Tricep Pushdowns & Abs/6-pack

I have recently set myself the goal of achieving a complete 6-pack by the end of my senior year, June 2011. I have some questions and your feedback is greatly appreciated .

I think I know everything about getting a 6-pack. Nutrition, cardio, bodyfat percentage, and lastly the ab exercises, and genetics. I'm wondering how long will it take to achieve a 6-pack starting at (I'm guessing here) ~11% BF? Rough/general estimate ?

I will be doing 30 minutes cardio everyday from Mon-Thurs. Ab workouts* 30 mins/day Mon-Thurs. My nutrition should also be perfect. I know genetics play a role in the shape of your 6-pack.

*inclined situp
*machine crunches (trying to do 100reps per set at 110-120LBs, by the end of the 30 minutes i think my body is gonna split in half from the ab soreness lol)

My second question is this: since I have started to intensify my ab workouts, my abs are currently sore. I can feel my 4 upper w/e's if I flex them. When I try to do a tricep pushdown, I'm half using my abs to pull it down  when I'm trying to do/use my triceps.. I'm guessing that my abs are sore due to the new routine and as thus are rebuilding.. umm, so how can I stop my abs from doing half of the tricep pushdowns :S?

If you have any other ab exercises or suggestions, it will be greatly appreciated. Do remember that I workout at my school's gym, and it doesn't have as many machines as a regular gym would.

Thank you =]

Well first off you've got plenty of time, so even if you're not that close come spring 2011, you just kick it up a notch and do carb cycling ^^

Starting with the pushdowns, like XeNoNN said, you should only be moving your forearms. Using your abs for pushdowns means you aren't doing pushdowns. Your entire body should be a rigid plank, with movement only occurring in your elbow joint. Your will be used slightly to keep your core steady, but you're pushing the weight with your triceps, no other muscles.

As for your ab workout, I say you should change it completely. Either just do exercises like crunches & bicycles weighted 3x8-12, straight up hypertrophy like any other muscle. Or try Scoobys killer ab workout, I really enjoyed it when I did it. Hanging leg raises have received lots of praise as well, so they're probably good to use in one of your routines (you're going to have to do 2-4 ab routines between now and June 2011). Going for hypertrophy all along won't only make your abs visible at a higher bf%, but also be more than just stripes on a flat stomach

Well he should avoid the machine completely, and when I say "straight up hypertrophy like any other muscle", I mean the same amount of rest as well. Abs aren't some exceptional muscle that's completely different from all other muscles. Calves and forearms are the exception, in being predominantly slow-twitch, and that's because neither calves nor forearms have any reason to exert huge amounts of force, but all the reasons for being able to keep pumping rep after rep, evolutionarily speaking. Abs are not unique in this way.

So if you work chest 3x8-12 twice a week, work abs 3x8-12 twice a week. People give abs & pushups a "do 'em every day!"-classification, for no reason whatsoever. It makes no sense.