1==== plugs yea they do improve...but no major effect on such a lil engine
2====wies r kind of differant allow mximum current to pass through to the apsrk plugs....so without them no use of plugs
3====air intake...put come improvements...but cant be runned if cng working...as AIR INTAKE needs maximum air..and CNG needs minimum air
$...exhaust system====u need to have exhaust tip plus piping plus headers..then u will lots of change in yr car.....but for sure hell of noise....
no engine worries..actually when u get stufff like these u run engine very fast and that comes out to be a problam
1===plugs ranging from 1800-3000
2===wiring u will get in between 2000-2500
3===air intake===around 2500
4===exhaust tip===from 1500 -3500 depands what u want
5===piping---2.0 inch from 3000-6000 depands from where u do
6===headers ====around 3000
all coted in rupeees....