Put an S13 red-top (with about 85K on it) in our 1990 240SX this winter and just took it in for the safety & e-test last week. Passed with room to spare. The only mods we did were blocking off the AIV hole (and chucking the control valve for it) and a new cat. Since we used a front clip, everything was completely stock. The only reading that came close to the limit was the high RPM HC reading, it was just under the max. limit.
:thumleft: Nice work…
I don’t see why it wouldnt pass anyways in the first place if everything is hooked up and running correctly.
We checked the boost pressure after and it is steady at 10psi under load. We thought it was supposed to be around 7psi (stock SMIC/BOV & T25 integral wastegate) so we tried another boost guage and it reads 10 psi also. Is it possible to be this far off? Maybe this one was tweaked by somebody in J.A. Pan Co.??
That is quite possible that the boost was raised in Japan.
Where are you taping off to get your boost readings?
Taping off by tee in the small rubber hose that connects the intake side of the throttle plate (left/smaller tube of the two that are sticking out of the intake plenum just above the throttle plate) to the wastegate control solenoid.
aftermarket wastegate back in japan?
Looks stock but I suppose somebody could have changed a spring inside. The ECU (#62) looks like it has been modified, the PROM inside looks like it has been changed and it is all covered over with epoxy - but I didn’t think it was possible to change the boost levels with the ECU mapping. There does not seem to be a speed limiter function however, it goes right up to the limit of tolerance of one’s dangling participals.
The ECU has no control of the boost. The car probably has an upgraded wastegate actuator.
My S13 SR boosted 14 PSI in the winter time without even a boost controller! 
everything was stock