Regarding the torque app and ELM327 combo, I don't think the ELM is the weak point. Our car has a baud rate of 10.4kb/s for VPW over a serial bluetooth connection that should be able to pump out 119.2kb/s. The torque app running on the phone simply does not have enough processor allocation to do all the calculations it needs. A dedicated module (such as a scangauge) does a much better job, because that's all it does.