Project Description

Throughout the years Subaru had different setups, but with the time moving on car’s configuration was more and more sophisticated and versatile. Biggest issue was manual 5 speed BMW transmission not holding the power and just breaking.

Selection of DCT transmission instead of sequential box has been made based on couple of facts.

First of all the cost of complete DCT setup including the box itself, HTG GCU, adapter kit and flywheel, cooling lines and radiator, pedal, selector and so on is less than 1/3 the price of old school sequential box.

Another fact is that dual clutch system does not require that much of ignition or fuel cut. In fact we didn’t run any in this car which in comparison to sequential box requiring full cut to disengage dogs is huge power saver during shifts!

Also nice thing is that shifts are insanely quick but still very smooth and fluent and precise.

We’ve been talking with Krzysztof about automatic trans swap for a sports car for a long time.
His Subaru BRZ has swapped 2JZ GTE engine making over 800HP and is fully built competition drift car with no space for mistakes and failures – competing requires reliability to make sure You can fight for top places on the podium.

Finally green light came up for the DCT swap.
2JZ got mated with BMW M4 7 speed dual clutch transmission (GS7d36sg). M4 version of the DCT is a long ratio gearbox with two overdrives. Overdrives are not usually used in drifting scenarios but Krzysztof’s Subaru features Winters differential so after quick play during tests session we were able to pickup a set of teeths allowing use of all 7 gears while drifting.

Car has just up/down shifter that acts both as a sequential shifter and drive mode selector, Clutch-by-Wire pedal allowing clutch kicks, programmable dashboard displaying both ECU and GCU live data.

Of course whole transmission system is operated with standalone HTG tuning GCU Gearbox Control Unit .

DCT setup for drifting made car easier to compete, reliable with great leverage compared to manual transmission cars with no chance for miss-shifts, quicker acceleration on start and of course ability to shift both UP and DOWN on full load!

Second thing is durability. GS7d36sg transmission is very strong and robust unit!

Subaru makes over 800HP, runs semi-slicks at pressure below 14psi and no camber on rear end. Krzysztof runs OEM clutches without any issues with clamping force even in really harsh scenarios and clutch kicks.


Car has been built by Krzysiek himself and it’s not the only one that he owns, hopefully also not the only one with the GCU!

Check out Custom 166 racing fanpage at