Is it safe to gut the cats on a 86 GXL? Will it affect the opening of the 5th and 6th ports? Does it need the back presure from the cats or will it run great with gutted cats?

 

Gutted cats may still provide enough backpressure to open your actuators. If not, wire them open and kiss your low end response good bye...

 

When you gut your pre- and second cats, you may/ may not have enough back pressure- mine was kinda iffy....ports work well, though, when using the ACV exhaust hose for a pressure source (mine did, anyway)

 

https://www.rx7club.com/showthread.p...tch+activation

RPM switches are great things.

 

just run the line that takes the pressure from the hose going to the cat that opens your aux ports, and run that into the ACV relief line or some other line (whatever you prefer) that has enough psi to open them.. then drill into it, put an adapter on the hose for the aux ports, stick it in, maybe put silicone around it so theres no leaks, and ur all good... no longer do you need the back pressure to open your ports

 

here, read this thread https://www.rx7club.com/showthread.p...hreadid=269286

this is where icemark helped me with it and explained how to do it