If you are going around a corner at high speed and high G's, if you bottom out in the back the car will immediately oversteer. If you bottom out in the front it will plow straight ahead. It can easily cause you to lose control and either spin or plow straight ahead. If you drive like an old lady, then no, it's no big deal.

Another common issue with bottoming is the alignment changing when you bottom out. The reason for this is that the forces in the shock act like a wedge and that puts a high tensile load into the lower suspension bolts.. The eccentric bolts that mount the control arm can't take that much load and they slip, which changes the camber and the toe. Very common to have to frequently realign the car if you hit a bump and bottom out hard. Again, if you drive like an old lady, it's probably not an issue, but if you drive the car the daily you are likely to need more frequent visits to the alignment shop.

Finally there was a case recently where the lower ball joint stud failed on a car that was lowered by removing the front bolts entirely. This car most likely hit a bump hard and this caused a fatigue failure of the stud. The reason is that these parts were never intended to take that kind of loading. This person was fortunate in that the failure finally occurred at low speed, but if it had happened on the highway or going around a fast on ramp the results could have been very different than just ruining a wheel.

So really, it's no big deal if you drive like a wuss, but if you believe that sports cars are to be driven briskly, you really don't want it that low. In addition, there's no performance advantage in lowering the car that much. These cars handle best at about 3/4 of an inch of lowering from the stock height. Lower it more and the handling suffers, so what's the point other than looks??

 

The car is lowered approximately 3/4 of an inch (measured from the jacking points and keeping a 1/2 of an inch rake) as I understood the stock heigth to be 5 1/4 front and 5 3/4 rear as I measured it prior to lowering. Is this not correct and could the car have already been lowered? As I said further up the thread it now measures 4 1/2 front and 5 rear. Is this to low? Also I am running 275 front and 295 rear on 18 inch rims all around. Thanks.

 

That's different. I have never seen a flat one before.

Here's a link to a set of C6Z06 shocks. You can zoom in and clearly see the offset plate.

http://www.ebay.com/itm/New-C6-Z06-s...item3f1df87e50

The plate on my original 98 shocks looked the same and I have a set of old F45 shocks that also have a plate that looks the same. The C6z06 shocks I installed also look the same.

Here is another shock picture;

http://www.zip-corvette.com/ProductD...GR-SR&CTitle=&

The offset plate is visible there too. So, even just make a flat plate and you gain 3/8" of travel.

I can't do it. Any further travel on my car would result in a big wheel to fender rub. They travel into the fender just a bit and then the sidewall just touches enough to leave a mark.

 

The flip side of this is that if you're on the street and going around corners at high speeds and high G's pushing the car to the limits when there are bumps large enough to bottom out the car then you deserve to crash. Just hopefully not into someone else.

I'm not sure about everyone else, but I think it's somewhat stupid to push your car right to the limits on every corner and curve you take. You never know what has changed since the last time you went around that corner. A truck leaking sand onto the road or an oil leaker misting the road with oil will ruin your day. And if you're going there the first time then I shouldn't even have to write why it'd be dumb to push it without knowing the road conditions at all. Driving at that level, it just requires one small driver slip and you've crashed. Also, it's rather dumb to be doing that when there could be pedestrians or other cars could be around or just "appear" at the wrong time.

You are involved in racing, right? People push their cars to the limit lap after lap on the track, right? You never see cars going off the track due to driver error?

The bottom line is that the car will bottom out when you hit a big enough bump. It doesn't matter what shock or what spring is in the car or what ride height you are using. Hit a big enough bump and it will bottom out. So, I don't know why you're making such a big deal about how the car shouldn't be or can't be bottoming out.

 

The stud could have had a defect from the factory and and it just finally failed.

 

You are forgetting that as the body rolls you lose suspension travel. If you are down near the bump stops, body roll will use up almost all of the travel you have. At that point serious a bump will cause instant oversteer. Even if you aren't at really high speed or pushing it, you can cause a severe handling problem. You don't have to be pushing it to have the car dart around when it bottoms out. Not only is is uncomfortable, but it causes erratic handling and you don't want that. I don't go at race speeds on the street. The limits of these cars are so high that you'd be crazy to go around pulling a G on an on ramp, but driving with a little brio is what these cars were intended for, and if you use up all the travel with body roll the car will handle weird and dart around, and that's no fun either.

The system is designed to have some travel before you bottom out, and while it is possible to bottom out the suspension on really big bumps, it doesn't happen often when you have some travel. Moreover, the bump stops are progressive and intended to give you a soft landing and not upset the car too much when you hit them, but if there's no travel before you hit the bump stops the handling can be erratic. That's just a simple fact of life.


Yea, and I've got a tower in Paris I want to sell you, real cheap... I've yet to hear of any failing on a car that wasn't lowered. I'm sure it's possible, but come on, it's more than coincidental. When you put huge forces into the suspension, something will break. Be it the spindle, the ball joint or something else, the parts just weren't designed to that kind of shock loading.

When my car was lowered all the way in the front it was at just a bit over 4" at the front frame rail on 275/40/17's. 4.5 is still a bit low, but it depends on the roads you have and how you drive. The front isn't as critical as the back, and 5" is probably not that bad in the back, so what you are experiencing is probably not that bad. I'm just saying that if you get crazy and lower it all the way on stock bolts, or take the front bolts out, or cut the rear bushings and lower it more you are going to mess things up.

 

[QUOTE
When my car was lowered all the way in the front it was at just a bit over 4" at the front frame rail on 275/40/17's. 4.5 is still a bit low, but it depends on the roads you have and how you drive. The front isn't as critical as the back, and 5" is probably not that bad in the back, so what you are experiencing is probably not that bad. I'm just saying that if you get crazy and lower it all the way on stock bolts, or take the front bolts out, or cut the rear bushings and lower it more you are going to mess things up.[/QUOTE]Thanks for the input. Think I will try the Bilsteins first and raise the car slightly if I still experience the problem. There is one dip in the road I drive everyday that I can use as the bench mark to see if improvements have been made.

 

You're throwing up arguements about a car that had the front bolts removed or otherwise messed with. The OP has his car lowered 3/4". Not the same thing. In other threads, you yourself have recommended lowering the car 3/4" for best handling.

 

I just purchased a 2001 Coupe. The PO lowered the car low enough that the air deflector under the car scrapes in dips. I'm having it raised to prevent this. What is a good compromise for the height?

I don't even drive the car now due to this as its an annoyance to me.

 

Bilstein Sports here, no more bottom out on lowered Vette. Handle excellent!

Nice thread hi-jack!

But anyway, scraping air deflector is not doing any damage; its got a spring to that allows it to bend back and take hits. Been scraping mine since 2004 and still looks the same.

 

I'm aware of this. The car sits 1/4" above it and its too low. Appreciate the help.