Re: drag
Originally posted by buickpower
I pretty much agree with what you are saying about the gearing, however, I wouldn't discount aerodynamics as playing a significant role. We modeled a gn in FLUENT, and lets just say it wasn't pretty compared to other modern cars, and this was only at 65mph.
The Aerodymanics may be 20% worse for a TR vs. a F-body, but from 100-130, this would have less of an effect than the gearing disadvantage. Assume a 350 HP Theoretical GN and a 300 HP theoretical Camaro.
If you use the Road HP numbers from Car and Driver, back in 1986 of 30mph - 7 HP, 50mph - 17 and 70mph - 36 HP and extrapolate that out to 100 and 130, it takes approximately 100 HP to go 100 and 200 HP to go 130 and with 350 HP, would have a Theoretical top speed of about 155 mph.
If the Camaros Aerodymanics were 20% better (a huge difference) it would need only about 80 HP and 160 HP to do the same 100 and 130. This theoretical Camaro would have a top speed of about 156 mph, which is about what a real stock camaro tops out at.
Now lets look at the 100 - 130 mph race:
with the GN with 350 HP and the camaro having 300HP, the GN has 250 HP to accellerate tha car at 100 mph and 150 HP to accellerate tha car at 130 mph.
While the Camaro has 220 HP to accellerate the car at 100 mph and 140 HP to acellerate the car at 130. The easily generated 50 extra HP in the GN trumps any aerodynamic advantage of the camaro. This GN should win this race, Right? but it usually does not.
The problem is that the GN's OD shift at 110 mph (or less) knocks the HP down by about 20% minimum (the sooner the shift, the worse it is), so instead of 250 HP to accelerate the car at 100, it only has 200. By 130 it is getting closer to its power band and may be only 5% down from its peak HP, but by then, the Camaro has made up a huge amount of ground, before it too had to shift into OD.
for the Torque calculations I was rounding and doing the calculations in my head. I said 500+, the actual number at 3300 RPM is around 480 to equal 300 RWHP. MOST manual LS1's have more than 300 RWHP (closer to 320) and 3300 is the "perfect automatic OD shift". If you let the car shift itself at WOT, chances are pretty good you'll have 3100 or 3200 RPM in or even less OD. Suffice to say, this isn't the Ideal contest for a GN.