Jeep JK Snorkel Tested with Data logs

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We weren't looking to add a snorkel to our Jeep JK, but...

We've worked hard to avoid protuberances on our Jeep. You see, unlike many Jeepers, we really don't want much "stuff" sticking out of our rig in various places, so we always do what we can to keep all the mods as understated as possible. A snorkel on our Jeep JK was one of those items we both agreed we didn't want, but this was purely due to esthetics. 

After much data logging and testing to solve some cooling inadequacies, we stumbled on some alarming data. The intake air on our Jeep would often climb to 80° above ambient, and rarely fell below 40° above ambient! These temperatures are terrible for air density, and therefore power. In addition, we wondered if lowering IAT might possibly reduce peak coolant temperatures.

How about an intake hole in the hood?

Having just chopped a massive hole in the hood, we now had the confidence to hack yet another hole in the name of science. After that, we snatched up a snorkel from AEV, and then carefully cut an opening per the instructions because this is where the factory intake draws air for the engine. After that, we did the same 70-100 MPH datalogging run as before. To our surprise, we found almost no difference in intake air temperatures! We think there might be a low pressure zone above the fender that prevents the intake from drawing in outside air, causing the engine to draw mostly under hood air as usual.

Finally - some snorkel data from our Jeep JK!

We went ahead and installed the AEV snorkel and ran the log again, followed by another with a Sy-Klone 9001 pre-cleaner from Snorkel Upgrade installed. The snorkel alone should draw in slightly cleaner air than a stock intake as dust/dirt is heavier than air and typically densest near the ground. A pre cleaner like the Sy-Klone has a rotor inside that helps separate particles and will result in significantly cleaner intake air, but at what cost? Here's some pictures so you can see what each setup looks like:

Pressure Data

As expected, the snorkel, like a long straw, increased the intake air flow restriction by a measurable amount. Although not ideal, the added restriction was very small - around 0.1 PSI. With the Sy-Klone 9001 pre cleaner however, this was a more significant 0.3 to 0.4 PSI. Keep in mind though that this is at wide open throttle and 4400-6200 RPM, under less demanding conditions, these differences are much smaller. See the graph below with the stock intake in grey, the AEV snorkel in Blue, and the pre-cleaner version in Green:

Temperature Data

During our data logging runs, we observed IAT readings as little as 12° F cooler and as much as 25° cooler with the AEV snorkel installed. Moreover, under normal driving conditions, these changes become even more significant. With the snorkel installed, at idle, in direct sun, we have seen IAT peak at about 40° above ambient, while highway cruising is typically 10°-15° above ambient - a full 30°-40° cooler than stock. Most importantly, the greatest change has been climbing steep grades at 30-50 MPH where the stock intake would regularly get as much as 75°-80° above ambient, and now those numbers are typically 15°-20° above ambient. On the other hand, after analyzing coolant and oil temperature data every way imaginable, it is safe to say the snorkel doesn't have a significant effect. 

Here's the intake air temperature data from our 70 MPH-100MPH run. Stock intake is grey, the AEV snorkel is Blue, and the pre-cleaner version is Green:

The elephant in the room, Air Density:

Here's where it all comes together - air density. Density is directly related to how much fuel you can burn, and therefore how much power you can make, so this is ultimately the unit we need to know in order to understand how this will affect power output. In the 70-100 MPH data, we can see that the run with the AEV snorkel produced greater air density across the entire run. Despite the added flow restriction, the snorkel draws in cool enough air to more than make up for it. This reduction in air temperature was unsurprisingly also observed with the Sy-Klone pre filter and compensated enough to neutralize any loss caused by the restriction it adds. This means the 3.6 will make roughly the same power as stock when running the Sy-Klone, and 1.2-3.4% more than stock with the AEV Snorkel and ram inlet under these conditions.

As with the others, stock intake is grey, the AEV snorkel is Blue, and the pre-cleaner version is Green:

Conclusion: The snorkel stays

Yup, despite our original distaste for these things, we're happy to have it now. We've grown accustomed to using carwashes in our Jeep and love unloading a clean rig after a dirty trip somewhere, so the thought of a feature that denies us this is bothersome. Thankfully, we discovered the snorkel really isn't affected by rotating brushes so long as the ram is mounted backwards, and we won't try a wash with brushes if the Sy-Klone is installed. They are super easy to swap, so this is proving to be no big deal

Cleaner intake air is a huge priority, and we've had trips that render an air filter trash In mere days, so we'll take any help we can get here. Without the pre cleaner, the snorkel will help some, but with - we'll likely need filters far less often. 

Cooler air = more power, and that 1.2-3.4% greater density translates into 4-10 HP. We'll certainly take all the extra power we can get out of this little V6.  Consequently, we will run the AEV ram on the highway and the Sy-Klone on the dirt. 

Of all the reasons we're keeping the snorkel, fording deep water isn't one of them. This is somewhat entertaining to us as that's the only thing most people think a snorkel is for. It will be reassuring though if we take a plunge that's deeper than anticipated.

Some final comments:

We tested more configurations than we shared here, but this snorkel was by far the best, so to keep the comparison clean, this is all we included. Even the Banks JK intake couldn't compare. Though it did produce slightly less pressure drop, it still consumed VERY hot air, and ultimately failed to produce appreciably better density than the factory filter assembly. Funny thing is, we used the Banks iDash Data Monster to run all these logs, and we LOVE that thing! We've even got alarms set up for coolant temp, oil temp, etc. and even added an analog input to monitor rear differential temperature!

Also, we are not affiliated with AEV or SnorkelUpgrade in any way. We purchased all our AEV components ourselves and have no vested interest in whether or not anyone decides to go buy one of these.