i was going to replace my crappy old radiator cap with all the other stuf i gotta get done on my car, i went to buy a new one today and seen that there are 13psi and 16psi caps.....what one do i need? why are there different ones?
To answer your question about why there are different ones: Water boils at 212 degrees F. and for every one pound of pressure you put it under it raises the boiling point about 7 degrees. So a 13 pound cap will raise the boiling point of the water to around 300 degrees.
I dont think it is that high. I think its about 3 degrees per pound but I need to check on that. With all the mods you have done to your engine go with the 16, it will give you the best performance.
keep in mind that the higher pressure cap will stress your cooling system more and may acquire a leak sooner.
Whenver going to higher rated caps ... make sure your heater core hoses and heater core itself is in decent enough shape to support the extra pressure. Wouldn't want a burst heater core ruining your carpet and your day ...
