PC COMMUNICATIONS LINK
The Twin Tec TCFI III system uses a USB interface cable that plugs into the original equipment (OE) Harley- Davidson data link connector. Direct access to the TCFI III module is not required. The OE data link connector is provided with a rubber seal that makes it impervious to moisture and dirt. The ThunderMax® system uses an older technology RS-232 link with an unsealed mini-DIN style connector on the top of the module. No provision is made for protecting this exposed connector from moisture and dirt. In some applications, such as Dyna models, the module is not readily accessible and connecting the RS-232 link presents a major challenge. Most laptop computers manufactured within the last 3-4 years lack RS-232 serial ports and using the ThunderMax® system with one of these newer laptops requires purchase of a separate USB adapter.
Figure 2 – ThunderMax® with Unsealed Mini-Din Connector
SETUP AND AUTO-TUNING
Basic setup for the Twin Tec TCFI III and ThunderMax® systems is very similar. In each case, a base map is uploaded to the module, a cold start is performed, the system is then allowed to auto-tune, and some final checks are performed. There are some subtle differences. The Twin Tec base maps are very generic and easily modified for particular applications by entering the estimated horsepower and injector flow rate. During the initial cold start with the ThunderMax®, a special manual step is required for the system to learn the correct idle air control (IAC) values. This function is automatic and always active with the TCFI III.
Because of the odd RPM and throttle position increments and limited real time display capability (discussed in detail in the following sections) of the ThunderMax®, auto-tuning on a dyno is difficult. With the TCFI III, auto-tuning on a dyno, such as common DynoJet units with load control, is straightforward. The dyno can be setup for stepped RPM runs with simple 250 RPM increments and the required throttle position increments are clearly displayed in real time with the Twin Tec data logging software.
Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 (386) 304-0700 www.daytona-twintec.com Page 2
TCFI III & TMax Comparison 4/2011