I just bought a 1984 Fiero with an LT1 350 v8.
The car does not handle well since the front suspension swings up and down whenever you accelerate or de-accelerate. Engine weight and too much power is the issue. I guess a modification to the front suspension should be done to improve handling.
What do you recomend?
Thank you in advance for your suggestions

Welcome to the Forum!

What you're experiencing is called "dive" (nose dipping upon braking) and "squat" (tail digging in upon acceleration). There are several complex ways to improve anti-dive and anti-squat but the only simple way is to increase the rates of your front and rear springs. That's a typical requirement when adding an Chevy small block since it adds about 150 lbs to the car, so perhaps the previous owner never swapped them out.

There are two ways to get higher rate springs. One popular method is to cut a coil or two from the stock springs which has the added benefit of lowering the car (if it needs it). Shortening a spring increases it's rate. The other method is to buy aftermarket springs that increase the rate.

Of course higher rate springs will also give you a harsher ride so knowing what spring rate to buy is pretty much hit and miss unless you know someone who's changed out their springs and you can get a feel for whether they're too stiff or not stiff enough. For a V8 Fiero, typical rear spring rates range from about 350 lb/in (softer) to 450 lb/in (stiff). The front should be increased to between 275 lb/in (softer) up to about 350 lb/in (stiff).

As mentioned, there are other ways to improve anti-dive and anti-squat but they require metal fabrication skills and a willingness to experiment a little more. Not knowing much about you or your car, I'd start with cutting a coil from each spring. It's cheap and can be done with only a couple special tools like spring compressors. If you like the feel but want it stiffer, cut another coil. If it gets too low, then buy aftermarket. Always remember to get a 4 wheel alignment after changing your springs. Fiero's get unstable without a proper alignment especially in the rear. Good luck!

Shocks and struts shot? Push down on each corner of the car - does in "bounce"? I built an 86 Coupe with a SBC/4 spd. Same issue - it was very squirelly. Replaced the front shocks and rear struts with Koni's and all was good. Still had some dive and squat but nothing that was scary. As Blooz says - Stiffer springs will help.

Torque in a Fiero is a blast. You have to hold on. My 88 Lt1 Fiero can be scary. I couldn't imangine it with 84 suspension. The 84s used tiny rivets for the rear ball joint mount. Check them for loosness or broken. If they are loose. Drill em out and replace with hardened 1/4 20 bolts. Enjoy. Buck sez you blow 2nd gear within 6 months of fixing suspension. I did.

[This message has been edited by bonzo (edited 01-27-2013).]

Thank you,
I just ordered the Koni shock ans struts as well as lowering and higher grade coils for the front and coli overs for the back.
Hope this takes care of the problem