From what I remember (went to Epcot last year), Test Track is a lot less intense in comparison to flumes (ie. Splash Mountain) or rollercoasters. This is, of course, my own opinion. I don't recall there being any drops at all (someone correct me if I'm wrong).
The ride starts off by going through tests in a huge building. These tests include testing the brakes and suspension and whatnot. Basically you go on bumpy areas, go through hot and cold areas, and speed around corners. The final test is on the actual test track. I read somewhere that the speeds really aren't that high but because of the way it's done, it actually feels a lot faster than it is in reality.
The first time I rode it, I sat in the front and I had a lot of fun. I went on it again right after (it was early in the morning so there wasn't much of a line) and this time sat in the back. I'm not sure if it was because I rode it in such a quick succession or because I sat in the back but I finished that ride feeling slightly dizzy (and my hair was all a mess!). It took a minute or two to feel normal again. However, it wasn't enough for me to avoid the ride. I was willing to ride it again later in the day and would even ride it twice in a row if given the chance. Personally, I definitely preferred the first row because it gave me a better view of what was going to happen next.
I think the best thing for you to do is have a family member or friend, who knows you well, ride it first. That way they can give you an honest assessment. My dad, brother and I rode on TT first and when we came out, my dad was trying to convince my mom to go on it. Knowing how she is with sudden turns and speed, I told her not to because she avoids basically any kind of thrill ride.
I do hope that you can go on the ride because it is one of my favorite rides at Epcot! However, I understand that you need to know the "truth" of the ride (my mom is the exact same way). Just remember that this is just my assessment of it. Have fun at Disney!
There are no drops on test track. You just go through an obstacle course with the car and then at the end it looks like you are going to crash into the wall and the wall breaks away and you are on the outside track going 60 mph. It does take a very steep bank where you are almost sideways but that is the extent of the thrills.
I hate rollercoasters myself, so I will tell you that there is an uphill climb test-where they drive the car UP a hill as quickly as possible.
If you don't like the feeling of "losing" Your stomach, it might be a bit of a shock, but it's nothing bad.
I liked the outside go fast on a bank thing-because you get the feeling of going fast (i like that) instead of the feeling of going downhill fast (don't like that). I even put my arms up-something I have NEVER done in a ride before!!!
One last word of reassurance, this ride is connected to a "track" at all time. That is to day, you're never freefalling/coasting. There's something pulling or pushing you and your speed is always controlled. It seems that way, anyway.
I really enjoyed it, I think you will too. It's a rollercoaster without drops etc... for people who don't like drops and such (barrel rolls, loops, lalala)
My nearly 70 yo MIL rode every coaster at WDW last Thanksgiving and loved them, buy TT was one of her favorites. It's not as much a "roller coaster" as it is a thrill ride. Her very favorite was Expedition Everest. I think you'll enjoy it.
OP, if fear of roller coaster effects has been what has kept you from riding Test Track, take a look at this video from Youtube and decide for yourself whether you think it is something you would enjoy. http://www.youtube.com/watch?v=KfIxKKNQIUU
Trust me - I put off riding Test Track for years because I thought it was going to be awful. (I hate "big" attraction rides - I'm totally a sissy!) Well I gave it a shot this past January expecting the worst around ever turn - I kept asking when's the scarey part coming, after it was over - I said "was that it?". I had a great time on the ride - expecting the worse. To make a long story short - I'll be in line to ride it again in January.
It was a blast!
(p.s. - The Peter Pan ride scares me more (the heights).