raj

First of all, I'd like to give credit where it is due and thank NineBall for the excellent dyno comparisons between the cars and the objective reporting of the data. His data is the source of my analysis but keep in mind that my plots are based on eyeball extraction of numbers from the original dyno graphs which, of course, adds a source of variation.

First plot shows the RWHP graphs of the two cars.



Thing to note here is the massive RWHP advantage that the Z06 enjoys at the lower RPM levels: ~90 extra wheel HP at ~2500 RPM. This is the result of the low-end torque that the LT4 develops so much more rapidly than the Viper's NA V10.

Since the gearing is nearly identical between the two cars, comparing the RWHP curves within the usable range of any specific gear makes for a valid powerband comparison. A 2nd gear comparison as shown below highlights the low RPM advantage of the Z06, with both cars starting from ~4500 RPM after a redline shift from 1st.



The LT4's torque curve peaks early and essentially stays prairie flat through ~4500 rpm before declining, while the Viper's V10 starts building steadily, peaking only around 5000 RPM. Result: the Viper's HP climbs at a more rapid rate than the Z06's, closing the gap as we head into the crucial higher rev range.

What happens in a 4th gear showdown between these cars?

Things get interesting now as the powerband of interest is shifted higher. Similar gearing means both cars start out at very similar RPMs and speeds within a few MPH of each other. The next plot compares the powerband from the start of 4th (~5400 RPM) through redline.



The massive advantage the LT4 enjoyed in the lower revs has now been whittled down to a much smaller one. The key here is to compare the area under the curve for each and estimate the mean RWHP within that RPM window. My calculations shows that the Z06 makes less than 20 additional RWHP through this gear on average, subject, of course, to any errors in my eyeball extraction of numbers from the original graphs. With both cars incrementing their speeds by nearly the same amount in this gear (26 mph for the Z06 vs. 24 mph for the Viper), the advantage for the Z06 is no longer significant.

Which car has the accelerative advantage in 4th?

These cars are in the rarefied regime of ~6 lbs/RWHP, so a ~20 RWHP delta is likely insufficient to overcome the Viper's 200 lb weight advantage. Mathematically, a ~30 wheel horsepower advantage for the Z06 should make the power-to-weight ratios identical. Then there is the elephant in the room: aerodynamics, which obviously plays a key role at triple digit velocities. Early test data on the Z06 suggests that top-end acceleration may not be the Z06's forte especially when it is equipped with the level 3 Z07 package, more than likely a result of the downforce to which GM has alluded. Pit a level 1 aero Z06 against a Viper TA and it will be a driver's race even at higher speeds. Indeed, these are the golden days of horsepower!

lawdogg149

You my friend are a math engineering geek. I love it. This really helps me understand what is occurring between these two cars. I own both as most know already. I cant seem to get a good seat of the pants feel of which one is faster. The Viper is indeed strong above 4000 rpm. This helps alot on the road course. Very rarely do we allow the rpms to drop lower than 3500 to 4000 rpm.

Thanks alot for breaking these charts down.

racerns

This has already happened a few times and did not seem to be the case.

JackTripper

They BOTH have kill vids.

rgkeller

The Z06 in 9B's videos was level one.

racerns

Nspec ran his Z06 again, this time against his Viper, with the same results. The cars even until 4th then the Viper pulling away. No video.

therealviper

Torque however can be in a tight cornering situation, make up for shifting mistakes....

Regards,

Viper

Flyboy22

Just because it was a Level 1 doesn't mean it doesn't have more aero drag than the Viper. In fact, the results seem to indicate that it does.

I simply can't believe a small weight delta has any believable impact on acceleration at 130+ mph speeds. The air drag is immense, however, and even a small difference in total drag could easily determine who wins with such close power specs.

I believe the CONCLUSION we should draw (besides the fact they are both awesome cars) is that the Viper has less drag. I don't think GM engineers are idiots, and I'm guessing they accepted drag as a penalty for the aero they wanted (ie serious downforce generation).

I would really love to see back to back track comparisons between these two supercars. I know who I'm predicting will win. By how much, though, will be very interesting.

AirBusPilot

I think a torque graph comparison might be more relevant. What rpm do both cars drop to once you shift to 4th after redlining 3rd gear?

NineBall

Very good analyses Raj! I appreciate the data, being an engineer myself. One thing that gets mentioned, but people are not discussing, is that the Viper has a legit "ram-air" system. That NACA duct on the front of the hood feeds directly into a sealed filter box. In fact, if you look straight through the duct, you see the filter. Ram-air effect is greater, at higher speeds. It can also not be measured on a dyno. On previous cars, where I've installed such aftermarket systems, I've picked up 1-2 tenths and 1-2 mph at the 1/4-mile. Vararam builds their business on this effect, as do others. I remember just making the nostrils on my old '98 Formula function as a ram-air added over a tenth and 1 mph to my trap speed. That was when it ran 11s, at only 125 mph on the track. When we race up to 140+, you have to think that the effect is even better. This *might* be the real reason that the Viper pulls away harder, the faster we go.

Torque and Horsepower are mathematically related by a simple formula. Area under the HP curve, within the racing powerband, is what matters. Not peak values, like too many focus on. If horsepower is higher, so is torque in that area. Their relationship does not change.

HP = (TQ x RPM)/ 5252

He shows the rpm start/finish by the blue and red dashed vertical lines in his graphs.

AirBusPilot

True, but wheel torque is what accelerates the car. Torque is multiplied by gearing.

In your next race with a Z06, have both cars start out and finish in 4th gear. Start at 3k rpm and take them both to redline. This at least removes any claim of driver error.

js59

There is another vid around here with the z06 running away from the viper. Not sure why it rarely gets mentioned in these discussions. I think the z won four out of four in that vid.

ZO6er

I still don't like that the Z has 7 gears...

nj02vette

NineBall, a blast from the LS1tech past!

Few in this world are as thorough or unbiased as you've been, and for so long. I agree with the ram-air hypothesis as well. We all saw what it did on the F-bodies and Vararams on the C5, yet no demonstratable dyno results from those installations.

Don't get to LS1Tech much anymore, but damn you had some good writeups back in the day. Great to see you are doing well.

NineBall

You can see evidence of the low rpm torque advantage on the two runs we did from 40 mph in 2nd gear. Both cars should have been in 1st gear, but neither of us had traction in 1st/40mph. On the hit, the Z06 would grab an easy car length each time. The Viper would have to play catch-up and eventually pass the Z06.

But, if we are racing, then what matters is that we are both in the proper gear for the given mph. I was clearly giving up the advantage on those 40 rolls, but it was worth testing.

NineBall

Thanks. I don't get to LS1Tech much, either. Really only in the Texas forum there, to hang with the locals. I'm over 4th gen f-bodies

C6Z06C6

Maybe his Z06 is a underachiever. I bet we see more videos like the 2nd video of the Z winning then Nspecs and Nineball's video. So funny how 1 person can become a legend/God on this site from posting 1 vid.

NineBall

Add this one to the ongoing conspiracy list.

BTW, nspec's car dynoed within 1 hp of another C7Z on the same dyno.

As much as some of you want to discredit the findings, I couldn't be more transparent with the info and data we've collected. I also plan on racing that other C7Z, if he can fit me in between his paint protection and detailing/waxing schedule (not kidding).

Tony

PDCjonny

That's ludicrous and you know it.
Not even comparable with the so called Z kill please.....heavy passenger filming from the TA....c'mon come up with something as remotely legitimate as NineBalls.

Callsign_Vega

Nineball, it's because an alien spaceship was using a tractor beam to help pull your Viper along. Clearly the Z06 is faster without the tractor beam..