In last month’s issue, we spent some time prepping our ’02 C5 for a FAST 92mm LSX intake-manifold swap. This month, we’ll wrap up the job by decking out our Vette’s LS1 with the new FAST piece. As this is a relatively easy procedure, the only things a dedicated DIY’er should need are a decent set of tools, a set of C5 Service Manuals, and a quick run to the local speed shop for some passes on the dyno.
Last month, we ended with...
Last month, we ended with this view of the LS1 minus its stock intake. After being subjected to a thorough cleaning, it was ready for the new FAST piece.
Speaking of dynos, a big thanks goes to the guys at Enhanced Street Performance, Inc., who provided theirs in furtherance of our quest for higher horsepower. Their service was fast, friendly, and accurate in regards to diagnosing a few minor issues we encountered along the way.
Now, without further ado, let’s get to going faster and breathing easier.
Editor’s Note: Since this project was completed, FAST has replaced the 92mm LSX with a 102mm version. This new intake is also compatible with the LS1 engine and should perform at least as well as its predecessor in that application.
The first step was to replace...
The first step was to replace the factory bolts with the ones supplied by FAST. We used a Snap-on Tech1FR240 torque wrench to achieve the lb-ft readings specified in the instructions.
Speaking of specifications,...
Speaking of specifications, all the factory numbers you need to complete this and other installs may be found in the C5 Service Manual series. We got ours from Corvette Central.
Next, we unboxed our FAST...
Next, we unboxed our FAST LSX manifold...
... and disassembled it to...
... and disassembled it to take a look at the inside.
Any time you remove your intake...
Any time you remove your intake manifold, it’s a good idea to replace your port seals.
We obtained a fresh set from...
We obtained a fresh set from FAST (PN 54009-8) and installed them as shown.
With the intake reassembled,...
With the intake reassembled, we plugged the MAP sensor into the rear of the unit...
... and slid the manifold...
... and slid the manifold gently into place.
The only issue we encountered...
The only issue we encountered on our car was a factory rear vacuum hose that was a bit too short. Utilizing a piece from a C4 harness, we cobbled together this working splice.
After torquing down the intake...
After torquing down the intake per the instructions, we reinstalled the fuel rails and related components.
FAST offers a “Big Mouth”...
FAST offers a “Big Mouth” throttle body designed to work in conjunction with the LSX manifold. It’s mechanically actuated, however, and won’t work with the stock drive-by-wire system, which we wanted to preserve.
Since the factory unit won’t...
Since the factory unit won’t fit without a custom adapter, we picked up an LS2 stocker that was perfect for the install.
The LS2 piece isn’t compatible...
The LS2 piece isn’t compatible with the factory wiring harness, so we obtained a conversion kit from Casper’s Electronics.
The new throttle body also...
The new throttle body also lacked provisions for the coolant lines. We simply used a 0.25-inch hose splicer (available at any home-improvement store) to make our own coolant-bypass kit.
While we were at it, we took...
While we were at it, we took the opportunity to install an oil catch-can. The guys at Enhanced Street Performance had great things to say about Elite Engineering’s version.
Made of billet aluminum (and...
Made of billet aluminum (and available in several colors), the can keeps sludge from cycling through the PCV system. It also disassembles easily for cleaning (shown) and comes with all the required hoses and hardware.
Installation is as simple...
Installation is as simple as it gets. The catch-can should prevent the kind of gunk buildup we found when we removed our stock intake.
With all the cables routed...
With all the cables routed and the factory covers reinstalled, our LSX intake was ready to impress.
Afterwards, Enhanced Street...
Afterwards, Enhanced Street Performance gave us the good news. Our baseline of 261 rwhp increased to 281—a 20-horse difference! Torque also increased, from 269 lb-ft to 285. Not bad for a few hours of work. Join us next month as we wrap up our LSX install with a PCM-tuning session. VETTE