When the Chevrolet Trailblazer SS first came to market it was praised for being a complete package – an SUV that can haul more than just the kids. Pair a 395hp version of the Corvette’s 6.0L LS2 with heavier duty brakes and suspension, then give it the looks to match, and you have an incredibly practical truck with the performance hot rodders love. Of course you can only keep hot rodders happy for so long. The first year TBSS (2006) is now nearly 10 years old, and if you want to keep it on the road and inject the same level of excitement you had when you first purchased it – you better get to modding. Plus, let’s face it, for some of us it is just now becoming affordable on the secondary (used) market.
1) Transmission Cooler
The 4L70E is a great transmission…for a much lighter vehicle. The ’70 needs all the help it can get, especially if you plan on racing or towing with it. And for those that just have a heavy foot, this applies to you as well. We’ve spliced in B&M and TCI transmission coolers in the past with great results, but this kit from PCM of NC is completely plug and play for the TBSS. No cutting, splicing, or even worm gear clamps. Three types of lines are offered including: stock-looking rubber rated to 300psi (Pushlock hose and fittings), Fragola black braided line and black AN fittings, and Fragola braided lines with red/blue fittings. Using one of two different mounting locations PCM of NC says it will knock off 30-degrees of fluid temp and installs in about 1 hour for around $220.
2) Oil Pump Pickup Tube
The rod bearings are another notorious Achilles heal of the TBSS, which is caused by an inherent oiling issue with the oil pan and pickup. The stock pickup tube grabs oil from the front, shallow part, of the pan. You step on the loud pedal, the oil sloshes to the back of the pan and starvation occurs. PCM of NC’s mandrel bent tube relocates the pickup to the middle of the pan where it is deepest. Problem solved for just under $260.
3) Electric Fans
Yes, believe it or not, your TBSS has mechanical fans. What is this 1957? They are sucking horsepower and just plain ugly. PCM of NC has two great solutions, which are both computer-controlled and require no cutting or splicing. The budget version uses ‘98-02 Camaro/Firebird fans that you can acquire at a junkyard or purchase for $155. The 3-relay version is recommended for variable fan speed, and runs just under $342. Meanwhile a custom Spal fan kit is also available, complete for around $554. This kit is designed for more modified trucks, and is a bit louder.
4) Air Intake
While there isn’t quite as much selection on the TBSS as with a Camaro for example, there are quite a few intakes on the market. Cold Air Inductions and Volant use a traditional sealed air box to prevent the engine bay heat from entering the intake tract. Meanwhile K&N, Airaid, and Spectre Performance offer slick designs with smooth bends and a high-flow air filter that seals to the hood. PCM of NC offers a fendwell kit that is sort of the best of both worlds. Each model and style has its advantages and disadvantages, but all should install in around 30 minutes with ease as well as increase power and fuel mileage. Combine this with the e-fans and tuning, and you could be looking at 1-2mpg more. Each will run about $200-300.
Performance gains from ECM tuning are substantial on any GM truck, and the TBSS is no exception. Whether you choose a handheld tuner, mail order tune, or custom dyno tuning you can expect at least 10hp and much crisper shifting. PCM of NC says 10-20hp gains are typical with its mail order tune, but 50-rwhp can be had when also adding an intake, fans, and 160-degree thermostat. Fast Motorsports is another solid supplier of mail order tunes; prices are typically $200-300. SCT and Diablosport are a few examples of handheld tuners, which are incredibly convenient all-in-one packages that start around $300. A custom tune is preferred because it will yield the best results, and can be done with HP Tuners or EFI Live software. However, if you don’t have a reputable tuner tickling the keys, this can be problematic and expensive. It is important to note that the ’06 and the ’07-08 use different ECMs.
The factory manifolds are very restrictive, and the single exhaust pipe is definitely an oversight in design. At least on the GTO’s second coming, GM fixed this for the 2005 model year. The Trailblazer SS wasn’t so lucky. Kooks, American Racing Headers, Stainless Works, OBX, and Pacesetter all make headers that fit – some better than others. Prices start around $700 with the crossover pipe and go up to $1,500. Dual exhaust is available from SLP and Stainless Works for those daring enough to cut the bumper. In fact, SLP provides a complete replacement piece, which requires paint. However, many offer the single pipe setup including Magnaflow, Corsa, JBA, Gibson, and Borla. Expect to pay $500 to $1,000.
The stock LS2 cam measures a scant 204/211-duration with .525-inch lift. Even the LS6 cam is bigger. Since the truck is so heavy, you don’t want to go too crazy and put a large duration cam built for top end power. Thankfully there are plenty of cams out there built for trucks, and even some specifically for the TBSS. Comp Cams and Crane Cams both have bumpsticks in their catalogue for trucks. However, if you want something TBSS specific you will have to go to places like Vengeance Racing, Fast Motorsports, Tick Performance, Futral Motorsports, PCM of NC, Speed Inc, Brian Tooley Racing, etc that have developed proprietary grinds. With the stock torque converter, cam specs should (roughly) be 212-220 on the intake side and 225-232 on the exhaust. The LSA and lift are also critical to having a cam that idles nicely, has an appropriate powerband, doesn’t beat up the valvetrain, and doesn’t cause any P-to-V clearance issues. Make sure you do your homework and talk to a professional. We omitted price on this one because opening the motor up means you will most likely incur other costs besides just the cam – valvesprings, gaskets, lifters, timing set, etc.
8) Lowered Suspension
If you want a lowered stance on your TBSS you’ll need to start with a lowering spring in the front, adjust the factory rear air bags, and then swap out the rear shocks. You should also consider replacing the front shocks to better accommodate the lowered ride height. Other options include swapping to a rear spring set (ditching the air bags), front lowering control arms, and coilovers at all four corners. These options will bring the truck even lower, and will necessitate an adjustable Panhard bar and front upper A-arms to dial the geometry back in. Fast Motorsports carries all of these products, and the basic kit is just under $272.
9) Turbo Kit
Generally speaking Roots superchargers are the hot ticket with these trucks, but the factory exhaust system makes for a unique mid-mounted turbo setup with comparatively minimal effort and nearly unlimited power potential. A 72-76mm turbo will be plenty for the stock LS2. If you are on a tight budget, deals can be had on eBay for turbos and intercoolers. Just remember to invest in a quality wastegate and fuel system upgrades to keep the engine safe. We won't venture a cost estimate here because it will vary heavily, but a quality wastegate will run $250-450 new. Turbos are typically in the four-digit range, and the intercooler will be somewhere in-between. If you opt to have a custom kit built by the likes of Vengeance Racing, Fastlane, Speed Inc, Redline Motorsports, or Kentucky Turbo (to name a few) it will be pricey but worth it.
10) Transmission Rebuild
It’s just a matter of time for the 4L70E, so keep your builder of choice on speed dial. RPM Transmissions is on a short list of quality shops that build these right, and you'll pay a pretty penny for it. The Level VI ($2,895) is typically what is recommended for heads, cam, and nitrous or supercharged stock engine combinations. RPM’s 3-4 clutch pack, upgraded forward sprag, and 300M output shaft are the main features that allow it to hold up to 700hp. However, depending on your driving style or combination, the Level VII or X may be required. Unlike the Camaro, RPM says a 4L80E is not exactly easy to swap and should be reserved for all-out race trucks. The crossmember and wiring are just the tip of the iceberg, as there are also some fitment issues. Sonnax Performance, Performabuilt, CK Performance, and Century Transmission are a few more reputable builders.