tune=lower ETs
Only if its the right tune for car. Its really hard to tune a car right without ever seeing the car. But if you have a base time like 13.7 and then run slower with the new tune you can call up and say hay this tune is off. I think once you get one of those mail order tunes you can pretty much get tunes for life of the car right?
Originally Posted by RedHardSupra
i've increased 2mph trap speeds on stockish cars just by tuning. et is more driver dependent, trap speeds are more of a hardware/weight/tuner measurement.
its also dependant upon conditions...if your 13.7@100 was done with a da of 0 and you get the mail tune & run 13.5@101 with a da of -1000 thats not saying much for the tune since the second run was in much better conditions. Its pretty easy to get 2-3mph trap speeds in the same conditions from a decent tune though. 
the problem with a mail order tune is the tuner cant see what it does to your specific car. all cars are different and will not react the same to the same tune. it is much better to spend your money on a tune where the tuner can see what happens, like on a dyno. its worth the money even though it can be a little expensive.
