We’re all looking for more power in our cars and trucks, that’s a given. Sometimes though, you just can’t afford to or just don’t want to tear into the vehicle and start bolting on complicated and expensive power producing products. That’s going to cost you an arm and a leg, and take you days to install, keeping your vehicle out of commission all weekend. I mean really, how much fun is that?
Among the many performance enhancing products available for GM, Ford, and Dodge/Chrysler cars from Street Legal Performance (SLP) is a collection of Chevy and GMC pickup truck and SUV performance parts. This offering for GM light trucks includes power adding products such as supercharger kits, exhaust systems, as well as the company’s Blackwing Cold-Air Intake System.
The SLP Blackwing Cold-Air Intake System consists of an air box, cone-shaped filter, air box tube, straight bellows, PCV hose, and all the hardware necessary for installation. The company claims the system yields a power increase when installed individually, calls out the installation difficulty rating as “intermediate,” and quotes a one-hour job time.
Perfect For The DIY Guy
We tried to make sure it could be installed in the driveway. – Jay Velthoven, SLP
“We tried to make sure it could be installed in the driveway,” Velthoven continued. Off Road Xtreme could not resist that sort of challenge, so set out to test not only the ease of installation, but just how much power the SLP Blackwing Cold-Air Intake System would provide.
The first step in this installation process was the removal of the plastic “Vortec” engine dress cover. After the cover was cleared away so we could get to work on the intake system, we loosened the worm drive clamp that held the stock inlet tube to the throttle body. The clamp that kept the stock bellows (looks a bit like part of an accordian) attached to the MAF sensor section was loosened next.
We then removed the stock intake tube and stock bellows as one piece (if your truck is equipped with one, disconnect the breather line from the tube). Now we could unplug the MAF sensor from the wiring harness. The next step was to loosen the worm drive clamp that held the MAF to the stock air box and remove the MAF sensor.
The entire air box could now be removed as one piece and there are only three rubber pins holding it in. You may need to pull it up and out with some force to remove the box from the truck’s engine compartment. The five bolts in the black plate under the stock air box will need to be removed. The rubber pins were also removed, as the stock air box will not be needed again.
Now we were ready to place SLP’s new cold air box in place with the large square opening in the box facing the fender. Only three of the bolts will be reused to hold the SLP air box in place. All three bolts were tightened to secure the box.
High Flow Dry Filter
SLP’s high flow filter was the next item on the list for installation. SLP offers and recommends an oil to maximize its filtering media, as well as a special solution for cleaning (you don’t want to wash it with water) the accumulated dirt and dust from it. The filter is a tight fit going into the box, so the next few steps must be followed carefully to make the job easier.
First, the filter was positioned so that the entire open end of the filter was underneath the mounting stub on the inside of the box. Then we pushed the filter down and in so that the filter was completely in the box under the mounting stub. Then we slid the filter to the fender side of the box so that the outlet of the filter could slide onto the mounting stub inside the box. The filter was slid all the way onto the stub and the worm drive clamp then tightened.
We placed the SLP cover on top of the air filter housing and then pushed the screw plugs into the housing. Then we inserted and tightened the four plastic screws into the screw plugs to secure the lid to the air filter housing.
The next step was to re-install the stock MAF sensor on to the outlet stub of the SLP air box. To do this we tightened the worm clamp and plugged the MAF sensor back into the wire harness. Be sure to install the MAF sensor in the correct direction, the MAF sensor will have an arrow that points in the direction of flow. This should point toward the throttle body and not the filter.
Inserting the supplied GM rubber inlet tube adapter in to the end of the SLP intake tube was the next step. By spraying some WD-40 on the end of the tube, the adapter slid on easier.
Next we installed the SLP connecting hose to the outlet of the MAF sensor and loosely tightened the worm clamp. Here’s where, depending on your engine option, you might find the need to trim the connecting hose for a perfect fit. Ours was just fine for the 5.3L V8 in the 2008 Chevy pickup.
We inserted the inlet of the SLP intake tube into the MAF connecting hose and then on to the throttle body. Again, a little WD40 here made fitting the parts together easier. If your rig is so equipped, connect the breather hose to the SLP intake tube, in the grommet hole.
Lastly, we made sure to go around and tighten all the worm drive clamps, and finished up the installation by replacing the plastic “Vortec” engine dress cover. Now it was time to see if our cool work had turned up the heat!
Roll The Numbers
We had previously strapped down the 2008 Chevy XtraCab 5.3L V8-equipped pickup to record a pre-installation baseline on our in-house Dynojet dynamometer and seen a peak of 245.5 hp at 5,280 rpm and 246.3 lb-ft of torque at 5,230 rpm. With the installation complete and the truck placed back on the dyno, we saw a best run of 251.9 hp at 5,210 rpm and 254.4 lb-ft of torque at 5,190 rpm.
That’s a net gain of 7 hp and 8 points of torque at peak. However, more importantly for overall drivability and especially off-road performance, are the large (as much as 90 lb-ft of torque at 3,000 rpm) power gains in the low- and mid-range engine speed areas that can be seen on the dyno chart below. It’s in these lower engine speed ranges in which most of your driving will be done and much of the truck’s real work performed.
The power gains in these areas, as well as the fact that the Street Legal Performance (SLP) Cold-Air Intake was clearly, as stated, easy to install, made it a winner in our book. For more information on the SLP Cold-Air Intake systems for 2007 to 2013 GM trucks and SUVs, check out SLP online or call (855) 757-7373.