Torque Convertor ?

[Shaggy]

You will be faster with a non-lockup BUT if you do that then you start running into what Rev is talking about and you start cooking trannys. I would go with a lock up style since you are talking primarialy street aplication plus with a lock up you can get a 3500 stall to get you out of the hole like a rocket but once you shift to 3rd then you are locked in and can cruise at 1500rpm if you want.

The reason you would be faster with a non-lockup is when you are racing the advantages of a proper torque convertor are lost once you shift into 3rd. IE when I go down the track in my car I launch between 35 and 4000 depending on track conditions (footbrake, 10" convertor) then shift out at 6000 to 2nd and shift out to 3rd at 5500, as loose as my convertor is I loose about a 1000 rpm between 1/2 and about 500 between 2/3. In your application with a lock up assuming same set up I have except lockup convertor you would loose the 1000 between 1/2 but close to 1500 between 2/3 because the convertor locking up and driving the tranny one to one so typically unless you are running big cubes or a power adder that has created a super flat torque crve to pull you through the extra rom lost between the 2/3 shift then that is will you loose you little extra "oomph"