MO POWR

I have a 2011 GS. I just installed some fresh take off NPP's. I am looking at the NPP in a box and need some help. I have searched this site and there are several posts covering this, however not the definitive answers I was hoping for.

1. In all the install pics all I see is one nipple on the control box for the vacuum, but if I am thinking right you have one line coming from the intake to the box and another line from the box to the mufflers.? Anyone have better pics of the box showing how the vacuum lines connect?

2. Some of the directions say the LS3 has to use the twist off nipple at the back of the intake instead of the EZ tap at the front. Is this the case on the 2011 GS?

3. Where is the best place to purchase the NPP in a box and are they all the same or are some better than others.

4. Lastly, Does anyone else have a install write up with pics instead of the same one that's all over CF. The one I'm seeing is good it just leaves some things to question. Like how best to run the line off the back of the intake to the rear? Also a actual pic with both Vacuum lines hooked up to the box in the storage well.

Thanks in advance for your help.

StKnoWhere

1) The nipple goes to the vacuum line connected at the engine, there is a smaller tube that comes out of the same side of the box and connects to a T that connects the vacuum actuators on the mufflers.

2) The rear vacuum tap can be used and there is a LS3 version of EZ Tap.

3) Several forum vendors sell NPP in a box, got mine from Gene @ GM Parts.

4) Routing the line becomes relatively obvious once you start but easiest done while installing the mufflers. I didn't so rather than running it in the tunnel, I ran mine through the rocker panel.

haljensen

Don't forget Sunset Orange and his Exhaust Commander, more options and similar prices.

MO POWR

Thanks. Has anyone come up with a way to install the NPP in a box without drilling any holes in the car?

Gene Culley

Thanks for the referral. I would be happy to help you out with it.

StKnoWhere

There is a method that goes between the rear of the hatch and the rear panel, pretty much the same location as the OEM module that puts holes in a hidden area. Checkout this Alternate Location for NPP Retrofit Box thread by TopFuel which includes some no drill options lower in the thread.

I installed mine under the hood (no drilling) but was informed by thevendor the receiver will not survive long at under the hood temperatures so I plan to move it.

Velcro'd and wedged between the fender and fuse box, I left all the wire since I plan to move it to a cooler, more protected location.




Tapped into the wiper fuse under the hood. You need to notch the corner of the fuse box to make room for the wire to exit. Beware the stud in the lower left corner is +12 from the battery so be sure to disconnect the battery before working in this area.