SLP PerformancePac - Quicker Trail Blazing

Feng shui is the ancient Chinese practice of ensuring harmony between things. If you've watched any of those home improvement shows on cable TV, you've encountered it, as the art is applied to placing furniture and choosing colors for a room that are balanced.

The same philosophy could be applied to automotive design, as some cars clearly have an appearance that suits its purpose, while others miss the mark-like placing a photo of your drunk, bikini-clad girlfriend on your mom's mantle.

When applied to the trailblazer SS, Chevy got the feng shui about 95 percent right, with only the odd, single-outlet exhaust causing any disharmony in the universe. It just doesn't look befitting of a hunkered-down, 400-horse factory hot rod.

The guys at SLP Performance Parts must eat a lot of Chinese food for lunch, because they've channeled that eastern philosophy into a new performancepac for the TBSS-or, at least, they take direction from the fortune cookies. Regardless, SLP's 440HP performancepac-as its name suggests-adds a little more than 40 horsepower while also curing that exhaust problem with a new, two-outlet powerflo cat-back system and new rear valance panel.

The exhaust system alone doesn't give the horsepower bump to the LS2 V-8; the rest comes from bolt-ons that include 1.85-ratio rocker arms; a lower-temperature, 160 thermostat; a high-flow, washable Blackwing air filter; and a diablosport Predator II handheld tuner with a custom SLP tune that uploads directly to the Trail- Blazer's ECM.

We recently visited SLP's Toms River, New Jersey, home to check out the trailblazer SS performancepac and see if it was a project most enthusiasts could do at home. We were encouraged to discover that even the rocker arm swap was a cinch, thanks to the efficient design of GM's LS engine family. As for the rest of the parts, well, they were pretty easy, too. The thermostat is an easy, not-too-messy change and, well, if you need our advice for swapping the air filter, then perhaps you're reading the wrong magazine.

The diablosport tuner is simple to use, too; it simply plugs into the under-dash port. You punch a few buttons; wait a few minutes and the ECM will then play nice with the new rocker arms and thermo. As for the exhaust, it's a cat-back system, but because of the dual-outlet design it has a non-OEM routing path. It can be installed without removing the spare tire.

The new, dual-outlet rear valance is the only part of the project that requires outside assistance-unless you've got a paint booth in your backyard. The SLP valance comes primed, but must be finish-sanded and painted prior to installation-a process that involves pulling off the lower-central section of the stock rear bumper and pinning the new valance in place. It's not brain surgery, but it requires patience and attention to detail to ensure a straight, smoothlooking finished appearance.

Check out the accompanying photos and you'll see what goes into the 440HP performancepac and details of its installation. Don't blame us if after you get your TBSS's appearance aligned with the cosmos that you rearrange your garage for increased spatial harmony.

Visually and aurally, the most dramatic enhancement of the slp Trail- Blazer performancepac (part no. 28140, $2,799) is the cat-back exhaust system and dual-outlet rear valance. The valance is made with an oem-type rtm molding process, which has a more consistent thickness and more stable construction than hand-laid or choppergun fiberglass parts. It requires prep and paint before installation.

A signature of SLP Performance Parts' exhaust is their polished, all-stainless construction, and the tbss parts exemplify that tradition. The muffler has a mirror finish and the premium-looking dualwall polished stainless tips are first-class parts.