could you boost an IS for less than 8k, probably. i tried that route and ended up spending twice as much. especially when you don't know what you're getting into, buying a complete, tested, and proven kit can't hurt. i have seen many people try to piece together a kit, myself included, and ended up spending way more than an SRT kit with similar power gains. Boosting an IS300 isn't as easy as bolting on a kit. you need to lower compression either by a headgasket or by pistons. you also need to tap the upper oil pan for a oil return line, you also have to add a fuel return line. there are so many variables on these cars its sad. the stock auto trans is only good to about 400 rwhp with a valvebody upgrade. fully built auto trans can only hold about 500. the 5 speed trans can only hold about 300-350 with a decent clutch. so if you are a 5 speed, you will want to convert to the r154. you will also want an lsd if you don't already have one. etc etc etc etc.


again, could you boost an IS for less than 8k.... more than likely yes. if you want my opinion, to do it right, you will need about 8-10k at a minimum.