You could try Tuning Tech FS (TTFS) in Crofton, MD. Website at http://www.tuningtechfs.com. TTFS performs in-house tuning, remote tuning, dyno testing and engine building.
My mechanic at MINI of Montgomery County races his GP on the weekends and recently recommended TTFS to me. Haven't been there yet but am planning on making a dyno appointment first to determine my car's "baseline" with existing mods.
TTFS' has a checklist to determine if your car is ready for a dyno appointment located on their website here: http://www.tuningtechfs.com/content/Dyno%20Ready%20Check%20list.pdf
Regards,
Paul
