The problem was that they were pulling out and air was leaking past that fitting.
Afe intakes/inlets with VF tuner tune (1 Viewer)
- Thread starter brian1234152
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email mcain@afepower.com hes the lead tech support specialist
Finally, got the air boxes and turbo inlets installed.
Looks great! How are they working out for you?
They work great, sound great. No issues so far. I used JB Plastic Weld on the hose barbs to avoid the pullout issue that others reported.
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- #26
I just want to post here on my original post to update everyone that I’m constantly still having issues after months of back-and-forth with AFE. One caveat is, I do have the VF tune, which I think is contributing to the problem, not in a bad way. Since the tuned boost is higher, I feel like the squishy inlet pipes are completely collapsing under high boost causing my engine to run rich, going into limp mode, Causing engine misfires per obd codes. I have done smoke tests for vacuum leaks, I have gotten the new updated longer barb fittings, and I’m still having limp mode to check engine light on wide open throughout or high boost scenarios. I have now installed the stock plastic OEM inlet pipe and I have not had a single issue for weeks. I can go full throttle full boost nonstop, and the car performs great. The AFE silicone pipes may work under stock tunes, but they are in no way shape or form Designed to handle the extra boost under these tunes. If anyone wants these AFE pipes, I will ship them for you for free absolute garbage
I almost guarantee you it's not because the silicone coupler is collapsing - those are used on builds with 600+ horsepower, though they do start to become problematic after that mostly because it's hard to get them to stay connected under boost.
The absolute most common problem with aftermarket intakes in my experience is the change in MAF sensor behavior - and it's the reason I think Intakes are absolutely garbage unless you know you need them and have your car tuned for your specific intake.
MAF values & airflow curves are carefully tuned for exactly the shape & diameter of the stock intake, the intake's exact airflow characteristics at all RPMs, as well as the precise location & angle of the MAF sensor in the airflow. As soon as you change any of those parameters, the MAF's readings become inaccurate. Aftermarket companies do some interesting Engineering to allow their airboxes to make more power without logging a CEL, essentially by purposely placing the MAF in a location that will read the airflow inaccurately (reading lower than reality), trying to trick the computer into letting more air into the engine. Theoretically, by reading the exhaust Air / Fuel sensor values, the engine will see that it did not inject enough fuel to match the air, and inject more fuel to compensate.
Notice the odd shape of that section of intake? How it starts wide, narrows down right where the MAF sensor sits, and then widens again afterwards? That's because they had to keep the diameter of that section exactly the same size as the factory intake in order for the MAF to read even remotely accurately. But that wide - narrow - wide shape changes the way the airflow behaves - it accelerates the air past the MAF sensor, then slows it down afterwards, potentially causing some weird turbulent flow that will further confuse the MAF.
HOWEVER, modern cars have moved way beyond "if there's not enough fuel, inject more fuel, get bigger bang". Our vehicles are almost certainly tuned via torque targets, meaning our vehicles know exactly how much torque is being produced at any time (either via fancy math or by measuring the acceleration of the crankshaft after every piston's combustion event), and will automatically adjust the throttle open or closed to achieve exactly the torque specified.
Fun fact - this is extra cool because our cars now calculate exactly how much torque is being drained by the AC compressor, the alternator, and even the friction inside the engine and will automatically compensate, meaning you'll get pretty much the same exact power every time, no matter how hard those accessories are working. On a hot desert night with the AC screaming, your giant accessory lights running, Dometic cooler sucking down power in the trunk - you'll get more or less the same 345hp as any other day.
So it doesn't matter if your car is tricked into breathing more air and injecting more fuel - it won't make an ounce of difference because the ECU will detect the excess torque and automatically close the throttle back to exactly the same amount of power it was making before you installed the intake.
The VF tune is almost certainly misfiring and causing problems because that tune is specifically, super-carefully optimized for the factory intake shape, airflow, and MAF positioning. By installing the AFE intake, you've changed that carefully calculated airflow measurement, lying to your ECU, and I'd bet the VF tune is simply not designed to accommodate such weird, inaccurate airflow characteristics, leading to an extreme fueling mismatch, creating that misfire. (It's also possible the VF tune is actually Speed / Density based rather than MAF based, but either way - changing the airflow breaks the tune). It's not VF Tune's fault - they're just running the engine as close to the ragged edge as is safe so that you can make as much power as possible - but the ragged edge means you're much closer to failure modes like misfires, so if it's not getting an accurate airflow reading, it's very easy to run out of safety margin.
Everybody: STOP BUYING AFTERMARKET INTAKES. THEY WON'T DO ANYTHING EXCEPT SOUND COOL
The absolute most common problem with aftermarket intakes in my experience is the change in MAF sensor behavior - and it's the reason I think Intakes are absolutely garbage unless you know you need them and have your car tuned for your specific intake.
MAF values & airflow curves are carefully tuned for exactly the shape & diameter of the stock intake, the intake's exact airflow characteristics at all RPMs, as well as the precise location & angle of the MAF sensor in the airflow. As soon as you change any of those parameters, the MAF's readings become inaccurate. Aftermarket companies do some interesting Engineering to allow their airboxes to make more power without logging a CEL, essentially by purposely placing the MAF in a location that will read the airflow inaccurately (reading lower than reality), trying to trick the computer into letting more air into the engine. Theoretically, by reading the exhaust Air / Fuel sensor values, the engine will see that it did not inject enough fuel to match the air, and inject more fuel to compensate.
