I haven't finished my swap yet, but I do have a 6.1L Hemi sitting on a stand, and Megasquirt 3 ECM in a drawer in the living room, so I have done A LOT of research, and have put my money where my mouth is, so to speak.
First Thought: The old rule was that a carbureted motor would make more peak HP but injected motor might make as much power under the curve and be more streetable. Personally, I think with modern sequential port injection and the right tuning those days are largely gone. The atomization of fuel from the carb might cool the intake charge slightly and bring the HP numbers up, but EFI has the benefit of not having an air restriction on the intake. Basically carbs need a pressure drop across them in order for fuel to be drawn into the motor. Thus, ALL carbs are a restriction on the intake to some degree. EFI doesn't have this disadvantage, so while some guys are running 650 CFM or 750 CFM carbs, I am able to easily run an 1100 CFM throttle body and have BETTER throttle response. Thus, the days of carbs having a large HP advantage over EFI are history.
Second Thought: Cams, yes if you are running the factory ECM you really need to choose your camshaft carefully, as modern EFI systems either use a MAF or MAP sensors that try to determine the actual amount of air going into the engine. HOWEVER, if you are running a fully programmable aftermarket ECM you can engage an Alpha-N mode. This mode basically turns off the MAP sensor and the ECM simply uses air temp, water temp, RPM and throttle position to determine how much fuel to send to the engine. Obviously tuning in this situation is much more difficult, but for those running radical cams, or Individual Throttle Bodies, this might be the best way to tune the engine. So you can have a really radical cam and fuel injection, but just like a carb, it might be more difficult to get the tune just right.
Third Thought: I have been a proponent of fuel injection from day one. That being said, getting a modern fuel injected hemi to run in an A-Body can be a challenge, particularly if you use the factory ECM. Some people have no problem, they buy or modify a harness, put the motor in the car and drive the snot out of it happier than a pig in ****.
Others have error codes that prop up, and still other end up for some unknown reason in limp mode. I still don't know anyone who has gotten an 2010 5.7 or later motor running in A-Body with the factory ECM, though I could be wrong. Which is too bad because the 09 and later 5.7 heads are worth about 30-40 CFM over the 03-08 5.7 Heads and flow nearly equal to the 6.1L Heads.
Even those who go with the FAST, Megasquirt, or AEM systems have their own learning curve to deal with. Tuning can be a real challenge particularly if you've never tuned a car with a laptop. On another A-Body website a guy who installed a FAST system ended up spending about 2K to 3K just to get the system dialed in, though that did include quite a bit of dyno time.
Fourth: I won't say some people need to lighten up. Why? Because every person I've ever told to "lighten up," has simply gotten even more pissed off at me. But I will say this, I've learned so much from this and a few other websites that even with the occasional name calling it is well worth the effort. For example, I've seen the full page ads for some Hemi parts. There were lots of good articles about how cool their parts were in all the mopar magazines. Then low and behold I come on a few boards like FABO and get the real story. Parts that don't fit. Parts that need to be returned. Companies that don't stand behind their product.
Fifth: I would like to see some deliberate collection of specific instructions to help people with the swap. For example, for Megasquirt your engine profile, your tune, is a .msq file. I'd like to see some of these shared. Not that it would be the exact tune you'd need, but it might be close enough to get someone going. I'd like to see some FAST tunes shared as well, and some AEMs. For the carb guys I'd like to see some specific recommendations on jetting, metering rods, and accelerator pump sizing. Why because this engine swap is hard, and the magazines don't give us information other than a sales brochure for solution that only costs X amount of dollars.
Sixth: Why do the swap. I've seen people say, "I can get just as much power out of a small block." I'm sure you can, but when I'm done I'll have a 500HP motor that will idle like a grandmas car; while, a 500 HP small block mopar is a beast. Oh, yeah, and I can say, it's got a hemi.
Regards,
Joe Dokes
