I gained 25rwkw by installing one of these SAFC's for $400 plus much better fuel economy. Even though you can only set points at 500rpm it averages out the changes across all revs to make an even curve. Sfitzy, skylines run incredibly rich and this wastes fuel and drains power. By tuning a SAFC you'll get a lot of power! They are pretty small, here's mine: http://www.performance-mod.com/nuke/html/m...ews&new_topic=5