How to mount radiator fans?

[cat007]

Do the fans not come with the little mounting feet that slip in there anymore?

Nah I bought them second hand. Although they were used f'all.

[loudstealthGT-Four]

And the last pic is showing how much space the fans take up, and how much the shroud is blocking the radiator. To cut this area out, or not to cut it out - that is the question

If you cut bits off the shroud around the fans then you are completely counteracting the whole purpose of the shroud in the first place

Unless you are going to do what Adrian/MrOizo said and make flaps that open at highspeed and close at lowspeed, which is quite a good idea

But seriously I dont see you having any issuses with the setup you've made

[cat007]

And the last pic is showing how much space the fans take up, and how much the shroud is blocking the radiator. To cut this area out, or not to cut it out - that is the question

If you cut bits off the shroud around the fans then you are completely counteracting the whole purpose of the shroud in the first place

Unless you are going to do what Adrian/MrOizo said and make flaps that open at highspeed and close at lowspeed, which is quite a good idea

But seriously I dont see you having any issuses with the setup you've made

Yeah I'm pretty intrigued about the whole low pressure flap idea.

How would you suggest the flaps hinge? Just a basic hinge from a hardware store?

[matt dunn]

WTF flaps?

Q.How much force will it take to open the flaps,
A. Some

Q. So how much presssure will the be on the back side of the radiator
A. Some.

Q. So how much flow will you loose through the radiator?
A. Some

Q. So how much cooling performance will you loose.
A. Some


So therefore no flaps is better.

A radiator fan doesnot need to draw through the entire core of the radiator.
If you need 10% of the surface area to cool it at just above idle,
then that's all the arear the fan really needs to cover.

[Mr Revhead]

Yeah thats true.
If you need the whole area of the rad when at idle or in traffic, then your cooling system needs more capacity

[cat007]

Ok I think I'm done.
Hopefully you all approve haha.

Shroud is 12.5mm from fins and fan blades are just under 17mm from fins.

[pc]

I guess that you've cut the effective area of your radiator to less than half. Can't be bothered drawing a diagram with measurements, as it looks fairly obvious.

Do you want the radiator to work at high revs while going forward, or just at high revs while going sideways? (with the fans running)

[DVSMOTORSPORT]

It will work fine

[Mr Revhead]

Where is the air going to go?

Air does not like 90 deg turns. Or flat faces

[matt dunn]

Ok I think I'm done.
Hopefully you all approve haha.

Yep, exactly how you'd do it for a burnout car,
and exactly opposite of how you do it on a circuit racing car.

[cat007]

Ok I think I'm done.
Hopefully you all approve haha.

Yep, exactly how you'd do it for a burnout car,
and exactly opposite of how you do it on a circuit racing car.

That doesn't make a whole lot of sense.

Sounds like you're saying circuit racing with high air flows at high speed require more cooling than doing a full throttle burnout relying on fans alone

I'm confused....

[DVSMOTORSPORT]

Ok I think I'm done.
Hopefully you all approve haha.

Yep, exactly how you'd do it for a burnout car,
and exactly opposite of how you do it on a circuit racing car.

That doesn't make a whole lot of sense.

Sounds like you're saying circuit racing with high air flows at high speed require more cooling than doing a full throttle burnout relying on fans alone

I'm confused....

He's saying s burnout car needs the fans operating at 100%, race car shouldnt need fans unless its on dummy grid.


The way I see this is, How many of your cars have a 20% blocked radiator? probably a lot of them, have any troubles? probably not. This setup would probably be equivalent to maybe 10%.

This setup will work ok, if he has troubles its not exactly a hard fix to remedy. Ive seen shrouds block a lot more than that and never have troubles.

[cat007]

Yeah but what he said doesn't make sense.
A track car would get way more air flow through the radiator than what the fans could produce, even with my current setup?

[Mr Revhead]

No it won't. Too restrictive. The only place air will flow through there at speed is the holes where the fan is. You will get some airflow from the shrouded areas out of the holes, but quite possibly not enough.

What Matt is saying is if you were building a burnout car that does not travel at speed, you would need to build a set up like yours so the fans provide 100% of the cooling flow. And also have to make sure the fans can flow enough air.

Imo you have just made the perfect overheating set up as you have blocked off a big chunk of the rad, and I doubt the fans can shift enough air to make up for it.

If your fans can shift enough air they will also pull air from the blocked off areas, but then you are going to be relying on your fans a lot more than you should.

In writing all of this I am assuming this is a track car/road car.

[sergei]

Yeah but what he said doesn't make sense.
A track car would get way more air flow through the radiator than what the fans could produce, even with my current setup?

What happens here is that fans generate negative pressure when the car is under the specific speed, while the car over that speed the fans generate drag (even when they are powered on) and act as restriction. Factory shroud is a lot more aerodynamic and thus does not cause that much of a drag. Additionally on many cars the fan shroud only covers half of the radiator.
A track car loads up the engine a lot more that burnout. Once you broken the traction, the power required to sustain slip is a fraction of full load.
A track car is under load for more prolonged periods as well.

[cat007]

Yeah but what he said doesn't make sense.
A track car would get way more air flow through the radiator than what the fans could produce, even with my current setup?

What happens here is that fans generate negative pressure when the car is under the specific speed, while the car over that speed the fans generate drag (even when they are powered on) and act as restriction. Factory shroud is a lot more aerodynamic and thus does not cause that much of a drag. Additionally on many cars the fan shroud only covers half of the radiator.

So then I should cut out the areas that are being blocked to allow the air to pass through the radiator without having to go through the fans whilst somehow sealing off the circular area that the fans suck through so they're sucking through the rad and not just the ambient air?

[iOnic]

It will work fine

This.

Try it, if it overheats all the time you can change it. You've gone to the effort so may aswell see what happens. Why fix a problem you don't have yet. I personally think it will work just fine. Its not a huge stretch from a factory shroud.

http://illsquad.files.wordpress.com/201 ... g_5010.jpg

[matt dunn]

you have to remember,

99% of the purpose of a factory shround on a modern car is to get airflow through the A/C condenser while stopped at the traffic lights.

Anyway,
will it work, probably,
it is the best way to do it, probably not.
Do I care either way. meh.

[iOnic]

you have to remember,

99% of the purpose of a factory shround on a modern car is to get airflow through the A/C condenser while stopped at the traffic lights.

Even on cars without AC?

[cat007]

you have to remember,

99% of the purpose of a factory shround on a modern car is to get airflow through the A/C condenser while stopped at the traffic lights.

Even on cars without AC?

That's the remaining 1%?