G50 Q45 clutch fan removal

[hk20000]

I took my fan out seeing how the car has a electrical fan ahead of the condenser and I hooked up a radiator temperature controlled switch relay (those flex-a-lite ones) to make the fan come on when detected coolant temp at 180F or so...

Now the question is is it safe to do so on a VH45? Coming from a BMW E36 and AE86 background the clutch fans always come off of those for parasitic loss reasons (for the E36 it's more of a plastic water pump issue)

I am not looking to gain any power here but I removed the fan hoping that the fuel economy might go up a tad... someone mentioned fuel economy with a VH45

But anyone else tried it and see any change in fuel economy and such?

[qship96]

Are you saying you replaced the clutch fan with an electric fan, or just removed the clutch fan and are using ONLY the factory condenser fan to provide cooling ?

[hk20000]

I removed the clutch fan and insatalled external trigger to turn on the a/c fan when radiator is warm enough

[qship96]

Good luck. That condenser fan is very small,and designed to supplement the much larger,more efficient fan you removed,not designed to cool the engine!You will be lucky not to destroy the engine running that as your only cooling fan. I would strongly suggest reconnecting the original clutch fan {which does not rob much power/MPG IF the clutch is working as designed, or at least replace it with a thermostatically controlled LARGE electric fan {which is really no better than the clutch fan as far as mpg/power goes,as the alternator just has to work harder to power it}

[Skibane]

Yep, that's probably going to be a problem.

If the engineers at Nissan had thought that the condenser fan could cool the entire engine all by itself, why would they go to the trouble of also installing a belt-driven fan, clutch and fan shroud? They don't add extra stuff - at additional expense - for no good reason.

[hk20000]

Yeah I just drove through traffic at 30C outside and the temp gauge is a tad higher than middle....so maybe running at 100C in the cooling system... While there is no ill effect I put the fan back in anyway.

As for other cars, did you know? In BMW the fan is absolutely redundant because the electric fan is just as big and, when running, pulls more air than the clutch fan... It is a common mod for the E36 community because the water pump is made out of plastic and the clutch fan will fall out and damage the radiator if the water pump blows. And more often than not the plastic water pump fails.

As for fuel economy I'm just taking a hint from the newest FR platforms from Nissan where there is no clutch fan to begin with (think 350Z, 370Z, Infiniti M56 as well as GTR) that it has more to do with performance and fuel economy than one might think. In the short time when I ran without the clutch fan it seems that the power pick up is a lot quicker.... But I haven't had it off long enough to gauge fuel economy.

Maybe I will add a electric fan in there later for supplemental cooling....if I can source one for cheap.

[Q451990]

Interesting about the E36. Unfortunately the Q's cooling system is marginal. If you watch the coolant temperature with Consult (Nissan's diagnostic tool) or on your '96 you could probably use a generic OBDII tool - you'll be alarmed at the temperature creep just sitting in a drive-through window in the summer.

If you're seeing movement in the dash gauge you're definitely overheating. The Q's gauge is very non-linear, with very little movement in the middle of the gauge.

Heath

[black g50]

A lot of cars being built, are doing away with belt powered energy sources.From steering to breaks,and the horses and mph go up every year.Electric seems to be the way to go now.I think the Q came this way for long term reliable operation,versus a electrical fan failure and the owner not knowing till it was too late.

[Skibane]

It's not uncommon for a belt-driven fan to consume 5 horsepower when running at high engine speed with the fan clutch fully engaged.

5 horsepower is around 3700 watts (5 HP x 746 watts) of electrical power - which means that supplying that same 5 HP with an electric fan motor would require around 275 amps at 13.5 volts!

In the real world, few electric fans consume even a small fraction of that amount of current - and thus produce only a small fraction of that amount of power for moving air.

[Q451990]

In the real world, few electric fans consume even a small fraction of that amount of current - and thus produce only a small fraction of that amount of power for moving air.

Are you saying that electric fans are more efficient - or that they produce drastically fewer CFM vs. the clutch fan?

Heath

[Skibane]

Drastically fewer CFM.

For the most part, a fan blade is a fan blade - They all require approximately X watts of power to produce Y CFM of air flow, regardless of what method is being used to spin them.

Show me an electric fan that moves the same amount of air as a clutch fan at 2000 engine RPM, and I'll show you the small nuclear power plant mounted in the trunk that they use to power it!

[willmoodom]

i am preparing to eliminate my clutch fan for a electric 2 speed from a 87-93 3.8l ford taurus. apparently outflows any mechanical or aftermarket fan available. and i think ill upgrade my condenser fan while im at it.

[qship96]

Good luck with that experiment!

[hoov100]

When it comes to fans and cooling systems to be used in the real world you have to look at idle and cruising RPM and loads. A mechanical fan has the POTENTIAL, let me say that again POTENTIAL to flow more, but fan blade design and the fact that almost no plastic fan blade is rated above around 6k RPM.

