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Squeezing Performance out of the 5.3L

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Squeezing Performance out of the 5.3L

mcphck mcphck
New User | Posts: 2 | Joined: 09/06
Posted: 09/22/06
12:01 AM

Hello everyone, new member here.  Thought I would give the forums a shot to see if anyone could help me squeeze more out of my engine.  I own a 04' Silverado 5.3L 4x4 crew cab and Ive taken it upon myself to increase performance and hopefully along the way gain some MPG.  This is what I have done so far:
K&N FIPK Series 77
Gibson Catback Duel Sport Exhaust
Hypertech Power Programer III (Tuned for 87 Octane)
Airaid Throttlebody Spacer
MSD 8.5mm Sparkplug wires and Iridium Plugs
Granatelli MAF sensor

With all of this I have awoken the beast that resides within the 5.3, but I feel there is more.  As well with controlled driving I have achieved close to 18MPG city, no good numbers on the HWY as of yet.  I am considering headers and dont know if I should go shorty or long tube.  I am thinking of a set of Doug Thorley shorties.  Is there anything else that can be done bolt on that anyone would recommend.  I love Chevy power and love working on my truck.  Thanks in advance for any ideas of feedback.  

mcphck mcphck
New User | Posts: 2 | Joined: 09/06
Posted: 09/28/06
01:16 AM

Apparrently not too many chevy fans on the web...kinda sad.  

redscare redscare
New User | Posts: 5 | Joined: 09/06
Posted: 09/29/06
03:24 AM

Headers is pretty much the limit of simple bolt-on power adders. You might be able to get more power through repogramming your ECU, but you would have to switch to premium gas. Beyond that, you'll end up having to take apart the engine to add power parts(heads, cam, etc)

You're pretty limited as far as MPG improvements.  
Ce n'est pas une voiture

Stang's Bane Stang's Bane
New User | Posts: 1 | Joined: 01/07
Posted: 01/03/07
11:21 AM

If you go throught the trouble of putting headers on, go with the LT's. IMHO shorties are a waste of time.  

Moderator | Posts: 40 | Joined: 07/06
Posted: 04/05/07
11:55 AM

I agree. I highly recommend the Stainless Works long tubes and exhaust we tested. A good custom tune will improve gas mileage, but as stated will most likely result in having to switch to 91-93 octane. An intake manifold and throttle body swap may also free up some power as the truck manifolds are said to be quite restrictive.  

tdaugharty tdaugharty
New User | Posts: 1 | Joined: 07/07
Posted: 07/15/07
08:11 PM

Going through more of a gas savings excersise where I've done everything cept the Mass Air Flow Sensor and the TBI spacer.

I'm going to pick those up from Barnette performance tomorrow and then it's close the wallet time.

So Granatelli MAF sensor vs the JET equiv. Any real reco for either over the other?  

New User | Posts: 1 | Joined: 09/07
Posted: 09/27/07
04:50 PM

I recently aquire 2 GEN III engines plus the one in my truck.  I'm already planning to do a cam up grade for my daily driver. The cam is from the 6.0L LQ9 engine.  That should bring me up to about 332HP and 352 FLBS of toque.  Now for the big question, What other performance upgrades there are to build a monster 5.3 motor other than blower and turbo.  I thanks for the help.  

chevyboy11 chevyboy11
New User | Posts: 9 | Joined: 09/07
Posted: 10/03/07
04:56 PM

Check out Chevy Hi Performance Magazine. They for a while they had a whole series on making a 5.3L truck go fast, then they hoped up a SS silverado. Good articles. With all the bolt ons you have a performance tune at a tune shop or do it yourself with SCT tune. That would really make the truck run awesome, but gas mileage will suffer greatly. Any more you do to the truck will make your gas mileage go down. Make the sacrifice. Want more ponies will have to do engine internals or throw a Turbo or Supercharger on it. As far as the headers go i would recommend the long tubes.  

silveraldoz71 silveraldoz71
New User | Posts: 4 | Joined: 02/08
Posted: 03/02/08
09:00 AM

Well, let's keep this going. Got a 00 Z71 with 185K on it. Installed an 02 vette cam and had professionally tuned at Henderson Performance in New Braunfels, Tx. Motor gained power but not what I was looking for. Also built the trans 4L60E to handle 400hp. Cold air intake, Lost the cats somewhere along the way and Flowmaster 40 sieries with 2.5in duals. Yeah it's loud, and probably faster than a stock 5.3L. Also with all this work, fuel mileage has stayed at 16mpg. The secret.  Having it tuned by a man that know what he's doing. Now, I aqquired an LQ9 and building it now. Stock bottom end despite ideas thrown at me for a stroker kit, the funds don't aggree. Stock bottom, stock heads (for now), but a heavy torque cam from Comp. I'm throwing my intake and throttle body from the 53 on this 6.0, I know it will fit, but is there a difference in intakes and throttle size between a 5.3 and a 6.0? I will probably find out on the dyno with this new plant if I need more air. But when I slap ported heads and long tube headers for more breathing room, do I need to address the intake?

