My cossie has the usuall stage 3 conversion:3 bar map sensor,803 green injectors,program from motorsport dev.(stu),and i have adjust the actuator to hold 22 psi,and also 044 fuel pump.
Which spark plug is more suitable for 22 to 24 psi???????I have listen good words for the iridioum denso Ik31 but some saying its better when there is a group a coil
Now i have the champion qc57 but i am not very satisfy when the engine is cold
Is it worth to try Ik31???

 

i use the IK27 in mine with similar spec to yours but i'm not just sure either

 

hello,you can test the denso platinum with this code: K24 PR -ZU,i'm very happy with these to my engine,works perfect when it's cold,and i run msd closed loop chip with 1.9peak and 1.58hold boost,i hope this help.

 

IK27

 

Imo IK31 are too cold, IK27 are a lot better, the QC57 foul very easily from what I've seen.
The IK will work a little better with a group a or similar coil, be smoother low down I found, idle slightly better, pull very slightly better low down as well is what I found.
tabetha