First off from your other post your girls car has a 2.2 Ecotec in it. As far as performance options there are many but it all depends on what you want and your budget. I bought my car for the purpose of daily driving and to do a few mods to but it will never be what i want it to be without going Force induction and full suspension swap and for that amount of money I will invest else where. With you having a diesel with mods as your daily driver your never going to experience that TQ, some will ask what that has anything to do with a Cobalt, well I had 2 S10 v8's one being pro street and a few other very fast cars and I for one will never be satisfied with dropping thousands into a car for what I call subpar performance.
Now with your girls car fully bolted (Header, Intake, Down pipe, Exhaust, 2.4 SS mainfold) and a tune (Trifecta tune is really the only tune anyone uses for Cobalts) on a Mustang Dyno you will see about 145-155 Wheel HP, on a Dynojet or Dynopac you will see 170-180. Some people will tell you they are at 200 without any internal mods and just all bolt ons and a tune but they are full of it. This will cost you and average of 2 grand based on the parts and companies you buy off of. Changing the suspension to help compliment the added power (which is not needed but makes a hell of a difference) to all SS (FE5) components will cost you about $400-$500 for Struts and shocks, SS Anti sway and bushings. If you want lowering springs to compliment the new suspension your looking at $150-$350 depending on the company. Adding a rear sway bar will cost you $150-$300 depending on the company and size, but it is well worth it.
With everything above, her Balt will be quite capable and quite fun to drive as a daily driver, but to me still not "Fast".
You can go turbo which I will say Roughly costs $2500-$3500 depending on the parts and bolt ons you choose and deals you find.
Going supercharged, most guys will say $1800-$2500 depending on the parts and bolt ons you choose and deals you find.
Last edited by DROPPEDATBIRTH; 03-24-2011 at 10:58 AM.