Provided in the thumb below is a spread sheet comparing the acceleration of my 2006 Z06 vs my 2002 Z06, both bone stock on stock tires.

My driving in the C5Z was dialed-in, while it's not in the C6Z. The difference is in achieving optimal shift points and speed of shifts. The DAs for the runs were very similar, about a positive 100 feet.

Leaving aside the 60' differences, the C6Z pulls stronger in every segment of the 1320 by pretty even amounts.

Finally, with dialed-in driving the C6Z should produce a best ET of 11.20-11.25, a tenth or so better with more practice, practice, practice.

EDIT: Updated the thumbnail to include my 11.31 pass from April 9th. The 60' on this pass was 1.90, leaving room for improvement. Also please note that the 1000'-1320' increment for the C6Z includes execution of the 3-4 shift.

Ranger

 

Great information Ranger. Its interesting to see that a car with 100 more hp isnt one second faster once you get into the 11s. I knew this "rule" didnt work for cars in the 10s or faster. Guess i might need to aim my hp needs a little higher. I forgot the cars are on street tires but i bet the difference on drag radials will not be one second but i would expect the 06z to have a bigger advatage once you compare both on drag radials. btw are you putting in a roll bar or are you just going to another track when you use drag radials I read that your car got kicked off a track for being faster than 11.5

 

Thanks for posting this interesting comparo. Almost a 10mph difference in the 1/4 is huge!

 

Cool comparison, thanks!

 

It is 10mph faster I've always heard that every 10 horses gives you 1 mph - seems this confirms it. The problem I'm sure Ranger is having is hooking up, with so much torque its a huge balancing act
to launch it. That's the concern I have with dropping in a 402 in my car. It will make around 500 rwhp & 490 RWTQ and I might not go any faster in the 1/4 with my tires Of course the added torque willbe a BLAST!!!!!

 

Great data, neat to see what an expert can do with a C6Z....

As you said, leaving out the 60 foot time, the C6 is stronger all the way down the track. I wouldn't expect the C6 to be much different at the 60 foot mark, even when you get it dialed in. It may be a bit better, but while the C6 has more power (and more importantly torque) it also has a much taller 1st gear. It has almost 20% more torque and almost a 20% taller first gear. Which results in very similar acceleration off of the line in first once both cars are hooked up.

This isn't a concidence, since if you had more torque in first gear it is obvious you'd just go up in smoke anyway on street tires. So they put in a taller gear since that was about all they could put down in first anyway. Also, it got the C6 over 60 in first, so the magazine testers would hit sixty without a shift and it would look good in the zero to sixty comparison. But it probaby isn't going to be any easier to launch the C6 with the taller first gear, I would think the bog/spin window will just get tigher. Maybe Ranger doesn't notice it as much since he is a very experienced drag racer......

So up to the point where the C5 has to shift out of first, don't expect the C6 to be much if at all faster than a C5, as the data clearly shows.

The difference comes when the C5 shifts to second, the rear wheel torque (and resultant acceleration) is much lower (from a 2.97 first to a 2.07 second, you have only 70% of the torque at the rear wheels that you had in first), while the C6 is still pulling in first it has almost 30% better rear wheel torque and acceleration compared to the C5 Z.. From there to the end, it is going to be all C6...

This is the limitation of a front engine/rear drive setup.. You can only put down so much power in the lower gears. If you had more traction, you could pull a shorter gear and accelerate harder in first. This is one of the key reasons that supercars are, for the most part mid-engined.

Tires have gotten better over time, but as you reach the limits of traction (and at 500 hp on street tires you are pretty much there) you need to think of a higher percentage of weight on the rear wheels to improve lower gear acceleration. With set of drag tires you can extend that envelope, but even with sticky tires you can overwhelm them with the torque we have in first...

Note that even with more power and less weight, the C6Z still isn't as fast as a 430 Ferrari (at least according to magazine tests) in a quarter, even though it is trapping at a much higher (like 10 mph) speed, the Ferrari is getting off of the line stronger and is putting down more torque (from a shorter first gear) out of the hole...

