Drag Tranny

[B1gFatCack]

I'm learning the flip method of tuning a tranny for drag. Watched some videos on youtube and read the dummies guide and a few other tuning guides but one thing still eludes me after all the reading. How do you know where to set the initial gear setting on the final gear before you flip the tranny and then lower the final gear to the lowest setting. I'm still confused on how to decide where I need to start. Did I miss something in my reading?

 

[Nickrows]

A lot of it will be trial and error.

When looking for the flip point, I usually do increments of .100 on the final until I get close to where I want to be, then fine tune.

 

[X3sgteX]

There's a mathematical approach that actually works fairly well somewhere in stickied threads, but I beleive in trail and error. Nothing beats making a tranny and running a lap, then using your ghost as a benchmark.

 

[ArticTrust]

In the corner, the lines diagonally across the rpm chart and where the power is at its max out put (powerband) can be used to accompany your shifts, not all cars red line, especially mid turbos. The higher is, is where you want your rpm needle to be revving through during the run down the strip.

 

[Master__Shake_]

This is a little outdated but I hope its still relevant.

When you're flipping a car that hits max horsepower near redline, you can divide the lowest gearbox by lowest final ratio then multiply by a new ratio to find out what it will trap at the shadow without moving 5th(6th/7th) gear. Assume loss of 15 mph if you move 5th or 6th all the way right. An example would be a 99 gearbox with a 2.500 lowest final; flipping this gearbox over 3.500 would result in a top speed of 138.6mph at the shadow without moving the last gear - roughly 123 if last gear is far right. Obviously a higher gearbox would mean a lower flip, unless you need to adjust for launch gear.

For a car that hits max horsepower at a substantially lower RPM than redline, you have to adjust the ratio to compensate for RPM at the shadow. A car that makes peak power at 5k RPM will not want to rev above 6k, so you'll need to flip on a higher ratio or stretch 5th/6th. It ends up being a lot of trial and error as those before me have said, but becomes second nature if you do it enough times.

I hope this helped.

 

[FastFurious77]

This is a little outdated but I hope its still relevant.

When you're flipping a car that hits max horsepower near redline, you can divide the lowest gearbox by lowest final ratio then multiply by a new ratio to find out what it will trap at the shadow without moving 5th(6th/7th) gear. Assume loss of 15 mph if you move 5th or 6th all the way right. An example would be a 99 gearbox with a 2.500 lowest final; flipping this gearbox over 3.500 would result in a top speed of 138.6mph at the shadow without moving the last gear - roughly 123 if last gear is far right. Obviously a higher gearbox would mean a lower flip, unless you need to adjust for launch gear.

For a car that hits max horsepower at a substantially lower RPM than redline, you have to adjust the ratio to compensate for RPM at the shadow. A car that makes peak power at 5k RPM will not want to rev above 6k, so you'll need to flip on a higher ratio or stretch 5th/6th. It ends up being a lot of trial and error as those before me have said, but becomes second nature if you do it enough times.

I hope this helped.

Spoken like a true Master.