Johnson removes the cover...
Johnson removes the cover from the circuit board.
Chris Johnson of SCT showed up at MM&FF headquarters with the chip and selector switch (included), the programming software ($349), and a chip programmer. The programmer (PN 7500) is separate and costs $300. On our Dynojet at the Source Interlink Tech Center in Tampa, a baseline pull yielded 262 rwhp and 287 lb-ft of torque.
After disconnecting the battery to clear the ECM's adaptations, power increased to 265 hp and torque to 291 lb-ft. "As you drive the car on the street, the computer learns and adapts to the conditions," says Johnson. So when we disconnected the battery, the computer was reset to factory settings-and a 3 rwhp and 4 lb-ft increase resulted.
He then cleans the terminals...
He then cleans the terminals on the port with provided pad, and plugs the chip into the ECM.
The next step was to burn the tunes to the chip. Johnson downloaded the tuning software onto our computer and began picking tunes for our application. A mild naturally aspirated tune is already burned to the chip, so Johnson modified another version of that same tune by retarding the timing to 14 degrees; he burned it to the chip as well.
Now we can get the best of our engine with maximized timing and with the flip of a switch, turn on our nitrous-friendly tune. As an added safety feature, Johnson raised the idle of our nitrous tune to 1,200 rpm, so we know that it is on just by how the car idles.
As you can see from the graph,...
As you can see from the graph, the chip free'd up 11 rwhp and 17 lb-ft of torque in naturally aspirated trim, and it also allows us to switch to our nitrous tune without even opening the hood.
Next, Johnson disconnected the negative battery cable and removed the ECM from its home behind the right kick panel. He then removed the computer cover, cleaned the terminals on the port, and plugged in the chip. The switch comes with a long cable, which plugs into the chip for easy placement anywhere in or under the dash (or console).
On our street tune, we made another pull on the Dynojet, which resulted in 273 rwhp and 304 lb-ft of torque-an 8hp and 13 lb-ft increase.
With new lower intake gaskets...
With new lower intake gaskets in place (not included), we installed the new lower intake manifold and tightened.
We took this opportunity to...
We took this opportunity to readjust the rocker arms, and then installed the new valve covers.
There are vacuum ports at...
There are vacuum ports at the rear of the upper plenum, and hardware is included in the kit.
After reinstalling the fuel...
After reinstalling the fuel rail, heater pipe, and wiring harness, we bolted the upper intake in place.
The studs for the throttle...
The studs for the throttle body and EGR spacer (or eliminator)...
...must be salvaged from a...
...must be salvaged from a stock-style intake manifold.
Before
After
On the track is where the...
On the track is where the big gains were made. On the first pass, the LX ran an 11.55 at 117 mph. That's 0.24 seconds quicker and 2 mph faster than before-not to mention, conditions were worse being a hot mid-August day at Gainesville Raceway.
In naturally aspirated trim,...
In naturally aspirated trim, peak power was up from 273 rwhp to 276. Torque, though, was down from 304 lb-ft to 279. The real improvement was above 5,400 rpm, which we hoped would help us at the track.
On the nitrous, we also noticed...
On the nitrous, we also noticed a small gain in horsepower and a loss of torque. However, power and torque were both up above 5,100 rpm. In fact, torque and horsepower were both up by about 15 at 5,700.