The problem isn’t just an open hood. It’s a dyno setup that no longer matches how the truck runs on the street. Without real airflow into the nose, the cooling package, intercooler system, and inlet air conditions all change. On a supercharged truck like the TRX, that means higher and less consistent intake air temperature, unstable charge-air cooling, and timing changes that can move power around for reasons that have nothing to do with the intake. Then there’s temperature conditioning. If coolant, oil, transmission fluid, and differential lube are not fully stabilized before testing, later pulls can show more wheel horsepower simply because parasitic losses dropped as the driveline warmed up. That is not an intake gain. It’s bad test control. Our point is simple: if you want intake data you can trust, the dyno has to reproduce road airflow and hold the vehicle at repeatable operating conditions. Otherwise the numbers are just a stack of variables pretending to be a result.
Gale Banks reviewed a dyno video featuring a Ram TRX fitted with a JLT, later referenced as an S&B, intake system and immediately challenged the test method rather than the truck itself. His central complaint was that the video claimed to present an apples-to-apples comparison, but the dyno setup did not replicate real driving conditions closely enough to support that claim. In Banks' view, the problem began with the hood-up testing configuration and the very small fan placed several feet in front of the truck. He argued that this arrangement could not provide meaningful airflow into the front of the vehicle, so the test environment was fundamentally different from what the truck experiences on the road.
Banks emphasized that the purpose of dyno testing is to remove uncontrolled variables such as weather, traffic, headwinds, and tailwinds while still reproducing the vehicle's real operating environment as faithfully as possible. If the dyno setup fails to simulate road airflow, then the test introduces new inconsistencies instead of eliminating them. He therefore framed the entire comparison as suspect before even discussing the power numbers.
A major part of Banks' criticism focused on the lack of Ram-Air into the nose of the truck. He said the small fan shown in the video was far too weak and too far away to force useful air through the TRX cooling package. According to Banks, that means the radiator, charge-air cooling hardware, and underhood airflow conditions were not being managed in a way that resembles street driving.
To explain what he considers proper dyno airflow, Banks described Banks' own "wind machine," built from a pair of large blowers recovered from a dismantled car wash in Texas. The blowers were rebuilt, bead-blasted, painted, mounted on a height-adjustable rolling stand, and fitted with a variable outlet nozzle. Banks said commercial fans could move a lot of air, but they did not provide enough velocity, which is what he considers necessary to simulate road conditions. His point was that dyno airflow must do more than cool the vehicle generally; it must reproduce the velocity and direction of air entering the front of the truck so the cooling package and intake system behave as they do on the street.
Banks then turned to the TRX's electric cooling fan strategy. He noted that the truck uses a very large electric fan whose speed changes according to operating conditions, including coolant temperature and, in his understanding, vehicle speed. On a stationary dyno with inadequate external airflow, the truck's control system is forced into an abnormal situation. The vehicle is showing wheel speed on the dyno, but it is not receiving realistic air through the grille, so the cooling fan and the rest of the thermal system are effectively trying to find a stable operating point under artificial conditions.
He argued that this creates inconsistency from run to run. At Banks, he said, cooling fans are either turned off completely or commanded to a fixed value during testing so airflow conditions remain controlled. Without that control, the cooling package sees varying airflow, and any resulting power changes cannot be confidently attributed to the intake system alone.
Banks also highlighted the TRX supercharger and intercooling system as a critical source of error in the test. The 6.2-liter Hemi uses a 2.4-liter IHI supercharger, and Banks explained that the blower discharges into the intake manifold, where the air passes through two charge-air cooler cores before entering the cylinder head ports. The cooling package at the front of the truck contains the heat exchanger for that separate intercooler circuit; it is not the engine coolant system, but its own cooling loop.
His argument was that if airflow through the front heat exchanger is inadequate or inconsistent, then the intercooler cannot reject heat properly. Under full power, that system is heavily loaded, so any reduction in cooling performance raises charge temperature and lowers air density. Banks stressed that boost pressure alone does not guarantee denser air. If the air is hotter, the engine may still see pressure, but each cubic foot contains less oxygen mass. That directly affects power and makes repeated dyno pulls less comparable when the cooling conditions are unstable.
The original dyno video explained that the truck had first been tested in stock form, but the operators found it difficult to get repeatable results because the ECU would enter catalyst over-temperature protection. To address that, they sent the computer to HP Tuners for unlocking, then disabled cat over-temp protection and also removed the speed limiter so they could complete a fifth-gear pull instead of being limited to fourth gear.
