Ramming Speed

BY Wes Dunkel Photography by THE AUTHOR

eneral Motors’ fourth-gen F-body was a radical design. With its steeply raked windshield and bird-beak nose, the groundbreaking LS1 powerplant was tucked halfway under the cowl. Function clearly followed form at GM headquarters.

But with the LS1’s factory intake manifold nestled neatly in the valley of the Gen III V-8, cowl clearance isn’t a problem. However, intake manifold options are severely limited to low-profile designs. Those with high-horsepower engines had two choices: one, use the stock or aftermarket low-profile plastic intake manifolds; or two, cut the stock cowl, lose the windshield wipers, and possibly even cut the windshield.

Fortunately, Holley has an option: the Modular Lo-Ram EFI intake manifold for LS1/2/6. Its large, short runners are great for making big top-end power, and its large plenum complements supercharged and turbocharged applications. If the factory-style intake manifold on your cathedral-port LS engine is choking its potential, the Holley Lo-Ram EFI intake manifold is the ticket.

This thing is designed to flow some serious air. The Holley Lo-Ram EFI intake manifold (PN 300-621) accepts Holley’s monstrous 105mm throttle body (PN 112-581) to guarantee your engine gets all the air it wants. The front-feed design is a direct replacement for factory-style intakes, and its overall height is the same as that of a factory LS1 manifold.

The cast-aluminum construction is perfect for high-boost applications where plastic manifolds puff up like a balloon. There are even bosses for additional fuel injectors or nitrous nozzles.

Holley even includes a new set of fuel rails and two sets of mounting brackets: a set for long (usually standard length) fuel injectors and a set for short (such as Pico, or LS7) fuel injectors. Holley doesn’t leave you to “figure out the details” because they’ve already thought of it!

To sample the benefits of the Holley Lo-Ram intake manifold, we went over to Boost Addicts in Gallatin, Tennessee, to install one on a customer’s twin-turbocharged ’98 Camaro. Shoving 19 psi of boost through a stock, plastic LS1 manifold, this Camaro was the perfect candidate to show what the Holley Lo-Ram could do.

Follow along on the installation details and some very interesting dyno results.

2. Here’s the problem: the low cowl on ’93-02 GM F-bodies eliminates most aftermarket “ram”-style intake manifolds—unless you want to cut the cowl, lose the windshield wiper mechanism, and cut the windshield, and we don’t think that’s the best option.

4. The modular design of the Holley Lo-Ram EFI intake manifold utilizes a front-feed throttle body inlet and a removable cover.

7. Holley gave the Lo-Ram room to grow, with additional bosses for dual injectors or nitrous nozzles.

9. Then, we started assembling the Holley Lo-Ram intake by laying the supplied rope gasket in the top cover O-ring groove.

11. With the top cover aligned and tightened down, we used a razor blade to trim off the excess rope gasket until it was flush.

13. We used a razor blade to cut the rope gasket to the appropriate length.

15. With the rope gasket in place, we installed the throttle body adapter bolts.

17. Surprisingly, the Holley Lo-Ram intake manifold is the same height as the stock LS1 manifold. (The angle of this photo is a little deceiving: the Lo-Ram would’ve disappeared behind the stocker had we crouched lower.)

19. When everything checked out, we installed the included port flange seals.

21. After using the included studs to fasten down the manifold, we prepped and installed the included fuel rails. These are billet aluminum jewelry. Note that we used the supplied “long” fuel rail brackets to accommodate these “long-style” fuel injectors.

23. We didn’t encounter any fitment issues. Even the throttle body was in the same location as the factory inlet. All it took was a larger silicone coupling to adapt the charge side tube to the Holley 105mm throttle body.

25. With the Camaro back on the dyno at Boost Addicts, we were ready to make some pulls.