Regarding WI, it's not just flow rate, but also when it's triggered.

What spark plugs?

I was having ignition break up with stock 9s all around until I switched to NGK R7420.

Have not had a break up since then.

So here's what ended up happening in my case...

I went with the SBG "RHD"/frame-rail mount. It worked fine. I used the SBG harness, mostly because I didn't to get it done and IRP was backup on their harness production.

I installed these at the same time as a set of BNR state 2's. Initially, I was having boost control issues with the BNRs so only pushing maybe 16psi, and the IGN-1As were fine with that and 250cc/min water.

After I got my boost issues figured out, I would start to get breakup again above 6-7Krpm & ~20psi with 250cc/min water and 4x NGK BUR9EQ plugs (9 heat range).

I then used 8 gauge wire and some heavy duty copper terminals and did the following:

1. Ground rear rotor housing to firewall
2. Ground front rotor housing to driver strut tower
3. Connect front and rear rotor housing together (note that the SBG harness grounds to only one rotor housing).

I also switched from 4x NGK BUR9EQ plugs (9 heat range) to 4x NGK R6725-105 (10.5 heat range), and went from 250cc/min water to 315cc/min.

Between the additional grounding and 10.5 plugs my breakup is completely gone even at redline, 22psi, and more water.