LC1 Wide Band O2 Sensor Upgrade for 2007/2008 HD Engines

What are the issues with the 2007 HD engine?

Right after the 2007 HD motorcycles were introduced the issue of high engine heat and poor throttle response showed up. Nightrider with its background and experience in fuel injection systems was able to quickly identify the HD supplied narrow band O2 sensors and the OEM EFI operating in closed loop mode as a significant source of the complaints. Even Harley-Davidson recognized that there was an issue and put out an EFI download to improve the situation for FLH's. But this HD supplied upgrade did little to address the real cause of the issue. Harley-Davidson was unable to do much more than it did for the FLH's because of Government EPA regulations and most Dealers had little idea what the real problem was or how to correct it. The most common fix "sold" to riders was a Stage 1 download, SE Race Tuner or installing a PowerCommander or similar "black box" upgrades. None of these upgrades was overly successful at reducing temperature because they never addressed the real cause of the situation which is the ECU operating in closed loop mode. Eventually some of the "black box" aftermarket companies started supplying O2 Eliminators for the 2007 bikes. The O2 eliminators would reduce the heat, but most riders saw large drops in fuel mileage due to overly rich idle mixtures. This is an overly  rich fuel mixture that drops gas mileage and can result in excessive carbon buildup in the engine.

Can the situation be fixed?

What was needed is a Wide Band O2 sensor upgrade for the 07 HD's that would allow the rider or mechanic to set an appropriate AFR for the engine and the way it is ridden. Under most circumstances, the more appropriate AFR is in the 13.5-13.0:1 range. This AFR helps keep engines cooler, provides good throttle response and does not severely impact gas mileage.

Without getting into the heavy technical details, replacing narrow band O2 sensors with a wide band O2 sensor is a lot more complex than just taking the NBO2 out of the exhaust and installing the WBO2 sensor. Narrow band O2 sensor basically only understand a single AFR, 14.7:1. This is a good AFR for gas mileage and water cooled engines. But 14.7:1 AFR produces the highest exhaust temperatures, which is not good for air cooled engines or motorcycles. A Wide Band sensor is able to accurately report on air fuel ratios from 10:1 to 20:1. This makes them ideal for performance and pollution controlled engines. But wide band sensors require special electronic circuitry to process the signals from the sensor and they also produce different voltages than the NBO2 sensor. A narrow band O2 sensor puts out a signal of 0-1 Volts where the wide band sensor electronics puts out a signal of 0-5 Volts, making it seem incompatible with the Delphi ECU.

But this incompatibility between WBO2 and NBO2 sensors can be overcome with some additional electronics.  Nightrider identified and successfully tested ways to upgrade from the OEM HD NBO2 sensor to a wide band O2 sensor. Along the way, some the operating characteristics of the HD engines EFI system were captured by data logging instrumentation. These EFI operating characteristics explained many of the issues that riders see on their motorcycles. It was also established that the WBO2 sensor upgrade would be compatible with all HD Stage 1/2 downloads, HD supplied engine upgrades (103, 110CID), SE Race Tuner, and aftermarket tuning aids like PowerCommander, Fuel Pak, TFI and other devices without requiring the use of an O2 eliminator.

Installing the LC1 Wide Band O2 sensor upgrade and setting it for a 13.5:1 or 13.0:1 air fuel ratio dramatically lowers engine heat and will reduce the instances that the engine goes into high heat/parade duty mode. Because we have seen stock 96CID engines go into high heat mode in 10 minutes of idling in the shade. This means that the OEM HD engines are "on the edge" when it comes to their ability to keep cool. We believe this marginal cooling ability is very critical for HD 110 CVO engines and HD 110CID engine upgrades due to known issues with scored/scuffed cylinder walls occurring. There is also a high probability that this situation is also occurring on the HD Stage 2 103 Big Bore upgrades.

Don't the HD downloads fix the high heat issue?

