02RedHawk

iTrader: (17)

For my own understanding, how the heck does the '02 LS6 Cam have so much duration at .200"? (copied and pasted cam-doctor data below, from previous posting of Patrick G)

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Here's the '02 Z06 cam:
02 Z06 cam.................. 0.006 0.050 0.200
Intake Duration - ID........270.....204...166.6
Exhaust Duration - ED.....275......218....178
Lobe Center Angle - LSA..117.....117.....117
Intake Centerline - ICL....117.4...118.9...118

Intake Valve opens IVO...17.6....-16.9...-34.7 BTDC
Intake Valve closes IVC...72.4....40.9.....21.3 ABDC
Exhaust Valve Opens EVO.74.1....44.1.....25 BBDC
Exhaust Valve Closes EVC.20.9....-6.1....-27 ATDC
Exhaust Centerline ECL... 116.6...115.1...116
Overlap.........................38.5....-23....-61.7 degrees
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I'm trying to make some comparisons to the LPE GT2-3 (#s below), along with possibly spec'ing out a slightly bigger cam using XFIs. Application is a Magnacharged LS2, Trailblazer-SS. Will be using stock exhaust for at least one year, then longtubes will be installed - so I do need to make it somewhat exhaust insensitive.

LPE GT2-3
.050": 207/220 .57x", 118.5 ICL 118.5 LSA
.006": 255/281 118.5

My choices are limited to keeping the stock LS2 cam (same as '01 LS6), doing the GT2-3, or something very SMALL on the XFI lobes (ie, something like a 210/218, 210/224 or similar) - I will keep my stock idle, and thus overlap needs to stay around -20 at .050".

One question I've been pondering is how/why the '02 LS6 cam has so much duration (possibly just a typo???) at .200", whereas the aggressive XFI lobes are only around 136-140???

I know many have loved the driveability, stealthiness, and power increase from the GT2-3 in LS1 applications - and that it also works very well for FI applications. But, I don't think its quite big enough to do the same job on a 6.0L as it does on the 5.7L, thus I'm thinking about a custom grind on XFIs to try and replicate the GT2-3 on the bigger LS2.

Thoughts/comments/help? Sorry, kind of a sporadic posting with several questions contained within....

Ragtop 99

iTrader: (7)

That 166* has to be valve duration and not the cam duration. You can see the difference on this stock cam card from a 1999 F-body:
http://ourworld.cs.com/ls1info/LS1-data-2.jpg


I've used the XFI lobes and like them

02RedHawk

iTrader: (17)

Good to know, thanks.

What would ya'll think a comparable XFI-lobed cam (to the GT2-3), yet a tad bigger, spec out to be...?

chrisj6

I had the 02 ls6 cam in my 5.3L Z71 truck and it ran great. That is the duration on that cam, 204/218 .551/.551 117.5 lsa. I tuned a GT2-3 on the same motor, i just threw on the tables I did for the ls6 cam from my truck and only the WOT fueling needed adjusted, and not by much. The gt2-3 is just barely bigger, and for the money difference, I would just go with the ls6.

02RedHawk

iTrader: (17)

I'm not considering the '02 LS6 for the motor - waste of time to "upgrade" from the stock LS2 cam (='01 LS6), versus doing the slightly bigger GT2-3, esp for my FI application. However, one of my roundabout original questions was also to see what sort of XFI cam could be generated to be slightly "bigger" than the GT2-3, but still incredibly "stock".... Same price as the GT2-3, and I bet I can get a little more ooomph from the XFI whilst still keeping the same sort of GT2-3 characteristics.

chrisj6

I was thinking you were wanting to upgrade to that cam. My bad. Yeah I was thinking it is a waste of time to upgrade to either one if you have that already. Because the gt2-3 is not that much bigger at all. You wanting just more duration with the lift of the gt2-3?

02RedHawk

iTrader: (17)

My original posting was worded (and structured) as if a middle-school dropout authored it. Heck I got confused after re-reading it myself.... Allow me to try and better reword my main intent:

For my LS2, I'm thinking that I can get an XFI (or XE high-lift, perhaps) cam to produce ~20 more rwhp than the stock LS2 cam, but have the same sort of stock mannerisms that the GT2-3 has when its installed in the 5.7L LS1.

Obviously, I know I can get a boatload of more HP if I "go big" with the cam, but that is *not* my goal.... Much like how the GT2-3 provides 25-30rwhp gains over the stock LS1 cam in LS1 motors, but everyone that has used it states how perfectly stock it idles, how stock it drives, how stock it sounds, stealthy, etc. etc.... That's exactly what I'm going for in the LS2 (and have it "work" like the GT2-3 does in FI applications).

Ragtop 99

iTrader: (7)

The answer is yes. The XFI lobes are a faster ramp so you can add a few degrees of overlap at .05 w/o increasing overlap at .006 and maintain the same idle quality. You really can add a lot more overlap and have great manners. -12 overlap will still drive like a pussycat with minimal tuning and would allow you really pick up some torque to get that beast moving. A 214/226 116 114 would probably do the trick nicely.

J-Rod

A ls2 cam is identical to an '01 Z06 cam. Look at the difference between an '01 and an '02 car. If you can keep the overlap in check, you can keep the lope down, and keep the manners in the car. A swap to just an '02 Z06 cam would pick you up some power for sure. Its really a matter of how agressive you want to get with the lobe. The stock cam has a pretty soft lobe to go 100K miles. Now, you do the same specs, but say swap in an XE-R or an LSK type lobe, and the area under the curve changes dramatically. But, you have to balance valvespring life against it.

Also, don't get toally hung up on cam doctor vs mfg book spec. There is some variance...