Project SC300 Road Racer: Part 17 – Get out there! Or not…

Since we were so pleased with the dyno results, and so eager to shake down the car, we decided to drive it all the way home from Ed’s dyno shop. A 20 mile drive combining streets and highway and stop-and-go traffic in fairly warm weather on a car that hasn’t driven more than onto or off of a trailer or dyno seems like a brilliant idea.

And I have AAA anyway.

But, I’m happy to report, despite the dashboard not showing all the right values, the car made it home in one piece and with no failures (other than the badly adjusted fan setting we mentioned earlier).

With the car at my house I was able to drive around my subdivision and continue to make tweaks to the dashboard and various other settings. Once we got the MPH output from the  RaceCapture/Pro properly displaying on the dashboard, we were able to calibrate the wheel speed sensor input to the Haltech ECU. This process involves driving at a known, constant speed and then hitting the “calibrate” button in ECU Manager with that speed entered. ECU Manager then determines the appropriate number of pulses (revolutions) of each wheel given the known input speed. Slightly higher speeds (above 15MPH) seemed to work more consistently.

SAFETY WARNING: First of all, you need two people for this job. It is not safe to drive the car, pay attention to the MPH, use a laptop, and trigger the calibration button in ECU manager. You want a passenger to hit the button. You need to pay attention to driving and not killing anyone. Or vice versa. Either way, do not attempt this alone and preferably attempt it only in a safe location, such as a big parking lot.

After calibrating the wheel speed sensor input, we were also able to calibrate the Haltech ECU’s gear detection feature. Since most older factory H-pattern transmissions do not have gear indicators (other than perhaps a neutural or reverse switch), the Haltech ECU can use wheel speed and engine RPM to roughly guess what gear you are in. This one requires going at a little bit higher speed (30-40MPH+) so, similar to before, use extreme precaution and a partner to properly calibrate.

Gear detection could be easily done on just about any dyno. Drive at a fixed speed and hit the calibration buttons. Wheel speed calibration for a 2WD car would require a dyno that would match the speed of the opposite axle. In other words, a dyno with a connection between front and rear rollers. Otherwise you would only be able to calibrate the powered wheels.

Having wheel speed sensors properly calibrated allows us to do fancy things like traction control via the Haltech Elite 2500 ECU, if we wanted. Maybe we will. We haven’t figured that out yet.

We had driven the car around a little bit in the neighborhood (it’s got a tag AND insurance, you know!) and a little bit around on the street. We had calibrated all the things. The dashboard was displaying correctly. Nothing had fallen off the car yet.

It was time to head to the track.

But not without stopping for a pre-track tech inspection from our friends at Gran Turismo East.

When it comes to wheels and tires, alignments, brakes, or just about anything suspension oriented, these are your guys. They are also a tech station for most HPDE groups, including JZilla Track Days, who we would be doing the event with.

We also needed to update all of our safety gear. Look for an upcoming article about personal safety equipment from me, and thanks to my great friends at Pegasus Auto Racing!

Car tech? Check.

Safety gear? Check.

Load ‘er up and take ‘er to the track!

Not so fast.