Quote Originally Posted by SuperSport View Post
What exactly does an HV3 do? I know you place it in your UIM, and you get some power increase. Ive read that you can get them from ZZP, but Ive heard ZZP sucks, so where would be a good place to get one? Would I need to tune my PCM if I get an HV3? Does the HV3 work with the revised Dorman UIM?
Lol.. All these replies, and very few straight answers.

#1 Lets your engine breath better at high RPMs
#2 In my experience the HV3 is a high quality product, it is designed well and fits like a glove. And if you want a new one, ZZP is the only place.
#3 You don’t need a PCM tune, although higher shift points compliment this mod.
#4 Sorry, I have no idea.

I have run with an HV3 for like 6 months now. I’m very happy with it, the change is most noticeable while passing people at highway speeds. It is definitely the best mod I have done to my engine.