For my car to basically just fall on its face at 100mph?

 

What are your RPMs in what gears? Even with 4.10's you should be pushing well past 140.

 

3000rpm at 80mps in 5th (o/d)... 2500 at 70mph in 5th(o/d).... I have an auto, BIG MISTAKE, but if you punch it from around 70 the car falls on its face at 100.. 100 - 110 took me about 5 secs

 

Have you manually down-shifted out of OD?

 

According to my speed vs RPM spreadsheet, you should still be limited by drag and be able to reach the 140+ MPH range while being around 5500 RPM in 5th. I'd try a different tune.

in 4th you hit 6250 RPM at about 120 MPH and 125 at about 6500 RPM.

 

No I just floored it from around 70mph as the highway was wide open with nobody on it. I was thinking about switching it out of o/d by pressing the button, flooring it, that putting it back into o.d near the shift point. I thought of this after the fact of realizing wtf why is it so slow. NEVER BUYING ANOTHER AUTOMATIC!!!!!

 

The thing is it took so goddamn long to get from 100 to 110 that I wouldve ran out of highway by the time I hit 120. Basically what your saying is I need more power , or switch out of od?

 

I don't think it could be the gear. Nukes calc's are on the money, sounds like a tune issue to me...speed limiter possibly???

 

Why did you get 4.10's? Certainly not for top end. How is it from 0-100?

Still, I can only assume that your O.D. simply can't overcome the drag which seems odd. And siggy has a good point; turn off O.D. and leave it off and see where you're at at redline. If you can make the 120 MPH range, then it's your 5th gear. When I run her up, I usually don't shift into OD until about 120-130 MPH. With my 3.55's, that's at about 5500 RPM. I don't redline (currrently 6500 RPM) in 4th until about 144 or so. But then, 5th gear won't add much due to the drag.

 

It used to be common for the power train control module to be factory set to flat line fuel delivery at whatever speed the factory tires were rated. Seems like your tune should have reset that but maybe it didn't. When fuel delivery is maxed out, so is your speed.