Anyone know where to find a comprehensive step by step plan upgrading my 96? I see many steps/stages for HP upgrades :D , but suspension
info seems more scarce and harder to determine in what order certain upgrades should be done.

What I am specifically looking for is a stiffer ride with less 'roll' in the corners. I don't plan on autocrossing in the near future, just want a 'tighter' ride. For example, should I upgrade the shocks and roll bar and if so what comes first?

Any pointer to good reading would be appreciated!

thx

 

I'm in a similar dilema. In talking with a well respected local Vette shop the recommendation is 1) replace bushings with a mix of polyurethane and stock bushings and 2) bigger sway bars front and back (if you have a convertible then definitely do the sway bars). Drive and re-evaluate.

He showed me examples of bushings that felt like mush, centers no longer in center of bushing, bushings with rubber almost gone. Any of the above will make your suspension geometry change while you are cornering. The stock bushings are good for 5-6 years of "normal" (whatever that means) driving.

The reason for the mix of bushings is that with all polyurethane bushings you will feel every pebble, but you will handle like you've never done before. Also, after a year or so they will begin to squeak (that was news to me). Graphite bushings are similar, some have grease fittings to keep the squeaks down.

If you are interested I give the exact mix of bushings next week and a road test report. I go into the shop Monday afternoon.

If your shocks are worn or leaking you should replace them. Stiffer shocks :: stiffer ride (more bumps). His recommendation, leave the stock ones in place till the above is done. Drive and re-evaluate.

Cheers,

 

>If you are interested I give the exact mix of bushings next week and a road test report. I go into the shop Monday afternoon.

Definitely interested in your feedback after the work. I have ~55k on the odometer and was considering new shocks, but I'd like to hear how your bushing replacement goes first.

thx
Conrad

 

First, make sure your alignment is OK. Factory alignment allows for positive camber which kills cornering. Also, after a couple years of driving on normal roads, your alignment settings will be off.

Definitely sway bars. I also have a '96 which is the softest of all the C4's. I installed 30mm front and 26mm rear bars with polyurathane swaybar bushings and end links. It makes the car handle totally different; ride is tighter, but not harsh. In the turns, it's FLAT with no body roll and very well balanced.

If you still want more after that, I'd look to the shocks (especially if your car has high milage). Bilstein can rebuild your factory shocks and custom-valve them based on your needs for $50 each (very cheap compared to the cost of new ones).

If you still want more, then it's time for springs. Be VERY careful here! Beside from the front spring being a total pain to change, you can very easily give your car a 'delivery truck' ride (too harsh and stiff).

By the way, with my current setup (base '96 suspension, bars I mentioned above, stock shocks, and BFG g-force KD's) I have no problem keeping up with (and ahead of) Vipers in the turns at the track. (OK, so on the straights, they leave me in the dust :D ).

Have fun!

 

Can someone post the ideal alignment specs for a street driven car. I don't want a track set up as I have heard this can cause very uneven tire wear.

Thanks.

 

I upgraded to poly control arm bushings a year or so ago. At the same time I put Bilstein Z51 spec shock on. I really like the handling of my car and overall ride of my car. It is a daily driver, and the downtown Austin road are bad, yet my car is no rattletrap. It doesn't beat me to death either. The guys at Austin Corvette recommended that set up and I have been pleased. The suspension just works quicker.

The dissapointment I have with poly is the squeeking. Aside from the handling upgrade, I changed over to get rid of the worn out rubber ones that had become noisy. The poly were just as noisy. However, I have found a cure ...

NAPA sells some penetrating graphite spray that looks like black WD-40. Works great. I just remove the wheels, clean the pivot joints with a foamy degreaser, spray it off, let them dry, and then apply the graphite spray. Doesn't take much spray, and it lasts for about 6-8 weeks of daily driving.

Wade

 

My suspension mods are in my sig.

Did shocks first, then bushings and last the bars. I am very happy with my results. No understeer, a very slight oversteer. Body roll is very minimal.

On my way to home there is a cool, long, winding ramp to highway I drive every day. Nobody has been able to follow me through that corner. Just yesterday I had lots of fun as a collegue of mine tried (again) to follow me with his go kart -like GTI Peugeot and failed. :D He beat me on a go kart track later that evening though (he is 35 lbs lighter than me)....damn! :cry

Okey, back to C4 suspension:

Also check your wheel bearings, with worn bearings you can also have erratic wheel angle changes.

'96 springs are softer than in earlier models but consider spring upgrades last when you see what other mods do for you. If you decide to upgrade the springs to stiffer ones, go with GM factory springs from earlier C4. Vette Brakes sells sport springs but many have said that they are way too stiff for even race use. Many other Vette part stores also sell these VB springs, so check before ordering.

My wheel angles are a step away from basic street angles and I like them. Tire wear should be quite minimal. My car turns into corner better than normal but it is slightly more nervous on the highway if there is serious grooves on the pavement.

You might also want to stiffen the chassis as the C4 stock chassis resembles wet spaghetti. Roll bars, X-brace or harness bars do the job.

There is no step by step plan that will work with every car, so you basically have to try everything out. There is some things most will say is defenetly bad though, so stay away from them.

ToniH


[Modified by ToniH, 12:17 PM 8/24/2001]

 

I'll go with the bushings first as I suspect they could use changing anyway. I really want to get the sway bars, but upgrading anything that is already worn out should come first. Upgrading one piece and re-evaluating the ride seems to be good advice.

I had heard about the squeaking of the polyurethane bushings, but that penetrating graphite spray sounds promising!

Thanks guys.

 

My 30MM and 26MM sways are on order right now, I'll post the results when I am done probably in a couple weeks.

 

Vette in the shop have new bushings, front & rear, and the "might as well" syndrome hit so new sway bars are now part of the mix.

I was planning on an incremental approach, but you have to pull the sway bars to put on new bushings. The shop gave me a good deal on the new bars and at this point the labor is free "so might as well..." :D .

He almost got me to bite on a good deal for a pair of GS calipers and rotors that were "slightly used". It was tough, but I resisted. I'll probably kick myself later :( .

Roadtest report forthcoming.

 

well, I've lowered my car, had an 'aggressive' alignment, and now z-51 shocks. My car handles great. the lowering and the alignment were by far the best mods yet. the difference is incredible. and yes, the car was at stock settings beforehand. I don't notice a whole lot with the Z-51 shocks but I do seem to be a lot faster in the autocross courses. Maybe I'm just getting to be a better driver.