I can't find the formulas right now. but about what boost level do the stock injectors begin to give up (80% duty cycle).

I'm running larget disk the spring that came inside the S-FMU ( I think thats the larger softer one) and hitting about 9.5psi . I got a chance to data log the car and found out I'm running lean up top.

I'm nice and rich on the bottom but up top I lean out. Should I change springs to make the fuel curve steeper?

IMO, i wouldn't run over 8 psi on the stockers. But if you must, you should be using the shorter, dark spring inside the SFMU. This spring lets the SFMU run a bit steeper rise rate, and should give a little more fuel up top. If that doesnt work, raise up your base fuel pressure like 5 psi. I suggest you run some 30# injectors past 8 psi.

Totally agree.

To get only 200hp, at 80% duty cycle, and 110 psi fuel pressure, you'd need 248cc/min injectors.

30# or 310cc injectors solve the 8-12 psi problem VERY nicely. You can keep your stock HRC kit, stock motor, and make some power.

(310cc + 80%duty + 110psi = 250hp)

http://www.rceng.com/technical.htm

well, I'm built with 8.8 to one comp. JE pistons I'm only stage one turbo set-up tho. Damn wastegate doesn't seem to be working right.

Would it hurt to try and lower my fuel pressure and run my 440's stage one just to be safe?