......................

 

honestly, just to make sure, take it to another dyno and if you can verify that it does dyno that low, its not making the power its supposed to be, over 25% drivetrain loss, let alone on a 6speed? cmon, they have to check into it!

 

That ticking file is hard to hear ticking on. Sounds like someone messing with the camera while holding it, I coudn't make out any distinct rpm-matched ticking sounds.

Here are some common causes for ticking sounds though:
-bent pushrod(s)
-loose rocker arm(s)
-broken valvespring(s)
-AIR check valves on the exhaust manifolds (they flutter, normal on an f-body)
-pre-ignition (detonation)

I would probably suspect the detonation if the noise sounds like a rattle can of spray paint at higher rpm, this will be picked up by the engine's knock sensors, and will pull a lot of timing out of the tune. That could easily make you lose 40-50 rwhp on a dyno pull.

If you have bent pushrods or a loose rocker, its more of a 'contact' sound of something hitting inside the engine. It would also stay matched with rpm.

 

Mine ticks a little when you first start it up when it's cold from overnight. I had a Mustang before this and never heard this type of noise before other than a guy I knew with 2 messed up lifters on his GT. I'm told it is normal for a pushrod engine though?

 

i really couldnt hear anything weird either. However the dyno numbers are indicating more than a heat soak problem.

 

Speaking of ticking. I noticed this same thing on my c6 z06. I have about 1300 miles on the car and i just started noticing this ticking. It is only "noticable" between about 1k and 3k rpms. You cant hear it at idle. If i am between those rpms and put the car into neutral and coast the noise goes away. I did miss a shift into second the other day but dont think i over reved the engine. I posted on corvetteforum and they basically said the noise is normal. I guess the only thing that gives me peace of mind till i can find another z06 to listen to is that it is under warranty. I had a ticking noise like that in my L98 corvette before i threw a rod so i am somewhat concerned.

 

I decided that before going to the dealership to raise hell, i'd give my car one last chance on a different dyno. I went over to ECS in Cream Ridge, NJ, changed the gas, checked all my plugs and had them dyno the car. Again, my car is bone stock, down to the rims and tires; the only thing thats been changed is the oil.

1st Run: 341.5 rwhp, 355.9 rwtq
2nd Run: 343.8 rwhp, 345 rwtq (this run was a little hot, about 4-5 minutes between runs)

As you can probably imagine, I'm much happier today that I was when my car dynoed at 280 rwhp just a few weeks ago. I'm not sure what made the difference, but I'm happy none the less.

I didn't get a chance to scan the results, but I'll have it up w/in the next few days.

 

That second set of dyno numbers are right on target with what I got out of my SSR 6 Speed with LS2 (346.0 RWHP 353.3 RWTQ). If you still need more power try the Magnuson Products "Radix" Intercoooled Supercharger, the dyno results are real good (469.7 RWHP 451.9 RWTQ). The best part of the "Radix" is that around town you cannt tell it is even there until you stomp the go pedal, and the gas mileage went up too.

 

If you've got a "tick" and low dyno numbers, I'd put money on bent pushrods. I say this from experience; I never once over-revved my LS1, but someone did before I bought it - I found 7 bananas in there when I went searching for a tick, a high-rpm misfire, and power loss...

Checking the pushrods is fast and easy - easy enough that it would definitely be worth your while to pop the valve covers and have a look...

 

It is easy to tell why you dynoed so low the first time. Look at your AFR on the dyno sheet, it gets lower and lower and is under 12 around redline. A tune would do wonders.