But we run down to the real world needs. And those needs are based around idle and cruising RPM. So you generally need to have your max amount of air movement anywhere from idle to 2200 RPM, which is where electric fans become so efficient over mechanical.

Nobody seems to mention this, but you can also rewind the electric motors in fans to have them flow even more air. If anyone is doing this other then to improve air flow through the radiator and condenser at idle and cruising RPM probably shouldn't be giving suggestions.

[qship96]

We are talking about old q45s that are now 16-22 years old,that somehow made it through all those years and hundreds of thousands of miles using their factory installed mechanical clutch fans.......and all of a sudden we think they need to be replaced with electric fans......kinda silly really when you think about it.A solution looking for a problem?

[hk20000]

I think electrically controlled fan has its own benefits anyway though, for instance you were stuck in traffic in hot weather and soon after shut off the car in the driveway.... the electric fan will make sure the residual heat is dissipitated quickly as heat energy makes its way through now stale non-flowing coolant. At least until the engine is cool enough that the thermostat shuts off. This could happen all while the engine is stopped because the electrical cooling fan can be entirely thermostat controlled.

This should keep the rubber parts from seeing high temperatures and enhance the lifespan of rubber parts like a coolant hose, valve cover gasket, small coolant hoses and the like. This is how other 90s cars I have come across from Toyota / Honda would do to keep its parts cool even when engine is shut off. (If you recall those "do not touch fan, fan will activate without warning" labels on those cars you would see what I mean)

but then, of course, that's some very extreme situations (hot weather, A/C full blast, stuck in traffic)....but you can't get too much cooling imo.

besides, heck it's just 4 bolts to stick it back on anyway.

[asoomal]

I think the EPA has something to do with newer cars having electric fans.

[black g50]

Would b a nice idea to hook up an electric fan to come on when car is off.Yesterday old girl seemed sluggish stuck in traffic,got home n popped the hood to let heat out.Later that night hopped in and temp gauge came to half instantly upon start up.

[Q451990]

I agree on the benefits of having the fan run for a little while after shut-down - reminds me of the mid 80s Hondas.

Heath

[black g50]

I agree on the benefits of having the fan run for a little while after shut-down - reminds me of the mid 80s Hondas.

Heath

Any simple way to do this?Delaware stuck in a heat wave.Although I travel on highway a lot,would like a inexpensive way to cool her down during heat soak.

[black g50]

The way the car is now,I was wondering does any air get under plennum when driving?If not,can a tube b made to run from fender area to plennum to force air to that area?

[willmoodom]

i get a kick out of hearing people talk about the Q as if it was perfect from the factory or my favorite, "engineers know better than us".
these same engineers took a beautiful engine built to the hilt and weakened it by installing plastic timing guides. some things are done for cost measures and i doubt they design this car for doing hole shots or racing around in it like most of us do. ive seen temps upwards of 220 by way of consult but the gauge shows half, implying temps are good. if rad temps are getting that high, how can anyone expect the transmission not to run hot? i will be installing an electric 2 speed fan out of the early 90's ford taurus and im looking to upgrade the condenser fan too. if it does better than expected, sweet. if not, then ill go back. but atleast ill know and tried. btw, does everyone know the oem condenser fan is actually used as a helper fan once temps exceeds 200 something. that tells me the mechanical fan is undersized. but hey, maybe im misguided.

[HG50]

im more for fellow q owners doing different mods to their cars. so do what u want, and hopefully its better then stock. if so, people will follow.

haters gonna hate

[asoomal]

i get a kick out of hearing people talk about the Q as if it was perfect from the factory or my favorite, "engineers know better than us".
these same engineers took a beautiful engine built to the hilt and weakened it by installing plastic timing guides. some things are done for cost measures and i doubt they design this car for doing hole shots or racing around in it like most of us do. ive seen temps upwards of 220 by way of consult but the gauge shows half, implying temps are good. if rad temps are getting that high, how can anyone expect the transmission not to run hot? i will be installing an electric 2 speed fan out of the early 90's ford taurus and im looking to upgrade the condenser fan too. if it does better than expected, sweet. if not, then ill go back. but atleast ill know and tried. btw, does everyone know the oem condenser fan is actually used as a helper fan once temps exceeds 200 something. that tells me the mechanical fan is undersized. but hey, maybe im misguided.

No, it's just in case the fan clutch poops all of the fluid out, or the fan blades shatter.

[hoov100]

Here is the truth on why newer cars use electric fans.

Because of the fact that electric fans draw their max amount of air whenever its on, not just when the engine is sitting at redline. This allows for the cooling system to stay cool initially and help keep an optimal temp at idle instead of a raised temp at idle and then optimal when the RPM increases. This also allows auto makers to use smaller radiators.

The ideal setup is an electric fan and water pump, but thats a little expensive for a production car.