[TopJimmy]

You can run full E85 on all stock no probs. When you run a Custom (Stage 2+) E85 tune it usually requires pushing the high side fuel pressure above 3600PSI and sometimes a fuel injector can break and leak (they do not stick from lack of lubrication [top lube does nothing], the internal gate breaks from running overpressure). You can simply ask the tuner not to push HPFPs too high, which limits the top end (no biggie, stock turbos decline at 6500RPM, no need or benefit from going to redline).

Another alternative would be an E60 tune (half gas, half E85) which allows the tuner to really give you awesome performance without pushing HPFPs into a risk zone. Torque and HP will be great (~550-575HP), just slightly less than "full E85".