[InFiD3ViL]

Originally Posted by LCPLPunk

Why not follow the advice of the company that makes the cams?



GPI SS1 VVT:
Works well with the stock torque converter, offers stable idle, excellent low end torque, and smooth lobe design for quiet valve train operation and longevity. We designed this cam for use in cars with minimal modifications. Idles stable around 675 RPM, and is very strong off idle to 6600 RPM.


2:


Tailored for the street / strip individual that runs a 3000+ RPM converter. It rivals the torque output of the SS1 VVT but packs on about 10-15 additional horsepower up top. Strong to 6700 RPM. Converter and increased rear end gear ratios recommended.


3:


This is our most popular street / race cam, and for good reason. This is the perfect cam for the hardcore street / strip enthusiast, and makes more torque and horsepower than our SS1 and SS2 VVT cams. Very strong to 6900 RPM. Track tested, developed,and proven! This cam requires 3600+ RPM Converter, and loves 3.91 gearing.


4:


All out performance application. Very street able, requires 4000 plus converter, prefers 3.91 gearing and requires flycutting. Track tested and developed 10 second cam with heads and supporting mods. Strong to 7200 rpm.

I did that. I have the LS3 version of the SS1 cam - supposed to be easy to drive without a convertor. I am right on the edge of NEEDING a convertor and in all honesty should have one with this cam. I love the way it drives, but some people would hate how it pushes so hard through the brakes, the slight loss of lower end torque (but massive power up top), and how it bounces like crazy from the lope. It lopes very hard for an SS1.

Here is the deal with that though. I swapped and run an LS3 behind a 6L80e, not an L99. The VVT cams were all built to run behind an automatic transmissions, where the LS3 cam is mainly used in manual cars, not always, but mainly. My SS1 LS3 cam has higher lift and duration than the VVT2 cam from GPI. Hell, I only have 10" of vacuum at idle max., which is why it's feels like it's pushing so hard.

My LS3 SS1: .647/.638, (224/237, 112 +4)
VVT-2: .637/.637 (223/235, 112 +4)

I had no idea that the LS3 versions of the GPI cams were larger than the same stages of the VVT versions until I researched it, but it makes sense due to PTV on the L99.

Now, the VVT-2 is recommended to have a convertor....But GPI says the LS3 SS1 don't need one. How does that make sense if you look at the specs and compare? I never really noticed that until after I got the cam. No big deal either way, as I am very happy with what I have, but I definitely need to get a convertor in there. Maybe my slightly raised compression (11:1) makes it a little rowdier, but I really doubt that as I have just a tiny .015 head mill. I know it's not the tune as Ryan from GPI spent a ton of time on the tune and did 7 revisions to get it perfect. It feels great. But I know it is not something many people would be comfortable driving daily.