check the air/fuel ratios coming from the vafc see if something is out of wack there, possibly the ecu ur using is making u run to rich causing that fuel out the back, compression is pretty high im guessing u guys are using at least 102 octane? or 92 with octane boosters? check ur spark plugs for signs of running rich, lean, etc. see if that helps u any, good luck on figuring it out. nice setup. and whats the mm size on that intake manifold?