Rotorua Motor Works

07/08/2026

A service you can trust

05/08/2026

Why Your Car Jerks Between Gears

One of the biggest misconceptions is that harsh or jerky gear changes are “just how a modified car drives.”

They’re not.

On modern GM platforms, every gear change is a calculated torque event. Before the transmission applies the next clutch, the ECU predicts engine torque and commands a specific amount of torque reduction. If those calculations are wrong, the shift won’t feel right.

We regularly see cars where the airflow model hasn’t been calibrated properly after fitting a camshaft, OTR or headers. The ECU is calculating the wrong cylinder airmass, which means predicted engine torque is wrong before the transmission even starts the shift.

When the transmission receives an incorrect torque value, clutch fill times, pressure commands and torque reduction strategies no longer match what the engine is actually producing. The result is a harsh bang into gear, an inconsistent shift, or a flare between gears.

It’s not always the transmission.

It’s often the calibration.

That’s why we don’t just adjust shift pressure and hope for the best. We validate the MAF curve, VE model, predicted torque, delivered torque, Driver Demand, Electronic Throttle Control, shift timing, torque reduction and clutch apply strategy so the engine and transmission are working from the same data.

When everything is modelled correctly, the transmission knows exactly how much torque it’s receiving and the shifts become faster, cleaner and far more consistent under every driving condition.

A good transmission tune isn’t about making every shift hit as hard as possible.

It’s about giving the transmission accurate information so it can do its job properly.

04/08/2026

THE TRUE ALTERNATIVE TO PAYING DEALERSHIP PRICES
Rotorua motor works 073492003
Services Repairs diagnostic work brakes drive lines alternators batteries starter motors water pumps radiators cooling systems timing belts PREPURCHASE INSPECTIONS Wofs and much more

04/08/2026

Creating n sharing a safe motoring experience for our future road users Rotorua motor works
This at one of our local high schoole classes provided by Rotorua motor works for the schoole students

09/07/2026

Happy Matariki to everyone have a wonderful weekend

03/07/2026

Rotorua motor works 343 old taupo rd Springfield Rotorua 073492003
Services Repairs diagnostic work brakes drive lines alternators batteries starter motors water pumps radiators cooling systems timing belts pre purchase inspection Steering suspension radiators clutch replacement WOFS and much more.....

26/06/2026

Mercedes Benz Evolution ❤️‍🩹

17/06/2026

17/06/2026

Working with our community and providing a positive experience for our young people in supporting their education n future.