Here's the official news as we're getting it from the first drive over at Milford:
Chevy Camaro SS Official 0-to-60 Time: 4.7 Seconds
Ray
Chevy Camaro SS Official 0-to-60 Time: 4.7 Seconds
Ray
Yes sir. That's what I'm talkin' about! :tup:: :dro:MEANING: That they took a 304HP (at the Fly) 3.6LDi and boosted it to 340HP with the Exhaust and Intake MOD.....:yup:
With SAE certified, I find it unlikely that horsepower would be overstated that much. 263/304 is 86.5%. Are you sure that 13.5% loss isn't a reasonable number for this dyno? Environmental conditions need to be factored in too.Aparently, a Dynapack takes its readings from the hub with the rear wheels OFF. I thought this was the case.
This definitely would give a more "optimistic" reading (closer to true flywheel hp) than a Mustang or Dynojet. That being said, wheels and tires (especially big one's like 18's and 20's, having more weight transferred to the outer edge) would be a large part of a modern drive train's loss. From what I've read during my research here and talking with my tuner friend who does a lot of dyno tuning, it's up to 50% of the total parasitic loss.
That puts a Dynapack at a more conservative 5-6% drive train loss from current (realistic) SAE flywheel horsepower ratings as opposed to a 10-12% loss experienced by a Mustang or Dynojet roller style dyno.
That being said, one can estimate the following taking your stock Dynapack figures of R(HUB)HP and obtain the following estimate:
263/.94 (6% loss) = 280 @ the crank
and checking this gives...
280 x .94 = 263 @ the wheels
24 HP bellow advertised. If this is consistent with other dyno tests......
Do I smell a lawyer?
Keep in mind that the below writeup was printed before the more conservative SAE rating system was adopted, so the loss to the hubs in newer models compared to their advertised rating is about 15 horsepower, not the 25 stated by Church (when using his Dynapack on a 230 flywheel horsepower test car). He did a comparison between the two different style dynos just to see what the differance was and found the Dynojet read 10 horsepower less than his Dynapack, further stating that as the wheel/hub horsepower increased from engine modifications, so did the widening of the gap in the reading between the two different dynos.The final difference between a Dynapack and virtually all other chassis dynos on the market today is that the Dynapack eliminates the tire to "road" interface. By using a special hub adaptor that replaces the wheel and tire, the Dynapack eliminates wheel slip, alignment losses, tire inflation/wear issues and more. However, by eliminating the large mass (and attendant inertia) of the wheel and tire combination, the Dynapack does tend to read higher than comparable "roller" dynos.
I just don't think they can get away with that -- not with SAE certified. Maybe the car that got 263 had an auto.I am almost convinced now that the 3.6DI's horsepower rating is embellished by at least 25 horsepower. Could this be why there is such a difference in performance compared to the competition?