As Clint Eastwood said, "man's gotta know his limitations"

 

Thanks for the thoughtful post, Solofast. Good analysis. I believe the C6Z can drop another .10-.15 with better driving. But the wheel spin that's had on stock tires seems to avoid most of the effect of torque management, a feature I don't recall dealing with on the C5Z.

TM essentially dumbs down the power when pre-set thresholds are exceeded. All done to protect the drive-train from breakage.



Ranger

 

Glad to see you’re at it right out of the gate. Not many out their will share all or tell all. Thanks Ranger, slong
Now if I can just convince my hot chili pepper "wife" how much I need a new Z.

 

Ranger,

I wasn't aware that the C6 had a TM system was specifically programmed to protect the downstream hardware. Gee, there is a problem the rest of us wish we had.....

Of course I guess that they could just use manifold pressure, throttle position, RPM and temperature (to figure airflow) and the fuel burned and generate a map and electronically limit the throttle opening so as not to exceed a specific output. Actually, with a known OAT, and a good idea as to what the barometric pressure is (correlation between throttle position, rpm and manifold pressure) the could, I guess would know pretty much what the throttle position that they don't want to exceed even before they get there...

I would also guess that you could address that with reprogramming....

Just curious as to how they managed it????

 

The tuners are working with the ECU-edit programmers to crack the GM SW/firmware as a mean of making changes to the stock programming. The early releases are out and in use. But I've yet to see a lucid explanation of how torque management works at launch.

being a stock guy, my interest is to learn what is measured and the thresholds for TM invocation, so that I can avoid it all together by driving techniques.

Still looking for that lucid and reliable expalnation, if you come across one.

Ranger

 

Not to be offensive, but it is pretty obvious that the new Z06 pulls harder (accelerates faster) than the C5Z. No chart needed to tell us that, but pretty neat all the data you gather to prove a point.

 

Having owned and raced three Z06s, I understand your point. But there are some lessons in the data for those with the patience to go to school on the spreadsheets. Not everyone wants to do that....

Ranger

 

My uncle recently had a 404 installed in his Z06. With 3.90 gears and 295 Wide Ovals he can easily light up the first 3 gears. It takes almost no effort in first and it seems that the TC can't keep up with the engine sometimes.

 

Does he like it A&A recommends Nitto R2's on 18's

 

The MPH is huge, but the car with the quickest TIME wins! And they are pretty close. Amazing. It really makes the C5 Z06 look great.

 

Remember guys, a half a second at those kind of 1/4 times is like a week.... At the finish line the new C6 is probaly on the order of 80 feet ahead of the C5 and is pullin away...

It is always as wise thing to know not only that you are fast, but WHERE and WHY you are fast. That way you will KNOW what to improve upon and what difference it will make when you do improve upon it....

Ranger has shown a very astute scientific approach to understanding the mechanics of what he is doing and clearly knows his stuff... I don't know many folks that can show a time slip for a stock Z, on stock tires, in the 11's.... Man that just blows my mind...

 

He loves it. At first he was kind of skeptical but he had to break-in the differential and clutch so he couldn't really get on it. After that, he drove it much harder and now sees the difference especially in the mid-range. Now we have to get a FAST 90/90 because the LS6 intake is holding him back.

 

At 127mph it would actually be slightly over 93 feet, about 5 car lengths!

Chuck

 

Nice numbers rang.

Interesting to see how the DR's really helped the C5Z and did not give you much in the C6Z. What gives? Are you babying the C6Z due to drive train concerns.... or is it the TM?

Now let's see some 10.9999999's!!!!

Also interesting to note that you'll need to bring more to the table in a C5Z than just DR's and intake mods.......... UMPH! UGH!

Or just hope the average C6Z owner is too concerned about sipping coffee rather than racing

 

On a strong launch on drag radials, the LS7 Torque Management routine is invoked, cutting power briefly to protect the drivetrain. This adds .1 to .15 to the 60' time. Also the LS7 clutch is more finicky (hating evern minor slip) than the LS6's.

Believe I can sort out these issues and find a better launch technique that avoids TM. Just hard to experiment when I get tossed after two passes for lack of a rollcage. So I'm awaiting some track rentals.

Ranger