Yeah me and my friend just intalled a HRC stage 2 with a 12:1 fmu and fuel pressure psi is at 48 which is healthy i suppose and when i hook the boost gauge up at full boost it reads 5 psi. Now my problem is when I floor it at low rpm it jerks and feels like its running real lean at low rpm. Stock injectors and everything except what I told you. What do I do? Or whats the problem?

HRC Fuel Mapper hooked up? Even if it is, it's likely to be working incorrectly.

Any boost transition problems quickly rise the suspicions of a faulty Fuel Mapper. Get the Missing Link instead. (MANY POSTS on that and where to buy...use Search!)

Ok Im going to buy a missing link then, that should solve my problems? I also thought my boost guage would read 7 instead of 5 when i hooked it up to a vacuum line whats the deal with that?

>Ok Im going to buy a missing link then, that should solve my
>problems? I also thought my boost guage would read 7 instead
>of 5 when i hooked it up to a vacuum line whats the deal with
>that?


Hmmm if you got the stage 2 setup from HRC then I think they have the 9lb wastegate spring which should result in 7 psi of boost. As far as your leanness (is that a word?) at low RPMs, you car should run lean if you're in lower RPMs cruising and not giving it much gas (Ex. staying in 4th or 5th going 30mph) but not to the point as to where the car is struggling. These other guys could probably help you with fuel problems better than I ever could.