Subaru Impreza STI For Everyday Traffic

This project is about one of our clients Jānis from Latvia who is in love with Subaru cars and owns Subaru Impreza STI. Jānis is a daily driver and uses this car for everyday traffic and hobby events until his Subaru’s engine let him down by rod knocking from the engine bay.

Subaru Impreza STI is his third Subaru vehicle and as an experienced car owner, he carefully considered whom to trust with his daily beater. After consulting with friends with rally experience and our friend Karlis from KN Autosprint, he was ensured that HCR will be the best solution for his needs.

We started this project with full engine disassembly and damage control where we found that there was rod bearing damages, which were caused by block warping and led further to insufficient oil supply from main bearing journal to rod bearing journal. As we already have mentioned before, if you own a Subaru, there is a huge chance that the main bearing bore alignment of your block is out of line. To correct the main bearing housing alignment the best solution by far is line boring.

To ensure the engine reliability we also did closed decking, full head service and used all new forged parts to improve engine strength and longevity. The flow of the heads was improved which gave better low-end response and high torque numbers.

After all engine improvements, Janis STI is more responsive, reliable, and more powerful. With all stock setup, he is able to achieve 325.6HP (+25HP) and 506 Nm (+113Nm !!!).

In the future, Jānis is thinking about improving his STI with a bigger turbo, improved exhaust system, bigger injectors, and maybe even aftermarket ECU. He aims to achieve up to 450HP, to have enough reliable and powerful car for daily use.

“The positive attitude and friendliness evoked only good emotions and I immediately felt that Hard Core Racing is trustworthy. I didn’t have to wait long until I receive my engine back well maintained, clean as new, and ready to install, nevertheless much more reliable and with a lot more potential to make higher HP numbers. In my opinion, those who really respect their engines will choose quality over price - and these guys just nailed it!” – Jānis.