Hi I'm new to the forum and have a few questions


i recently swapped the 5.3 for a 6.0 in my '13 sierra RCSB 6L80e 3.42's and so far I love it but I feel as if its lacking its dead stock aside from a custom tune stock 2.75" exhaust from the 5.3 stock intake from the 5.3, the 6.0 is untouched but I wanted to know some things before I go modding

first I'm in desperate need of a stock 3.5" 6.0/6.2 exhaust from the Y pipe back

1-3/4 or 1-7/8 LT headers I'm going to be boring out the motor this spring to 4.065 for a 6.2CI if it matters but heard the 1-7/8 rob torque down low on small cube motors. Also want to buy factory pistons

VVT cam I have not put much thought into this just that I want to keep the VVT

it's my daily driver but I'm thinking 4.30 () or 4.11 I'm gonna be running max 30" wheels with minimum 28" anybody have this combo and can tell me real world gas milage on 22" reps with 30" tires I know the difference between 4.11 and 4.30 is like 200RPM in 6th at 65


I had my first race against a intake/diablo tuned 2012 R/T with the 6 speed factory stall/4.11 gears and out of 6 races from a 25 hit I won once with roughly 200-250 LBS in the bed but he only beat me by a fender didn't get to race from a dig unfortunately

 

Go 1 7/8 on headers with a ORY and never look back. Get you a nice stall converter and some 4:10's or 4:56's with big *** heavy wheels and a nice dyno tune and it will be a completely different truck. Those heavy *** wheels are a large part of your dead off the line. Put a set of 17s on and she'll walk and talk

You'll never find a stock 6.2 catback they are made out of unobtainium. I have a magnaflow 15204 3.5 6.2 sierra denali catback for sale in the want ads depending on how bad you want 3.5 setup. It has less than a 1000 miles on it. The 5.3 Y pipe is same save for the connection point and any competent exhaust shop can make the 3 to 3.5 connection. It's not a direct fit but manageable.

 

If your keeping the motor stock other than wanting a 6.2 put your money elsewhere. 01WS6 is on point.

 

do you know if the 2500 6.0 muffler is the same cause I've found a few of those cat backs for a good price and I love the way 6.2 trucks sound with longtubes ORY and stock cat back.


right now its on stock 17" steelies with factory 245/70 tires but I'll be buying some CK156's reps in 22" with 305/45 on all 4 corners and I know they're VERY HEAVY but even now I'm having a hard time breaking the tires loose it does a burnout no problem but i can't even chirp second and my rear tires are BALD like smooth

 

Tune is set up so you can't do a burnout it's not motor it's way gm intended it to act.

 

Good luck chirping second in anything thats basically stock!!

 

It has a custom tune from Colorado unlimited performance but I'm starting to suspect that he put a pretty mild tune on it, he didn't seem very interested in doing it when I had him unlock the ECM but I know for sure he removed all the tourque management I think he maxed my shift pressure and adjusted the timing not sure how much but it's tuned for 91Octane

 

1 You need torque managment or you will trash transmission it's there for a reason it just needs to be reduced.
2.You don't want to max out the line pressure or it will destroy a trans also.

There are parameters that you need to disable in the tune to allow the truck to do a burnout but it is still limited in it'a ability because the trucks stabilitrack system system steps in and applys the brakes in a attempt to bring the vehicle back under control. You have to kill power to the ABS unit to get a unihibited set of smoky tires.

Chirping second on a 6L80 is a death sentence the chirp doesn't come from making power it comes from the tranny binding up between shifts. Take that truck to the nearest forum sponsor you can find and figure out exactly what they did. They may have done a great job or they may have turned it into a ticking grenade.