Cars have low top speeds and fast acceleration

Part of it is due to a resonance "pit" that tires fall into at high speed, where it takes an extraordinary amount of power to overcome it. Once you get past that pit, with just enough power and the right torque curve and gear ratio, you can accelerate to a fairly realistic top speed. The Bolide was seemingly falling into this resonance pit. And yes, stiffer tires help with the rolling resistance, but they're at a realistic stiffness already and as stiff as I can make them in other ways within stability (i.e. not exploding). The tire expansion at speed is negligible - it is maybe 2% at 150 mph. You can measure the expansion by looking at the discrepancy between wheel speed and air speed - wheel speed will read low as the tire expands.

I'm still not sure why the V beams only help with very fast cars. If I add them to the standard Covet, which seems to hit a resonance pit around 87 mph and sometimes sputters its way up to 100 - it actually makes the top speed worse... it never gets out of the 87 mph pit (unless I give it more power). The Covet Race (which used to be the Sport) with the turbo is only capable of 133 mph at best, and again, the V beams make it worse. I would expect more like 140-150 mph out of it, since it does 0-60 mph in 6.3 seconds and has 180 hp for its ~2150lb curb weight. It just hits a wall in top gear, at peak torque, where it simply won't accelerate anymore.

On the other hand, there are cars whose top speed I'm quite happy with. The new version of the D15 Sport (which is now a factory option) with 423 horsepower can go 149 mph. The Grand Marshal Sport with the same engine can go 163 mph. I haven't tested thoroughly the effects of V beams on those cars, but I imagine they wouldn't do much, since they're right on the threshold of V beam effectiveness.

 

Woo! I found that if I set the expansion spring high enough on the V beams, they work for all cars, not just fast ones Got 102 mph out of the standard Covet, 137 mph out of the Covet Race (which I found out is actually gear limited), 172 mph out of the Bolide 350 GT, 142 mph out of the Bolide 320... will come back with more numbers as I add the V beams to every car

 

You'll find out when we release the race update

I dialed some aero drag back in to the cars (since the tire rolling resistance is more reasonable now). Standard Covet can still go 100 mph so that's good Also got the T75 above 100 mph (used to top out at 93).