I've seen numbers frommore than oneactual test for the viper that showed 0-60 times in the 3.5-3.6 range.
ALSO...
+ and - for vett vs viper
ACRloses weight (-60 lbs rotating mas, -40 for hardcore, + 20 lbs of aero tidbits = 80 lb savings) -- ZR-1 gains a few hundred
ACR keeps near 50-50 weight distribution -- ZR-1 adds all of its weight to the front, screwing things up big time as far as distribution.
ACR recieves vast aerodynamic upgrades to produce massive downforce (1200-1500lbs reported) -- ZR-1 looks much like a Z06
ACR adjustible suspension makes no comprimise in order to put performance first -- ZR-1 suspension is adjustible, but still makes comprimise to appease critics of ride quality
ZR1 predicted power output keeps dwindling (700 reported when rumors first came) -- Viper power reportedly under-rated, according to Hennessey Performance Engineering, the Viper makes more like 620 stock, and 675 hp with intake and exhaust upgrades.
ZR-1 ESC and TCS limit the car to what said crutches will allow (once you hit the limit, there's no room to improve)-- ACR comes with no such crutches, thus allowing you to find the actual limits of the car and to improve your ability to drive the car.
ACR's naturally aspirated 8.4 litre engine has much room for adding power via forced induction if necissary -- ZR-1 engine is already supercharged.
ACR is scientifically proven through stringent double-blind studies to magnetically attract 10x the amount of beautiful woman than ANY corvette EVER.

 

the fastest C6 Z06 i've seen at the track was 11.8's. Z06's running 10.9's are on a good track good weather on a good day. My car dynoed 580RWHP and 700RWTQ and run's 10.9's on the track the same nights theZ's are there.

 

Very few people have taken a STOCK Z06 below 11 seconds......but its been done....on regular street tires.....with less HP and torque then you have in your car.....

Stock #'s for a Z06 are around 11.7-11.9

 

If the SRT vipers were at the track the days the Z's run 10's they might be a couple of them below 11 seconds also.