Diamante VRX Intake Manifold tips + before and after pics!

[onlyhuman]

I had found a Diamante VRX (2002 w/o traction control) intake manifold at a junk yard for $45. I thought it would be a fun project to clean up and install on my 2003 Stratus RT. I started by sanding and polishing the outside. This was very easy but time consuming. Then I cleaned up the inside and did a mild P&P. I also stripped the paint from the valve cover and polished that. This mod was well worth the $45 and time invested. The throttle response is much better and the car has a more throaty tone! It also looks amazing compared to stock!

Before:

After:

The junk yard find:

Stock vs VRX:


For the most part I followed the instructions and tips I found on these forums. Great information, thanks to everyone who shared their experience! The install went pretty smooth. There were some issues but I enjoy a good challenge.

As you should already know, the EGR tube will not align with the new VRX plenum. It is off by a few inches. I didn’t want to lose the EGR or mess with any SES issues, so I needed to make it work. I found a great tip from White Knight here, worked great! EGR tube is now a perfect fit.
egr tube won't fit! suggestions?

I replaced out all the vacuum hose with new. If you do this there is one stock hose you will need to retain. The hose coming from the vacuum control valve has a white stripe. This hose has a restrictor in the line which is required. All of the other lines can be replaced without any problem.

The rear brackets will no longer be used. I removed the passenger side, but left the drivers side attached. I was able to bend it back a few inches to make clearance for the EGR valve. This was easier than removing and cutting the bracket.

After the install the engine would not idle properly, but ran normal at higher RPM’s. I picked up a hand vacuum gauge and discovered there was a slight vacuum (3Hg) at the EGR valve on idle (should be none). This was opening the EGR valve at idle and causing the rough idle. If I disconnected the EGR hose, the engine ran normal. I tested all the valves and lines, everything was ok. Then I pulled the throttle body and found the problem. The VRX plenum will bolt up to your stock throttle body just fine. However, the throat is much larger. The stock TB has some vacuum passage ways that need to be sealed. The VRX plenum did not cover the gasket enough to make the proper seal. Here is what I did to fix. I found a machine shop with a band saw and cut the ½” lip off my original intake manifold opening. I used this as a spacer. Drilled the holes out and cleaned it up. This bolted between the TB and intake manifold (using two gaskets). It sealed the passage ways and bolted up just fine (needed to buy longer TB bolts). Vacuum fixed and EGR is working normally.







I would definitely recommend replacing all gaskets (upper and lower intake manifold, EGR, and throttle body).