006rcsb

i was looking at a couple of cams for my 06 rcsb truck its 4x4 and has the 5.3 in it and didnt want anything too crazy, because i'd still like to be able to tow with it, and i didnt want to have problems with the trans.being a resident of cali i didnt want issues with the smog police either so here are 2 i was looking at tell me what you guys think and let me know what else i would have to change to make these work, valve springs etc...

and for that matter what is the stock lift and duration? anyone know? and would it honestly be worth the effort for the power? would i see an mpg gain with either of these?

http://www.compcams.com/Cam_Specs/Ca...csid=1095&sb=2

http://www.compcams.com/Cam_Specs/Ca...csid=1084&sb=2

InchUp

iTrader: (2)

I am using the XR259...the 2nd link in your post. It's a torque monster in the 5.3L with a really low peak torque, good choice. All around good towing/fun cam IMO.

006rcsb

would i need to change valvesprings on either of these?

i dunno why but i liked the 260 cam better... i think just because i saw in the description that its made for the 5.3 trucks, works with oe comp settings and mid and upper gains, xfi truck roller cam.... wheras the 259 looked good too and not much different on lift but much different valve opening and closing timings and an lsa of 112 instead of 115.... what made you choose the one over the other inchup? how did you know what one to choose? or was it all just lucky guestimations?

lo&sloSierra

iTrader: (8)

i dont think ud have to change the valve springs out, the lift doesnt seem high enough to bind them over if u do though ive heard everyone say the ls6 springs are the way to go

lady3bglover

iTrader: (3)

Here's my shopping list for the Cam Swap, though a smaller cam than you're selecting, we still went with the new springs.

InchUp

iTrader: (2)

You will need to change springs, but no worries, the springs are only $53 bucks for all of them, check Lingenfelter's website.

The XR259 that I chose was based on it's RPM band and torque producing numbers down low. If you look at the two cams side by side, you'll not only see that the XR259 has a wider range of power (800-5800 compared to 800-5000) but the XR259's 112LSA also means that you will feel the torque come on sooner. A lower lobe separation angle brings peak torque town a few RPM's, so in my big truck I wanted to make sure I got all the torque I could down low ASAP. A lower LSA (within reason) tends to give better gas mileage as well because of that peak torque being lower, thus the motor is already in a higher torque curve at a lower RPM right where you cruise at on the highway. The XR259 also has just slightly more aggressive lobes, meaning steeper ramp rates, so the cylinder pressure is increased and therefore the torque as well...you can see this by comparing the degrees at different angles on the lobe. .515/.522 lift compared to .513/.520 as well, the XR260 being the lesser. All in all you're going to pay the same price for either cam, I chose the one that will make more torque across the entire rev range and make it at a lower RPM, while holding the power damn near all the way to my red line of 6000.

Just because it says it's for trucks doesn't mean diddly squat. Put the "truck" camshaft into a car, now it's a "car" camshaft. All it is is a steel rod with bumps on it, what you put it into makes it what the cam was meant for. All camshafts should be accompanied by a tune no matter what, so forget the nonsense COMP Cams says about being computer compatible. They all are once you get the PCM tuned.

006rcsb

ok well that about answered all but a few questions i have for your knowledge of the subject,
1. im in california do you think the smog man would even notice... does the cam idle like a stocker or does it lope enough to be questioned, and if it did would it pass the sniffer still? because im assuming there is no eo # for this cam...
2. will going with the xr259 cam work well with a magnacharger later or is 112 too narrow of an lsa? because i dont want to have to buy a different cam later and redo all of that...
3. since a tune is a must is this something i can do with a hand held? or will i have to have a shop do it, and if its tuned aftermarket will the smog man notice, or object when he hooks up to it?
i just want to cover all my bases and be absolutely sure that i can do the swap without getting crap from the smog guy, because i dont want to this and find out i have to put the stocker back in, that would suck...

ForcedTQ

iTrader: (1)

Allrighty, here are your answers:
1 & 2. For this purpose, and since you have mentioned your possibility of installing a Radix down the road I would say look at the LPE GT 2-3, it seems that many have had good success with this cam combination. It should also be docile enough to not cause smog issues. Check with Trever1T on this site, he could probably give you a good description of how this cam performs, as well as a few other members in the California area.

3. I say skip the hand held and if you're going to be tuning it yourself pick up HPT or EFI Live. If you're going to have someone else do it, have them do it in person. We can give you various recommendations on who to have tune it for you based on where you are regionally in California. A proper tune should have no problem passing smog based on the GT 2-3 and a Radix, or with just the GT 2-3 for the time being. Magnacharger's tune that comes with their kits was created to pass smog, and I'm sure a few of the talented tuners (Synergy Motorsports) could come up with something that would pass smog.

Mark Johnson

iTrader: (1)

And just when I was eyeballin the Vinci 65 cam. BTW how do ya make out the overlap on these cams.............

InchUp

iTrader: (2)

Skip the hand held tuner X2. Find a local tuner with HPTuner software or EFI live.

The XR259 will pass all emissions. It's very much like the stock camshaft when it comes to idle and the "sniffer" test.

Here's an idle clip of the XR259 in a 5.3L.

http://s87.photobucket.com/albums/k1...headers020.flv