Yep nothing like opening the exhaust on a turbo car to make it fly! 86-91 RX-7 TIIs pick up about 65hp from a full 3 exhaust alone.... the only problem is that it lets it boost a bit more causing fuel cut problems and a lean condition. Also if the wastegate isnt big enough it may run into boost control problems (from too much flow). You might want to re-tune your car now just to make sure it still has a good a/f ratio and watch your boost..

Those new numbers are very respectable.. Congrats!

-j0lt