Let me cover the basics.
2003 silverado RCSB 5.3 with 3:73 rears and 4l60e 22" wheels 285/40-22 tires
Had a shop swap in a Truck Norris cam, new springs, new plugs, new intake gaskets, etc. Then got it tuned. Ran it on a dragy and it ran a 16.2 1/4 mile, I said well its just the lack of a stall converter causing the slowness.
Week after I installed longtubes with an offroad y pipe, and a 3" flowmaster exhaust, also a S&B Cold air intake. Got it retuned and it still runs a 16.2 1/4 mile.
My son took it out this weekend and raced a friend of his, 2012 sierra extended cab short bed. Bone stock 5.3 with 3:42 rears. From a dig or a roll he lost by quite a bit.
In stock form my truck is quicker than it is now, I am completely lost as to what would cause this.
Help me out here, I'm not sure where to start.

 

So when you say you got it tuned, did they dyno tune it or just get it to idle and send you on your way?
Check fuel pressure?
check engine light on?
Not sure where your located but a 16.2 is terribly slow for that setup in stock form if your close to sea level.

 

How much power did the dyno say it made?

 

Just street tune, no dyno time unfortunately. Same truck as mine, same cam same tuner minus headers and exhaust ram a 14.5. So that kinda makes me wonder what the difference is on this one. Could my cam be a tooth off on timing?

 

Hard to say without tearing it apart. Without power figures you have no idea what is happening in the power curve.

Did he atleast have a wideband oxygen on this street tune?

Does it have enough injector headroom? Because the stockers are way too small for an engine that can spin to 6300-6400 rpm with that camhaft.

 

Nope, no wideband. Injectors are stock, I’ll get a log run on it I guess and see what it looks like. Sure sucks spending money to make it slower.

 

Find a new tuner. Any tuner that is worth a damn would use a wideband on a cammed engine. How can anyone tune without knowing what the real time air fuel ratio is?

Plus it has stock injectors, makes it even worse.

I've been using HP Tuners for probably 11 years now, this is the stuff that annoys me. It's not all your fault but holy cow why can't people who offer a tuning service at least do it the proper way.

 

If it has flex fuel injectors it may be OK? Mostly this though ^

 

I see it everyday. thats why i asked if it was a tune to get it to idle. Some these tooners charge too much for a idle only tune haha.

 

What is it shifting at? What was the mph in the quarter mile?