is there a way to open rides without testing?

[but im a creek im a weir oh]

I have been trying to make a death park but can't open any rides.

[Jupiter3927]

Any track rides your make have to be tested first.
You're allowed to change the launch speed after opening while guests are on it though.

[unca.alby]

Originally posted by weed nose:

I have been trying to make a death park but can't open any rides.

maybe it's because most of your customers don't want to die?

[Voice From Beyond]

Guests go on rides partly based upon the fear rating of the ride. If the ride is too frightening they won't ride it at all, so you can't make a death ride. The best you can do is crash coaster cars into a large crowd of guests (achievement), but all that does is send them flying. No one dies.

FYI: If you change the sequence of a flat ride, it must then be tested again before it can be opened.