Help w/basic 5.3 engine mods

Rojo · April 23, 2002

I know there is a lot more horsepower and torque waiting to be awakened in the 5.3 engine, but being an old motorhead (54), I am unfamiliar with this engine! I am not interested in Turbo's, Superchargers, NOS, but rather basic, long term, lasting mods. Such as whether 1.6, or 1.8 roller rockers are best, what are some of the shortcomings of each? Who makes the Best, most long-lived product for the least amount of money? Also, the headers, which are the best for this engine, Tri-Y, Stepped, Short or Long?

I am shooting for all the low to mid-range tourque and horsepower I can achieve! Not only for Economy, but also to leave some younger-people's chin on the ground at Redlights. You see,, the Kid in me still Rages!!!!!!!!!

July 8, 2002

Your rockers are stock 1.6 if I remember right, and are considered un-adjustable anyway... Some good mods would be an AIRAID throttle body spacer, intake tube and filter (K&N, MAC, AIRAID) , possibly a reprogrammer, and a granatelli mass air, ... as far as headers I would look into some JBA's. There are a few free mods you can do as well, like the egr (exhaust gas recirculation) mod. The tube comes in behind the throttle body and is considered restrictive of incoming air, so it is cut (shortened)... All the ls1 guys do this on there camaros, firebirds... not a noticeable gain at all but every tiny bit helps right?

MarkD · July 8, 2002

FIPK(air intake system) $275 - 10-15 hp

Hypertech Power Programmer $340 - 10-20 hp

Flex-a-lite electric fans $400 10-20 hp, 2-3 mpg

Long tube headers $750 - 20-30 hp

SLP Roller Rockers $600 19 hp

Catback ? ask others (have heard they work well w/FIPK)

July 8, 2002

Hey MarkD,

So SLP makes roller rockers for 4.8s and 5.3s? I figured somebody had to make some but wasnt sure... I guess thats right because Ive seen ls1/ 4.8,5.3 roller rockers for sale in some catalogs... Same rockers in an ls1 as in new gm engines right? My mistake... It is true that they are 1.6 ratio though right?

gandolphxx · July 8, 2002

FIPK(air intake system) $275 - 10-15 hp
Hypertech Power Programmer $340 - 10-20 hp

Flex-a-lite electric fans $400 10-20 hp, 2-3 mpg

Long tube headers $750 - 20-30 hp

SLP Roller Rockers $600 19 hp

Catback ? ask others (have heard they work well w/FIPK)

Definitely do the headers, The Other Guys are great for power. As to the exhuast, save money and effort, the Magnaflow 5x11 will do everything you need with the rest.

I would skip the MAF, little return and high risk unless you can monitor possible lean conditions and adjust.

My $.02

July 9, 2002

GOOD POINT GANDOLF... UNLESS SOMEONE JUST HAS THE MONEY AND WANTS TO GO AHEAD AND BUY A MAF TUNER W/ THEIR NEW MASS AIR, ITS NOT WORTH IT. NOT SOMETHING TO FOCUS ON RIGHT AWAY... GET SOME OTHER THINGS OUTTA THE WAY FIRST.

grrickar · July 10, 2002

10-20 ponies for the electric fans? Wow! How does that help? I have heard that a lower temp thermostat (like a 160 or 180) gave better gas mileage, and I suppose the engine is running cooler, but that big of a difference?

Avalancher · July 10, 2002

I think the fans are rated ~17-24 (can't remember for sure tho). That's considering you remove the stock fans. I would say significantly more in hot weather. When the stock fan clutch starts firming up. If you have a Chevy, you know what I mean!

MarkD · July 10, 2002

So SLP makes roller rockers for 4.8s and 5.3s?

SLP Online

I changed my Camaro from factory 1.52 to 1.6 and gained a dyno proven 19 peak rear wheel hp, 9 peak tq. (272rwhp to 291 rwhp).

I think our factory rockers are 1.7 and the SLP's are 1.85. That is almost twice the difference as my Camaro. I would expect at least similar results.

MountaineerTom · July 10, 2002

10-20 ponies for the electric fans? Wow! How does that help?

My understanding of gaining HP's from electric fans is because it frees up the motor - the motor doesn't have to turn the fan.

CityTruck · July 10, 2002

FIPK(air intake system) $275 - 10-15 hp
Hypertech Power Programmer $340 - 10-20 hp

Flex-a-lite electric fans $400 10-20 hp, 2-3 mpg

Long tube headers $750 - 20-30 hp

SLP Roller Rockers $600 19 hp

I havent't really done any performance mods to my truck, but I know from past experience modding other vehicles that when adding up these mods and their "claimed" hp gains you usually get something like 2 + 2 = 2.5. I'll bet if you add all the mods above, you won't get 61 to 77 hp (even at the crank). I could be wrong though. Like I said I haven't modded an LS1.

Sierra5.3 · July 11, 2002

Whats the egr mod? I know what it is, but what do you do to it? thanks

SilveradoWV · July 11, 2002

I know from past experience modding other vehicles that when adding up these mods and their "claimed" hp gains you usually get something like 2 + 2 = 2.5. I'll bet if you add all the mods above, you won't get 61 to 77 hp

Yeah you cant really go buy the advertised HP gains! Not saying the manufactureres are false advertising but they do tests on a lot of vehicles and list the HP numbers from the vehicle who picked up the most!

ForceInjection · July 26, 2002

Looking for more power and torque I see. You should look into the Whipple Supercharger kit...they are saying you will see an increase up to 50% or torque and HP. Check out this link:

SuperchargersOnline.com