I agree that mail-order canned tunes are normally sub-par. They're the limp-home mode of LS performance. This isn't to say the canned tunes aren't viable and not just fine out of the box so-to-speak. Sure, they can get you pretty close to optimum based on the parameters given to the tuner, but it's always best to be able to tweak and dial one in that little bit extra for that particular engine to nail it. It's really nuance at that point. It's like trying to fix someone else's problem on this forum long distance. Usually not enough data points to get it exact the first time.
Keep in mind that the newest G-body is over 30 years old. And the SBO technology the V8's had is nearly 60. And the proverbial pre-LT/LS platformed SBC is nearly 70. It's like having one of those Butabi brothers cell phones today (Night at the Roxbury movie reference).
I'm pretty impressed with people that can build those engines to make lots of power while still understanding the limitations of the "old-tech". While the LS has its drawbacks as all engines do, pound for pound they pack a punch like no other as long as you know the keys to getting the power out of them. No matter how you try, you can't beat the EFI/DI systems on the newer engines compared with a Quadrajet. Sure, a Q-jet is a great carb when it's dialed in, but it's still a carb. And if you DO find an example, it's going to be an outlier. What may take you a weekend "dialing in" a Q-jet, you can do in a matter of minutes with the computer programs.
I'm not a fan of LS swaps, but I get it. It's hot-rodding. I've had my run of doing mods and hacking and cutting wires, etc., on cars I modified and tweaked. Color me unimpressed when someone tosses up another LS swap thread. (yawn) I just don't care. "But I get a gajillion miles per gallon....I run the quarter in 12 seconds....blah blah". Go back a couple of sentences...I just don't care. I didn't buy any of my cars for gas mileage, nor I could give 2 craps about 12 second quarters any more. BUT- the LS engines are more than capable, even with a mail-order tune. For a pig, my ZL1 handles extremely well and has enough power to get my jollies as is. While it's true GM left a lot of performance on the table with their "make everyone happy tunes", it's no different than what they always did. Tune for the masses. And *wink wink-nod* to the guys tweaking and pulling out all the power on these engines. Where do you think a lot of the performance information originates? GM tunes there engines in all sorts of variations during development, so they know what it takes. Leak out the right information to certain people and the power-hungry customers open up that GMPP catalog and start ordering!
I won't do a swap to any of my cars, but if you get wood over it, do it. I own LS engines, but they're in GMC's and Chevrolets because that's how they came. I'm nostalgic. I don't care. What I do find hilarious is that somehow an LS swap makes your car automatically worth more...that should be very scary. Especially if you got the engine for $50. The G-bodies I look at and would want to buy don't have LS associated with the car unless it was a Monte LS or something. I find it even funnier when some people have swapped ONE LS engine in their car and struggled with it for the longest time and now they're somehow considering themselves experts and start trashing old-tech. To those types, I say f**k off.
EFI tuning can take much longer than a few minutes or even a weekend. A LS ECM has thousands of tables for a tuner to go through. Its easy enough to just improve max top end power for good dyno results, but maximizing the entire powerband including idle and cold starts under different weather conditions is not so easy. It takes OEMs thousands of hours to develop the stock ECM tunes for that. Even the self learning EFI can take months to develop a decent tune. Either way, good engine tuning takes patience.
