So as the title states I'm already tuned well on my 305cc injectors. I'm picking up some RX7 injectors and want to know what the easiest way to re-tune the car would be.

 

I'd say, figure out what your current required fuel setting is, and change that number to whatever it would be for a 550. I used 13.2 for my stock injectors on my 99 and when I put my 460's in I use 6.9. I bet if you searched or took a poll of what others who use 550's run for their required fuel, you could find the number. By changin it, it won't give you a perfect tune, you'll still have to VEanalyze your fuel table, but you'll be close.

 

Thanks, sounds good. Ill give that a shot

 

Hey fastrax, im using the 305 supra's and want to know your req fuel? I have mine set at 10.1 and think it may be a tad too much.

 

req fuel is simple to set... use the built in calculator LOL. if you dont do it that way then it skews your entire map, and you'll have to do a full retune if you switch injector sizes.

 

very easy using built in calculator. I went from 440s to 750s. Used calculator and started fine. Then used turnerstudio autoune to tune the idle.