Maybe you should get your car looked at. I drive to Mallala all the time in the skyline for tracks days from down south and it uses stuff all fuel for a car that cranks out 300+rwkw.
Well today i dropped my S2 Stagea off at my local exhaust shop to get my dump and front pipe installed. I used a second hand dump and front pipe that i had on my R32 when it still had a RB20 in it. Both parts fitted with no modifications at all So if people are looking for a dump/front pipe R32 stuff is the way to go, you can pick them up pretty cheap second hand
i know your pain I think my record was rego on my Skyline, hilux, commodore, road bike, jetski, jetski trailer. So if i decieded to rego the jetski + trailer + bike I'd be back up to 6 rego's again