Increase has lengthy been the large equalizer. Add enhance to simply about any engine, and unexpectedly you could have remodeled your in any other case mundane motor into some type of tremendous hero!
This appears to be very true of LS engines.
Everyone knows that boosted LS motors make big energy, however while you go searching for boosted efficiency, do you have to be issues like wilder cam timing and consumption upgrades?
…Or do you have to simply run extra enhance?
For our take a look at, we determined for instance what occurs while you make bolt-on modifications to your 5.3L and what occurs while you mix them with extra enhance. As we all know, enhance is only a multiplier of the unique NA energy output, so the extra NA energy you make, the extra boosted energy you can also make at any given enhance stage.
Whereas our 5.3L from Strictly Efficiency was not what you’ll name a junkyard motor, all of the mods carried out to the 5.3L can simply as simply be carried out on a junkyard 4.8L, 5.3L, or 6.0L truck motor. Simply add the required ring hole to your junkyard motor an away you go, however let’s check out what occurred once we carried out some mods on the 5.3L take a look at motor geared up with a Vortech supercharger.
The 5.3L Motor Baseline Configuration & Take a look at
In essence, the Strictly Efficiency 5.3L could possibly be considered an augmented inventory 5.3L brief block.
The inventory block was geared up with a inventory crank, Gen. IV rods, and forged pistons. The forged pistons have been exhausting anodized to additional enhance power, and the ring gaps have been opened up for boosted use.
The lone efficiency modification to the 5.3L was extra head circulate within the type of ported 706 heads from Katech. The 706/862 heads featured full CNC porting however retained the inventory valve sizes. Consider this as a low-buck, however efficient model of race porting.
The rest of the combo embody a truck consumption and throttle physique, a set of 80 pound injectors and lengthy tube headers. The 5.3L was first geared up with an LS9 cam and the heads have been handled to a BTR twin valve spring improve in anticipation of future cams.
Run on this method with a Holley HP administration system, the 5.3L produced peak numbers of 428 hp and 400 lb.-ft. of torque.
The manufacturing unit LS9 cam has lengthy been a favourite of LS fanatics, principally as a result of it’s the strongest manufacturing unit cam provided by GM (a title shared with the LS7). The LS9 cams are additionally available, with loads of used ones from guys who’ve carried out cam swaps on their manufacturing unit supercharged LS9 motors. The draw back of the LS9 cam (designed for a constructive displacement blower software) is the final lack of low-speed torque.
However worry not—we had a treatment.
Including a Vortech Supercharger & Different Mods
After working the 5.3L in anger, we put in the Vortech SI-trim supercharger equipment, together with a (not inventory) air-to-water intercooler from ProCharger. The motor was run on a mix of 91 and 100 octane to permit for correct timing values to maximise energy. The Si-trim Vortech was geared up with a 3.6 inch blower pulley. When mixed with the inventory truck damper (pinned in place), this produced a peak enhance studying of 8.4 psi.
In typical centrifugal supercharger vogue, the enhance provided by the Vortech rose from 2.5 psi earlier than hitting the height of 8.4 psi, the place the supercharged 5.3L produced 647 hp and 561 lb..-ft. of torque.
Wanting much more energy, we changed the LS9 keep on with a wholesome camshaft from Brian Tooley Racing that upped the spec ante to incorporate a 0.613/0.596 elevate break up, a 227/244 diploma length break up and 115 diploma LSA. To additional maximize energy, we changed the 91/100 combine with E85 bought from a neighborhood gasoline station (we by no means even examined the true combine, which might range drastically).
Run with E85, the BTR cam and identical pulley combo, the height numbers jumped to 716 hp and 607 lb.-ft. of torque.
The mix of cam timing and E85 improved the facility output of the 5.3L by means of the complete rev vary, all the time a great signal, however we have been nonetheless had 1 extra spherical of mods in retailer for the Vortech 5.3L.
Extra Upgrades to the 5.3L LS Take a look at Engine
The ultimate record of modifications (many of those have been examined individually-but offered right here in mass on account of house constraints) included a brand new consumption, bigger cam and supercharger. The manufacturing unit truck consumption and throttle physique have been changed by a FAST LSXR consumption manifold and matching FAST 102mm throttle physique.
The consumption improve was teamed with wilder cam timing within the type of a Stage 4 camshaft from Summit Racing. The Stage 4 cam featured a 0.625/0.605 elevate break up, a 234/247 diploma length break up and 113 diploma LSA.
The cam and consumption improve got each extra circulate potential and enhance within the type of a T-trim supercharger from Vortech. The T-trim was spun up with a ten rib ATI Tremendous Damper and eight rib, 3.33 inch blower pulley. The FAST consumption improve additionally necessitated an injector swap. The mix of the ATI damper, 3.33 inch pulley and T-trim blower resulted in a peak enhance of 13.8 psi provided to the brand new 5.3L mixture.
It needs to be famous that the NA model of this 5.3L touched 500 hp, however with the enhance provided by the Vortech, the combo belted out 895 hp and 766 lb.-ft. of torque.
Given the facility positive aspects vs. rpm, we determine the close to 900 horsepower output was a great distance from being maxed out at simply 6,200 rpm.
As soon as once more, the one factor higher than bolt-ons OR enhance…is bolt-ons AND enhance!
