All sr20det turbos are water cooled... I've owned them all s13-s15. They are small though, if you were looking for an upgrade I'd go with the s15 t28bb or a gt28r (same thing no divider wall). They are good for roughly 320whp at 18-21psi max. I personally had a gt28r on my sr20 and it pushed 318whp at 19psi.