2009 5.3l Cam Upgrade

nickvrebel · December 21, 2011

my background:

I've installed about 12 or so cams in LSx based motors. None anywhere near stock, not off the shelf cams - custom cut. I also custom tuned these trucks.

a few facts:

As stated earlier you will need new lifters to eliminate the AFM, this will require pulling the heads to change.

Someone mentioned needing new rocker arms... actually the stock rockerarms perform just fine up to way beyond the original poster's desires, but yes, as part of the cam swap new springs would be needed in the valve train.

You can't just walk in to a mechanic shop and tell them to install a cam to make you go fast.... There is a metric shit ton of variables. From the pic in your sig it appears you have a lifted truck with oversized tires. What we don't know is: do you rock climb? mud race? street cruise? tow heavy loads? When selecting a custom cam you need to decide what you want to do with the truck. If you want to say "do all of the above", then stick with the stock cam, that's what it was designed for, not the best of anything but decent at most all.

Long tube headers is a quick reliable and save mode for more Hp/Tq..lots of choices for LT???

long tube headers on a lifted truck with an otherwise stock motor would be a huge mistake. The stock catalytic converters/ manifolds breathe plenty well enough for even moderate cams, the only thing you would accomplish is a loss of torque, which is what that heavy pig of a truck needs most.

my opinion:

Unless you are doing the install yourself you aren't going to swap the cam in an 09 5.3L for that budget. Any cam worth installing will require a retune to even idle. A cam worth installing will also require a torque converter change. You are correct that with the 6 speed you are probably just fine with your factory gearing.

Your best bet? Without knowing how your truck is used start with a custom tune. A good tuner will not only find a little bit more power for you but the most substantial changes come from the changes in drivability - often times perceived as more power.

4wd · December 22, 2011

Everyone (including tuner claim LT is great mode for power and tq, don't know about lifted trucks..Anyway, good info!.

nickvrebel · December 22, 2011

Long Tubes:

most people want to know a horsepower number, or they want to look at trucks that already have a cam installed with ported and polished heads, intake manifold (not the filter and tube, the piece behind the throttle body), ported and polished throttle body etc. If you have all of those mods then install long tubes, you will see nice gains. I doubt any reputable tuner will tell you that you will get more torque from long tubes on an otherwise stock motor.

Big trucks need torque. there is about a 10 hp difference between the 4.8L and the 5.3L. That's not much. The difference is in the torque (roughly 30 ft/lb difference).

The idea behind long tubes is to make room for the exhaust gasses to get out faster. An engine is nothing but a big air pump, the faster it can get air in and back out the better. A cam is nothing but mechanical programming for the intake and exhaust valves - it tells them when to open, how much to open and how fast then when to close. The factory setup is plenty sufficient and will outflow the stock heads on the truck at any reasonable RPM.

You may make a higher horsepower number with LTs at say 6,000 rpm, but most driving, even aggressive driving is well below that speed. Reference back to what ken1mod was saying about the economy cam - it's called "power under the curve". Peak horsepower means NOTHING except on the dyno chart, anyone looking for the best performer will be more concerned with how the cam will perform in the rpms you spend the most time in.

4wd · December 22, 2011

Long Tubes:

most people want to know a horsepower number, or they want to look at trucks that already have a cam installed with ported and polished heads, intake manifold (not the filter and tube, the piece behind the throttle body), ported and polished throttle body etc. If you have all of those mods then install long tubes, you will see nice gains. I doubt any reputable tuner will tell you that you will get more torque from long tubes on an otherwise stock motor.

Big trucks need torque. there is about a 10 hp difference between the 4.8L and the 5.3L. That's not much. The difference is in the torque (roughly 30 ft/lb difference).

The idea behind long tubes is to make room for the exhaust gasses to get out faster. An engine is nothing but a big air pump, the faster it can get air in and back out the better. A cam is nothing but mechanical programming for the intake and exhaust valves - it tells them when to open, how much to open and how fast then when to close. The factory setup is plenty sufficient and will outflow the stock heads on the truck at any reasonable RPM.

You may make a higher horsepower number with LTs at say 6,000 rpm, but most driving, even aggressive driving is well below that speed. Reference back to what ken1mod was saying about the economy cam - it's called "power under the curve". Peak horsepower means NOTHING except on the dyno chart, anyone looking for the best performer will be more concerned with how the cam will perform in the rpms you spend the most time in.

since I only have a tune and exhaust , I can't benefit from LT. Thanks

vettelovralexand · December 22, 2011

Long Tubes:

most people want to know a horsepower number, or they want to look at trucks that already have a cam installed with ported and polished heads, intake manifold (not the filter and tube, the piece behind the throttle body), ported and polished throttle body etc. If you have all of those mods then install long tubes, you will see nice gains. I doubt any reputable tuner will tell you that you will get more torque from long tubes on an otherwise stock motor.

Big trucks need torque. there is about a 10 hp difference between the 4.8L and the 5.3L. That's not much. The difference is in the torque (roughly 30 ft/lb difference).

