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Discussion Starter · #1 ·
Hi yesterday I've done some offroading for the first time since I installed the ScangaugeII system. Other than the very low mileage when climbing up a hill in low gears (1MPG or something ;) ) another interesting read I had was the engine and air intake temperature. After heating up the engine its temperature stays more or less constant around 85C normally (should be 185F). Under greater stress, especially at low speeds, it can go up until 90C (194F).

Air intake temperature: at freeway speeds it is similar to ambient temperature. In stressfull offroading situations it goes up to 50C and more (122F). Now my question is, would the "cold air intake" or a snorkel contribute to lower this value AND what would be the real impact on performances? How does a CAI work?

Next time I'll keep an eye on the Ignition Timing in function of the engine stress and the type of fuel (I normally use regular 87 but fill the tank with 91 while driving to the offroad site), Fuel System Loop type, Engine Load and Manifold Pressure.

Anybody else has used a system like the ScanGauge for this kind of readings?
 

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Air intake temperature: at freeway speeds it is similar to ambient temperature. In stressfull offroading situations it goes up to 50C and more (122F). Now my question is, would the "cold air intake" or a snorkel contribute to lower this value AND what would be the real impact on performances? How does a CAI work?
In general it takes a difference of about 10F (lower) to see ~ 1 HP change at peak power on an engine. Of course that is a general rule and very definitely depends on the particular engine, mods, other conditions, etc ....

To put that in perspective. If it were 82F out and your air intake temps were at 122F, then you might assume that you were losing 4 HP at peak power which is at about 5,200 rpm or there abouts. I can't say what it does to torque, I don't have any data but I would expect a similar loss since TQ is somewhat a function of HP.

So, no big deal. You wouldn't feel it and not a big enough difference to justify the cost based solely on air temp reduction. Where aftermarket intakes really shine is in their ability to flow much more air with less restriction. That's where they provide the biggest gains.

DEWFPO
 

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Discussion Starter · #4 ·
So, no big deal. You wouldn't feel it and not a big enough difference to justify the cost based solely on air temp reduction. Where aftermarket intakes really shine is in their ability to flow much more air with less restriction. That's where they provide the biggest gains.
DEWFPO
I also have the "air pre filter" included in the "offroad package". Can this affect the airflow or something? For the aftermarket intake you mention you mean the snorkel or the 'cold air intake' like the TRD?
 

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I also have the "air pre filter" included in the "offroad package". Can this affect the airflow or something? For the aftermarket intake you mention you mean the snorkel or the 'cold air intake' like the TRD?
The Cyclone pre-filter does impose a slight restriction in the intake. For those of us that drive is very dusty conditions, it may be worth having it in.

The stock intake is a Cold Air Intake. But is has a restrictive air tube and filter to keep things quiet and clean.

For more airflow with less restriction, any of the high performance Air Filter/Air Intakes commonly referred to as CAI's (and some are not) will flow better than the stock unit. As far as their filtering capability (as compared to stock), that's open for discussion.

The snorkel per say is all about clean air. Not necessarily more air, although as speed, with the intake head in the forward direction you may gain some from a ram air situation.

DEWFPO
 

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Discussion Starter · #6 ·
The snorkel per say is all about clean air. Not necessarily more air, although as speed, with the intake head in the forward direction you may gain some from a ram air situation.
DEWFPO
Ok I am not going to remove the pre-filter because I am often in very dusty offroad environment (Truck Hill at Hollister anyone?). I am considering anyway the ARB snorkel (is ARB the only make for FJ snorkels?). Do you see any problem in the coexistance of the two, is the installation going to be more complex?
 

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I'm not 100% positive because i haven't installed a snorkel (yet!) but from what i can tell from the installation instructions on the manufacturer's site there should be no conflicts with installing an ARB(Sarfari) Snorkel on your rig and preserving your cyclone prefilter. I just got 2008 Trail Teams Special Edition FJC and it comes with the cyclone pre filter too. Just be sure that you get the correct Snorkel kit! There are two, SS410HF and SS415HF. SS410HF snorkel requires modification to the cyclong prefilter.
http://www.fjcruiserforums.com/foru...fari-snorkel-install-instructions-w-pics.html
So be sure you avoid this by purchasing the SS415HF. However, it will be "available soon". Here's the site if you want to check though.
Safari - Snorkels
Good Luck!
 

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ARB and Volant both make a snork for the FJ, I'm not sure if the precleaner will work with the snorkle. anything is possible with modification but as it is designed the snorkle has a tube that connects directly to the intake inside the engine bay. the prefilter is in the wheel well. Even if it were removed there are prefilters for the snorkle availiable that do as good if not better with less restriction.
 

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I am interested in getting a snorkel for several reason. First i want protection from water/ dust being ingested if i get a little carried away offroad. Second, I am getting a TRD supercharger put on and i want to maximize the performance of it. Would a snorkel provide colder air? I've read that the supercharger actually heats up the air as it pressurizes it and then the water cooled intercooler cools it back down between the supercharger and the intake manifold. So two questions: 1. Would i see any HP/Torque gains from a snorkel's cooler intake temps or would it just be a little extra insurance from the elements? 2. Would a snorkel provide enough air for the TRD supercharger?
 

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I am interested in getting a snorkel for several reason. First i want protection from water/ dust being ingested if i get a little carried away offroad. Second, I am getting a TRD supercharger put on and i want to maximize the performance of it. Would a snorkel provide colder air? I've read that the supercharger actually heats up the air as it pressurizes it and then the water cooled intercooler cools it back down between the supercharger and the intake manifold. So two questions: 1. Would i see any HP/Torque gains from a snorkel's cooler intake temps or would it just be a little extra insurance from the elements? 2. Would a snorkel provide enough air for the TRD supercharger?
1. you wouldn't notice the difference.
2. yes

DEWFPO
 

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I can't say what it does to torque, I don't have any data but I would expect a similar loss since TQ is somewhat a function of HP.

DEWFPO

I thought HP was calculated using torque and RPMs
 
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