Our test subject pauses to...
Our test subject pauses to catch its breath between pulls. At the end of the day, the car had gained 13 hp and 10.5 lb-ft of torque for a total investment of well under $300.
Contrary to what our predilection for megabuck tuner cars might suggest, we at VETTE are acutely aware that our readership is not composed entirely of professional athletes, real-estate magnates, and other car-crazed croesuses. And while our saturation point for bespoilered quad-turbo street freaks with outlandish DayGlo paint schemes will always exceed that of our colleagues in the auto-mag world, we're not above occasionally making room for a vehicle that represents a more reasoned approach to the modification game.
With that in mind, we've decided to introduce a project that more closely resembles the sort of thing we coupon-cutting types are likely to undertake. Our mission is simple in concept, even if its execution is certain to prove more daunting. We'll be shooting for Z06-challenging accelerative performance-low 12s in the quarter sounds about right-while minimizing our cash outlay and avoiding extraneous (read: non-performance-enhancing) modifications. Simply put, if a part isn't designed to make the car run faster or launch harder, we won't be expending any ink on it here.
Cast in the role of the working-class hero is a 75,000-mile '96 automatic coupe, complete with Florida-issue Rebuilt title, sun-faded Polo Green paint, and a headliner that droops like Cronkite's eyelids. At a sale price of $9,000, the '96 not only conforms to our bucks-down build philosophy, its year of manufacture dictates that it was factory equipped with one of the most underappreciated V-8 engines in the Vette's 53-year history. And while it certainly won't make realizing our e.t. goals any easier, using an LT1 car will give us an opportunity to explore a lesser-known nook of the Corvette aftermarket-and, we hope, to confirm or refute some of the prevailing wisdom regarding the Gen II's potential as a high-performance engine.
For our first round of installations, we decided to focus on the cheapest of the cheap, the idea being to effect a verifiable, if not noticeable, improvement in the Vette's output for the kind of money one might drop on a couple weeks' worth of groceries. All of our installations and dyno tests were performed at Anti-Venom, a Seffner, Florida-based performance shop specializing in late-model Corvettes.
A comparison of the factory...
A comparison of the factory air lid and the Breathless piece appears to lend credence to BPP's claims of a 70-percent flow improvement.
Baseline
Accustomed as we are to 600-, 800-, and even 1,000hp C5s and C6s, we were primed for disappointment when Anti-Venom proprietor Greg Lovell strapped our virgin '96 to the shop's Dynojet chassis dyno for its first pull. We were pleasantly surprised, then, when the car registered a respectable 263.3 horses and 291.5 lb-ft of torque at the rear wheels, not too far off what one might expect from an early automatic C5. After a backup test produced virtually identical numbers, we unlimbered the tools and got to work.
Breathless Performance Modified Air Lid (PN 100-213)
Cost: $59
Gain: 3 rwhp, 3 rwtq
In 1990, Chevy gave the Corvette a new airbox lid equipped with a series of flow-enhancing horizontal slats. Breathless Performance Products' C4 Modified Air Lid does the factory one better by incorporating a fully open-faced design reminiscent of a picture frame. Made of ABS plastic, the BPP lid can be installed in a matter of minutes, with no modifications to the factory box. At a piddling $59, it seemed like a natural fit for our low-lucre outing.
Surprisingly, swapping the...
Surprisingly, swapping the paper filter for a K&N had no effect on our dyno results.
We tested the BPP lid with both a conventional paper filter and an $80 K&N replacement from Mid America (PN 603-962). We encountered a little trouble getting the lid and airbox base to seal properly with the K&N, this despite the fact that the oiled filter came packaged with an adhesive-backed foam-rubber gasket. After a few minutes' futzing to ensure a decent seal, we found that the BPP/K&N combo added 3 hp and 3 lb-ft to the Vette's rear-wheel tally. (All of our "gain" numbers are based on a two-pull average.)
Follow-up tests with the paper filter yielded identical results. While 3 horses may not sound like much, the extra airflow provided by the BPP lid is sure to play a more critical role as we bolt on additional performance gear.Had the K&N made more power than its conventional counterpart, we likely could have overlooked its fitment foibles and comparatively high price tag. Since it didn't, we'd be inclined to simply leave the paper filter in place and replace it at the factory-recommended intervals.
Note: Although its price tag prevented it from being included in this ultra-low-buck test, we decided to see how SLP's "Claw" cold-air induction setup (PN 21028) acquitted itself on the rollers. Equipped with three conical filters mated to large-diameter stainless steel tubing, the $267.75 SLP setup bettered the budget BPP lid by 3 rwhp, for a total of 6 extra horsepower over stock. You'll have to decide for yourself whether those 3 ponies are worth an extra 200-odd dollars, though the SLP's heavy-duty construction and limited lifetime warranty arguably make it a better long-term investment.