Everyone raises valid points, but I am interested enough to pursue. My shop does mostly Miata work, and admittedly, they are far simpler than the xfire. That said, I am not convinced the ecu issue is a dead end. Mostly it depends on the cost of the parts and their availability. So far, I haven't found any donor 3.2 engines w/blower, not to mention all of the ancillaries that are required.

I believe the fueling issues under boost can be resolved. I further believe that the stock na motor can tolerate an increase in power AND that the drivetrain is up to it. Mostly this is based on the premise that we are putting over 300 HP through a Mazda transmission/differential "designed" for about 116. Surely, MB has a bit of safety factor in their design? Worst case? Rebuild the dang motor with better bits. No biggie.

I realized AEM will not be making a xfire specific ecu, but we have had excellent results with those things in the Miatas, and am amazed at the flexibility and power of that ecu. Their generic unit has the same programming capabilities as their model specific ones do, but come as a blank canvas vs. one mostly painted in.

Like I said, I'm dumb enough and interested enough to tackle this thing. I also believe we have the expertise in house to handle a great many of the issues - I do the mechanical stuff and my partner does the electronic part.

I looked at xfires for over 2 years, and looked at a lot of competing models, M series bimmers, G35, 350Z & RX8. Style and mechanical layout of the MB drivetrain were a huge +. Lack of a manual in the SRT a huge - , lack of power in the NA version was a - . At the end of the day, I decided it would be better to add a blower to the six speed then to add a six speed to the SRT. Was I right? Damifino, but I will find out.

Henry Payne
HPMotors
Miatas for the Street or Track