This post is just for basic information to the forum, since it's a popular and constant topic.

When I picked up my 03 in July, I was stunned at the *John Deere* look of the wheelwells....my whole fist could slide between the tire and the wheel lip on the rear. Really goofy looking!

So, I lowered the car the other day at 2400 miles, as far as the stock adjusters would allow, no bushing cutting. The stock settings were 27 3/8 inches high on the front (center of wheelwell) and 29 inches on the rears.

After lowering, the front dropped a mere 3/8 inch to 27 even, and the rear dropped (one thread showing) 7/8 to 28 1/8. Not very much. My 2000 FRC (also with Z51) didn't drop much either, so I'm convinced that the Z51 cars don't drop nearly as much as coupes and verts do, turn for turn, when cranking the adjuster screws.

I'm not going to cut bushings, etc. as I don't want to mess with the Z06 geometry and total suspension travel. But the slight drop from this effort at least makes the car look a little less absurd. I did have the car realigned, BTW.

Since the rear dropped 7/8s and the front 3/8s, I notice that my Euro headlamps, which I had perfectly adjusted to spec, are now a little high and hitting the tops of signs and probably blinding other drivers. Gotta tweak 'em down a bit. :smash:

Anyway, just info in case you're wondering how far your Z will drop. Basically, not much!!



[Modified by Tracy, 12:37 AM 11/19/2002]

 

Thanks for the info Tracy.

 

Another thought on lowering--I believe there are some guys who think that the suspension will "settle" some more, after some driving and perhaps in a few days, to a final (lower) ride height.

That is simply not true. The springs have been stressed to the point of supporting the full car weight since it came off the assembly line in June. Period. This is true regardless of where the adjuster screw is turned to. If this WAS true, that means that the very careful computer alignment of these cars as they come off the line is probably wrong, on every car, a few days after leaving the factory.

When I lowered my 2000 FRC in the fall of 1999, the height never changed a millimeter. I happened to check this for the new owner when I sold the car in July 2002.....I had written the before and after heights in my service manual and had them handy, so I'm sure of my numbers.

On my 03, I've put 240 miles and 9 days on the car since lowering. Zero change from the "just lowered" height numbers. There ain't no settling going on after the first 10 feet of driving/bouncing.

 

Be careful about your measurements. I would measure from the lip of the rim to the wheel well. Tire pressure, temp and the ground itself can influence your measurement a bit as well. Do it from the rim to be most accurate.

PS I was with ya on the setteling thing ... until after udjusting mine and getting it dead on, then checking it a week later to find I was a 1/4 off in the rear from the pass side to the drivers side. But it isn't much, sometimes the bushings will not seat correctly and it takes some "Dukes of Hazzard" driving to get them settled in. :)

 

Thanks Tracy, I know what you mean about the 4X4 look of the Z06. :U I had to cut my front bushings and use longer bolts in the rear as I felt it still was way too high. I measured mine after I lowered it and went around the block, then again after two weeks just before my wheel alignment and it was exactly the same height. I know that when you take the car down off the jacks it looks like it never lowered very much but after you take it for a short ride it settles to it's proper new height, but then it doesn't move again. (at least for me.) :cheers:

 

Anyone have before and after photos?

 

inferno--while your point about measurement location is possibly true, I'm talking about a dead stock car (tires, wheel sizes, air pressures, etc) and I'm using the method that has most been used on this fourm.....center of the wheelwell to the ground. Fact is, I actually recorded the amount of "exposed bolt", front and rear, using a depth guage. But then my post would have been "raised my front bolts 11/32nds above the spring, raised my rear nut 22/32nds up the bolt". And no one would know what the heck I was talking about.

I recall that on my Cuda, the ride height was supposed to be *7/8ths inch*. Huh? Howzat? Well, the service manual called for the difference in height from an inner edge of the lower control arm to the outer edge at the ball joint. When this was 7/8ths, the car was correct. Of course, nobody used that terminology. Everybody, even the Direct Connection/Mopar Performance factory gurus. used the distance from the frame at the front tires to the ground (or rack) for height in their how-to manuals. This number would be something like 13 inches........certainly not 7/8ths!! I suppose our ride height is specificed in some other manner than wheelwells, but I'm too lazy to look in the manual.

racer44--I doubt I'll cut bushings or go to longer bolts. I'm satisfied that John Deere didn't built my car.

I was looking at a new stock vert the other day. It sits where mine now does, within an eighth or so. And it has PLENTY of adjustment left on both sets of bolts. I guess the Z51 is like buggy springs! :lol:


[Modified by Tracy, 3:54 PM 11/19/2002]

 

I just had a look in the manual.

