[SRT Engineers]

Viper X:
Another question on the ACR. It is likely that those of us that buy this car will run 18's all around due to a better "sticky" tire selection. What will we have to do to adjust the aero features, i.e. wing and splitter, to accomodate shorter 18" rear tires?

It would be impossible for us to recommend setup changes unless we specifically tested and tuned the tire combination you are thinking of. We have run the following R6 DOT Radial Road Racing Hoosier tires on the ACR:

Front: P295/30ZR18
Rear: P345/30ZR19

These tires will fit well on the ACR standard sidewinder wheels. The ACR performed well on these tires, however, the soft sidewalls of a Hoosier tire results in more vehicle roll angle and the suspension settings and alignment could probably be optimized to fit these tires better.

We would recommend that any tire substitutions attempt to maintain a diameter very close to the original equipment. Tire diameters have a large effect on braking operation in the Viper as well as some suspension geometry relationships and it is best not to deviate a large amount from that supplied by Dodge.

The great part about the ACR, however, will be your ability to tune the car if you decide you want to change an area like the tires. Here are some tuning tools to consider if you decide to take this path:

Compression and Rebound Damping
Ride height and Rake Angle
Corner Weights (wedge)
Wheel Alignment (Camber, Caster, Toe, Bump Steer)
Wing Angle
Splitter Cable Pre-load
Spring Rates (ACR is equipped with standard 60mm ID race springs)
Tire Pressure

Remember there are warranty implications with any changes you make as well as track use of the ACR. We simply cannot cover this area and still offer the ACR at the bargain price that it is selling at. I’m sure everyone understands this and recognizes the aftermarket costs of the content included in the ACR package compared to the factory pricing.