Ghost Knight

No, he meant what he said. A 600whp NA Z06 will beat a 650-700whp SC Z06 driver for driver. These pare peak numbers (same dyno), where the SC graph makes more power everywhere. Real world results vs. just math. Clearly there is a way to model this mathematically (transient response, etc.), but it doesn’t change the outcome.

Da Z06

Interesting, my cam is also 249 duratiom, my CR is 12:1 and I further reduced quench by .011".

jayyyw

I do wish I had gone with the cometic gasket for a tighter quench. I wonder what the difference would be.

nuke61

Assuming that what people say their cars ran on a dyno is the truth, I've seen it over and over on YouTube. I think the math is the math - but the SC cars simply don't make in the real world what they make on a dyno. Whether it's heat soak, or the BOV opening as they shift... whatever the case is, they just don't perform as the dyno says they will.

jayyyw

I've ran door to door with a 750whp LS2 car when I made 608whp on the same dyno.

nuke61

My only personal experience is that I lost to a cammed (don't know what else) C6Z, walking away, not just a jump, several years back in my blown C5Z with 600rwhp / 600rwtq

jayyyw

Sounds about right. Probably a 550whp car.

jayyyw

So, had a very uneventful track day. Been fighting an issue where the motor will "break-up" after a fast shift. Pretty much narrowed it down to a head/valve spring issue. Most likely valve float, even after tightening up my install height on my BTR springs.

I'll be pulling my heads and sending them to LME to get new guides (if needed), valve job, and their port program done on the heads. Also need to choose a new spring that can keep everything under control in the higher RPMs that I'll be running. Any suggestions?

jayyyw

PAC 1209x
Install Height: 1.800"
Closed Spring Pressure: 160 lb. @ 1.800" Installed Height
Open Spring Pressure: 510 lb. @ 1.100" Height (.700" Lift)
Maximum Spring Lift: .750"
Coil Bind 1.000"

I am running Morel drop-in lifters with plastic trays. Would these springs be too much for those lifters?

TXGS507

Damn bro... no good

Da Z06

What is your valvetrain achitecture?

Springs (install height ans cold bind)
Retainers (Steel/Ti)
Valves (Ti, Steel, Hollow Factory or Ferrera)

Im running the following:

PSI LS1516ML springs
BTR TI-Retainers
Stock Locks
Stock Ti-Valves
Latest batch Stock Hollow Stems Exhaust Valves (COPO)
Stock Rockers with Straub Bronze Bushings

So far weight comparison (based on my own scale) it looks like.

Old Set-up (stock locks/retainer/intake valve/PSI 1515ML/Ferrera F2042P HS):

Intake: 164g (179g stock)
Exhaust: 174g (177g stock)

New Set-up:

Intake side weight: 149g (179g stock)
Exhaust side weight: 147g (177g stock)

That is a 30g weight reduction or 16.75% on the intake and 30g or 16.94% on the exhaust over stock which is significant.

Install height is set at a nominal 1.790" intake, 1.780" on the exhaust. I was looking for a .050" CTB. Actual came out an average of 1.792" in and 1.783" on the exhaust.

Car pulls extremely clean.

I would dish the BTR springs, and go for the 1516 PSI. Use the LS3 style Ti-retainer, .060" spring cup, and I belive it was .030 and .015" shims to getvthe nice and tight to .050" bind.

Unreal

1209 are a pretty hardcore spring, and I believe larger OD than stock, so would have to check to see if they even fit your spring pockets.

Da Z06

Again, cant go wrong with the PSI1516LS.

Below I attached a screen capture based on the PSI1516LS and your cam specs with a .050" coil to bind clearance for max control. This is my own calculator.

Of course, you will have to check your install height and check CBC.

Da Z06

I agree with Unreal. Thats a lot of pring and not needed.

jayyyw

BTR .660 springs - 1.775" install height
Titanium retainers
OEM intake and Ferrera Exhaust Hollow Stem
Stock rockers

Unreal

I seriously doubt it is a valve float issue unless you just have one bad spring or something. Take them out and measure the pressures.

jayyyw

I'm hoping it's not. Trying a few more things to see if it might be some kind of electrical issue. I'm able to rev the car out to ~7500 easily, with no sort of stumble or noticeable issue. It's only AFTER the shift and I get back on the gas when the car will break up as if it's hitting the rev limiter (but the tach does not rise, so it's not clutch slip). Talked to another tuner in the area and he suggested a MAF sensor. Many people suspect a ground issue.

I really need to log it. At this point, I'm just grasping at straws.

Kingtal0n

I'm not sure if serious or not

you seem serious. 1 horsepower is a meaningless unit somebody invented. I can say 1 cat power and 1 llama power and be just as accurate to do so. That said, the unit llama/cat/horse power is a measure of work, we could easily interchange with Watts which is Joules/second iirc


Force is Force. 10 newtons. 50 pounds. 1 Newton is 1 kg*m /s^2
Distance is Distance. 3 meters. 3 miles.


Fd = Work
is how they write it in physics books

1 horsepower = 745 Watts, how many 60watt lightbulbs is that? 745/60 lightbulbs for 1 hour or 1 60 watt lightbulb for 745/60 hours.

Wait, did I just get hours out of watts? And watts out of horsepower?

How is that possible that we can know how many hours a lightbulb will be on for from horsepower?

Because it uses time in it's equation. But I thought work was just force times distance? Lets look at the equation and then ask ourselves what happened.

Joules = Watts times seconds
or
Watts = Joules per second

i c what they did there? When somebody hands you a watts or horsepower figure you just assume its equal to that # of watts in joules over 1 second. Because they would have mentioning the "over something" part if it wasn't, in order to be accurate. So horsepower has an immediate assumption of being in terms of per second because we removed the denominator to make it a 1 in order to not need to speak of the units. But regular people don't even think of the "over 1 second" part which confuses a lot of discussions, such as this one.


Bottom line: Vehicle A and Vehicle Z both are held at any steady state output which we measure and determine in terms of Watts, if this is then transferred to the road completely the final distance is determined by the number of Watts given the time elapsed. Whoever has more Watts wins, at the farthest distance given some time amount. The essence of drag racing at its most basic principle.

Da Z06

Bro',

You are correct, and at a constant -750 will go further than 749....BUT-On the real battleground it takes on average 100+HP forced inducted difrence to run-with or beat a C6Z.

That is where theory meets reality.

jayyyw

Sometimes intelligence hinders your ability to account for real world results.