Is the C4 ZR-1 the Fastest ?

[XfireZ51]

BTW, the motor used for the 24hrs. was a spare that set aside because it was deemed to have a slight vibration.

[rush91]

If we are talking fastest, naturally aspirated motors, The Viper GTS's of the 1990's have the top speed. I believe it was 5MPH faster than the ZR-1.....But Dodge needed 2 more cylinders to do it. And if you have every drove a Viper really fast, it's a miracle your still alive. Not as stable/ planted as a Corvette at speed. Dodge needed to add Aero packages to go any faster safer. Hence the ACR's and special big winged Vipers.
I'm hard pressed to think of an American factory stock car, that could touch the ZR-1. That is until this new breed of Muscle cars hit around 2008......The 2012 Ford GT500 could hit 201MPH and I believe the 1989 Turbo Trans AM could hit 165MPH.

[Bob Eyres]

Originally Posted by MarkSS

Fastest American production car of the 20th century would go to the ZR1s cousin... the 1991 Callaway B2K areobody was clocked at 192... Vipers of that era were 185.

JMHO, but I don't consider the Callaway a factory production car, B2K or not. Those Corvettes came from the factory with 350/245hp. engines. Lingenfelter, or Callaway cars, as great as they might be, are really tuner cars. Not from Bowling Green.

As to the Vipers, can anyone cite a road test, or other documentation that states a 20th century Viper can clock 185?

Much as I'd like to, I don't think a C4 ZR-1 with 3.07 gears, (and headers/no cats), can be considered "factory" either. But that documented 194-195 on the straight at Fort Stockton is surely impressive, regardless.

Even with more horsepower, the Vipers and early ZO6's were limited by bad aero, but would a bone stock C4 ZR-1 really do 185? Who's done it? Not me. I've not come within 10mph of that.

[BigJohn]

You'er funny!

[Bob Eyres]

OK, just found a Motor Trend road test of a stock 97' Viper GTS that clocked 187.5

http://www.motortrend.com/cars/dodge...dge-viper-gts/

I don't know if any bone stock C4 ZR-1 could top that.

[BigJohn]

American made Panoz sports cars are very fast 560 hp and weight at 3128 lbs !

[Bob Eyres]

1997 Panoz Esperante (of which one was sold), Est. top speed = 155. Gee, a "factory" (pre Callaway tune), Corvette can do that.

[BigJohn]

Panoz also has a 750 hp 32 valve engine. You get what ever gearing you want.

[BigJohn]

Originally Posted by Bob Eyres

1997 Panoz Esperante (of which one was sold), Est. top speed = 155. Gee, a "factory" (pre Callaway tune), Corvette can do that.

My 1971 Plymouth GTX can do 168, just ask the Troupers.

[KILLSHOTS]

The street version of the Esperante debuted in 1999, and I actually believe it may have officially been classified as a 2000 model. That car was built with the 305HP Ford modular V8 from the Mustang Cobra. Later, more powerful versions certainly wouldn't have fallen within the realm of the OP's question, vis-a-vis 20th century American production automobiles and in fact, I'm not sure that ANY production Esperante does.