Originally Posted by Larry

Assuming your 02 Z06 gears are the stock 3.42s then that is most of the problem. Based on my calculations you need a 4.30 gear to trap 6615 rpm in forth gear. Going through in 3rd is not ideal. Don't know what your peak hp is but ideally you want to be about 200-400 above peak hp at the lights and in 4th gear. You say it hooks nicely at launch but spins at shift. That tells me you are not getting the torque to the ground at launch. Probably because of too tall gearing. A good side effect too of lower gearing is clutch longevity. Don't have to slip nearly as much at launch.

17" ET Streets might not be enough tire for your hp level. A 15" that has more wrinkle effect would be better. I know it probably won't fit without modification. Perhaps that's out of the question. In light of that then you need to be sure you have adequate rear anti-sway bar stiffness. Don't know how strong the stock 02 Z06 is but you can determine if you need stronger if the drivers side lifts any at launch (with traction of course). Perhaps some polyurethane bushings that mount the bar would be in order. They actually make the bar stiffer as they decrease the amount of wiggle that the soft factory bushings allow. Also adjustable rear bar end links would allow you to preload the bar more. They are available on C6. I'm sure too for your C5. Or perhaps a stronger aftermarket bar.

Your launch rpm sounds about right as long as you are maintaining that rpm and are at full throttle. Don't go below peak torque or hit the rpm limiter at launch. Holding that 6000 sounds good!

I'm assuming you are not getting any wheel hop.

Now keep in mind, my idea of launching is for closer to optimum. If this is a daily driver then you might want to sacrifice some et. With that tall .50 6th gear you can go pretty low gearing and still be satisfactory on the street. A bigger rear bar with poly-bushings would be considered for drag racing only as it can effect handling on road coarse racing. None of my suggestions are for round track.

Originally Posted by Ranger

I'd sure freeze the engine/driveline mods and refrain from the bottle until you get the "driver mod" in place. That will take making 10-20 passes at a minimum.

I must admit too that after 500 passes in C5Z06s with the 3-4 shift just before the 6600 limiter occurring at 100 mph, I'm stuggling to understand how you are managing to get the same gearing to 119 in 3d at 7200. I must have missed something.

Ranger

Originally Posted by LostCauseZ06

lol im actually getting it to around 12x MPH... if you listen to the vid the car kept going for a second after the traps before hitting the limiter. my limiter is set at 7400 RPM's from what i remember.


stock trans, stock rear end gears, and 26" slicks. maybe the balooning of the slicks running at 18 PSI is whats getting me the little extra MPH out of it?

Originally Posted by Ranger

My math says 7400 in third is 112. With a 26.2' tire. Hard to get +10 from that no matter what.

What is mph at the limiter in 1st gear?

Ranger

Originally Posted by LostCauseZ06

ya know, i really have no idea. i sure as hell hope my trans gears has the Z06 gears in it still.... a vendor on here rebuilt the trans made me wait for the "special order" part for the 3rd gear Z06 gear when i got my trans built... if they threw in a non Z06 gear **** will hit the fan.

Originally Posted by Larry

Whoops! 7467 rpm in 3rd with a Z06 1.43 third gear at 119 mph. Assuming 26.2" diameter tires. Who knows what the diameter really is at 119.

Originally Posted by LostCauseZ06

ruh roh.... for future reference if you mount 26x 11.50x 17" MT et streets on some 8.5" C5 Y2k wheels you do not have 26 " tires...


sitting at 30 PSI my outside diameter is almost 27.5" hahah guess that solves the dilemna of why my tires rub sometimes... i had no idea they were that tall.






kinda hard to see but it is in fact almost 27.5 inches...

sorry for the misinformation


27.5 x 3.14 ='s 86.35


7400 / 1.43 / 3.42 * 86.35 / 12 / 5280 * 60 ='s

123.7 MPH @ 7400 RPM... which comes out to just about exactly where it should be givin where i hit the limiter at the end of the track in the video.

Originally Posted by butcher1

LostCause , please don't take this the wrong way , but the problem appears to be one of two things. It's either your driving style or the track conditions. Your motor appears to be making good power (given your altitude) based on the 119 trap speed , but the numbers for the first 660' are not that good. With the rear tires you have and the 119 trap speed , you should be able to get 1.70-1.75 60' times all day long. Those are conservative numbers unless it's spinning all the way thru 1st gear. Another thing that's a little bit off (and that makes me think your motor is making plenty of power) is the fact that you're only running 90 mph at the 1/8 mile. Usually these cars run about 94 mph at half track when they trap at 119 mph. There really is a learning curve when it comes to getting the most out of these cars at a drag strip. Keep trying , you'll get into the 11's eventually.