Alignment Specs for Eibachs?

[Russ M]

I know there have been several posts regarding alignments, but none have been specifically addressed to Eibach springed Vipers. The car is a Gen 2 RT/10, and is primarily used for weekend cruising/canyon carving, very limited track use maybe 1 or 2 events a year. So basically I want an alignment which will give me the best handling on city streets.

Thanks in advance for the info.

 

[Russ M]

Bump

 

[Mike H]

If you are running on the street stick to the low end of stock ride height and to stock alignment specs. It will keep the geometry right and maximize tire wear. Changing ride heights means you need to change bump steer. More aggressive setups, mostly for racing wear more on tires, thats ok for racing but not for the street.

 

[Frank Parise]

Russ, the brand of spring you use has no bearing on what ride height or alignment specs to use.

The stock ride height as measured from the bottom of the frame to the ground is 5" at the front axle centerline and 5-1/2" at the rear axle centerline. If you lower your car by more than an inch in the front or rear, you will diminish handling capability because you will screw up the suspension geometry such that your roll centers are actually beneath ground level. This makes it very difficult for your car to "take a set" in a turn.

Unless you're doing it only for looks on the street, the only functional reason to lower your Viper is for track purposes. Lowering the ride height results in a lower center of gravity which results in a reduction (albeit a very small one) of weight transfer under braking, acceleration, and cornering. The more you reduce weight transfer, the more you improve overall traction, but only under extreme driving maneuvers. It also reduces body roll by a very small amount. None of the benefits are even detectable in street driving.

Your new Eibach springs are presumably stiffer than the stock springs. Do you know what your new spring rates are? Unless you have adjustable shocks or you have revalved your original shocks specifically for the change in spring rate, your ride quality for both street and track purposes will be diminished, especially over bumps.

For street purposes, use the alignment specifications shown in the factory service manual. They work wonderful in terms of both performance and tire wear, even for open road racing up in Nevada. I used these factory settings to achieve an overall average speed of 171 MPH in the 1998 Elko Gamblers Run, which was a 100-mile hill-climb race.

For track purposes, assuming your ride heights are 4" in the front and 4-1/2" in the rear, try these alignment settings as a good starting point: CAMBER: negative 2.0 degrees front, negative 1.5 degrees rear. CASTER: positive 6.5 degrees front, positive 1.0 degrees rear. TOE: 1/16" out on each front tire, 1/16" in on each rear tire.

Good luck amigo.

 

[SoCal Rebell]

Frank is right on with his full track settings, but it is too much for the street. If you want an alignment that will make the car handle better and have good streetability and tire wear I went with:

Front, +6.00 Caster, -1.75 camber
Rear, -1.00 Camber