I read that the ideal compression for my 420a should be 9.6:1. So, when I buy pistons for my car, they should be 9.6:1, correct? Or is there a better set up for nitrous? I want to buy a zex kit and run the 55 shot on stock internals then by pistons and rods and run the 75 shot. Also can you do a bigger shot on the zex kits than a 75 shot? Thanx

its all in how well you tune it (air/fuel/spark)

If I were you I would stick with stock 9.6 or go with 10.5 compression with the 10.5 your gonna have atleast a better fuel pump. and will probably have to run mid-higer grade gasoline

If it was me and I was going to build my own motor I would use 10.5 or maybe even higher cause there is no sense in just building a stock motor again, Id go crazy muuhhhaaaaaa. id upgrade fuel system to more along the lines of a turbo car, (better/bigger fuel pump, larger injectors or the 8 injector setup with the extra 4 kicking on with a big shot of nitrous

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

ok the higher the compression, the better for nitrous right? Ok, I am not that good about internal motor stuff again. As for the fuel syste,, I plan on upgrading the pump, injectors, rail, get a adjustable fpr and maybe a safc. So, 10.5:1 would be better? Thanx, another other suggestions or tips guys?

how much of a shot are you going to be running?
if above 150 shot might want to ceramic coat the pistons to be safe
10.5:1 would be optimal

you should get a EGT and a/f guage to monitor the system and use a wet system

i have a fuel rail that has a port on it for fuel to a nitrous system. might be nice for ya to have.

Bill

You can have it cheap, fast or good. Pick any two.

If you want it cheap and fast, it's not going to be good.
If you want it cheap and good, it's not going to be fast.
If you want it good and fast, it's not going to be cheap.