Super Charged 2005 Chevy Z71
Dialed In to Suit My Needs
A Mild Example of Obsessive Compulsion
The Only Signs Of Customization are a Joe Gibbs Spoiler, Corsa Exhaust Tips, and GMC Door Guards
The Engine Bay
Specifications and Modifications
· Options - Fully Loaded LT, Z71 4X4, Leather, Bose Premium, Satellite Radio, Tow Package Metallic Storm Gray, 3.42:1 Locking Differential.
· Engine We began with The Stock Aluminum Blocked RPO Code - "L33" 5.3 Liter V8 GM factory rated at 310 hp/335 ft·lbf of torque the crank. We dyno tested mine in stock form before any modifications were made near the 5000 mile mark and verified a 267HP at the wheels.
The L33 was only used in 2005-2007 extended cab 4x4 Sierras and Silverado's. Less then 5000 trucks in 05 had the L33.
One of the biggest differences between an LM7 and L33 besides the aluminum block are the cylinder heads. The LM7 uses the same heads as the 4.8 (LR4) where as the L33 uses 799's which are identical casting to the 243s found on the Ls2 and Ls6 in the corvettes, which have heavier valve springs and hollow exhaust valves not found on the 799 heads.
Another major difference is the pistons. The LM7 uses dished piston and the L33 uses the same flat top pistons found in the LR4 which gives it a bump from 9.5:1 to a 10.0:1.
A cam only used in the L33 which has slightly more lift and duration then the LM7's.
· Engine Modifications
MagnaCharger Radix Supercharger 112 intercooler model a roots type Eton Supercharger kit complete with larger injectors and higher capacity fuel pump replacement. Installed July of 2005 @ 5K miles. Current Pulley is a 3.4" providing 7 PSI of Boost. HPTuners Tuned. Gates belt tensioner, 90mm steel idler pulleys. Under hood photo and Dyno history listed in order of "Stock Engine with No Supercharger", "Supercharger" with Magnuson supplied Superchips tune with 3.5 inch pulley, and final tune and 3.4" pulley HERE.
The Magnuson supplied belt tensioner, and 80mm idler pulleys were replaced with Gates p/n 38042 90mm idlers, and Gates p/n 38131 Belt Tensioner for the best in a tensioner and more pulley wrap to prevent rapid deceleration slippage when the blower doesn't want to slow down as fast as the belt. Picture.
Stock Photo Polished Radix
· Tuning - I own and use HPTuners software as a novice, mecanicman is the mentor of this tune that includes MAF and VE tables, strict WOT plug reading and more via his care and guidance.
This heat exchanger, other than running a noticeably cooler really shows a marked improvement in much faster recovery times over the Radix Magnuson supplied heat exchanger.
Another improvement to the system was insulating the coolant lines and moving the pump and reservoir out of the engine bay heat to the grill area.
Showing the Insulated Coolant Lines and the 90 mm Blower Belt Idler Pulleys
The Mercado Heat Exchanger and Reservoir Re-location
The Pump is Behind the Bumper Air Slots
· Exhaust Corsa Performance Touring Edition Cat back system for great performance with in-cab comfort. Loud on the outside only when romped, always nice inside. With GM's improved exhaust manifolds this system really complements the performance package of the truck without demanding an aftermarket exhaust header system.
· Transmission The factory 4L60E transmission lost its 1st gear thrust bearing @ 44k miles. We took the opportunity to convert it to the GM 4L65E specifications, including the extra clutches in the 3-4 pack, a better sun shell, a 5 gear planetary gear set, better input and output shafts along with all the other GM upgrades going into their 4l65E transmission. The shift kit contains all Sonnax parts and valve body configurations using their Performance Pack (p/n HP-4L60E-01) and their 2nd, and 4th gear "Super Hold" servos. All frictions are aftermarket performance parts. A fantastic behaving transmission build. The truck is a 4-wheel drive via electronic transfer case.
· 6/27/14 70k Miles the OE Torque Converter failed. It was replaced with a Circle -D Stock Stall 300mm unit.
· 7/25/14 70500 Miles the input drum failed. The transmission was fully gone over, the torque converter was sent back to Circle-D for a cut and clean.
· At this time we installed a GM TSB recommended 1-2 accumulator valve kit, GM P/N 24255821 to once and for all cure the occasional rude slide bump 1-2 shift that lots of GM trucks across several years came with. Link To information.
Torque Converter - The stock converter failed @ 68k miles. It has been replaced it with a Circle-D
GM 300mm HP 4L60 LS Torque Converter in a Stock Stall. I like to crawl in the North GA mountain back
roads and a high stall is not suited to this application. I went with a Circle-D to better handle the added torque.
· Gears Locking 3.42's are a perfect match for the added low end torque providing spunk off the line and pure
joy on the highway where she really breaths well.
· Brakes - Front brakes use R1Concepts Premium Series Rotors and Raybestos Police Formula (Tahoe P/N) Pads. The rear system uses Raybestos Advanced Technology drums with GM OE shoes. Brake lines are the Russell Performance braided stainless steel 3-line kit providing a faster and firmer pedal feel. Brake fluid is Valvoline's Synthetic DOT 3 & 4 and is changed regularly using Speed Bleeders.
