After running replacement-type intakes on both our 302 and 347 engines, this month we’ve stepped up to the street-strip intakes for those folks running small-blocks in the mid-400hp naturally aspirated zone. First up we installed a Holley Hi-Ram intake manifold with a dual 4150 plenum and twin 4150 throttle bodies. The intakes set to be tested were a Holley Hi-Ram with dual 4150 throttle bodies, dual 4500 throttle bodies, a front feed plenum, and MSD’s popular Atomic AirForce polymer intake. Run as described with the stock LS7 intake, the stroker produced peak numbers of 641 hp at 6,800 rpm and 553 lb-ft of torque at 5,400 rpm. The combination was dead repeatable, so off came the factory intake and on went the FAST LSXR.

While peak power gains offer enticing Internet banter, changes in the entire power curve are the real story. In short, this was the most extensive LS intake manifold test ever devised. To establish a new baseline with the larger 415 stroker, we started once again by running the big-inch LS3 with the factory LS3 intake.

Testing The Intake Air Temperature Sensor Off The Car

Equipped with the stock intake, the CMP LS7 produced 641 hp at 6,800 rpm and 553 lb-ft of torque at 5,400 rpm. Replacing the stock intake with the FAST LSXR resulted in a gain of more than 20 hp, with peaks of 663 hp at the same 6,800 rpm, but 569 lb-ft of torque at a slightly higher 5,600 rpm. The FAST intake improved the power output starting at 4,400 rpm, and those gains increased with engine speed. We also ran the Holley Mid-Rise in carbureted trim, though the dual-carb Mid-Rise was a more significant change in the intake design than the simple lid swap on the Hi-Ram. The Mid Rise required an intermediate section between the dual-quad lower and lid, which extended the runners slightly on the EFI version. The dual-quad-carbureted intake was run with a pair of 4160 carbs that lacked secondary metering blocks for jetting.

When our retest resulted in numbers within 2 lb-ft and 2 hp, we decided nothing had changed since those numbers are within a half-percentage point. If you test at the track, air quality can affect performance more than that during one day of testing. These numbers underscore just how competitive the market is for single-plane, small-block Chevy intake manifolds. Looking at the intakes, the single- and dual-plane manifolds were decidedly different.

Dyno Tested: How to Choose the right Intake Manifold for your LS Engine

When the intake test for a module is successful, it can be recorded and stored in a library as a proof and testing for this module can start. Turn the car’s ignition switch on without starting the engine of the car. Connect the black lead of the Digital Multimeter to the ground wire of the Intake Air Temperature sensor and the red lead of the Digital MultiMeter to the battery voltage. Testing The Ground Circuit Of The IAT Sensor With A MultimeterTurn off the car switch. Testing the Resistance of IAT Sensor With a MultimeterDisconnect the Intake Air Temperature sensor from the electrical connector.

A special type of test “to smoke” for taking a decision, whether component or system is ready for further detailed software testing. Our patent-pending technology uses urine spectral analysis to report hydration. Scientific studies and customer field data prove our technology as more accurate than dipsticks and interchangeable with digital refractometry. GM may have offered a couple of more powerful factory LS motors, but the LSA and LS9 each required a hefty dose of forced induction to top the magnificent 7.0L LS7. Uneven flow of fuel briefly while the engine is running at near idle speed.

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Though the cam was a mystery, previous testing with a pair of carbs and headers showed us the crate motor ran well and was healthy enough to compare the manifolds. Our testing began with what is arguably the best factory intake ever offered on an LS. Many aftermarket manufacturers have discovered that the stock LS3 intake https://www.globalcloudteam.com/ is tough to beat. Sure, you can add power higher or lower in the rev range, but there will almost always be some sort of trade-off compared to the stock intake. Equipped with the factory LS3 intake and FAST 92mm throttle body, the cammed 6.2L crate motor produced peak numbers of 580 hp and 527 lb-ft of torque.

• The forged slugs relied on a Total Seal ring package to maximize sealing and power production.
• Porting a plenum and runners can easily get you an additional 15 plus hp.
• Either version should easily fit under the hood where a factory manifold works.
• For most street, and even dual-purpose, street/strip applications, the extra grunt offered by the dual-plane intake will likely be more useful on a daily basis.
• There was also a slight change in the plenum volume between the two tops for the Hi Ram.
• We had very good success with the Pro-Flow in our test on the cathedral-port intakes, and this rec-port version continued the trend.

For this test, we replaced the standard LSXR upper intake section with the larger LSXRT intake. Often referred to as the truck intake, the LSXRT top simply offers increased plenum volume on this adjustable intake application. This combination was still equipped with the short runners used in the previous test. Equipped with the short runners and FAST LSXRT top, the LS3 produced almost identical power to the standard LSXR top. The plenum volume changed the power output very little on this application. Equipped with the FAST adjustable LSXRT intake , the 6.2L still produced 603 hp and 495 lb-ft of torque.

More from Merriam-Webster on intake

While the Sniper offered more peak power than the factory LS3, torque production suffered through much of the rpm range. Equipped with the low-profile Sniper, the 6.2L produced 608 hp and 501 lb-ft of torque. Equipped with the LSXR, the modified 6.0L produced 591 hp and 505 lb-ft of torque. The FAST intake offered impressive peak power and the highest torque production of any of the intakes tested. Though some of the shorter runner intakes made slightly more peak power, it is hard to beat this long-runner design for average power production. The internet will be quick to grab the peak numbers from this test and run with them, but there is much more to an intake, or the power curve it produces, than simple peak values.

We measured carb pad height because the manifold has to be able to fit under your hood. We’ve also calculated average torque between 3,500 and 6,500 because that is the rpm band where these engines will spend the majority of their time during a quarter-mile run. We think average torque is the most important factor that we measured in this test. You https://www.globalcloudteam.com/glossary/intake-test/ will get tired of hearing that in this story because that’s the hammer we’re bringing. Apply a higher average torque, and it will accelerate any vehicle quicker. You might have a manifold that makes good peak horsepower, but if it loses torque in the middle rpm band, the peak-horsepower number is not nearly as important as the average power.

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We tested the taller of the two optional plenums, and it’s still more than an inch shorter than the Edelbrock Super Victor II. A radioactive iodine uptake tests the function of your thyroid gland, which helps regulate your metabolism. It works by measuring how much radioactive iodine is absorbed by the thyroid gland, using a controlled amount of radioactive iodine in a specific time frame. Early automobile intake systems were simple air inlets connected directly to carburetors. We gathered these prices from ads in this magazine, and retail prices will vary. The BBK intake includes fuel rails, which are required to fit its intake.

Like the single-plane, carbureted intakes we tested, this piece offered short intake runners designed to promote power production higher in the rev range, and that is exactly what it did. The short runner lost out in torque production to the LS1 at less than 5,300 rpm, then pulled away strongly thereafter, peaking at 587 hp . Named after the Australian arachnid, the Funnel Web was designed to maximize high-rpm power production of high-performance, carbureted engines. Like most single-plane designs, the Funnel Web featured a large, common plenum feeding eight individual runners.

Testing The Power Circuit Of The IAT Sensor With A Multimeter

Things got serious when we installed the 105mm throttle body on the Holley Hi Ram. Holley also offers a 92mm top for the Hi Ram, but you will need the 102mm version on almost any application except a turbo 5.3L. The tunnel-ram intake offered impressive peak performance, but torque production did suffer compared to the stock LS3. Equipped with the Hi Ram and single 105mm throttle body, the LS3 motor produced 612 hp and 509 lb-ft of torque. The torque curve was much more telling, as the loss of low-speed power was more pronounced.