Quote:
Originally Posted by german gt
Than it's very strange, that GM put a 264 hp engine in it and a gear box which is made for 185 mph in the 5th gear.  |
You have three options when designing a top speed:
1. Electronic/governor control.
2. Redline (gearing).
3. Drag.
The last two deal with gearing. If you have the top gearing redline before drag take holds, you are redline limited. If you have drag take hold before you redline, you are drag limited.
Why would you design a car to allow drag to limit you before you redline it? Because the fifth gear is designed as an overdrive gear for normal highway cruise...and you design overdrive for FUEL ECONOMY.
The SKY is not designed to go 150mph. It can. But it's not designed to operate there. And even if you beefed up 5th gear and made the RL redline limited, the payoff would only slightly extend the top speed.
***********************
And on the drag front, I'll re-emphasize that the lack of a low drag design (or any drag design) does create vibration. When you reach those speeds, any laterally deflected air will induce a lateral force (i.e., a force with components of acceleration perpendicular to the direction of travel). For example, a 45 degree deflection at 150 mph will act just like 100mph side gust at that point on the vehicle. If these drag components are disturbed (which they will be in a dirty drag design) they will fluctuate wildly (at all sorts of frequencies) at those trap points. So you have 100 mph winds banging point on the vehicle at a high frequency in directions out of phase with the direction of travel. Off axis high frequency banging is just a fancy engineering way to say "vibration".
Oh, and that doesn't mean a suspension tweak won't help. A suspension that can dampen the vibration will...well...vibrate less.