The idea behind long tubes is to make room for the exhaust gasses to get out faster. An engine is nothing but a big air pump, the faster it can get air in and back out the better. A cam is nothing but mechanical programming for the intake and exhaust valves - it tells them when to open, how much to open and how fast then when to close. The factory setup is plenty sufficient and will outflow the stock heads on the truck at any reasonable RPM.

You may make a higher horsepower number with LTs at say 6,000 rpm, but most driving, even aggressive driving is well below that speed. Reference back to what ken1mod was saying about the economy cam - it's called "power under the curve". Peak horsepower means NOTHING except on the dyno chart, anyone looking for the best performer will be more concerned with how the cam will perform in the rpms you spend the most time in.

The reason that LTs are recommended over shorty headers is because they not only outflow the stock manifolds, but also provide a torque benefit at lower RPMs due to scavenging. LTs could be very effective at gaining torque in lower engine speeds, but that all depends on exactly the length that they are. I would be shocked to hear a reputable tuner say that you couldn't gain from LT headers even on a stock truck.

I also refute the statement that the OP will not get a worthwhile gain from a cam swap in his stock engine. There are numerous cams out there which would benefit even an engine with stock 243 heads like what most 2009 engines have. Yes, it will cost 1000 bucks in parts to change a cam the first time due to the need to change to non-DOD parts, but the gains could be much more significant than what a tune alone could provide.

With 1400 dollars, it would be hard to do LTs or a cam swap if you didn't do the work yourself, especially since you would need to get the truck tuned afterwards to maximize the benefits of either. However, it can be done if you do some shopping around and were willing to use some used parts. As most say, always start with a tune, since that will be needed if you mod the truck anyway. And, if you are happy with the way it is after only the tune, you just saved big $$$.

nickvrebel · December 23, 2011

The reason that LTs are recommended over shorty headers is because they not only outflow the stock manifolds, but also provide a torque benefit at lower RPMs due to scavenging. LTs could be very effective at gaining torque in lower engine speeds, but that all depends on exactly the length that they are. I would be shocked to hear a reputable tuner say that you couldn't gain from LT headers even on a stock truck.

he's not going to get the air in to the motor to benefit from more flow ability without a high lift cam. Headers are all about balancing flow.

I also refute the statement that the OP will not get a worthwhile gain from a cam swap in his stock engine. There are numerous cams out there which would benefit even an engine with stock 243 heads like what most 2009 engines have. Yes, it will cost 1000 bucks in parts to change a cam the first time due to the need to change to non-DOD parts, but the gains could be much more significant than what a tune alone could provide.

I never said he couldn't get gains with a cam, I just said that in total if he was having someone else do the install after springs AFM delete, tune and other related expenses it would not be in his budget.

vettelovralexand · December 24, 2011

Do you have any dyno graphs that show that headers don't give gains? My discussions with tuners lead me to believe a 15-20gift hp gain could be seen from LT headers on a stock truck with 243 heads. I know a GTO my friend put headers and a tune on gained him nearly 50 rwhp. Ls2 engines have the same 243 heads. Again, I think there is plenty of growth to be had from an intake manifold like the fast 102, a set of LT headers, or a cam on stock headed engines. Of those three options, a small cam would probably net the most gain but take way more work to do.

yukon25008.1 · December 24, 2011

Gentlemen,

I have had to replace several chevy cams in my tenure as fleet manager. I usually used Crane and went withstock or more aggressive cams. These were OK.

One time I used an "economy" cam. This was a short duration, low lift cam that had its power peak at 4000 rpm. I know this decreased total horsepower at 6000 rpm but the increase at drivable rpms was staggering. None of us run our engines at 6k.

The torque (feels great under your foot) at normal rpms was absolutely delightful. The gas burner 350 felt like a diesel. Gobs of right now power right where the engine was already running. Fuel mileage improved and all the drivers wanted that truck even though the total power was probably decreased. The pleasure of the engine went through the roof.

If I had to change cams, I would definitely investigage the economy option. Burning less fuel was nice but the engine became much more pleasureful and fun to drive. The quarter mile time definitely dropped but the day to day fun was great.

By the way, these trucks pulled heavy trailers, we once weighed 28000 lbs at the weigh station.

I would gladly trade my 315 hp at 6000 for more power at 3000 rpm. Really.

Comments?

ken

Im debating on a comp cam for my 05 8.1, What do you think and recomend about that..

I already have intake,black bear in person tune,and im working on shorty headers and decent mufflers.

BlackZ71Silverado · December 24, 2011

dont quote me on this but i have heard that to put a cam in the newer trucks you have to get rid of all the afm shenanigans... so i believe it would be alot more than 1500, like others said, get the tune ad a set of long tube headers, or save up for a super charger

You are correct. He will also need to replace other internal parts IF getting a different cam. (see post #11, he has it right). Not worth the money IMO. May as well do a 6.2L swap.

uh6tdrvr · December 26, 2011

If you are set on a cam check out cams on performance trucks. They do about every kind of swap.....twice! Another worth mod may be gears. IMO, the 3.42 isn't enough. Gm options the nearly +100 HP/TQ engine with 3.73's and not the smaller lower power engine....which makes sense how?? I understand doing it to a "tow" package but doesn't the lower HP/TQ engine benefit from it as well? Hopefully with the "next" gen we will get to make some choices with what we'd like....but probably not....