As we revealed last month, installing a FAST LSX intake manifold on our '02 C5 gave us some impressive net gains: 20 horsepower and 16 lb-ft of torque. But we're not stopping there. For better or worse, those numbers are plug-and-play results. And while it's a great take-home for a few hours of work, there's room for improvement. Our goal this month is to optimize our '02's PCM tuning work in unison with the new intake, and for that we needed Enhanced Street Performance's expertise.
Met by owners Dave Brady and Greg Gemme, we were introduced to the shop's tuner-at-large, Scott Peitzsch. With laptop in hand, Peitzsch took some time to explain to us the concept of "safe horsepower" and why it's important to get a post-installation tune any time you perform a significant modification on an EFI engine. For instance, while the FAST manifold gave us the power we were looking for, the increased airflow resulted in an inefficient and potentially dangerous lean (i.e., fuel-deprived) air/fuel ratio. Since the cost of a tuning session is far below that of a replacement engine, we were all in. Besides, we can think of worse ways to spend a Saturday than next to a Vette on a dyno.
After Peitzsch ran some new tables through our C5's powertrain computer and selected the best one, it was time for a real-world road test. Although we didn't pick up any extra power with the new tune, our lean issues were safely put to bed, and driveability was noticeably improved. Acceleration was crisp and ready to unleash with little more than the twitch of one's lead footùa huge difference from how the LS1 acted when first purchased. Overall, the session was well worth the time and money. And the service? Well, one doesn't need extra-sensory perception to pick out high-hp parts, but one does need a quality shop such as ESP to ensure those parts are installed and tuned correctly. With that in mind, a big thanks goes out to Brady, Gemme, and Peitzsch-and to the helpful Corvette Forum members who introduced us.
1a Here’s a comparison of...
1a Here’s a comparison of our ’02 C5’s filthy stock intake manifold (top) and the new, upsized LSX unit from FAST...
1b ...The FAST piece has...
1b ...The FAST piece has a clean, factory look and red lettering that matches the Corvette script on the factory engine covers.
2 Just bolting on the LSX...
2 Just bolting on the LSX netted us a shocking 20 rwhp and 16 rwtq (up to peaks of 281 and 285, respectively). Unfortunately, the engine also developed a lean air/fuel condition that needed to be addressed before we could safely exercise the car.
3 After a quick look at...
3 After a quick look at the ’02’s previous dyno results, Enhanced Street Performance’s tuner, Scott Peitzsch, stepped in to work his magic.
4a Contrary to popular opinion,...
4a Contrary to popular opinion, there’s much more to the tuning process than simply pushing a button...
4b A qualified shop such...
4b A qualified shop such as ESP will use a chassis dyno, a wideband O2 meter, and specialized tuning software to extract the maximum safe output from your fuel-injected Corvette.
5 After the first two runs,...
5 After the first two runs, Peitzsch made some minor adjustments to the C5’s tables. On the third round of tuning, he nailed it—the perfect combination of power and reliability.
6 While our dyno numbers...
6 While our dyno numbers were virtually unchanged with the new tune (this graph compares the post-install figures with our baseline), that’s not what this trip was about. It’s actually a bit surprising that output didn’t see a pronounced drop—a common side effect of a richer fuel mixture. Clearly Peitzsch’s efforts paid off in a big way.
7 Afterwards, the ’02 was...
7 Afterwards, the ’02 was pulled off and taken around the block for a driveability test. The car drove better than ever, with crisp throttle response and an ultra-smooth idle.