Many have talked about the perfect RPM to shift and I thought I would put something out there to explain about how gear ratios have a lot to do with dictating when to shift.

Some people (including myself) have thought that when the horse power starts to drop then that is when one should start shifting, but it has more to do with that.

Horse Power is actually derived from torque so we'll focus on just the torque.

This is what you need to know:

1. The Torque curve throughout the RPM band with your car. Someone else's curve may not necessarily be the same as yours so their shifting points may be different.

2. The gear ratios of each gear.

I'm going to use a Torque curve from my GIAC Stage 1 flash.

I used the Dynograph to determine the torque at each RPM that I randomly chose. I tried to pick increments of 250 RPM.

**RPM TRQ**
2500 327.7

2735 333.15

3009 360.32

3264 357.89

3498 359.51

3767 363.05

4008 367.43

4270 368.73

4504 369.67

4737 369.7

5006 367.14

5290 354.53

5502 347.33

5743 334.45

5998 320.76

6246 307.97

6501 291.56

6763 271.74

6997 229.74

Since I have an MT, I'm going to use the MT gear ratios.

1st--4.06

2nd--2.4

3rd--1.58

4th--1.19

5th--1

6th--.87

Now, take the torque numbers and multiply the numbers by the ratio of each gear.

1st gear numbers will look like this:

1330.462

1352.589

1462.8992

1453.0334

1459.6106

1473.983

1491.7658

1497.0438

1500.8602

1500.982

1490.5884

1439.3918

1410.1598

1357.867

1302.2856

1250.3582

1183.7336

1103.2644

932.7444

2nd gear numbers will look like this:

786.48

799.56

864.768

858.936

862.824

871.32

881.832

884.952

887.208

887.28

881.136

850.872

833.592

802.68

769.824

739.128

699.744

652.176

551.376

Now, graph each curve. I used excel.

Get the peak number of the gear you're shifting into (in this case it's 2nd gear) and draw or make a horizontal line ratio numbers.

The peak number is 887.28.

When 1st gear numbers, 2nd gear numbers, and 2nd peak number is graphed, it looks like this:

Notice that even at redline (7k RPM) you will never reach the amount of torque that 2nd gear puts out so there is no need to shift early.

When doing the same thing with 2-3 shift, you’ll see that at approximately 6800 RPM is where the peak of the next gear torque hit’s the curve. This is the optimum shifting point.

Do this with each gear and you’ll find the following:

**3-4 Shift 6600 RPM**
**4-5 Shift 6200 RPM**
**5-6 Shift 6000 RPM**
So, to summarize, the best ultimate shifting point

__for this car making this amount of power__ is the following:

1-2...7k

2-3...6800

3-4...6600

4-5...6200

5-6...6k