Ok, so its safe to say i don't know much about dyno tuning or hand held tuners in general. I'm just wondering if these handheld tuners actually live up to their hp claims or if its just another "oooo 15 hp for a CAI issue" haha. So basically i understand tuning at a dyno yields much better results, but lets say i feel like using the built in tunes for a little while..... like a 93 octane tune.....will i really be gaining 15-20 hp?
2002 4.6L gt, automatic.It's stock except for slp catback...getting 4.10 gears soon.

Also, will my automatic shifts improve from the stock tune? I'll eventually have it dynoed, but i want to buy some **** first haha.

 

Iam not sure about making your tranny shift better? ive herd people say it helps, but i really doubt you'll make 20 xtra horses with a handheld tuner?

 

with a tuner it all depends on what u have on the car as fas as boltons go
if ur completly stock or not going to see those HP #s but say u have exhaust CAI throtle Body and other stuff
u can get those #s
the More Bolt ons u have the more power u will get and yes it will adjust your shift firmness quite a bit
programers are something you buy once u have put in a considerable amount of "bolt ons"

 

nope u wont get 20hp from the tuner ive got...

BBK 56mm Throttle Body, Aluminum Driveshaft, 1/2" Intake Manifold Spacer, 180 Degree Thermostat, SCT XCal 3 Tuner , Custom Port and Polish Upper Intake Manifold, BBK Underdrive Pulley Kit, Aftermarket Cold Air Intake, 3" Exhaust Tips, PYPES Stainless 2.5" True Dual Converter Back, w/o Cats, Pypes Street Pro Mufflers, Screamin Demon Ignition Coil, 10mm Livewire Spark Plug Wires (Red)

and i think ive only gained like 20hp from all of these mods (and that is to the crank) cuz at http://www.supersixmotorsports.com/ on the left hand side there is a horsepower calculator and i entered my weight of my car with me in it and my ET and it gave me 170hp to the flywheel (stock for me was 150hp or 145hp)

 

Well, that's assuming a correct ET and not driver error! jk The best way to tell is to go run it on a dyno, even if it is just for a/f ratio, do a before and after. A/F ratio pulls are only like $35

 

YA ummmm that is with a 3.8L
now dont get me wrong I know you can make serious Poer out of a v6
but ur gonna get more Hp gains out of a GT

 

you aren't going to get 20hp to the wheels just with a tune. When I had my mach 1 it had a catback, mid pipe, CAI and a custom dyno tune and the custom dyno tune was good for about 10rwhp and that's with a 4v engine. So if you can get between 5-10 out of a tune you'll be doing pretty good.

I've never had an automatic, but the tuner can adjust your shift points, which will help. Also, when you get 4:10 gears the hand held can adjust to your speedo to the gears.

I've said this a million times, but here it goes. Find out what program your local tuner uses before buying a hand held tuner. If the tuner uses Diablo and you buy SCT or vice versa you are going to be PISSED off. This happened to me, but thankfully I live in an area where I could find another shop, but it wasn't the one I wanted to deal with.

 

My 99GT with bolt-ons Full exhaust, TB, CAI, u/d pulleys and 3:73 gears made 237hp! w/a custom dyno tune Diablo chip it made 250hp. As you can tell by other posts, far from the easy 20hp they advertise? It sounds disappointing but its reality. They are useful for other things as mentioned above though, Adjusting shifts on an auto, recalibrating speedo, injector sizes etc;