Project Viper GTS: Part 3 – Baseline Track Testing (Data & Video)


Accel 2nd GearExiting Turn 2 in 2nd gear, the Viper was able to accelerate at an impressive 0.71 longitudinal Gs while sustaining 0.6 Gs through the entire gear.  This is surprisingly on-par with the acceleration in 2nd gear of the 616hp McLaren MP4-12C that we reviewed at Buttonwillow.
Accel 3rd gearAccelerating out of Turn 8 onto the back straight in 3rd gear, the Viper was able to pull 0.4 Gs through almost the entire gear and 0.3 Gs of longitudinal acceleration in 4th gear. For reference, the McLaren 12C was able to pull around 0.55 to 0.6 Gs in 3rd gear.



The Viper’s braking performance is horrible and it has always been a shortcoming of the car in every magazine competition.  The main issue here is not a lack of stopping power since the Viper’s 38/42mm 4-piston Brembo front calipers are larger than the Brembo “Lotus” (Esprit V8) and 2000 Mustang Cobra R front calipers and the 13 x 1.25” front rotors are quite large for the day.  The problem is that due to the lack of ABS, Chrysler built in so much front brake bias in attempt to make the Viper “Safer” under braking so it will never spin out.

The use of a 36mm single-piston Lotus Esprit rear caliper (which is the same as the rear Elise caliper) on a 13 x 0.87” is not powerful enough to make the rear 345 tires contribute very much to of the deceleration of the car, thus making the front tires do all the work.  Increasing the rear brake bias will greatly improve the stopping ability of the car, but we will cover that in a future article.

*The ABS-equipped 2001 & 2002 Gen-2 Vipers had a larger 43mm rear caliper which reduced the 60-0 braking test from 122-155 feet (depending on the driver’s ability) down to a consistent and competitive 110-115 feet.  The 2003+ Gen 3 cars were able to shorten that distance down to 97 feet.

During our test, the stock 18 year old pads did not hold up very well to track use.  After a couple hard braking zones, we still had good pedal stiffness but the car would not stop.  We are unsure of the age of our brake fluid but due to our pedal not dropping to the floor, we glazed the stock pads before we boiled the fluid.  We will be changing out the pads and fluid and be sure to re test.

Braking Peak DecelBefore fading the brakes, we were able to produce a spike of 0.96 Gs of braking before locking up the front tires.  You can see a drop in longitudinal Gs in attempt to unlock the tire before the deceleration stabilized around 0.8 Gs.  For comparison the McLaren 12C could brake consistently at 1.0 to 1.2 Gs.
Braking SustainedThe Viper easily sustained 0.80 to 0.83 Gs without locking up the front tires, and spiked almost 0.90Gs early in the brake zone.

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