The above braking modifications just add to the already great braking that came on the truck. In 2005 GM went to drum brakes on the rear of their 1500 trucks.
Most are confused how going from disc to drums on the rear was an improvement. All I can say is this truck stops really great as shipped. The upgraded components added contributed greatly to ending pad material transfer to the rotors (some mistake for rotor warping). You can really feel the rear brakes doing their job in a precise proportionate manner. I managed to get 65k miles out of the rears before servicing them (See Pics This Link).
Since going to the R1Concepts Premium rotors and the Raybestos police pads the distance has decreased noticeably, and brake fade is hard to make happen. The Police pad formula was engineered for pursuit conditions and it shows.
· Tires The Michelin LTX M/S2 P265/70R17. These replaced the LTX M/S after more than 66k miles on 7/20/13. The M/S were speed rated @ S=112 mph. The M/S2's are T=118 mph. The compound changes can really be felt in the wet. Great Tires.
Tire test by FOURWHEELER Magazine reports on the M/S2 improvements over the M/S version.
· Suspension - Bilstein HD Shocks all around. Airlift Company's Ride Level Control rear air bags filled by Viair's 450c air compressor with in cab gauge and controls. The compressor is a 100% duty cycle 150 PSI unit. For keeping the ride level when loaded and a very fast tire fill setup.
I can level when loaded and have a ride that does not sag or sway with properly aimed headlights. I have repaired many a tire for stranded motorists and myself.
Back lighted In Cab Ride Control Panel with lighted 3-Position Toggle Switch, On/Off/Momentary and a Bleeder valve button
An Air Bag & Three Way Valve to the Bags, Tire Fill Outlet, or to Isolate the Pump
The Tire Fill Hose Port and Manual Bag Fill Valve
The Tire Fill Setup. This and a Plug Kit Has Saved My Bacon More Than Once
The VIAIR 450C Air Compressor Mounted Under The Cab
· Tire Pressure Monitoring System - By Orange Electronic Model P409.
I Have Used the Orange Electronic P409 in three Vehicles Over the Years. A Great Unit.
The Next Time You Get New Tires, Consider This System
· Radar/Laser Detection - Lidatek Laser LE-30 Jammer providing excellent and reliable warning while scrambling police laser probes for 5 seconds while I heat up the breaks. The Escort 9500ix Radar Laser detector with GPS aided false alert prevention is a really great radar detector.
· Bed Cover ACI-AGRI-COVER Inc's Access limited edition Tonneau cover. After trying several other brands this is simply the best cover system and material out there. It still looks and works great after 8 years of use.
· Head Lights - High beams are modified for optimum brightness with Kennedydiesel.com's Head Light Booster Wiring Harness powering Philips HIR1 (9011) and HIR2 (9012) Halogen Infrared Reflective bulbs. Factory fog 35watt lamps are replaced with 65watt 9005 lamps.
This truck is really fun to drive. With a modest 7psi of supercharger boost she is somewhat of a wolf in sheep's clothing. It looks, feels and handles like any stock truck running smooth and quiet not consuming any more fuel than a normally configured engine ....... until we mash it. The supercharger screws are bypassed under normal loads only coming into play on demand. The exhaust flows really well but is very quiet in the cab at all times. When we need to pass or harass she demonstrates a very noticeable amount of added power and noise getting the job done nicely as the blower whine turns heads.
· Dual Battery Power Along with the Current add-ons I am adding auxiliary driving lights soon. GM provides an auxiliary battery option by adding parts TRAY, AUX BATTERY 15246518 / The Clamp 356668 / And the Bolt 11509853.
The Batteries are Sears DieHard Platinum's Group 34/78, a re-branded Odyssey PC1500DT . Same battery, different color and price.
Batteries are connected in parallel and manually isolated using a Bear DC 225 Amp 100% Continuous Duty Cycle Contactor. The controls are via a dash 3-Way Toggle Switch with LED Lighted lever tip - Position 1 Green Light = Ignition On Main & Auxiliary Batteries Connected, Position 2 No Light = Ignition On or Off Main Battery Only, Position 3 = Red Light = Main & Auxiliary Connected with Ignition On or Off.
Auxiliary positive cable joins the main battery positive cable at the starter. The Aux battery ground cable connects the block. All cables are 2GA.
A Hella Time On Delay Relay is in the position 1 circuit and allows the Main battery to start the engine alone and run for 2 minutes before connecting the Auxiliary battery.
Ignition On signal is provided from a wiring outlet in the factory harness for factory installed Aux battery. This female plug comes on all trucks regardless the option and is factory fused. Its location is kind of hidden behind the HVAC Dryer on the firewall
The Contactor Mounted on the Side of the Aux Battery Tray
The Aux Battery RPO requires a fender support removal. I fabricated a replacement.
The power and build configuration of this truck is balanced to provide nice amount of performance increase without sacrificing reliability. With nearly 400 horsepower at the wheels in the heat of the summer she is not the average running pickup.
Updated 10/12/2014 @ 73,157 Miles