ya man 4 cm housing so that a 49135-04500 you have there ?? did you drive this turbo whats spool like compared to us on the 6cm housings are you going to open it ?? if so measure the inducer and exducer of the compressor wheeel if you can ?? see if its same on us 6cm boys virtual credits added :) ha ha that housing does look A LOT narrower very curious about this performing at the stock limiter