More than 13 years ago, Pontiac began rolling Trans Ams off the Sainte-Thérèse assembly line with the new LS1 engine under the hood. This sophisticated powerplant would further the perception of the Trans Am as a top-notch performer that provided great value. Over the past 13 years, we’ve seen the prices on these cars fall from $30,000 new to $20,000, $10,000, and now they’re even cheaper in various conditions, making them a phenomenal performance/dollar value. We decided to apply the same formula to a ’99 T/A with a new plate nitrous system from Zex, and Chris “Whistler” Kirchner helped out on the install and testing.
We explained to Zex that we plan to grow into the nitrous kit. Trent Goodwin at Comp Cams, Zex’s parent company, told us that the new LS Series Perimeter Plate Nitrous System for cable-actuated throttle bodies (PN 82391) would be just the ticket. It’s adjustable from 100 hp all the way to 250 hp, and since we don’t plan on spraying anything less than 100 hp, it’s a perfect choice for us so we can step up to higher levels later on.
The kit was designed with the large 90mm four-bolt intakes in mind, as well as the FAST LSXR 102mm. Our Trans Am came equipped with some aftermarket goodies, including the old-style FAST 90mm intake—FAST has since moved on to the 102mm.
The plate uses 12 injection points around the perimeter of the intake manifold’s inlet to create what Zex calls, “a perfectly atomized blend of fuel and nitrous.” It’s also part of Zex’s Blackout series, which uses black nitrous lines and a black bottle for a stealthy, cool look. The kit comes with everything needed to install it, but depending on how you would like to personalize it, you may need to have a few parts on hand. We required a 90-degree elbow fitting, an 18-inch nitrous line, and assorted electrical connectors.
This is the new Zex LS Series Perimeter Plate Nitrous System for cable-actuated throttle bodies (#82391). The kit comes with everything you need to hook up to an LS-engine using a 90mm or larger throttle body, but it is not car-model specific. As we found, you may need a few pieces to custom fit it to your Bird. In addition to common hand tools, you will need a good wire cutter/stripper, assorted AN lines if you want to alter the solenoid mounting location, and a pack of assorted electrical connectors.
In order to install this kit in what we felt was a professional and clean manner, we opted to make a custom bracket for the nitrous and fuel solenoids, and wide-open-throttle switch. Because of this, the install took longer than anticipated. Figure on setting aside a full day for the install, but know that it can be done quicker. If you want something more plug-and-play, look into one of Zex’s kits made specifically for your Pontiac model.
After about 12 hours (including taking photos), we had our customized kit installed and ready to go. In Part I, we cover the installation of the parts and plumbing. For the second installment, we will wire the system, and discuss the nitrous and fuel pills and how they correlate to a power increase. Additionally, we’ll get some dyno numbers and track times. So stay tuned!
Part Numbers And Prices
Parts
Price
Part Number
LS Series Perimeter Plate Nitrous System (Cable)
$750
82391
Big Mouth 102mm Throttle Body
$510
54102