They have a convoluted procedure for "Trim Height" adjustment, which I barely read. As for the adjusters, for the front they gave a bolt thread height of 2mm to 24 mm "gap" between the bushing and the bottom of the arm. Not very *forum user friendly*, but that's how GM does it. Didn't see the rear "specs".

I guess I'll stick to the wheelwell height on wheel centerline.

 

Oh yea!! here you go. :cheers: Click on pic for full size 4x4 look.
BEFORE


AFTER






[Modified by racer44, 5:13 PM 11/19/2002]

 

racer--

Oh, yeah!!! 4x4 here you come, baby!! Jump them ruts and rocks! Lookit them lovely WHEELWELLS!!!

The second pic looks similar to my car height, but certainly a little lower since you cut your bushings and went to the longer bolt.

That sure is a black beauty!!

 

This is one project that I definately have to do. After looking at the before and after pics I wondered WTH GM was thinking. The Z06 should have been dropped at least 1 1/2 inches from the factory. Last weekend when I first took a look at my Sisters new BMW, I asked if she had it lowered. The car sets perfect in the tire / wheel well relationship in stock form.
At least we don't have to cut and flair the fenders to install wider rubber like they did on the C2's................... :lol:

 

You guys are exaggerating a little. I don't see how you can lower the car much from stock and have it be driveable on the road. My car already just barely gets out of the driveway, without scraping the bottom, (already scrapes the front air dam) and driving in the mountains I have bottomed out the car hitting dips. I think you guys have seen too many rice boys driving around.

 

I can say that the Z06 sets at leastone inch higher in front than my 94, the rear is even more. I had to drive the 94 up on ramps to change the oil, with the Z06 I can do an oil change with the car on the ground. :yesnod: ..................... :lol:

 

I've cut all of my bushings, and although I scrap the plastic air dam under the front a bit, so freaking what, it's just a little plastic...the car looks and handles better......mainly just looks alot better....

 

Tim--No, we're not exaggerating. The 02 and 03 Z cars sit much higher than coupes and verts, plain and simple. It certainly sits higher than my 2000 FRC did before I lowered that car, looking at identical side view pictures. At a minimum, we want what the BMW look is......concentric with the wheelwell. From your sig pic, I can see that you have the 4x4 look......the circle of the wheel arch is higher than the tire's corresponding arch....giving the wheelwell a sort of "U" shape around the tire.

I can get a floor jack under the front framerail on my Z, even after lowering. I can not do that on a stock coupe or vert. They're lower.

And your driveway is not my driveway. Sure, the front wing touches occasionally at various places around town, but it does that at stock heights. And it doesn't hurt anything, anyway.

Please recall my original post--my front dropped a mere 3/8s, and the rear only 7/8s. Not enough to bottom out all over the place, but at least the tractor look is better.

And finally, there are guys here on this forum who have cars that are absolutely SLAMMED, to where the top of the tire is inside the wheelwell. I doubt they would appreciate your *rice* comment.

 

I set mine to have symetrical gap between the tire and the wheel well...


BEFORE :U


AFTER :D





[Modified by PoBoy Racer, 9:51 PM 11/19/2002]

 

PoBoy Racer - did you keep a record of the heights you set yours to? No two cars will be exactly the same, but it would be a good number to start with.

I'm not sure if I'm really in the market for a Z06 as opposed to a convertible yet, but the added cost of the vert plus the requisite headers + blower to make up for and exceed Z06 straight-line performance tend to keep my attention focused on the Z. Now if only I could make a solid decision between Torch Red and Millenium Yellow........ :lol:

 

I didn't record before and after numbers, I just lowered until I got the gap symetrical, and made sure both sides had the exact same measurements.

 

I found, on both of my C5's, that when I fully lowered all four corners as much as the stock adjusters would allow, the side-to-side measurements were identical. There was no need at all to go back and tweak one corner or side to get things evened up.

Of course, I was delighted that this was the case, as the tweaking would have been a PITA. Of course, if you've whacked a curb or have really gotten hammered by a pothole, your results might vary, but probabaly not.

 

Right on Tim!
I don't believe that I'm more enlightened on the ZO6 suspension issue than the engineers who designed the car, so I'm not going to hack it up. Others are certainly welcome to do as they please with their cars; I'll keep the shock travel, thanks.

While I heartily agree that the looks of the car are improved by lowering (with cut bushings), I challenge any of you who have asserted that the car "handles better" to quantify that same assertion.


Jim


[Modified by graemus, 7:07 AM 11/20/2002]