Suspension question

[1963SS]

Hi, since everyone seems to think that I need to lower my C4 vert I was wondering.......The rear seems pretty straight forward but the front raises a few questions. Since the spring is going to be off, is there any reason to put it back on. I'm thinking about coilovers on the front only. Any of you that have coilovers, are they a downgrade, a lateral change or an upgrade. It seems like a fairly easy job to install them. What spring rate would be recommended to maintain the front/rear balance as it is now? Or, should I just lower it and keep the leaf spring. It would seem that coilovers would improve the handling but I dunno. Thanks. --Bill--

 

[vetteoz]

Given the cost of changing to coilovers most only do it on cars used for track work where they require spring rate adjustment.
Plenty of serious handling C4's around just with upgraded stock suspension ( swaybars / shocks /bushes /etc )

 

[Hib Halverson]

The first step in lowering a late C4 is to get it up in the air and see how many springs shims are in the front and how the shims are arragned in the rear.

The Service Manual gives details of this but the exec. summary is in the front you want no shims and in the rear you want all the shims below the spring rather than above.

In some cases, just getting the shim situation right, lowers the car enough.

Lastly, remember that C4 convertibles have less ground clearance due to the X-braces so, once lowered, they're more likely to scrape going across driveways or over obsticles.

 

[1963SS]

Thanks guys, I'm just going to stick with the leaf spring. I read another post that had all the guys selling coilovers telling their virtues. Most seemed to say that the ride would be stiffer and I really don't need that. I went out and looked under the car and it just needs a couple of inches. I'll be putting it on a lift to see why I seem to have the 4WD rpo code. She does sit high but I'll get her down.

Mine does seem to be about the tallest that I've seen:

I probably can't go real low or I may rub something. I measured the rear wheels and they appear to be 11 1/2 inches and the fronts are 9 1/2. Too low and something probably would rub.

When the weather get a fuzz warmer I'll commence this lowering job and start bothering you fine folk more....I'm sure. Again, thanks for the info. This is a great forum you have here. I know the tint needs re-done on the rear window. I've only had her a couple of weeks. I promise to do her good. Have a great New Year everyone.

 

[Rex S]

Someone has raised that car! No stock Vette sits that high, maybe he lived on a dirt road like I used to.

 

[roger longman]

Hi 1963SS, The lower profile tyres accentuate the clearance but it still looks too high to me. I measured mine: front, 26"(66cm) ground to outer edge of arch. 25 1/4"(64cm) ground to top of tyre. Rear 27 1/4"(69cm) ground to outer edge of arch. 25 1/4"(64cm) ground totop of tyre. That's with 245/50/16 tyres. The suspension setup I believe is standard. I hope this is of some help. Roger.

 

[1963SS]

Thanks Roger, I'll check that tomorrow and use your heights as a gauge. The rear wheels and tires are 295/35/18 and the fronts are 255/45/17. If I read the tire size calculator correctly they are both right at 26". That should be about the same as the stock tires at 275/40/17. Less than 1/2" difference.

 

[roger longman]

Hi 1966SS, So I start off 3/8 " lower than you ? Roger.

 

[1963SS]

Thanks again Roger. I measured mine and I had 27 1/2" to the top of the arch on the front. That is 1 1/2" more then your stock setup. I also measured 29 on the rear compared to your 27 1/4. Wow, someone must have raised this up or sumpthin'. It looks like I've got some lowering to do. Of course I could always pick up a fat woman and take care of the problem. Maybe that's what it was. The previous owner and his G/F were "big boned" people. I appreciate the help. If it wasn't ZERO outside I'd start playing with it now.

 

[roger longman]

Hi Bill, There's a thread posted on 01-01-10, that deals with lowering, although on a standard setup. The guys have chipped in with tips regarding shims and pads and stuff. It seems you may have a lot of those ! The car shown is way too low for me, Mine scrapes on things just fine as it is. Roger.

 

[Ugolino]

Actually, that looks like a stock ride height for a c4 convertible, I doubt that anyone actually raised it. I notice the convertibles are higher than coupes anyway, for the reason that Hib mentioned: ground clearance for the cross brace. The factory seems to have tinkered around with c4 convertible height during its production run, as any casual glance through the cars on ebay can attest; the convertibles seem to go up and down, or maybe they even differ from car to car. I have seen some very high convertibles. My 1990 convertible was quite high, i could practically stick my whole head in the rear wheel well, and it was factory ride height.

 

[Rogue]

I think part of the height issue is with those 18" wheels/tires combo that gave it a "Plus 3" upgrade. All cars that go to larger diameter wheels and lower profile tires look like they get jacked up like a 4x4.