05chevyz-71 05chevyz-71
New User | Posts: 1 | Joined: 11/08
Posted: 11/30/08
06:03 AM

SLP has a performance package deal that pushes the 5.3 to 350hp w/ bolt on performance parts. Here's a cut of the list:
This GM Truck PerformancePac features:
-55 horsepower improvement over stock, a 19% increase
-High-Flow Cold-Air Induction System (#21051), flows 32% more air than stock
-Stainless Steel "Shorty" Headers with Aluminum-Ceramic Coating (#30152), 15 pounds lighter than stock exhaust manifold
-Stainless Steel PowerFlo™ Cat-Back Exhaust System (31054), the only true dual rear exhaust available for 2004-2005 GM SUVs
-1.8-Ratio Roller-Tip Rocker Arms (#53305)
- DiabloSport II Programmer with SLP Custom Tuning (#27001T)
-350HP OEM-quality Fender Badges

I have heard of people doing the LS-6 intake swap on these trucks also, suppose to be somewhere around 15-18hp gain I guess.

GM upgraded the 5.3L to a 5.3L H.O engine by just doing a cam & piston swap: What makes the 5.3 High Output crate engine so special is that the GM engineers have added a GM Performance Parts custom cam and Grafal-coated pistons. With these simple upgrades, the 5.3 HO kicks out 332 horsepower and 352 lb.-ft. of torque.

Hope some of this may help.  

littlesdaryl littlesdaryl
New User | Posts: 1 | Joined: 03/09
Posted: 03/18/09
03:32 PM

Thats what I will do.  So far, I ported the throttle body, installed a KN airfilter, and a Summit cat-back dual exhaust system.  I have notice a difference when taking off under hard throttle and highway driving.  I wonder if I swap my factory intake tube to an after market one, will that make a difference.  

genXhunter genXhunter
New User | Posts: 1 | Joined: 04/09
Posted: 04/03/09
04:15 PM

Hey fellow chevy enthusists, I have a 2006 5.3L Silverado Z-71 4 x 4 crew cab. My warranty recently ran out and I am looking to do some more mods but don't have much money to work with. So far, I have a K&N flat filter, reprogrammer & flowmaster exhaust. I am kind of frustrated in that I can only get an average of 13.3-14.3 in the city and almost 17 on the highway. My "average mpg" reading stays at 14.5 even though I get less than that when I manually calculate it. I tried a Granatelli MAF sensor pn 350115 and noticed a little more power and better throttle response but my mileage decreased almost immediately. Within 15 miles, the "average mpg" went down to 14.3 and then later to 14.2. I took it off after that and returned it. My "average mpg" went back up to 14.5. I had a hypertech programmer 3 for a few years and just recently switched to a Superchips 2716 programmer. It makes more power and torque with the Superchips but sligtly less mpg when calculated (even though the average mpg stays at 14.5). My questions are these: 1) how is the "average mpg" calculated and how often is it calculated? 2) Is there an stock MAF from another application that will flow better and give me better mpg? 3)How can I improve my MPG for the cheapest dollars? 4) Are shorty headers really a waste of time? The truck has decent pickup but I know it can be better. My driving includes alot of stop & go driving and I just don't have the cash for an SLP power pack. Any help would be appreciated.  

Justin_at_GMHTP Justin_at_GMHTP
User | Posts: 135 | Joined: 03/09
Posted: 04/06/09
08:07 AM

Instant and average MPG is usually found by the ECM using a fairly simple equation. It knows the injectors flow (rated) at a certain fuel pressure and it also knows how long it is open (using Injector Duty Cycle)

Most modern cars use time x duty cycle to find the instant and average. As you have seen, this is close but not always perfect.

I would look at increasing air in and air out, the shorties will help some. Your best bet for MPG is a CUSTOM tune where you can have a good tuner go out with you and datalog the car as you drive. They can pull fuel and still keep the motor safe, which will help greatly.  

h_friesen h_friesen
New User | Posts: 1 | Joined: 04/09
Posted: 04/17/09
08:03 PM

Well lets keep this going guys, if you dont mind. I have a 2005 Silverado with 5.3 cold air intake and aero exhaust. Rest is completely stock. Im lookin at a turbo upgrade. What all will i have to do in order for it to work properly?  

h20son h20son
New User | Posts: 40 | Joined: 06/09
Posted: 06/24/09
02:29 PM

Icon Quoteh_friesen:
Well lets keep this going guys, if you dont mind. I have a 2005 Silverado with 5.3 cold air intake and aero exhaust. Rest is completely stock. Im lookin at a turbo upgrade. What all will i have to do in order for it to work properly?

tranny upgrade, rear end upgrade, custom tuning, custom fueling, custom exhaust, intercooler with custom piping, etc...  
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!

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