I have the Ultra MDI fitted to my car (was on it when I purchased). From the very start I've had ignition problems, first with the standard coil packs (which were quickly replaced with Splitfires) as well as spark plugs.
In the 18 months I've had the car I've probably gone through over 10 sets of spark plugs and just recently a set of Iridium's only lasted 10 days! Most of the time I've been using BCPR6EY-11 gapped to 0.8mm. Everything's fine for a couple of weeks then the car starts misfiring / spluttering. I'm thinking the extra voltage / current from the MDI is killing my spark plugs but I'm not 100% sure. I got a 2nd hand coil pack wiring loom (in bad condition) to bypass the MDI but it makes the car even worse with brand new plugs. I've tried colder plugs, and gapped a couple of sets to 0.7mm but no joy. I'm thinking a new loom from Nissan might solve my issues but at $300ish it's a gamble.
The engine is stock running a Power FC, runs 1.1 bar of boost on standard R34 GTR turbos. Pic of MDI units below, any advice would be appreciated.