[HUMMERcustoms.com/TAZ]

Ken
You, PARAGON, and Phil have hit the nail on the head with the tuning and octane of fuel used.
The over the counter programers leave so much HP and torque on the table You could gain easily 50 HP or torque with wideband tuning and really more. The superchips programmer that comes with Radix SC leaves about 40 HP on the table as a cushion, so Magnuson does not want the average guy who is a good mechanic and that will do the install himself to get full benefit of SC so that in case He puts 87 in instead of 91 or 93 He is not going to do damage until He can add octane booster to cover mistake or just burn till ready to go back in tank with 91. Yet handhelds work because the factory also leaves even a greater amount on the table. I have been researching wideband and talking to Allen Nelson and HP Tuning and what the wideband does is as Ken explained. You can with a very well written program go and get all the HP etc. left by other tuner programs safely because You are getting more acurate numbers in detail. You decide how much power You leave for a cushion. The handhelds are conservative because they do not want anyone going out and blowing up an engine and getting blamed for it. Allen can do a PCM upgrade that will get some of HP on the table left by handhelds but, He as a good business man does not get overly aggresive just as anyone else who would wideband tune Your rig hold back for safety and liability. Yet Allen does push the outer limits more than others to get more. He knows what he is doing and has already set limits that He will not go beyond because He is not there everyday to watch and see what you are doing right or wrong. To really do it right You have to go deep into the PCM and tune each little point that handhelds just tune in general. Ken You gave as good an explination as could be given about the tuning. Allen recommends HP Tuning and said it is so good most anyone can take it with a learning curve in consideration, study up on it and learn to program better than handhelds. He said the more You use it the better you get it.
HP Tuning will soon have their software with a 3 bar density ability that will remove MAF from the intake system completely. I mean figuratively as well as physically take it off and not use it. But, it requires time to learn it and safely do that and get all that the engine and ignition will deliver. Honestly unless You are racing or just like to play with this stuff most do not need to tune to such detail. I feel that most just do not need more than a handheld will do. Wideband is really for a person to just be able to know and learn more about what the setup is doing with forced induction. You could take wideband and add nothing to Your engine setup and tune it to run better with all stock setup. This is what the handheld is doing, you would just be more aggresive with wideband. You would just be limited to how much you can do by having stock engine components. If You shop around the handheld can be gotten for as little as $325 where as the software will run $1000 plus depending on the add ons You put with it.

Phil on the octane and programers You are on the money. I have mentioned it several times but, You reinterated My points made before about handhelds and octane. I have been running handhelds on 87 octane on both My Silverado since 1999 and Mall Queen since last 10/04 but with programmer set at the most high performance setting. There are 2 reasons a person can get away with this which You and Ken covered. The programmers are not overly aggresive and more importantly the octane You see posted on the pump is a minimum rating it can be at any given time that an inspector from the state comes by and does a test to see if retailers are within the guide lines. I have a friend who is a Chemical engineer with a big oil company and He said 87 could be any number above that as when gas sets it loses it's rating value or ability to prevent detonation. He said because of the time it is produced and delivered it usually starts out higher. The lower the octane the more volatile it is and the lower the octane is, the greater power it in theory will generate. This is contrary to what most think octane is about. Higher octane in itself will not give you more power. It just let's You advance timing and gain HP that way without detonation. But, the lower the octane is the more unstable it is. This idea is what causes it to detonate just by the pressure put on the air/fuel mix in chamber as piston comes up to top, compress and igniting it before you even add spark. The lower the octane You can run and not get detonation the more power You can get from that explosion along with advancing the timing. A very tricky little dance or game to play is finding that limit and every engine can be different. The higher the octane the harder it is for it to ignite and thus You can advance timing for more power. But, again the more You can advance the timing and run lower octane the more power you will have but, if You do not do it gradually with software you can jump past that point of safety and BOOM. New engine.
Well guys you did a very good job explaining it all and all I can do here is back up what you have already explained with the indepth discussions I have had concerning this stuff.
Good info by You all.
TAZ