Clutch Class and Information

Below you will find information to help you understand the changes you make and why.  We try to help educate our customers as to know when to make changes and what steps to take upon seeing certain variables. 

Correction Factor:
When looking at the weather conditions, the first thing to look at is the correction factor which takes into
account multiple readings such as actual elevation, barometric pressure, air temperature, dew point,
and humidity. In order to know about what first gear ratio you will need to run in a given change of
correction factor, you must perform the following calculation with the information you have.
Example: Let’s say on your quickest pass to date had you were running a 2.35 first gear. You
performed that pass with a correction factor of 1.045. You are now running in 1.023 corrections.
2.35 divided by 1.045 = 2.248 THEN Take 2.248 x (New Correction Factor) 1.023 = 2.300
*** So, with the correction factor you now need approximately 5 points less first gear ratio to apply the
same amount of power to the tire.

Humidity / Water Grains:
You will see pro teams use both of these numbers, but generally speaking
the more water that is in the air, the less efficient the engine will be. If you see more humidity/moisture
in the air, generally the more timing you can get away with on the top end (finish line). A note to be
made is that if you see great air conditions, say 1.010 but the air is cool, barometric pressure is high,
but the moisture is also high... often times this will give you the impression of the air being better than it
is. You can still use the correction factor to make your changes, but keep in mind that you might find
you will slowly add a little gear/power back to it on the starting line.

Barometric Pressure:
Simply put the thing to keep in mind with pressure is that the more there is, the
more oxygen there is in a given amount of space. If the barometric pressure is at 28.68” but then goes
to 29.85” then that means there is more oxygen in every CFM of air you put through the engine,
allowing for the engine to burn more fuel and in turn make more power.

How to look at horsepower in relation to correction factor...
Let’s say your engine on the dyno makes 1200 hp with a correction of 1.055...

If you take 1200 and divide that by 1.055 you get 1137.44.

Now take 1137.44 x 1.023 (new factor) = 1163.60. 1200 - 1163.60 = 36.4

So... 1200 = 36.4 = 1236.4 horsepower... which is approximately a 3% increase in power.
Air Gap Explained (Clutch Air Gap When Engaged)
There are more than one way to setup a 2 Step Switch, however let me provide a couple things to
make sure you do to avoid unwanted results!

First... Make sure that you install a “clutch light” that can either turn off or on upon the clutch switch
activating. This allow you to know exactly when or at what point the ignition box will allow for increased
rpm gain. No two cars are alike, however some prefer what we call “ramping it in” as opposed to those
that like to leave at the exact number set.

Ramping it in: If you were to set the launch rpm at 5000, but the rpm just starts to climb prior to full
release of the clutch to say around 5050 or 5100... this would be ramping it in.

How to set this is to press the clutch pedal down until the fork just touches the fingers on the clutch. If
you press it down a little further with a dial gauge in a Billet Assembly you will see the needle move,
and you could go to, say .005 which would allow the switch to come off .005” before full release.

Doing the same thing every time is the important part as it leads to consistency, as you are better able
to duplicate your results each time.

Air Gap refers to when you press the clutch in and the amount of space created between the surface
plates and the clutch disc. This is another thing that is best to remain constant to allow for consistency.
The thing to remember is that the less air gap you have the quicker the reaction time can be, however
the more heat and friction that will be applied. This will generally take more brake pressure on the line
to hold the car. On the other hand... too much will slow the reaction time and if you get far too much air
gap it will slap the clutch and shock it, not allowing it to softly drive into the disc material.
More to come soon!