It is a more efficient housing than the Garrett housing Z1 uses and the compressor wheel is slightly different. The turbos are also perfectly clocked from HKS and fitment is as bolt on as you can get for a Z. Is this worth the grand or so premium you pay over the 675's? Thats up to you to decide. I just had my Z tuned with the 2530's and made a ton of power, be posting charts shortly once they are emailed to me.
2530'ed up!! xxx rwhp, yyy lb ft /tq tuned by GDupree and Seb from Specialty Z on 5/23/08