cooler overall.

the last option is that i'm thinking in way to simple of terms and nissan's cooling system is much more complex than i'm imagining . . heh

just make sure you get the proper fans (pusher or puller)

 

hksjza70,

Flex-a-Lites Variable Speed Controller is really a trick set up. It always starts the fan at 60% speed and then ramps up as necessary (up to 100% speed) in order to maintain temperature at setpoint. You can also add direct start off the AC compressor lead if you choise for two way control. I recommend you check it out on their website.


DaveO

 

The problem with removing thermostats completely is that it takes longer for the engine to reach optimal operating temperature, and there's the slight possibility that it will be running coolor than optimal at times for extended periods.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

hksjza70,

Read your post and agree with some of your points and disagree with others.

Your question - "... why not just remove the thermostat completely?"

My opinion - Removing the engine's thermostat is not a good idea, especially on street driven vehicles. Overcooling can be as bad as undercooling. Cold cylinders allow increased blowby and reduce engine performance. In worst case scenarios running without a thermostat can allow the water pump to move coolant through the radiator and back to the engine without adequately cooling the fluid. This can result in engine overheating at higher rpms.

There are at least three different thermostat assemblies available for the G35. A 180F used in the AT Sedan. A 170F used in the 350Z/G35 Coupe. And the NISMO which I'm told is 160F. I've elected to go with the 170F as soon as it gets here.

A clarification. The Flex-a-Lite VSC temperature sensor (thermocouple) doesn't control the engine's thermosat. It only controls when the electric fan starts and stops.

Flex-a-Lite's VSC replaces the usual on-off fan control relay. It incorporates an external temperature sensor that's mounted through the radiator core between the fins near radiator's inlet or hot return hose... the upper one on the G35. The VSC can be adjusted to turn the fan on anywhere between 155F and 230F. The VSC starts the fan at 60% speed and provides a "soft start" that prevents the fan from drawing a large amount of in-rush current as it starts. As I said in my previous post, it's a trick set up.

DaveO