Banks objected to calling this apples-to-apples testing because the truck being evaluated was no longer operating with stock protections intact. He acknowledged what catalyst over-temp protection does: at roughly 1,648 degrees Fahrenheit catalyst temperature, enrichment begins with an air-fuel ratio around 11.8:1; by about 1,701 degrees Fahrenheit, the mixture drops to roughly 10.8:1; and by around 1,746 degrees Fahrenheit, the system can become so rich that misfire-like behavior appears as the ECU tries to protect the catalytic converters. He did not dispute the function of the strategy. Instead, he argued that disabling it changes the test conditions in a way ordinary street-driven trucks will not experience. In his view, if the goal is to evaluate an intake for a stock truck, then the intake should be tested on a stock truck with stock protections active.
Banks further criticized the video for monitoring inlet air temperature without, in his opinion, accounting properly for its effect on power. He stated that once intake air temperature exceeds 113 degrees Fahrenheit, the calibration begins removing ignition timing at a rate of 1 degree for every 4 degrees Fahrenheit of additional intake temperature rise. That means later runs can lose power simply because the engine bay and intake tract have become hotter, especially when the hood is open and the engine is drawing underhood air rather than the cooler air it would see in motion on the road.
He argued that the second and third pulls in a sequence are therefore not directly comparable to the first unless the thermal state is tightly controlled. In his reading of the video, the operators were watching coolant temperature, inlet air temperature, vehicle speed, and catalyst temperature, but not demonstrating that those variables had been stabilized in a way that isolates the intake as the only meaningful change.
Banks' most detailed technical objection concerned heat saturation. He said proper dyno testing requires more than bringing coolant to a target range such as 195 to 200 degrees Fahrenheit. In his process, the vehicle is loaded on the dyno until the engine coolant, engine oil, transmission fluid, and differential lubricant are all stabilized. He cited 208 degrees Fahrenheit as the heat-saturated coolant control point the factory system is trying to manage, implying that 195 to 200 degrees is not yet fully stabilized for this application.
The reason this matters, he said, is parasitic loss. When lubricants are cold, they are more viscous, increasing drag in the crankcase, transmission, and differential. As those fluids warm, parasitic horsepower losses decrease. If the stock intake is tested first with colder lubricants and the aftermarket intake is tested later after the driveline has warmed up, some of the measured gain may come from reduced mechanical drag rather than improved airflow. Banks estimated that this effect alone could account for 10 to 12 horsepower in favor of the later test. In that case, the dyno would show additional wheel horsepower that was not created by better combustion or air handling, but simply liberated because the lubricants had thinned and the drivetrain was easier to turn.
Banks also questioned several procedural details visible in the video. He noted that some pulls appeared to last only about five to six seconds and seemed to begin from different rolling conditions rather than from a fully standardized starting point. He also pointed out that the video mentioned three runs in one place but later discussed only two comparison runs, which he saw as another sign that the presentation was not rigorous enough.
He commented on the dyno hardware itself as well, observing that the rollers appeared relatively small in diameter and that the tire sat very close to the cover plate. He speculated that it might be an inertial dyno rather than a load-cell dyno, though he did not claim certainty. The broader point was that if the test setup is not fully instrumented and controlled, then the resulting graph cannot explain why power changed. At Banks, he said, every relevant parameter is instrumented so that any gain can be validated against supporting data rather than inferred from a single before-and-after chart.
The dyno video reported a peak gain of 24 horsepower and 17 lb-ft from replacing the stock air box with the aftermarket intake while still using the factory grille and hood air inlets. Banks did not accept those numbers as trustworthy. He argued that the combination of hood-up testing, inadequate external airflow, unstable cooling fan behavior, compromised intercooler performance, altered ECU protections, intake-temperature-related timing changes, and incomplete heat saturation made the comparison invalid.
His conclusion was that the test did not produce a true apples-to-apples result either from dyno run to dyno run or from dyno conditions to real street operation. In his view, the measured gain could not be taken to the bank because too many uncontrolled or improperly controlled variables were influencing the outcome. He closed by saying that a valid comparison requires the same kind of disciplined procedure Banks uses: realistic airflow into the nose of the vehicle, fixed and repeatable thermal conditions, stabilized lubricants, and enough instrumentation to prove the reason for any power increase rather than merely displaying a favorable number on the dyno.