can i install a vortech kit without doing anything else to the car and how much HP can i get.

 

Theoretically, you can, but it's a stupid idea to try to cheap out on something as risky as FI. Get gauges (A/F, boost, oil temp) and an oil pan at the very least. There's a hundred little things you should upgrade (hi flow cats, aftermarket radiator; hi stall TC and valve body if 5AT). That's up to you. My guess would be around 350rwhp, but it depends on the tune.

 

bone stock Z will see about 100whp and 60 tq increase - mostly from 4500-redline.

all the extra stuff helps of course and can help make the kit more reliable and control engine temps better though