Lil'John

Is there a general rule of thumb regarding the benefits of cold air to the intake versus hugely complex intake routing?

Longer version. I've got LQ4 in an old Land Cruiser FJ55(SUV wagon style) Right now, I've got an open air element in the engine bay. I'm not happy with it but it will work for now.

Here is initial swap picture:


Here is vent that I would get air from:


Using the above pictures, I would have a tube straight to where the PCM sits. It would get a drop-in filter style air box(roughly 18-24" worth of tube from intake to that location). From the box, I would go inside the fender panel to the black vent(again roughly 24")

The vent to the left is where I'd like to draw fresh air from.

I'm not expecting seat of the pants gains. But is it worth going through the effort of getting outside air in this manner?

1CAMWNDR

iTrader: (21)

Sure, that is fine idea. Just keep the water level below the top of the fenders and have all kinds of fun!

Lil'John

If I am ever dumb enough to get water to that vent level, I'll be in well over 3 feet of water

My curiousity stems from the claim of lost power due to hot air. Since I'm currently sucking engine bay hot air, I've got to be losing some power.. 5hp?

But I've also heard that a lot of complex routing also causes power loss. Again, no idea what kind of power loss. Same 5hp?

I don't want to due a bunch of extra fab on routing tube if I'm not gaining anything in the bargain.

Guess I should also point out that the LQ4 is bone stock aside from headers, no cats, and that open element filter. The tune will be some sort of a MPG tune.

Shon Herron

iTrader: (25)

if the idea for the vehicle is to run thru woods, rocks, mud, then you wont notice the difference, if you are ET/MPH things then it matters.

Bo185

It'll be fine there. Just put a small drain in the bottom of the vent hole so if it did get water, from road spray or splashed in, it will drain out.

I would be more worried about the fan hitting the rad if you get into water.

I would also swap to an electric fan. Pickup HP and MPG!

Lil'John

I think the fan should be safe from water... roughly 24" from ground to bottom of fan.

I've got two concerns with electric fans:

• Power draw - a good electric cooling fan usually has a "HUGE" current draw...like 60A. Add in offroad lights, winch, etc and I don't think my electric system would be happy.
• Cooliing capability - Rarely will an electric fan have the CFM that a mechanical fan will. An aftermarket fan that might have the CFM usually has the price tag to go with it.

For those two reasons, I'm leary of going to an electric fan. Plus, I'm not sure what I'm going to do with the 300hp+ I've got If I found out a fairly solid MPG gain from going to an electric, I'd almost consider it.

The cruiser will mostly see duties as a daily driver with "log road" wheeling along with rock crawling. 100% no mud in its future

Shon Herron

iTrader: (25)

in the jeep set ups we have done, ended up doing the mechanical fan b/c it cooled better in the way the jeeps were being used, ie rock crawlers.

Old Geezer

iTrader: (3)

"Power draw - a good electric cooling fan usually has a "HUGE" current draw...like 60A."

In the FWIW dept.. I just got a pair of Spal, 11" fans for my 55. [2760 cfm @ 13.5V.] We tested the draw.. A quik hit at 35A, and dropped instantly to 11A, each. We then blocked flow, and looked at draw.. very little difference.

Pop N Wood

iTrader: (1)

I would *think* a mechanical fan would be more reliable out on a trail, for just the question about electrical overload that you mention. Kind of amazing how much current a FI motor draws. The O2 heaters on my Yota have 25 amp fuses, each. Like you said with lights, heater, motor and charging up a drained battery and the alternator can get tapped pretty quick.

I wouldn't worry too much about the winch. A winch draws a lot of power for a relatively short period of time. That is going to draw off the battery. Don't think many alternators can keep up with one of those running full time.
The alternator just charges the battery back up when the winch is off.

The thing to be careful about with electric fans is current draw = power = the ability to move air. 11 amps at 12 volts is less than 2 tenths of a horsepower. That's not going to move much air no matter how efficient the blades are. Even 35 amps, what a Tarus fan draws on high speed, is just a little over half a horse. A mechanical fan draws straight off the motor, so HP is not an issue.

The only way an electric fan saves HP is when it is not running. With my car that usually happens when moving at speed. Rock crawling means the engine is putting out highway horsepower but at slow speed. With no airflow through the radiator cooling like this is going to be all fan.

Mavmavv

Tons of crawlers run Taurus fans with great results. They move a ton of air and have relatively low draw.

I have one on my mustang and it works great.

Lil'John

Thanks for the heads up on that.

The Taurus fan which puts out 4500cfm has a 35-40A draw(as mentioned above) and around 100A at start. But I do have a cool controller that could reduce that spike.

As Pop n Wood mentions, the cooling demands of an offroad vehicle are a little different than street driven car.

But also worth stressing, reliability is also key with offroad rigs in my mind. Very often, I will be miles away from a tow truck or parts store... so having a dead fan isn't cool

With this reliability in mind, I converted my LQ4 from automatic to manual transmission. I also have left the LQ4 stock rather than putting a lot of performance parts.

Shon Herron

iTrader: (25)

5.3 with Ford 4spd. Mech fan


5.3 with TH400, Mech Fan b/c the E-fans would not keep it cool and this one got a 'old man' cam too


I loved going with these guys, stuff breaks and they have to fix it or get towed out and that is not the coolest thing.

Bo185

The 1/2 ton trucks have had E-fans since 2005. They added a bigger alt. to make up for it. And those cool just fine! I wouldn't be worried about cooling cap. unless the LC rad is small.

Lil'John

I'm not using cruiser rad. I'm using a Griffen 1-28202-T: 24"x19" aluminum rad. This is dual core 1" tube with tranny cooler integrated(ie my engine oil cooler)

I'm fairly confident in the cooling ability of the radiator. But I still want to get a shroud on it.

Shon Herron

iTrader: (25)

that helps alot!