I think the question should be why you wouldn't want an oil cooler. If you have an 8th gen si it already has an oil cooler on it. It is a true oil cooler. You'd be fine going turbo with the oil cooler that's on the car. I mean hell people have bought stock k24s and turbod them without putting an oil cooler on it which is stupid because of all the extra heat an oil cooler adds. You can find kits on Amazon or online for oil coolers, I'm sure there's kits out there you just have to search, otherwise you just buy a kit and modify what you have to to get it to fit. I'd also suggest a oil catch can as well. Going turbo or building a motor is not cheap. If you want to turbo your car go for it and don't listen to the people saying you shouldn't. Just make sure you install the kit or have it installed right and take it to someone who knows how to tune to dyno tune it and just save your money up along thr way so you have some cash to fix parts if something goes wrong. I'd highly suggest doing a compression test and a leak down test before going turbo though so you know you're rings are still good. The good news is that if you do blow your motor you could rebuild it or buy a used stock k24 with 50k miles for like $800 and swap in it on an 8th gen si pretty easily, I know because I put my k24/k20 in for my build. 300 on up is great power for these cars as with fbos you might hit 220-230whp and that's it so 300 on up is crazy good lol. My car with my setup is around 300whp, of course I'm on e85 and tons of other mods but ya. I'd also suggest putting some cams in it if you're going to go turbo but it's not needed you'll just make more power. Hope this helps.