Originally Posted by Myhardtop

Your biggest problems are: 1) tuning, 2) weight and possibly 3) gearing.

Allow me further elaboration, and this is totally my opinion. I have had my fair share of trial and errors:

1) Tuning: Whenever you introduce a cam into a motor you are essentially changing the manner on which the car will behave...the whole package is now altered. A good tuning however, will/can make all the pieces come together but only if you or whomever had carefully chosen all the pieces. I've seen many people add a cam into a car and go slower; they may sound mean as hell but run worth a damn. If all your parts were chosen properly for your set up...ie TB, heads, intake and so on, then a good tuning can yield 20 to 30 additional rear wheel horses or more!

2) If I recall correctly, the Z51 C6 is lighter than your Automatic C6. Taking that into consideration, the package of that Z51 is such that it works around it’s given components. In other words, the whole thing was designed to maximize and complement what’s there (suspension, braking and power band due to gearing). Your friend essentially improved the already decently stout stock set up by adding headers (better exhaust flow) and CAI (better breathing capabilities).

3) Gearing plays a huge role. Remember, he has 3.42 gears PLUS his trans is geared to totally take advantage of the giving powerband of the LS2 mill with stock heads and cam. Great trans gearing was one of the C5 Z06’s advantages over the C5 coupes, Verts and FRC's.

Your improvement of let's say 30 to 40 rear wheel HP from stock will roughly net you about 2 to 2.5 tenth AND possibly 1.5 to 2.0 mph gain in the 1/4 mile considering your current weight and choice of transmission. By the sound of your set up, I believe that you really need a properly stalled torque converter to take full advantage of the new cam. Remember, if everything being equal (traction/power and driver) automatics really has an advantage over sticks from a stand still. Your particular combo vs his from a rolling start is not a big advantage right now over his better geared rear end and trans, lighter chassis and possibly better tuned Vette. Now, once you get that bad boy tuned and do something about that converter, you will smoke him from any point (rolling or standing start).

Replacing gears is a good idea, but if I were you, I would do Converter before a rear gears. The cost of gears and a torque converter I believe is about the same. Torque converters are typically good for at least a 0.3 tenth in ET reduction and it will compliment your new cam a little better than the gears at this point. In fact, a converter will "wake up" that semi-sleeping beast!

Again, this is just my opinion and this is what I've seen work on automatic C5's, 5.0's, Fbody's and also GN's.

Thanks

Originally Posted by Z51 6spd

You might want to think about L92 heads and L96 intake

Originally Posted by xstang

I think with the Heads, you get what you pay for... (I think the L92 heads are too big for stock cubed motors)

I have several race videos posted on my myspace page http://www.myspace.com/rickschildge pulling a new C6 Z06 and a new Viper..

I think my heads/intake selection are a big part of why my car runs so well... - especially when you consider I have a very small cam.... 215/232....

Originally Posted by Evilways

What head would you recommend for my set up, almost the same as you, but 228 on the intake and same as you on the exhaust.Just wondering because if I do upgrade again, it'll be heads only unless it's the general concensus the stock intake won't hold up.

Originally Posted by xstang

I'm running the AFR 205s now, but I'm considering switching to the AFR 225 Small bore heads... I'm also considering the Fm14 high lift cam to take advantage of the better flow at the higher lift....

If you are running under 600 lift, the AFR 205s would be perfect (with a 228 cam)... If you run bigger cam 230+ or more lift, my preference is AFR 225 small bore heads.... The 225s also give you more room if you decide to up the cubes later...

Originally Posted by Z51 6spd

You get what you pay for, not always. Like in your case AFRs are nice heads, but....... Stock LS2 with L92 heads L76 intake, and a somewhat warm cam (232/236 .050, .600 112 lobe) will make 547 hp 495 lb-ft per GM High Tech. Would bet money your 205 AFRs Fast 90 and somewhat warm cam wont make that. Hey I have A Fast 90 and love it, but #s don't lie, and you payed to much. Some times it pays to wait. By the way I really like your car, and ya its fast.