I figured I’d do a write up on a pretty effective mod system for the Ecotec... this mod is compatible with MOST IONs and L series cars with the 2.2 liter engine...

1. The throttle body...
its simple, remove the TB with four 10mm bolts, then remove the IAC valve with a T-15 bit and some prying(if it’s never been cleaned before nows the time)

the theory is that you enlarge the inlet side of the TB as big as you dare and taper it down to the stock size as you get close to the throttle plate... some also grind down the throttle shaft and might knife edge the throttle plate itself but the main improvement is the taper on the inlet side... it allows the air to more smoothly transition from the 2.75-3” intake tube you’re running into the throttle body... best to start with a coarse grit sanding roll and work your way down as you approach final shape/size...

this mod doesn’t gain much power by itself, maybe as much as 2-3whp with a really aggressive porting, but it does help with throttle response...

2. The intake manifold...
basically if you’ve ever looked at one of these, off the engine, you can likely see the problem areas... there are a couple restrictions under where the TB goes on, and the ports are WAY smaller than the intake ports on the head... using a sanding roll, you just grind down(as smoothly as possible) the internal intake runners that pass under the TB opening... there is enough thickness to clearance them so that the TB port is mostly unobstructed, without punching through and messing up the runner(if you’re careful)...

then start on the intake ports using the same sanding roll... you’ll need a digital dial caliper to get the port size exact but they need to be 1.245” tall and 1.875” wide... this is .005-.015 smaller than the ports on the head, which should be enough to combat reversion but make port size as big as possible... after getting the size dialed in, go back over and taper the new size into the rest of the runner, as far back as you can reasonably reach... there is a nub on the port for cyl 1 that if you grind too much off of it makes a hole that would then need filled with epoxy...

this mod actually ally does make some upper RPM power, I noticed it not falling off as severely approaching and surpassing 6000 RPM as before... some report up to a 10whp gain from the porting alone..


it * should * be noted that both the pieces need a good cleaning with carb/choke cleaner(with all sensors removed) to make sure there aren’t any metal or plastic particles that could find their way inside your engine, and fresh gaskets couldn’t hurt...

pics to come soon!