street car suspension problems!, totally low-tech Options

[Gradinger]

Newbie here, hello. Car is a 1995 Formula. Set up for Ozark road trips loaded full of camping gear, driven legally but aggressively on mostly great pavement. Planning to start doing a few autocross events/yr. Here's a rundown of current setup, which I gather is a mishmash of all the wrong parts. Most of this crap, I understand, is designed for straight-line racing and/or impressing techs at tire and muffler shops. Any advice is welcome.

-Stock 16x8 wheels, 245/50/16 BFG G-force SS, 37psi front/32psi rear cold pressure.
-BMR goodies (yeah, I know) - rear control arms (non-adjustable, poly bushings), welded frame connectors, strut tower brace, adjustable panhard rod (poly both ends), stock torque arm.
-Eibach pro-kit springs
-Bilstein HD shocks
-poly motor + trans mounts
-stock sway bars w/ poly end link and clamp bushings.

The car has gained a "bit" of power recently thanks to cam and head work and some old fashioned displacement, and the weaknesses are beginning to show.

Issue #1: The car now squirms around in the rear on hard acceleration, even with no apparent wheelspin. Quite frightening. Difficult to keep it in it's lane even when accelerating from 40-60mph. The rear axle seems to be steering the car.

Issue #2: A recent alignment indicated something funny. Camber and caster were no problem, but with the tie rods adjusted to the limit, toe setting is 1/8" out. No less can be had. Previous alignments presented no problems with setting toe to zero, which I always preferred. Is it possible that the wrong tie rod ends were installed at some point, or is this a function of the lowering springs? How durable are the spindles, and should I suspect them as well after 135k miles?

Question: Should the rear control arms be relocated for the lowered ride height, or is that another Summit catalog myth? Launch traction is definitely reduced now that it sits lower.

Also, the car is under-represented in the braking department. C-5/C-6 brakes or something aftermarket? Don't really want to go larger than 17" wheels.

[CrashTestDummy]

Get under the car and check all those replacement parts for loosness or blown bushings. Give everything a good hard shake and inspect the bushings carefully. Also check the swaybar mounts and ends. While you're under there, I'd verify the torque arm bushing/mount at the transmission is in good shape.

Additionally, with that many miles on the car, check the front end, especially for a broken sway bar mount, or blown bushings in the end links. Your alignment issue could be associated with worn hub bearings (common problem) or a bad rear bushing on the front lower control arms.

[Blainefab]

In the rear, look closely where the upper panhard brace ties into to the frame - the bolts on each end should be tight, no signs of stress on the spot welded sheet metal tower on the pass side. Check the torque arm for cracks at the diff bolt holes. Check the torque arm to trans mount. What is the rear toe? Has the car been curbed recently? Did the rear steer start all of a sudden or has it gotten worse gradually?

In the front, check that the Kmember to subframe bolts are tight - there's 6 of them. Check the rack mount bolts. Check the outer tie rod ends and hubs for wear. The uprights won't wear from miles, but they will bend if the car is hit on a wheel or curbed. The inability to get the front toed in indicates something is seriously wrong: bent or wrong parts.

for brakes your best bang for the buck would be a LS1 upgrade, next up the C5/6 setup. No need for anything aftermarket here.

[cccbock]

In the rear, look closely where the upper panhard brace ties into to the frame - the bolts on each end should be tight, no signs of stress on the spot welded sheet metal tower on the pass side. Check the torque arm for cracks at the diff bolt holes. Check the torque arm to trans mount. What is the rear toe? Has the car been curbed recently? Did the rear steer start all of a sudden or has it gotten worse gradually?

In the front, check that the Kmember to subframe bolts are tight - there's 6 of them. Check the rack mount bolts. Check the outer tie rod ends and hubs for wear. The uprights won't wear from miles, but they will bend if the car is hit on a wheel or curbed. The inability to get the front toed in indicates something is seriously wrong: bent or wrong parts.

for brakes your best bang for the buck would be a LS1 upgrade, next up the C5/6 setup. No need for anything aftermarket here.

Alan knows our 3rd and 4th gen cars as well as anyone out there.

I'm with Alan on the brakes. The LS1 brakes are plenty adequate for street/AX. And cheap. And bolt on. And work with 16" wheels. And serviceable by anyone you might sell the car to at a later date. The 95 brakes (LT1) are pretty bad, and to my way of thinking, barely adequate for street use and totally inadequate for anything else.

[FASTFATBOY]

If you have a toe out issue at rest, when you accelerate its gonna get much worse. When you lower one of these cars the rack is lower than the outer tie rod ends, when yo accelerate the rack rises pushing the tie rods out further. This MIGHT be an issue.

How old are those poly bushings in the rear? I would pull them and inspect them. What your describing is a rear end bushing issue in general.

[RumbleZ]

Set up for Ozark road trips loaded full of camping gear

Sorry for the off topic, but Ozark as in Southern Missouri or northern Arkansas? If so, where do you plan to auto-x?



Only other thing I have to add is that I've got C6 brakes (using Trackbrackets!) on the front of my 93 and I love them more every time I drive it. Night and day compared to the stock LT1 brakes. Good stuff.

[Gradinger]

Set up for Ozark road trips loaded full of camping gear

Sorry for the off topic, but Ozark as in Southern Missouri or northern Arkansas? If so, where do you plan to auto-x?



Only other thing I have to add is that I've got C6 brakes (using Trackbrackets!) on the front of my 93 and I love them more every time I drive it. Night and day compared to the stock LT1 brakes. Good stuff.

Southern Missouri, not Arkansas. I live in Memphis, and with any luck, the track here will be ready for the spring season. It was just sold last week after sitting dormant all year.

Thanks for all the advice, plenty to check on next time I get the car up. The bushings are fairly new all around, with the exception of the torque arm. The plan for now is to replace tie rod ends and ball joints (again) and to replace the rear control arms and panhard bar with rod ends rather than bushings. I also plan to replace the torque arm, just because. Re-align, re-apply thottle, re-assess. Once the bad manners are sorted out, time for a brake upgrade.