Squeezing Performance out of the 5.3L

I have a 2007 Avalanche Z71 4x4 5.3.
My goals were to gain 30 hp/lbtq under 3500 RPM for towing without hurting my MPG.

What I did . . .
- AirAid Cold Air Intake.
- Under drive/Overdrive pullies
- JBA shorty 1 5/8" headers.
- Small duration, 216/206 .585" lift, 115+4 camshaft.
- CompCams valve springs and pushrods.
- Dyno tune.

The end result . . .
- The Dyno tune resulted in 10 HP/LBSTQ across the power curve.
- The cold air intake (installed earlier) netted zero.
- The shorty headers, pullies, and camshaft gained me 10 HP/LBTQ under 3500 RPM and 40 HP/LBTQ above 3500 RPM.
- Sadly, even after tuning, I lost 1 MPG around town and 4 MPG on the highway.

Recommendation: Don't go with a camshaft.  I had Patrick G. spec. the camshaft and even after showing him the results he was happy.  Somehow he believes my coming up short of the goal and losing MPG is a victory.  These camshaft guys know how to make power in the upper RPM levels, but not in the lower RPM levels that are practical for everyday use.  An exhaust system might help, but then there is increased noise.  What I would do next time is get a junk-yard 6.2 engine with the DoD and toss it instead of the 5.3  

Hey guys I have a 1999 GMC Sierra with a 5.3L. I have been wondering if you can put the LQ9's camshaft in without any re-programming needed, and if so how much horsepower will this most likely give me, and how bad would it hurt my mpg?  

its not going to do anything at all


if you want a really mild cam that won't need too much tuning, go with the z06 cam out of a vette

if anything, I'd probably go with just a tune, it'll feel like you just swapped out to a 6.0, hit up www.blackbearperformance.com  
2003 Chevy Silverado

you have a 4.8/5.3/6.0? you need: cold air intake, exhaust system and a tune, see my posts for more details!

to GTO_gregory - you'd definately benefit from proper gearing, and a proper tune  
2003 Chevy Silverado

you have a 4.8/5.3/6.0? you need: cold air intake, exhaust system and a tune, see my posts for more details!

Thanks thats what i was wanting to know.  

The GEN III engines are a great one to build, I'm boring mine to LS-1 bore size and with a Scat stroker 4.125" crank it will put it right up about 396 cid. Head porting is a good improvment, I did a basic flow improvement, not an all out port job and went from 216.6 cfm to 250.0 cfm flow on the intake @ .500" lift and 28" of water, and from 174.5 cfm to 192.3 cfm on the exhaust side. Not too bad for a stock head.
As for a tuning a 5.3L check out blackbearperformance.com they do a good job taking most of the torque limiter out of the computer, and power and mileage will come up.  

I have a 2006 5.3L Z-71 4x4 crew cab that I did a cam swap, 1.8 rockers, cold air intake, ported my TB, added MSD coil packs, added long-tube headers and custom tune to. I can honestly say that I am now producing about 360 hp (up from 295 factory) and I am getting noticeably better gas mileage than before I did anything to the engine.
I have a few suggestions for you:
I tried shorty headers and did not see much increase from the stock manifolds. Long tubes tend to generate a wider torque band which gets the vehicle moving. The cold air intake is great as long as you can accomodate with the right amount of fuel. If you did a dyno tune, they should have been able to adjust your air/fuel ratio to make the hp and the mpg. If they know what they are doing, it should work out great. If they don't, it will not. Possibly try another tuner and see where that gets you. Porting the TB is an easy FREE way to flow more air. There are several posts online that tell you how to do it. This will also help improve your mpg.
The camshaft you chose makes good power but might be too big for your needs. I have a 202/207 @ .050 with a .500/.507 lift cam and it does pretty well from just off the line to 6000 rpms. I can say that either way, something doesn't seems right. The combo you have should make good power w/o too much effecting your fuel consumption.
The other obstical might be gearing. I have a 4.10 gear and have to drive 65 on the highway to keep the rpms at 2000 and get any kind of mpg. If I go up above that, the mpg drops off dramatically. The optimal rpm for mpg in my application is 1600-1800 but that would have me driving at 55mph. I make wonderful mpg at that rpm but can't stand to go that slow. The same holds true for having too little gear especially with a big cam. It can make the engine seem real sluggish at times.
These are just a few ideas to ponder. I would try long time headers with a y-pipe and high flow cats. If things don't improve, try a slighlty smaller camshaft still on a 115+ centerline. If you are looking to tow something, you needs a lot of low end and mid range. Hope this helps.  

