Cam selection for twin turbo LQ9

[zeeshan]

I am thinking of replacing the stock cam with something different to decrease the amount of overlap between intake and exhaust. This way I don't have to run as much boost to make the power I am trying to aim for.

A couple things I want:
1. I want to use beehive springs (Cam valve lift should be max .600")
2. I want to prolong the life of valve train so I don't want aggressive lobe profiles.
3. MORE POWER!!!

I searched and see people recommending LS6 cam (they arent specific on if its the 2001 or 2002 they're talking about. there is a lift difference between the two and some duration difference). This recommendation doesn't make sense to me.


LQ9 Cam 207/196 int/exh 116 LSA 0.479" / 0.467" int/exh lift -> overlap = -30.5
2001 LS6 Cam 207/217 int/exh @ 0.05" duration 116 LSA 0.525" / 0.525" int/exh lift -> overlap = -20
2002 LS6 Cam 204/218 int/exh @ 0.05" duration 117 LSA 0.551" / 0.547" int/exh lift -> overlap = -23
GMPP Hot cam 218/227 int/exh @ 0.05" duration 112 LSA 0.525" / 0.525" int/exh lift -> overlap = -1.5
Tick Performance Turbo Stage 1 Cam 227/227 int/exh @ 0.05" duration 114 LSA 0.62x" / 0.59x" int/exh lift -> overlap = -1

It seems like both the LS6 cams have a crap load of overlap, while both the GMPP hot cam and tick performance stage 1 cam have significantly less overlap. This is why I don't understand why people recommend the LS6 cam.

Is there a cam like the tick performance turbo stage 1 cam that has like <.6" lift? I really want to stick to beehives.

[zbrown]

Need to know the rest of the combo. The can is the last piece

[zbrown]

You can look at the comp matter catalog and pick whatever lobes you want. I speced my own and I picked the tamest lobes they had

[zeeshan]

Need to know the rest of the combo. The can is the last piece

-Twin t3/t04e-50 trims with .82a/r turbine housings
-Completely Stock LQ9 (317 heads)
-LS1 Intake manifold
-T56 Transmission

[zbrown]

What turbine?

[zeeshan]

 http://www.thedodgegarage.com/turbo/adv_comp_map_50.gif
^ compressor map for turbo

65mm exducer for the turbine wheel

[BeasTT]

02+ LS6 or an LPE GT7

[largeorangefont]

02+ LS6 or an LPE GT7

The discontinued the GT7, as the LS9 cam is almost identical.

[awd-rwd racer]

im running a tick performance 226/235 .605"/.610" 115+2 camshaft in my setup.

i called and spoke to martin and told him what i was doing and this is a custom grind they had for me.

[BeasTT]

02+ LS6 or an LPE GT7

The discontinued the GT7, as the LS9 cam is almost identical.

Brain fart. I have the last GT7 ever made in my Avalanche. You'd think I would have remembered that.

[gnx7]

If you need an RXT clutch to hold the power...... I sell them

you can even reuse your LS1 flywheel if you wanted.

[zeeshan]

I've been reading about turbo cam design and there is quite a bit involved. I think i'm going to keep my cam stock right now, get a baseline dyno with the turbos and then change cammotion cam. The cammotion cam I am looking at is: http://store.cammotion.com/turbo-stage- (220/216 i/e, 114LSA, .578/.561 i/e, -10 overlap). This is couple notches  above the ls6 cam i'd think just based by the specs.

By having a baseline to compare with, I want to know for sure how much of a difference the cam makes on my engine.

[MPbdy]

A reverse split makes no sense at all to me.

[zeeshan]

A reverse split makes no sense at all to me.

It doesn't make sense to me either, but that is what cammotion offers for their turbo grinds. I think the idea is to reduce back pressure, but these might be designed for really big turbos. Now thinking about it, with smaller twins, back pressure isn't as big of a deal so maybe I do need a cam that is designed for N/A.

Like this one:
http://store.cammotion.com/57-ls1-346ci-101-compression-3  (222/226 i/e, 114LSA, .544/.535 i/e, -4 overlap)

[digitalsolo]

My Thunder Racing CheaTR cam worked well in my car (214/230 .601/.578 117 LSA)

My theory was to pull the duration toward the exhaust to crutch the smaller turbo and decrease spool time.   Car made excellent power and was a ton of fun to drive.   If you have plenty of turbine flow, you probably don't need as much exhaust bias though.