Well, since the 'comparison' on Wyatt's site has been brought up again, in the interest of equal time, here's some points to consider. The following points can be researched further in the archives of this forum and dsm.talk, as well as explained on our website (turbosystem.com):

Powerful, correct exhaust manifold design (symmetrical vs. offset log).
Detailed fuel system development and resultant engine longevity.
Intercooler options (SMIC or FMIC); larger FMIC with HRC.
Wastegate durability, effectiveness, and open discharge dangers.
Turbocharger efficiency, response, and modern design.
Properly equipped fuel system vs. turbocharger size option (no larger turbos without safe fuel system!)
ALL performance records for 420A engine vehicles.
Fuel Mapper (equivalent to VC1 but easier to install and use) included at no extra cost.
Intercooler pipe fit and quality.
Detailed extensive instructions with drawings and photos.
Downpipe durability (no cracking due to absence of flex joint).
Completely researched/fully equipped turbo and fuel system upgrade options for higher power levels later.
Extensive experience with Diamond Star vehicles and resultant customer assistance with many aspects of car other than turbosystem.
Access to daily available tech support from turbocharger and Diamond Star experts with decades of experience.

With even more support, development, records, and customer options to come!

Bill Hahn Jr.
98 RS Turbo: 10.87 @ 136 MPH
HRC Stage V with N20
Nation's Fastest Street FWD 2G DSM
www.turbosystem.com