I have the PSI pipes on my newly acquired ZR 580 Carb. With the carb you can increase the jet size to take advantage of the better flow characteristics of the pipes. On an EFI, you would have to somehow reprogram the ECM to find the right mixture. The good news; the EFI would jump into "limp home" mode if things "heated up".
1995 ZR 580
1997 ZRT 600
1999 ZR 440 Sno Pro
2000 ZR 440 Sno Pro (VForce reeds)
2000 ZR 440 Sno Pro (Boysen reeds)