Hi all,
I've got a red top ECCS RB20DET in an R31 that I just bought. It's running 10psi with standard turbo, R33 guard mount cooler, standard computer.
It seems to drive fine up to 5000rpm, then the sound of the motor changes and it gets really sluggish revving past that up to about 6500. From 6500 to 7000 it seems to clear out and haul ass again. It idles fine and I'm not sure how to explain this but say you rev it in neutral from idle, it takes like a second from when the throttle opens before the motor revs up.
I thought it must be fuel or air. I have changed the plugs, new fuel pump, checked the base pressure on the aftermarket reg, set to 44psi. I can't find any leaks in the cooler or piping.
Any ideas?