RandyM, can you tell a difference? I just don't want to "waste" my money!!! Plus trying to decide how difficult it is and what extra parts I need for the swap. Thanks. Anyway, there is a Youtube video that a guy has done to show the swap. Not sure why that link was removed as well.
Difficult? Not particularly.
- The old manifold comes out pretty easily - loosen all bolts, unhook the MAP sensor (passenger side rear of the intake), unhook the throttle bodies (no need to unplug them, just lay them aside), and pull all of the vacuum lines (one to the brake booster that attaches to the driver's side rear of the intake, the u-shaped mess underneath behind the throttle bodies that connects to the EVAP system, and the crankcase vent that goes to the passenger side front of the manifold)
- You won't be reusing the Gen 4 intake manifold bolts - they aren't the right length. If you buy a Gen 5 manifold from someone second-hand, make sure it comes with the bolts.
- The MAP sensor is a direct swap over to the Gen 5 manifold - unbolt it from the Gen 4 manifold and put it on the Gen 5 as-is
- The throttle bodies are a direct swap - the 2013-2014 Vipers used the same plastic throttle bodies that came on all '08-'10 Vipers.
- You'll have to do something with the torque/compression limiters since the Gen 4 heads aren't machined to accept them. You can either cut them yourself (I'd recommend doing it at an angle), or save yourself some time by buying the pre-made ones from Doug Shelby Engineering (which is what I did)
- You'll also have to do something with the crankcase vent - the stock Gen 4 setup comes out of the passenger side valve cover, takes an immediate 90 degree turn, and goes pretty much straight into the side of the Gen 4 intake. The Gen 5 manifold connection point for this is underneath - behind where the throttle bodies mount. This is where you'll have to be creative, but it depends on whether or not you already have an oil catch can. I did, so I had to go the custom route. There are lots of pre-formed rubber hoses out there with tight 90 degree bends...I ended up using one to make my new connection. Using the entire Gen 5 PCV hose setup isn't really an option unfortunately - they changed where the PCV valve comes out of the valve cover on the Gen 5s (it comes out of the side instead of out the front).
- I torqued the intake manifold bolts to 75 in-lbs - I think the book calls for 95 in-lbs, but I didn't want to take the chance of cracking the manifold. You'll have to retighten the bolts after each of the first few heat cycles, but that isn't hard to do.
- Make sure all vacuum lines are fully seated - I secured mine with zip ties. The ones to pay special attention to are the ones that make the u-shaped configuration behind the throttle bodies on the underside of the intake...those can get knocked loose easily and cause a vacuum leak.
- Tuning shouldn't be required...mine ran a bit richer at WOT after the manifold swap, but it wasn't a massive difference.
Bottom line: the hard parts are the compression limiters, which can be solved by sending Doug Shelby some money or by whipping out a Dremel, and the crankcase vent connection. The rest is just right-tighty, lefty loosey.
The real question: is it worth it?
Performance wise is a little more iffy. Will you notice 15-20 extra HP on top of an already 600 HP engine? Probably not. Every little bit adds up, but it isn't a night and day difference by any stretch of the imagination.
