Adjust front end lift on acceleration?

[Dangerous Doug]

Bob, et al:

I notice more lift in the front-end than I'd like when I punch the throttle. My Cobra doesn't feel like it's squating in the rear, it feels like the front end is lifting up a bit. Can I adjust this out, that is, can I adjust the shocks to get less front end lift on acceleration? Or is this a rear shock hardness issue?

DD

Hey, by the way: Did Peter send out the "street interior" door jams that I ordered for my FIA?

DD

[Tommy]

Doug,
What little I know about the ERA 289 FIA comes from their web site, so take this for what its worth. The web site says:

Front coil-over shocks are mounted to the X just like the original Cobra. We recommend our custom made Spax units with external adjustments for both damping and height, but you can use any brand that meets the proper specifications.

So, it sounds like you may or may not have adjustable shocks depending on what was ordered with the car. If you do have adjustable shocks, it should be possible to dampen the rebound action to slow the rise of the nose under acceleration.

[strictlypersonl]

For street-driving considerations, the wheel rates in the front are softer than the rear, with a larger front anti-sway bar balancing out the actual roll rate. A change in the rebound damper rate won't significantly change the front lift without the car losing traction when encountering real bumps. If it really bothers you, the only path to reducing lift is a significant increase in the front spring rate (with a smaller front anti-sway bar), but with the changes, there's a commensurate reduction in ride quality.

[Dangerous Doug]

With ride quality costs for street driving, this is less of an issue (who many times do I pound the throttle on the street?).

This evolves into a track question, then: If I take my primarily street-driven FIA to a track event, what suspension adjustments could/should I make to tighten the suspension for track activity?

DD

[bobcowan]

Unless the suspension is set up for it (like a drag car) front end lift is generally caused by a shift in CG to the rear, and compression of the rear suspension. Fortunatly, that's a cheap and easy thing to test for.

Jack the car up in the back, and put a cable tie around each shock shaft. Put them very close to the shock body. Go drive the car around as you normall would for about 5-10 minutes. Take a look at the cable ties, and see where they're at.

Now do a couple of hard launches that causes the front end to lift. Take another look at the cable ties, and see how much suspension compression you're getting.

If it's a lot - or if the shock gets completly compressed - move to a higher spring rate. Or increase the shock compression rate if possible. Changing springs is the the best choice. But adjusting the shock is free and easy. You can always change the springs later.

[tboneheller]

Just don't "punch it". Problem solved!

[Dangerous Doug]

Originally Posted by tboneheller

Just don't "punch it". Problem solved!

You're kidding, right? Do you realize how much self-control that would require, driving a car like this?

DD