The only drawback to driving one of the most popular mini-trucks ever built is that they are obscenely underpowered. The Mazda B-Series, Chevy S-10, and GMC Sonoma, in four-cylinder form, are slow going and certainly not the most exciting machines to drive. There isn't a snowball's chance in hell of ever smoking another truck from stoplight to stoplight in one of these minis without performing some healthy modifications. Just how weak is the stock 2.2L four-cylinder engine in a GMC Sonoma? According to our tech center's Dynojet chassis dyno, our test truck made just 84 hp at the rear wheels! Of course you know where we are going with this story. Like you, we want more power from our four-bangers.

In the most basic of terms, your mini's engine is a large air pump. Its job is to suck in air and fuel, compress and burn it, and then push it out through the exhaust system. The quicker we can deliver air into the motor, efficiently burn it, and force it out, the more power the engine will make. The stock parts do a reasonably good job of performing these duties, but the aftermarket does offer something better. Our test mule was a body-dropped GMC Sonoma that had plenty of style, but not enough power to go along with it. We decided to perform the most basic bolt-on power additive by installing an aftermarket header. Our search for a smog-legal header for a 2.2L engine led us to Al's Headers and Fabrication for one of its ceramic-coated, tig-welded headers. Al's header bolts into the stock down tube and requires zero modifications to install. Once in place, the Sonoma came alive with more bottom-end grunt (good for burnouts) and extra top-end horsepower. In a nutshell, we spent 30 minutes installing the header and gained 12.6 hp and 22.4 lb-ft of torque at the wheels! These are mighty impressive numbers for a stock four-cylinder engine with no other modifications. For more information on this header, contact Al's Headers and Fabrication using the contact information listed in the source box.

Dyno Sheet
Stock 2.2L Four-Cylinder Engine
RPM POWER TORQUE
2,500 44.4 93.2
3,000 51.3 89.8
3,500 61.4 92.1
4,000 71.8 94.3
4,500 81.4 95.0
5,000 84.0 88.2
5,500 81.9 78.2
2.2L Four-Cylinder Engine With
Header Installed
RPM POWER TORQUE
2,500 52.0 109.3
3,000 67.0 117.4
3,500 76.7 115.1
4,000 84.8 111.4
4,500 94.0 109.7
5,000 96.6 101.5
5,500 94.6 90.3
SOURCE
Al's Headers and Fabrication
2831 Whitestar, Ste. F
Anaheim
Ca  92806
Dept. MT