I have a '91 Bird with just under 100,000 miles on it. I'm starting to collect all the parts I need for a suspension upgrade, here it was I have so far.
1. Eibach Pro-Kit springs
2. KYB gas adjust rear shocks
3. KYB G-2 Front struts
4. Moog ball joints, inner and outer tie rods and sleeves
5. PST bushings

Now I want to buy Spohn rear suspension parts but need help. The car is a daily driver, I might do some light to light racing, but the car won't see the drag strip. I have done a lot of searching and found info on why I need and adjustable pan hard bar, but will I also need adjustable LCA's? I also know I will need LCA relocation brackets.

The biggest question I have is what type of ends do I need for the street Poly, Rod or a combo? I don't mind some harshness in driving comfort, but I don't want the car to rattle my teeth out either, a nice middle ground would be great.

If you guy's see anything I'm forgetting or think I should also look at PLEASE let me know.

Thanks,
Rick

 

Poly is considered the good middle ground. They are way better then the rubber bushings used on the stock suspension, but aren't as harsh or noisy as spherical rod ends. That's the other compromise that gets made. Spherical rod ends can be very noisy, especially if you have them all through your car. Noise isn't a consideration in racing. Rods have the lowest static friction (which greatly reduces binding) as well as the lowest deflection, but they're noisy. Poly bushings aren't noisy so long as you keep them greased. If you forget to grease them, they'll eventually start to squeak, and that can be more annoying then the noise rod ends make.

 

One more thing I forgot. If I'm just looking for a little light to light racing on the street are the standard parts ok or is it worth the money to upgrade to the 4130 full chrome molly parts? Or would those parts be better suited for an all out drag or autocross type car?

 

If you want to just mildly mod the car then save yourself some $$$ and go with the standard parts.

As far as the LCA ends, I prefer a poly/rod end combo. But I also like to run the local canyons by my house, so handling and turning corners are a big concern for me. I run the poly bushings on the body side with the rod ends at the axle. This is a good compromise and yields great performance without being too harsh on the street.

If you're mainly concerned about straight line performance then the full poly LCA's will suit your needs.

 

I've been running the poly to the body and the metal joint to the differential on both lcas and the panhard bar. The torque arm has the metal joint at the top end of the pivot link and poly at the pivot. I get some vibration at WOT under hard acceleration but other than that the system is quiet. It rips corners.