Hey guys I'm a new user to this site. I have a 2002 z71 and I'm trying to get some more power out of this motor. Currently all I have done is exhaust, cai, and spark plug wire and plugs. I'm not just looking at bolt on setups but nothing to extreme because my budget is limited. I've been thinking about swapping the corvette cam and looking for what to do about intake and throttle body. If yall could help out I could really use it. Thank You  

increase perfromance by reinstalling the stock MAF aftermarket ones are garbage GM puts the airfoil and screen on the delco ones for a reason i lost 25 hp on the dyno because i descreened my MAF sensor  

02_Z71:
Hey guys I'm a new user to this site. I have a 2002 z71 and I'm trying to get some more power out of this motor. Currently all I have done is exhaust, cai, and spark plug wire and plugs. I'm not just looking at bolt on setups but nothing to extreme because my budget is limited. I've been thinking about swapping the corvette cam and looking for what to do about intake and throttle body. If yall could help out I could really use it. Thank You

I've said it before, and I'll say it again, Tune, tune, tune, the best power you're going to make without tearing into your engine is a good performance tune, especially on our trucks, almost guaranteed 25hp just from changes to your computer, don't even consider the handheld tuners (hypertech, diablo, banks), they're a waste of money

google Blackbearperformance, Wheatley performance, Nelson performance, or depending on where you live, you may be able to find a dyno tuner near you

and to answer your question, buy the cheapest intake you can find (or whatever one trips your trigger), hell, even just a smooth tube will help as its been proven before that unless you're making 500+hp, it doesn't really make that much of a difference, leave your throttle body alone for now, you can spend money elsewhere to make power, don't touch throttle body spacers (completely useless on our trucks since the fuel is injected after the throttle body)  
2003 Chevy Silverado

you have a 4.8/5.3/6.0? you need: cold air intake, exhaust system and a tune, see my posts for more details!

Pauls325:
increase perfromance by reinstalling the stock MAF aftermarket ones are garbage GM puts the airfoil and screen on the delco ones for a reason i lost 25 hp on the dyno because i descreened my MAF sensor

word, anytime you mess with the Mass airflow sensor, you're begging for trouble and throwing away your money  
2003 Chevy Silverado

you have a 4.8/5.3/6.0? you need: cold air intake, exhaust system and a tune, see my posts for more details!

I find it hard to believe that you "lost" 25 hp by descreening your MAF. I have read of hundreds of people who do it and I have done it with success. It may take some extra tuning to accomodate for the increase air flow but it should help in my opinion. Only thing is to make ABSOLUTELY sure that you do not touch anything but the screen when removing it. If you damage the sensor in any way, it will effect your airflow readings which will effect your performance. I would look further into it.  

go to compcam website down load camquest cam simulator 6,try different cam grind numbers to get the most power for combo.also check out grind #54-455-11.  

Hi, new to this forum.  I have a 01 Sliverado 5.3, stock with 53000 miles.  Has anyone used the Bully Dog Triple Dog GT Gas tuner?

This is available for Chevy, Ford, Dodge and Nissan trucks, gas or diesel.

The part # for gas is 40410, on their web site Bullydog.com it lists for 469.99 with a 30 day money back guarantee.  I have seen it various places for less.

They say it will improve mileage by 1 - 4 mpg, increase horsepower,  has 3 power level settings, driving coach for improving mileage, monitor with 4 parameters and can read and clear diagnostic codes.  Sounds like a lot of bang for the buck.  Some of the posts I have read claim 50 to 230 hp gains but I have seen very little factual user data.  

dude, for $470, you can scoop up a used cam and a real-live tune

and the only way a handheld tuner is going to net you 50-230hp gains is if you're hooking it up to a diesel  
2003 Chevy Silverado

you have a 4.8/5.3/6.0? you need: cold air intake, exhaust system and a tune, see my posts for more details!