I still don't see how the 3.8 copied the LS1 when the 3800 series I even had that style intake back in the early 90s. But that's not all that important.

The whole point I was trying to make is that "box" cams are good for some of us. Now, if someone could make a custom cam that fits my needs (smooth stock idle and better TQ and HP than an LS6 cam) I'm all for it and so would a good number of other people on this board. Ever notice what happens when an LS6 cam is posted in the Parts For Sale section? Someone snapps it up. In part because of the price and because not everyone wants a lumpy cam. Not every cam has to be max effort.

Another point I was trying to get across is that every cam designer has his own way of looking at what an engine's cam requirements are. Unless every cam design is tried on the dyno and track then all you're getting is a cam in a box that should do what the customer wants. Like I said give the top 5 cam designers all the info they require to design a cam for you and you'll get 5 different cams. That is unless they're all using the same software to design that cam. So it's not as simple as all that.

Call me fickle.

I love going fast like the next guy. That's why I've been running the awesome Thunder Racing reverse split 230/224 111LSA cam for quite some time. It's tops for max power. But I gotta admit something, I sure love the way a stock ZO6 idles and runs. Super smooth idle, no shake, no stinky exhaust, but BIG power. My SS convertible is so nice, I figured I could try to find my own cam that would idle like stock, but still pull over 400 rwhp. Back in the old days on another board, we used to have discussions on what would make for an ideal "old man" car.

Here's what we were trying to achieve:
1 Quiet exhaust, but free flowing
2 Smooth shake free idle, but not wimpy
3 Gobs of torque down low plus great power up high
4 Emissions legal
5 Low underhood noise (stealthy)
6 Wife, girlfriend, police approved

I got a call a few weeks ago from Geoff at Thunder Racing. He said he felt like he had come up with the ultimate "sleeper" cam (or Old Man Cam as I like to call it). The key elements to making power everywhere while keeping a super smooth idle would require using all the latest technology and experience Thunder Racing has developed for the LS1. Here's the cam:

214/220, .600/.527, 115 LSA, -2 degrees ground in

Now look at the specs for a little bit. At first glance, it looks like a conventional "split duration" cam. It is and it isn't. The ramps on the intake are super, super fast. The total area on the intake is quite a bit bigger than the exhaust. In essense, this is really a "reverse split" cam in execution (just like the ones Thunder Racing has had so much success with). The big lift on the intake side allows my SAM ported heads to breathe, but the short duration and wide LSA keeps the idle smooth. Most people make the mistake of running a short duration cam (like a 214-218 cam) with several degrees of advance ground in. This is wrong. When you're running too small a cam, you want to close the intake valve later (to keep peak power up high). We accomplished this by having the cam ground 2 degrees retarded. This allowed the intake valve to close at the same exact time as my 230/224 111LSA cam. Guess what? I still was able to make peak power at 6200-6300, just like my 230/224 cam. Most 214 cams make peak power at 5700-5800 rpms. Not this one. The rwhp numbers stayed with the 230 cam all the way to 6400 rpms (where the 230 kept on pulling). By extending power to 6300, I make at least 10 rwhp over a 214 cam ground +4 degrees advanced. The 214 cam was done by 6500 rpms, but the low and mid range torque and hp matched or exceeded the 230/224 cam. It's like having your cake and eating it too. No small cam I've seen ever made this kind of power everywhere. It flat kicks ***. Idle is smooth. Torque down low is abundant. Pull to 6400 is incredible. I now shift at 6400 vs. 6700 with the 230 cam. Under hood noise is noticably less (since only half the valves have super fast ramps).

Thunder Racing is encouraged by the results. Next they want to install it in a 6 speed car. Keep in mind, this cam was made for MY combination. My heads flow well to .600 lift, so I could use this kind of lift to my benefit. Also, I run double springs. I'm afraid 918 springs aren't up to the task on these super fast intake lobes. Gas mileage has improved, no more stinky exhaust, got to lower idle speed from 900 to 800. Sounds completely stock. Can't ask for much more than that. Call it a 2002 ZO6 cam on steroids, haha.

If you were wanting to lower the peak torque and hp points you could easily do that by advancing the cam 4 degrees, but that would give you less total hp and torque under the curve. Here's the thought process. A 214 cam is too small for a 346 with great heads. A 236 cam is too big. A 224 cam is just right. If a 224 is just right, it would run best with 0 advance. A 214 cam, being too small benefits by retarding the timing a few degrees. A 236 cam would benefit by running a few degrees advanced. The key is placing the intake closing point exactly where you want to make power. Close the intake later, you make peak power later and vice versa. I chose to mimic the intake closing point of the Thunder 230/224 111LSA cam, which is 45 degrees ABDC. The 2002 LS6 cam is 204/218 117.5 LSA with 2.5 degrees of retard ground in. It has an intake closing point of 42 degrees ABDC which is really late for a 204 @.050 cam, but that is why this little cam pulls to 6500. The Thunder Racing "Sleeper" cam makes more torque and hp at low and mid ranges than the TR230/224 cam, so I think that it would work incredibly well even with no gear!

The reasons why this cam is so awesome:

1. The wide LSA flattens the torque curve, makes power down low very smooth and strong, plus cleans up the idle and emissions.
2. The short intake duration with lots of lift gives as much "open area" under the curve as most 224 cams with.560 lift. The short duration cleans up the idle and keeps the torque down low nice and high.
3. The lazy ramp on the exhaust is easier on the valvetrain, reducing under hood noise, plus the longer duration helps with overlap. The reduced area under the curve (compared to the intake) makes this cam more like a "reverse split" duration cam. The cam would be more like a 214/208 cam if the exhaust had fast ramps too, but the added duration of the slower ramps help with overlap (which is a benefit when running headers).
4. The intake closing point of 44 degrees ABDC allows the motor to make peak hp much higher than most comparable cams with 214 intake duration. This is key in making the big rwhp numbers. Most 214 cams have 114 LSA and are ground with 4 degrees of advance. This makes the intake closing point 37 degrees ABDC which will only allow the engine to pull to 5700-5800 rpms before the power peak starts to drop. The extra 7 degrees of intake opening make this cam 7-10 hp stronger than a normal 214 cam.

The RAM effect is a proven phenomenon, but I think it's kinda pointless when it comes to LS1s with plenum intakes and aftermarket cams. It would take ALOT of dyno time to get right combination to get a RAM effect in an LS1. For the "most" part it's race car stuff, but obviously it's taken into consideration even by the factory when they design an intake manifold.