Boost controller, Tuning instruments, Tuning tips – BoonDocker ARCTIC CAT: 800/1000 Turbo 3D User Manual

Page 11

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BoonDocker – 2379 Heyrend Way Idaho Falls, Idaho 83402 – (208) 542-4411

website: www.boondockers.com - email: [email protected]

Revised 03-14-07

Page 11 of 14

Boost Controller:

It is recommended to start with your Electronic Boost Controller set below 4psi. If you are using a boost tee, set it
to the lowest boost setting. To find this starting point, remove the boost tee, loosen the knob all the way, blow
through it while tightening the knob until you start to feel resistance (the valve starts to close off). Make sure the
engine is tuned properly before increasing the boost and watch closely for proper fuel mixture and detonation (see
topic in Tuning Tips).

Tuning Instruments:

Air/Fuel gauge:

A good wideband O2 gauge is highly recommended as an effective tuning tool. The sensor will have a limited
lifespan due to exposure to pre-mix oil and leaded racegas, but in many cases it can last for a season and it is a
very valuable tuning tool. If desired, after initial tuning is completed the probe may be removed to prolong its
life.

Be aware that too rich a mixture can cause the gauge to read lean due to unburned fuel not being read by the gauge
(the oxygen will produce a lean reading). Whenever the engine is decelerating, your A/F numbers will be lean -
these readings can be ignored. However, whenever the throttle is being applied, pay attention to the readings!

Higher numbers are leaner (less fuel), lower numbers are richer (more fuel). A 14.7:1 ratio means all the available
oxygen has combined with all the available fuel. Numbers from 11:1 to 13:1 generally produce the best power
(extra fuel helps cooling and can help prevent detonation). A lower A/F ratio (10.8 to 11.2:1) is considered safer
on a turbo since the extra fuel prevents heat build-up and helps prevent detonation. We recommend you find the
lowest ratio where the sled still runs without being too rich.

EGTs:

Exhaust Gas Temperature gauges can also be an effective tuning tool and are recommended, but they are not a
substitute for reading spark plugs and piston wash and for a general feeling of how the engine runs. Use EGTs
only as a backup to verify what you see. They can be misleading under certain conditions and safe readings can
vary greatly from engine to engine depending on such things as probe placement, fuel, timing, pipe design,
porting, etc. Typical EGT temps can be between 1250 – 1325degF after a long pull.


Plug and Pipe Color:

Color will develop inside the pipe and on the plug after running a while which can be used to determine fuel
mixture. A tan/cardboard brown color is desired. Light-gray is too lean, and dark brown is rich.

Tuning tips:

Important: Find the settings where your motor runs rich before you decide to go lean!

1. Tune with the engine and pipe at operating temperature. The sled’s ECU will make adjustments as the engine

warms up – you might think the engine needs leaner settings then later realize you are too lean once the
engine warms up.


2. Use the Load/Save Map feature to quickly change and compare fuel settings when testing. This can also be

useful for riding under different conditions. For example, changing elevations or temperatures may require
different adjustments if the stock ECU does not compensate properly for your modifications. For drag
racing, you might want to run richer settings for longer distances than you would for short distances.

3. One method for finding out where a fuel adjustment setting is effective, greatly increase only that setting.

Run the engine to find out when it suddenly becomes too rich – this is where that setting is effective. Be
careful – you can easily flood the motor, especially with low (LO) load or low RPM settings. If this happens,
to restart the engine you may have to pull several times with the throttle held wide open.

4. The Stats Capture feature can be used to determine RPM and whether the load setting is LO, MD, or HI.

The handlebar button can be configured to capture these stats (see nitrous configuration section). From the
Main Menu, select N2O, set Btn to CAP. Whenever the button is pressed, the Stats: Capture screen will be
displayed. The current stats will be captured when the button is released.

N2O Menu in “Capture” mode:

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