Testing FAST’s LSX Intake & Throttle Body

Fastest Street Car’s LS-Wonder Camaro is a typical LS1-powered automatic SS with bolt-on’s. It made 309 rear wheel horsepower with under drive pulleys, exhaust, cold-air, and a tune. However, we were looking for more, and beyond the nitrous we had been squeezing at the track, the next thing on the install list was to dyno test the FAST LS1/LS2 Intake Manifold and “Big Mouth” 92mm Throttle Body. Here’s an overview of that experiment and the results.

Fastest Street Car Project LS-Wonder

It’s been quite a while since FSC tested their LS1-powered Camaro, the LS-Wonder. With the amount of time they were working on their personal projects, the “company car” sort of fell to the wayside. To give a recap of what the LS-Wonder is armed with, under the hood is an 88,000 mile 2000 LS1 with a ton of bolt-ons; underdrive pulleys, Hooker long tube headers, a K&N cold air kit, Flowmaster/Mufflex exhaust, a 150-shot from a Nitrous Works system, and a performance tune from DiabloSport. But what makes the LS-Wonder really work well on the track is the TCI 4,500 stall converter and a set of 4.10 gears. With this combo and set of BFGoodrich drag radials we were able to bust low 1.60 60-foot times.

FAST LSX intake and 92 MM Throttle Body

With all the added power elsewhere and the need for more airflow, the FAST LSX manifold and 92mm throttle body were the next parts we planned to upgrade. Forum members noted power increases of 20 or more horsepower over the factory LS1 intake with no loss of drivability or low RPM torque, which is what really got our attention.

Though the FAST intake is made from a polymer material like the stocker, it’s considerably stronger and is designed with porting in mind.

Intake Design

For the design, the guys at FAST assembled a team of some of the best manifold experts in the country, including Keith Wilson of NASCAR and NHRA fame, with the goal of making a high-flowing intake for the growing LS engine market. They engineered a unique, three-piece design that allows you access to every inch of the manifold. The middle and upper shells can be changed to allow for additional engine modifications.

Finally, the intake runners can be match ported and include witness grooves to indicate how much material you can remove, and the intake is low enough that it is easily concealed under a stock hood, too. The polymer construction means that the F.A.S.T. intake is significantly lighter than aluminum intakes (11 pounds vs. 26 pounds).

”Witness grooves” cast into the runners show how deep the intake can safely be ported, taking the guesswork out of the process.

The intake is made from similar materials to the OEM piece, but is 30-percent stronger thanks to the “Amodel” polymer material, and unlike a metal aftermarket intake, it won’t heat-soak and warm up the intake charge. The intake also features integrated ports for use with direct port-nitrous injection. Even though this is a composite manifold, the added runner material is a sign that it can still be ported and a patented three-piece design allows easy access. Additionally, we received the Wilson Manifold version of this intake that includes burst panels to help prevent engine damage caused by nitrous backfires or boost pressure overload.

For protection against damage caused by backfires in nitrous or blown applications, the manifold is available with blow-out discs on the underside.

To compliment the manifold, we also opted to go with FAST’s new Big Mouth 92mm throttle body. Compared to other throttle bodies on the market, the Big Mouth features a series of innovative design changes and a slightly enlarged throttle opening. But the increased size of the FAST Big Mouth throttle body is just a small part of the added benefits. FAST invested significant testing and engineering resources into optimizing cross-sectional flow and eliminating airflow turbulence, especially in part throttle operation.

In addition, these throttle bodies offer increased throttle blade thickness to eliminate deflection commonly found with other throttle bodies, especially those in boosted applications. A smoother-operating offset blade pivot improves throttle response, corrosion-free stainless hardware is a step up from the typical plated screws, and a beefed-up linkage and dual throttle spring mechanism ensure total throttle control. It works on GM’s Gen III & Gen IV to increase horsepower and maximize the potential of performance upgrades.

FAST’s 92mm throttle body is designed to compliment the manifold, but it’s more than just an oversized version of the stocker, with improvements in blade thickness and pivot placement, as well as a heavy-duty linkage.

Enough! Time to install the parts!

With FSC Technical Editor Jake Amatisto behind the wheel, the LS-Wonder showed up at the back of our shop, eager for some thrashing. This Camaro is no trailer queen and sees a lot of driving on the street. One thing that makes the LS-Wonder a great project is it really hauls ass, and it does it with parts that can easily be put on in the garage. Before the install, we put the LS-Wonder on the Dynojet to see what it was putting down. It pumped a cool 309 horsepower and 296 lb/ft with the stock intake manifold.

Baseline testing delivered 309 horsepower and 296 pound-feet to the wheels with the stock manifold and throttle body.

The one thing the Camaro doesn’t have going for it is the fact that virtually half the engine is under the dash, which doesn’t make this installation all that quick. The first tasks started at the front, removing the pipe to the airbox, the two bolts that hold the Idle Air Control tube in, the throttle cable, and the coolant lines off the throttle body.

From there we moved to removing the components off the back of the intake. The injector plugs that were easy to get to, except for the last one on the drivers side. A little cussing and some contorted arm movements later, and it was off. One of the last steps before loosening the intake bolts was removing the fuel lines. Grabbing the stock lock fitting with a pair of needle nose pliers seemed like the easiest route to take. With some patience and a little wiggling, the stock intake was free.

Ah, the pleasures of working on a 4th Gen Camaro! It’s handy to keep a little guy like FSC Tech Editor Jake Amatisto in the toolbox for situations like this.

Though the intake came equipped with some sweet Wilson fuel rails, we weren’t set up to take advantage of them yet and transferred the stock rails and injectors to the new intake manifold. We also installed a new set of intake port seals from FAST. Before you can bolt the intake down, you must replace the stock valley pan bolts with the corrosion-resistant stainless fasteners that are supplied in the kit.

The stock bolt heads are a bit too tall, and if they are not changed, it could lead to sealing issues. Now do it was time to do the same things we did to remove the intake, but backwards. One thing you have to pay attention to when installing this intake is the fragile oil pressure-sending unit. One little tap when we mocked the intake up snapped it like a twig. A new one is about 70 bucks, so don’t be like us and watch out for this.

A little patience is required, but the removal and replacement process holds no surprises.

Time for the Dyno with our New Goodies

With the intake installed it was time to get the LS-Wonder back on the rollers and see what we could pick up. We were stoked when the FAST intake netted a gain of 21 horsepower and over 7 lb/ft of torque, for a new total of 330 horsepower and 303 lb/ft of torque. We did have to adjust the tune with the Diablosport software, but that was hardly responsible for the power gains. That was the act of optimizing the air/fuel ratio and timing curve for the V/E differences in the intake manifold.

Eventually, the Camaro will receive a built engine that will really utilize the power capability of this intake. With a few scratches on the arms and a half-day’s work, we were able to rig one of the last power adders the Camaro needed before it is ready to make some serious horsepower. We’ll hopefully soon bring you some track results from our local 1/8 mile at Irwindale.

With the new manifold and throttle body installed, we found an extra 21 horses and 7 pound-feet on the dyno.

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About the author

Mark Gearhart

In 1995 Mark started photographing drag races at his once local track, Bradenton Motorsports Park. He became hooked and shot virtually every series at the track until 2007 until he moved to California and began working as a writer for Power Automedia. He was the founding editor for its first online magazines, and transitioned into the role of editorial director role in 2014. Retiring from the company in 2016, Mark continues to expand his career as a car builder, automotive enthusiast, and freelance journalist to provide featured content and technical expertise.
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