FM just sent out an email explaining that "a bunch" of 1.6 and 1.8 turbo kits will be going live, and that they've resolved 2 major supply issues so the kits should be in stock much more often.
And a new exhaust manifold that flows better. I'll be watching for that, myself.
Was something changed on the FM kit (maybe to make it CARB compliant) that caused a reduction in performance? I thought that I heard something like that but could be totally wrong.
Comparing this kit to some others such as the MKturbo, it doesn't appear to replace or modify the ECU. How are they able to achieve what I've seen appears to be similar gains?
They're advertising the same HP levels I recall from before the CARB certification, so I suspect you may have heard wrong. It was always possible to get more power out of the kits with not-Voodoo-Box engine management. Other kits aren't CARB-compliant because they use aftermarket ECUs. The CARB-compliant Voodoo Box is basically a piggyback or bandaid—depending on your POV—and retains the stock ECU.
They use a piggyback device that is spliced into boost and, based on that, delays spark/extends fuel pulses. It is possible to squeeze a little bit of extra power out of the voodoo box with slightly larger injectors from what I've seen, but I could be wrong on that and FM doesn't recommend it themselves. If you want any more power than that you have to upgrade injectors/ecu.
Right, there's a limit to the power you can easily get out of stock injectors, which I'm pretty sure are required to be retained for CARB certification.
Ahhhh, a piggy back system. Got it now, that makes sense. Thank you!!