Notice the odd shape of that section of intake? How it starts wide, narrows down right where the MAF sensor sits, and then widens again afterwards? That's because they had to keep the diameter of that section exactly the same size as the factory intake in order for the MAF to read even remotely accurately. But that wide - narrow - wide shape changes the way the airflow behaves - it accelerates the air past the MAF sensor, then slows it down afterwards, potentially causing some weird turbulent flow that will further confuse the MAF.
HOWEVER, modern cars have moved way beyond "if there's not enough fuel, inject more fuel, get bigger bang". Our vehicles are almost certainly tuned via torque targets, meaning our vehicles know exactly how much torque is being produced at any time (either via fancy math or by measuring the acceleration of the crankshaft after every piston's combustion event), and will automatically adjust the throttle open or closed to achieve exactly the torque specified.
Fun fact - this is extra cool because our cars now calculate exactly how much torque is being drained by the AC compressor, the alternator, and even the friction inside the engine and will automatically compensate, meaning you'll get pretty much the same exact power every time, no matter how hard those accessories are working. On a hot desert night with the AC screaming, your giant accessory lights running, Dometic cooler sucking down power in the trunk - you'll get more or less the same 345hp as any other day.
So it doesn't matter if your car is tricked into breathing more air and injecting more fuel - it won't make an ounce of difference because the ECU will detect the excess torque and automatically close the throttle back to exactly the same amount of power it was making before you installed the intake.
The VF tune is almost certainly misfiring and causing problems because that tune is specifically, super-carefully optimized for the factory intake shape, airflow, and MAF positioning. By installing the AFE intake, you've changed that carefully calculated airflow measurement, lying to your ECU, and I'd bet the VF tune is simply not designed to accommodate such weird, inaccurate airflow characteristics, leading to an extreme fueling mismatch, creating that misfire. (It's also possible the VF tune is actually Speed / Density based rather than MAF based, but either way - changing the airflow breaks the tune). It's not VF Tune's fault - they're just running the engine as close to the ragged edge as is safe so that you can make as much power as possible - but the ragged edge means you're much closer to failure modes like misfires, so if it's not getting an accurate airflow reading, it's very easy to run out of safety margin.
Everybody: STOP BUYING AFTERMARKET INTAKES. THEY WON'T DO ANYTHING EXCEPT SOUND COOL
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Thank you for this detailed explanation.
Want to clear up a few points (and points where we agree)
1. We are not running the engine anywhere near the ragged edge. Actually the stock turbos are not large enough to get it anywhere close to the limit.
2. Our tunes ARE, as you correctly pointed out, designed for OEM INTAKES. The OEM intakes are designed so that the airflow reading is exactly what the ECU expects.
I have seen some companies lately making WONKY looking intakes, and WONKY MAF housings which skew MAF readings and while it "may" work and "may" sound cool the ECU is working overtime to correct it.
if you install an intake and NO tune, you have a +/- basically 30% trim margin where the ECU can correct for wonky engineering.
With the tune installed, boost is higher, everything else is tuned, and you have a much shorted window of correction before things get out of hand.
This is not only unique to the GX. The AFE intakes are causing the exact same problems on the Tundras.
I can confirm that the silicone Afe inlets ARE super squishy and IMHO probably won’t hold up to serious vacuum pressure. I noticed this immediately when I got them out of the box. Also, the hose barb issue is still a worry because the upper operating temp range for the JB Plastic Weld is 200 degrees, so the will have to come off before it gets too hot here.
Plus, I plan to do the 87 octane VFTune, so that’s going to require them to be removed anyways based on comments from Brian.
Plus, I plan to do the 87 octane VFTune, so that’s going to require them to be removed anyways based on comments from Brian.
Apologies for using the term "ragged edge" - I didn't mean to imply your tune was pushing an unsafe amount of boost, fueling, or timing under intended (well maintained factory hardware) conditions. I'm sure with everything in factory condition, your tune will be plenty safe for many tens or hundreds of thousands of miles.
I will say, though - what I mean when I say "closer to safety margins" is that the factory calibration clearly has a little more margin when it comes to transient, high-load situations vs. the VF tune, as the factory calibration isn't (to my knowledge) known to misfire w/ the AFE intake, whereas the VF tune seems to do so. I can't comment as to why it's misfiring, as I don't have any experience with either product or any freeze frame data, but a misfire means the ECU has exhausted all of its many correction mechanisms.
Essentially, VF Tune is doing its customers a favor by giving them as much power as is safely reasonable, but you don't magic it out of nowhere. Like any other aftermarket tune, you're utilizing some of the correction margin that's normally built into the factory calibration, in exchange for much more power. It's much easier to end up outside the ECU's ability to correct for problems when you start to modify parts that aren't expected by the tune - especially if those parts purposely manipulate the data going to the ECU.
Check out the 6 minute mark of this YouTube video - it demonstrates just how incredibly restricted your airflow has to be before it actually starts creating a meaningful vacuum in the intake:
Remember - there's only vacuum in the intake if there's a restriction blocking the flow into the turbos. If those silicone couplers are collapsing, it means that the AFE intake has to be like 95%+ more restrictive than the factory paper filter. Which I guess might be the case, but if so, then back to my point of why even use an aftermarket intake?
From my experience, modern factory air intakes provide plenty of airflow and usually the coldest air charge you can get compared to aftermarket intakes. You usually only run into airflow problems once you start changing hard parts like turbos, supercharger pullies, cams, that kind of thing.
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