Chevrolet Camaro Engine Upgrades - LS1 Hop-Ups

Easy 20 Horses in Under an Hour

The Dyno Doesn’t Lie.
The idea was to see what kind of real-world horsepower gains we could generate with only a few simple bolt-ons. Enlisting the help of Mike Taylor and his stock ’99 LS1 SS Camaro, we baselined the SS on the Morgan Motorsports chassis dyno in Reseda, California. Initial numbers revealed an impressive 305 hp and 322 lb-ft of torque. Next we plugged in the Hypertech Power Programmer III (PP3) into the data link connector and waited 10 minutes for the non-reformulated gas (non-RFG) tune to upload into the LS1 computer (see sidebar “Gas Is Gas...Right?”). Back on the dyno, we immediately witnessed the horsepower jump to 312 with the new lb-ft figures reading at 328.

Now for the bigger test. We had Morgan Motorsports install its 20 Rear-Wheel Horsepower Under an Hour package, which actually took less than 25 minutes from start to finish. This included replacing the factory airbox lid, mass airflow (MAF) sensor, and throttle-body with a higher-flowing ’99 Corvette airbox lid, Granatelli MAF sensor, and ported Morgan Motorsports throttle-body. The results were an excellent increase to 325 hp and 334 lb-ft of torque. However, we found that the non-RFG tune was slightly aggressive with minor detonation. Next we tried the RFG tune, and with slightly less timing and a richer fuel curve, our next dyno pull showed that we were only down 1 hp and 2 lb-ft of torque. So to avoid detonation, be sure to use the RFG tune unless you have access to at least 93-octane fuel.

For our final test, we removed the Hypertech tune and allowed the factory LS1 computer to do its job. Interestingly, we found that our power levels increased even higher with the numbers peaking at 328 hp and 339 lb-ft of torque. Looking at the air/fuel ratio, it seems the factory computer didn’t lean out the fuel enrichment quite as much as the PP3 tune and was able to make use of the extra fuel for the additional air that was now flowing via our upgrades.

Cracking Codes
Knowing how to tune a car is one thing, but creating computer hardware to do the work for you is something else. Mike Morgan of Morgan Motorsports is one of the leading aftermarket tuners in the LS1 market. He’s installed and rebuilt everything from old-school TPI cars to the latest high-tech LS1 turbo kits. Building on this experience with big-horsepower packages, Morgan now has the ability to tune EFI cars with his own line of custom programs that go directly into the factory computer. This ability to read the factory’s binary coding enables Morgan to manipulate and punch in the ideal tune on everything from mild to big-horsepower motors (which really need it) through his own hardware. While we couldn’t get the exact details since he’s currently looking to patent his hardware, we did manage to sneak a photo of it. For more information, contact

Step By Step

The larger-diameter Granatelli Motorsports MAF sensor (right) was utilized along with Morgan Motorsport’s ported 75mm throttle-body (left). The combination of larger components helps eliminate the factory’s bottlenecked pieces by allowing greater airflow and creating a much crisper throttle response.

Upgrading the throttle-body to the ported piece was a snap. With the airbox lid and MAF sensor removed, unclamp the two coolant lines (arrow) on both sides of the housing, and then use a 10mm socket to remove the three housing bolts. Reverse the process with the new 75mm MMS unit and that’s it!


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