[Igovert500]

You can get away with 12psi on 91 octane, granted every car is different, and alot of factors can cause knock, so when people say you can get away with x amount of boost, or should be seeing x amount of power...it's always relative, and modding your car is your own responsibility.

As far as the LM1, I have no personal experience with it whatsoever. Linebckr has some great posts on dataloggers I would check out. They are definantly cheaper, plus scanning over that description, it seems you have to buy something additional to be able to datalog in real time. Meaning, if you get a palm pilot off ebay adn some free/cheap software, you can actually view what is being datalogged as you are on the road. LM1 you need to take home and hook up to a computer, or additionally get a laptop or palm or whatever to view it in hte car. Lastly, I don't know all the parameters the LM1 scans for. I didn't see any mention of knock counts, the ability to control specific cylinders, the ability to pull codes from the ecu, etc.