ZEx shots are rated to flywheel!!!

[klde94]

i know that zex kits are rated to flywheel horsepower! so a 50 shot is actually going to be more of a 35 shot right? so for example if i want to run a true 55 shot can i throw the 75 shot jettings in and expect somewhere close to 50 WHP?? because i installed it in my car and the 55 shot is horribly weaker than my other friends NX kit at same shot!! so is it safe to throw in a 75 shot jetting and expect it to perform like a 55 shot,, and for a true 75 shot just throw in a 100 shot jettings..? please help!

[amick]

Yes ZEX rates our shots at approximate FWHP and NX rates theirs at RWHP. The biggest differance is they simply use a larger jet size for the same suggested HP shot. Your assumption about going up one size in jetting is about right if you are trying to get RWHP numbers. It can vary depending on setup and what individual combination you have. Typically you will see a 15-20% drivetrain loss. Most dyno results for ZEX kits, I have seen tested by others, tend to make a little more to the wheels than their flywheel rating would suggest but less to the wheels than the given HP for the shot. Also if your kit does not feel like it is making good power you may want to check your bottle pressure. We suggest between 900-1100psi. A cold bottle will have low pressure and will not give the suggested HP numbers.

[bluzman2004]

I wouldn't think there would be any other way to rate a nitrous system but to the flywheel. There would have to be a rating sheet a mile long with every type of transmission, differential, flywheel weight, gearing, tire size, and on and on to rate them at the real wheel (or god forbid the front). I'v seen drivetrain losses from 10 to 30 percent on the chassis dyno.