The various HD downloads and Stage upgrades do not address the high engine temperature issue. Harley-Davidson is limited by Federal Emissions Standards, therefore can not provide an upgrade that might violate or alter the emissions of the engine. This prevents them from providing a "Fix" that is going to make all riders happy. The Dealers are in the same situation because they risk very high fines from the EPA or State emissions control agencies when they install unapproved upgrades on motorcycles. California is a good example of a State that is beginning to crack down on upgrades that do not meet emissions standards.

What are my options if I don't want to use an LC1?

The use of O2 eliminators has become fairly common on the 2007 engines. When using an O2 eliminators supplied by PowerCommander, TFI, V&H Fuel Pak, etc., the engine idles at a very rich 12.0:1 AFR. This will reduce the engine temperature, but also reduces gas mileage 3-5MPG on an FLH and can result in excessive carbon buildup in the combustion chamber.

Nightrider has developed an plug-n-play HD O2 sensor Inline Enrichment Device. This simple, cost effective upgrade can be used on the OEM narrow band O2 sensor and will raise the closed loop AFR from 14.7:1 to a slightly richer 14.2:1. While this is not as desirable a fuel ratio as the LC1 can deliver, any improvement is going to help lower the engine operating temperature..

SE Race Tuner gives you full control over the Delphi ECU. Using SERT, you can eliminate the closed loop operation mode, or alter the RPM ranges that it effects the engine. With SERT you can actually richen the close loop air/fuel ratio up to about 14.2:1 by altering the O2 bias table voltages to 750.

There are at least two popular aftermarket ECU's available on the market that can replace the Delphi ECU. The Daytona Twin Tec and Thunder Max ECU upgrades will work without any O2 sensors, or they have an option to add wide band O2 sensors to the upgrade. The addition of the WBO2 sensors with these kits provides a level of "self tuning" for the air/fuel ratio that is accurate enough for accurate tuning on most engines.

Are there any issues with the LC1?

There are no "problems" with the LC1 that Nightrider has been able to establish. The ability of the LC1 to accurately alter the close loop air fuel ratio of the Harley-Davidson Delphi ECU to any desired AFR is well established and works exactly as anticipated.

We know that you can not use a single LC1 to control both cylinders and get satisfactory results. If you decide to try a single LC1, install it on the rear cylinder to reduce the heat your feel while riding. But we can not fully support the single LC1 upgrade.

We highly recommend installing two LC1's on your bike. One LC2 WBO2 upgrade for each cylinder, replacing the OEM O2 sensors. This is the only way you can ensure your engine runs at the lowest possible operating temperature.

The LC1 is a product of Innovate Motorsports. Nightrider is a Authorized Distributor for the Innovate Motorsports LC1 and its other engine monitoring products. Click Here to order the LC1. 

Before you order and install the LC1 on your bike, we strongly recommend you review the Innovate LC1 manual and Nightrider LC1 Installation Guide.

Nightrider put installation information online. All this information is listed just below in the LC1 WBO2 Upgrade Installation Instruction section below. It will also give you access to some very specific setup information for the LC1 that is required to properly configure the WBO2 for your Harley-Davidson.

Is installing the LC1 hard to do?

The wiring of the LC1 to make it work is not very difficult, but finding locations to install a controller for both the front and rear WBO2 sensors can be difficult. While we believe that the engine will run fine with a single LC1 installed for the rear cylinder, we recommend the use of two LC1's. One for the front cylinder and one for the rear.

The LC1 Wide Band O2 upgrade installation instructions are located on our Training Site at www.spmullenllc.com/training/ . You may be required to register to get a login on this site. The registration process also requires you confirm your information online through a valid e-mail address.

You may also be asked for an enrollment key. The current enrollment key for this installation instructions is "nightriderfix".

The installation instructions will be periodically updated and improved as better information becomes available.

For other LC1 Installation Information

Information contained on the LC1 Installation Guide site is Copyrighted information and may not be reprinted or distributed under any circumstances. Any person registered on the site caught distributing this information will have their access rights removed.

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