Best gears for an Auto??

[StangFreak]

Originally Posted by kdanner The problem with a gear like 4.10 and this trans is traction. I did run a 4.30 for a long time and on the rare occasion it would hook it was badass the way it picked up the front end. The 3.31 just made it a better car, it was just as fast, and it goes down the track every time now. Think of it this way, let's go old school C-4 trans, those had a 2.46 1st gear. The 6R80 has a 4.17. So, 4.17*4.10=17.097 ratio in 1st gear. Now try to get a C-4 the same. 17.097/2.46=6.95. You'd agree a C-4 and a 6.95 is a hell of a lot of rear gear right? That's the same you're getting with a 4.10 and a 6R80. Even the stock 3.15 gear is like a 5.34 axle with a C-4. If you wondered why these automatics run so good, right there is a big reason why. Leave the stockers in it, or maybe change to 3.31 to get the very slightest bit more out of it.

What do you think about the 3:55 and you think they trap me in 3rd if raised the rpms to 7700 with the BIM?

[kdanner]

Originally Posted by StangFreak What do you think about the 3:55 and you think they trap me in 3rd if raised the rpms to 7700 with the BIM?

I'd say you won't make it in 3rd unless the car runs a really low trap speed, or unless you put a really tall tire on. 3.31 with a 28" is the best bet for most cars to be able to trap in 3rd. Once you get to like 126-127 MPH, time to start thinking about 3.15 with a 28" or 3.31 with a 30" tire.