Thought I'd share a few thoughts and comments about going from a M3 street/track to a formula mazda. I know there are several people on this board that either already have dedicated racecars or are working that way, so I thought somebody might like some info on going all the way to open wheel.
Price: Very affordable buy-in for any E9X M3 track person, around $14k-20k depending on spares and condition.
Vitals: 1100 pounds with fluids; just under 200hp; 8" slicks front, 10" slicks rear; dogring sequential gears with h pattern shifter.
Operating costs: Similar to E9X M3 (cheaper consumables plus trans work). Brakes are wayy less ($100 per rotor and $80-100 per axle for race pads); tires are less ($1k for brand new slicks, $200-300 for good take offs); transmission uses dogrings and is around $1k/year for maintenance, but if something failed on an out of warranty M3 that would be chump change for sure. Engines last several years between rebuilds, and price for rebuilds is $5k-8k depending on who you use (legal FM engines are $7k, but for DE's or FS you could run a cheaper build).
Driving dynamics: Freakin' awesome. You just use the clutch to get off pit lane, and shift the h pattern up and down without clutch. It has Hewland sequential gears, and shifts are almost DCT speed when done right. The downforce has to be felt to explain really, just seemingly infinite grip at high speed. The steering ratio is super fast compared to a street car so a quick flick of the wheel is all it takes to save slides. No ABS/DTC/anything, and it took me a bit to stop locking the skinny front tires under heavy braking.
Speed: Very very fast. I am still learning the car, but I know the records at VIR and Road Atlanta are 1:56 and 1:25 or so. The car has lots of pull until it gets going fast, and then it becomes obvious that the downforce comes with a high drag price.
Getting/keeping the thing running: Coming from a E92 M3 street/track car and E36 racecar, it is more of a pain to operate the FM. You have to remove the engine cover to fill the fuel cell, and you can't tell how much gas is in the thing due to the foam in it. It doesn't like to idle too long, and can take a few tries to start when cold. Definitely a bit of a PITA compared to a BMW based racecar that just takes a flip of a switch or turn of a key, and has functional fuel gauge etc. Overall worth it IMO, but this is the biggest downside to FM to me, that it is kind of a pain to keep the fuel cell topped off etc. 10 gallon cell lasts about 45 minutes of track time (burns down to 2 gal and then begins to starve).
Side note: I was really sore from driving the car the first time. Between the lack of any aids (no power steering) and the very high cornering forces, it is a serious upper body work out. I'm sure that'll be less of an issue with more seat time.
Overall I'm very glad I made the plunge, it is one thing to read my words on the internet, but driving it is just fantastic. The price is so low it barely cost me more than my mods on my M3, and now I have at most a $15k bill if I smash a wall and I'm going much much faster. Come join the FM party!
My best at Barber on street tires in my M3 was a 1:47-48, and I did a 1:34 in the FM my first weekend out. Not that they're competitors obviously. I still have and love my M3, but for those of you considering full blown racecars, I figured a review might help you decide.