Quickly Access Your Favorite Track
This article is an almost direct copy from our partner site at AirDensityOnline.com. We are planning on adding a feature for our users to be able to save their most visited tracks to their user dashboard. This is another option for users who wish to access a direct link from their phone's home screen.
Note: this applies to iPhones only. However, there is a similar task for Android devices as well. See the links at the bottom of this article.
Figure 1
Did you know you can save a quick link to the weather on your favorite track on your iPhone's home page? It's pretty easy but you have to know where to look. Follow these steps.
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Fuel Injection High Speed Bypass for NA Engines
The high speed bypass is often used in a fuel injection setup.
NORMALLY ASPIRATED ENGINES
The high speed leans out the engine as the RPM go up and the volumetric efficiency goes down.
The VE is often near 100% at the torque peak.
The air flow per revolution is max.
A typical norm asp engine cammed up for racing may see a torque peak around 5,000 RPM.
Tuning should be with the main bypass for max power up to the torque peak or just beyond.
We often recommend an AFR of 4.8 to 1 for methanol fuel for the torque peak.
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Fuel In. Jetting Calc. for Top Fuel, BDK Bypass Valve setups
Our fuel injection calculator can provide a valuable
air to fuel ratio (AFR) computation for professional top fuel and normally aspirated A-fuel racing for land or water sports.
- For example, a typical blown high percentage nitro V-8 setup will have an AFR less than 1 to 1 at the start and lean out to over 1.5 to 1 at the finish of a 1,000 foot drag race. Incremental tuneup changes to the fuel curve can be determined ahead of time with precise numerical references.
- In a second example, a typical 90% injected nitro V-8 setup will have an AFR less than 0.3 to 1 at the start. Leanout to keep the 'candle lit' can be numerically determined ahead of time; then set into the fuel bypass controller for numerical control.
Our fuel injection calculator also provides a valuable
oxygen to fuel ratio (OFR). Oxygen to fuel ratios (OFR's) from the calculator are a "next level of advance tuning".
- The oxygen part of the combustion process is determined from all sources: nitro, methanol, blower, & air density.
- The total amount of the other parts that contribute to combustion are determined from the fuel. That is specifically carbon, hydrogen, & nitrogen that combust.
Nitrogen in the air, excluded from combustion, is also excluded from the OFR calculation, making the OFR tuning value way more affective.
Engine Tuning Using the Main Bypass
When you’re thrashing in the pits getting ready for the next run, a quick way to update your jetting is to adjust the main bypass while leaving the rest of the jets alone. If you have a really well dialed-in jetting combination with good fuel system pressure, this form of tuning simply controls how much fuel is going to the engine and how much is being diverted back to the fuel tank.
Tuning Steps
The larger the main bypass jet, the more fuel is diverted away from the engine. This can sometimes feel counterintuitive.
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Setting up a new fuel injection system
If you're thinking of buying a new fuel injection system there are a few things to note when getting it calibrated with your existing setup.
Most fuel injection systems are shipped with a small main bypass which makes the engine run rich. While some systems run richer than others out of the box, they all come precalibrated with their own jetting. In addition, most new systems will run at the higher rpm's with a fuel pressure between 50-150psi. That means that at lower rpm's, the fuel pressure can be so low that the engine runs sluggish. Read the rest of this article »
Tuning with methanol vs nitro
The basics of engine tuning involve finding the right ratio of fuel mixed with air to get the right amount of power out of your engine. When you have a familiar engine setup and always race with methanol, that task can become tried and true. When you add percentages of nitro, things suddenly get more complex. Following are some of the differences between nitro and methanol.
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Using Air/Fuel Ratio
Updated October 4, 2024
This article is taken from our partner site at AirDensityOnline.com
On this site, we talk a lot about finding your ideal air/fuel ratio. It is the concept that our mechanical fuel injection jetting calculators are built on, and it is the concept used in electronic fuel injection in order to maintain a good fuel system setup. Understanding air/fuel ratio can be very helpful when setting up your fuel system. It can mean the difference between a successful run and a blown engine.
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Measuring the Atmosphere Around a Track
Note: This article is taken from our partner site at AirDensityOnline.com. It provides information we think may be useful for users of both sites.
We provide a lot of weather information for each track with the assumption that racers know what each value means. If you need a brief crash course in how to interpret the information found on each track page, see the information below. As always, if you have any questions about this or any information found on this site, contact us.
The air around a race track
Imagine a cubic foot of air near the ground level at the race track. It may seem empty but there are molecules moving around within that area. Depending on various environmental factors, that cubic foot of air can contain oxygen, other elements such as nitrogen and carbon dioxide, moisture, and particles of pollution. Each of these vary depending on the location, elevation, and current weather environment.
We need oxygen for combustion in our engines. However, as we can see, the amount of oxygen in the atmosphere fluctuates. This is why, for instance, you might notice a great engine performance at certain times of day and bad performance at others. Tracking the weather can help us determine jetting changes in order to compensate for the changing atmosphere. Using the information we provide on the tracks pages of this site can help you do that.
This article will explain those variables. Hopefully it will help you to better understand the atmosphere and better tune your engine for optimum performance.
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Historical Weather Data
Historical weather from Sacramento Raceway. Click on the image to view more historical weather for Sacramento Raceay.
Note that this article is taken from our partner site at AirDensityOnline.com. This information is useful for users of both sites.
We've gotten a few questions recently asking about historical weather data. We just added the option to view hourly weather including air density, density altitude, and grains for past dates!
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