What Mod do I need?

[Tweeker]

I'm try to come up with a Metric to evaluate rocket engine, And it would be extremely useful to have way to make precisely timed burns, for example burn 60 seconds from a fixed start. I'm sure there is a mod to do this, but I have no idea what it is.

Any help would be greatly appreciated.

[Mr.Rocket]

I'm thinking either mechjeb: http://forum.kerbalspaceprogram.com/threads/12384

or Kerbal Alarm clock:http://forum.kerbalspaceprogram.com/threads/24786-0-23-Kerbal-Alarm-Clock-v2-7-0-0-%28December-20%29

Not really sure if they will do exactly what you want. Mechjeb is pretty much autopilot, and kerbal alarm clock allows you to set alarms. Hope i found what you needed

[Vanamonde]

There is a sub-forum for mod help and advice, and this thread is being whisked there even as I type this.

[helaeon]

Mechjeb does do what you want. You would set up a very precise maneuver node (mechjeb has a window for you to do that too). Then tell it to execute that node.

The only thing that trips it up is if the burn is slightly off and your craft is heavy or doesn't have much turn authority it will stop the burn to turn towards the drifting node then start again.

Also if the craft is too light and on RCS sometimes it will **** out when you try and get mechjeb to hold a specific orientation.

MechJeb also has tools for use in the VAB and SPH to help you evaluate your designs by TWR, and Delta-V before you even launch them. Add in one of the RCS assistant mods and you've got a pretty good engineering setup.