But GM's performance parts division decided that just wasn't enough, and through a combination of remapped engine calibration and upgraded MAP sensors, the LNF now puts out 290hp and 340lb-ft of torque in manual-transmission variants of the Sky Redline and Solstice GXP. Automatic versions are limited to 325lb-ft, and the HHR SS tops out at 315lb-ft.
A penalty of upgrading to the higher output from the 2.0L mill is the requirement to use premium fuel. However, the good news is that the kit is 50-state emissions legal and the kit won't void your warranty.
The most enticing aspect of the $650 kit for some, however, is the enabling of the ECU's 'learning' feature, which enables the computer to adapt to and benefit from basic bolt-on mods such as intakes and exhausts. That opens up a whole new world of tuning potential for the LNF cars, as well as packing a huge performance punch for a relatively small price tag. The final benefit of the kit is a slightly raised rev-limit - now 6,500rpm, up 200rpm from stock.
Those with a keen memory will recall the GM Performance Parts enhanced Pontiac Solstice GXP Coupe (pictured) shown off back in November at the SEMA auto show. That car boasted the same Stage 2 upgrade kit, plus some other mods to show what is possible. To revisit that car, read our original coverage here.