[serialk11r]

Nice. It's hard to tell from the picture, can you manually control it? Does the TSX have wiring to control it with a hypothetical ECU flash?

With external EGR, the ideal valve timing changes a bit, since you'd want the intake cam retarded and the exhaust cam advanced to reduce pumping losses, and supply EGR flow externally. The literature suggests 15% EGR dilution is usually not an issue, 10% is definitely not an issue, 20% is starting to push it.

In the absence of internal EGR, 15% dilution would heat the air up enough to raise MAP by around 25%. I would guess that the actual improvement would be closer to half of that, which still isn't bad. Might turn out to be something like 2 mpg.