zeshawn

Part1:

Well, I had to say it, I am extremely dissapointed with the Z06's high-speed stability, at 186MPH the car feels like its all over the place and more like the front will lift off, crazy steering wheel vibration, simply put the car is NOT made to handle that speed, it is advertised as a 200mph supercar.

FYI, im not just saying this out of the blues, weve tested a bently GT at 200mph, a bmw M6, bmw M5, Carrera GT (WITH THE WINDOW A LITTLE DOWN), Ferrari 599GTB. Those cars listed glide smoothly at 200MPH, it kind of makes you want to break the speed limit (im not suggesting that anyone does, but im simply saying its so smooth and feels so secure it would make you want to do it).

Before the mods start getting suspicious, those tests were NOT by anychance done on a public road, hell id be more afraid to kill myself than to kill other people.

Part2:
I havent given up on the car though, I am noW looking for methods to improve on this, what is causing this unstable feeling at high speeds? Can a wing, diffuser, hood and front lip help keep the car planted on higher speeds?

Also can someone explain the relation between drag and downforce? I always thought they came in a package - in a sense - if you're asking for downforce, you're also asking for more drag, which will slow you down on a straight line at the expense of better handling downforce. However, seems most of the wind-tunnel tested Z06 Aero products such as the MTI Racing front splitter and rear wing-spoiler + the breathless performance diffuser, and an LG Hood for example seem to claim that while increasing downforce they furthermore REDUCE drag by certain counts, and thus beleive this will improve gas mileage.

So is it correct to say that for example the breathless performance diffuser will provide MORE downforce thus MORE stability, yet reducing DRAG and thus increasing STRAIGH-LINE acceleration? win-win situation? Best of both worlds? possible or not possible.

I need positive arguments and/or opinions, facts. Please no silly comments asking where and why would you need to drive that fast, or if you dont like it buy a bently, please if you have one of those comments, follow the cursor to the upper right hand side of the screen and click the magic button.

gotjuice?

Positive commets only.

avacorvette

Allot of the Z's came from the factory out of alignment. Get the 4 wheel alignment. GM will do it for free if you are under 5K miles. I had it done and it feels great at 140. Thats about as fast as I can go where I live. before that she wandered a little too much.

bluemagoo

I can't speak to 186 mph though.....

zeshawn

I know I know, the biggest problem is you first gotta learn how to read

thanks for increasing your post count, increasing bandwidth usage on the forum, wasting your time and my time, and other reader's times who are wondering just as I am as to what you're trying to say, KINDLY do not post back

Im sure there are people who would be more than interested on discussing this in more depth, knowledgeable people mind you. Im hoping to hear from LG Motorsports on this given their last standing mile run. Guys who visited the standing mile might have something to say about this, whether they agree or not, whether they found a cure etc...

zeshawn

Thanks for the input guys, my car is A LITTLE lowered you can't even notice it, but going for a re-alignment is one option that ill have to try!!

The car feels fine at 130mph though, its after you get out of 4th that the horror begins. You can consider me someone that has the ***** to do it, but when something feels DANGEROUS I simply stop, having ***** is much different that attempting suicide.

Ruf-Racer

I have averaged >160 mph for fifty miles (legally) in Nv. My 07 Z06 was not always so stable however an alignment, properly balanced wheels/tires and a little selective taping was all it took to make the Z06 feel very comfortable at high speed. Thanks to AllanLaw for the alignment specs.

BTW,the Z06 had to be shutdown after about fifty miles because of an error signal,tranny too hot. Dealer changed sensor.

FYI,I know many Z06 owners that have averaged at least 150 mph for ninety miles.

Cheers

R

GMuffley

I would like to add to the discussion, but I have never been close to 186 mph. No problems up to 150 mph.

Gramps

I am just wondering at which stateside tracks that are typically used for HPDE events is there a straight long enough to reach those speeds in a stock Z?

ptaylor_9849

Thank God, finally someone on this forum agrees with me. I also feel that my Z06 is unstable at high speed. It wanders all over the place and grabs grooves in the road and pulls you in whatever direction it feels like. I've had an excellent alignment and all wheels are perfectly balanced. The car just has a mind of it's own and doesn't feel stable. I have felt this way since shortly after I bought it. I also have $900 worth of PFADT shocks installed. I'm beginning to think this is the reason that so many used Z06's are for sale with very, very low mileage. It doesn't take long to realize what we're describing here so people dump theirs as quickly as they bought it and I would love to do the same. Anyone want to buy a mint condition VY 2LZ with Nav, chromes, clear bra, PFADT Shocks, Lloyds Mats and 3500 miles? Send me a PM. Please. I think I've had enough. One thing before I end this post. Why does a crown victoria, my old C6 or even my girlfriend's Mercedes C320 feel more stable at 120 than my Z06?

4GS7

Did you maintain any rake when you lowered the car? I know with the C5s, you had to keep the light forward rake or air would get trapped under the nose and the front end would wander up top.

zeshawn

Okay, I wouldnt do that if I were you, this is my second C6 Z06, and I LOOOOVE this car. Id like to find out wha I could do to solve or at least attempt to make it better, more stable at such speeds, although I rarely RARELY go up there and when I do, its just for a matter of seconds until I slow down.

ill try to start with an alignment, then the coilovers I have already, just need to install them first, ill see if it improves by any chance, and ill make my findings as realistic as possible.

zeshawn

if you're asking me, id probably say im clueless, but thats yet another thing that I would have to check soon. Makes sense.

Problem is, its been common knowledge that there is a front-end lifting issue at high-speeds when I say high speeds I mean just into 5th gear.

gotjuice?

Mine seemed to wonder at high speeds. I lowered and added coilovers. Seem to of gotten worse. I did a 4wheel alignment. It did improve, but I have not gotten above 130 after the alignment yet. Hopefully in the next couple of weeks I can find out if it is much better.

patton

ive no issues at high speeds,car is very stable. imo putting wings,coil overs will make you chase your tail trying to fix it then its a 3k car with 100.00 mats that meets OOF owner occurred fault

OnPoint

I haven't seen 186 - but I have repeatedly seen 172 in driving events. I wonder if the suggestion on alignment should first be investigated. That would seem to be easy/inexpensive and pretty easy to get performance feedback on whether it works. My car has been stable at speed. I'm running a Katech alignment, but I ran it close to those speeds when stock and it felt similarly stable. With that said 14-15 more mph would make a huge difference, and perhaps this chassis just gets jittery at those higher speeds.

Only a guess but I'd wager that lowering the car, and re-doing the alignment would help and be easy to experiment to see it.

trumper Z06

My 07 Z06 feels a little "loose" above ~ 160 mph.

Stock suspension/not lowered, track alignment & 4 corner balanced.

Kumho V-710's 315/18 all four wheels, tires are balanced.

But I'm only @ that speed for a few seconds before braking for the up-coming corner.

Cya @ the track,

Trumper

ranger1

I havent tracked my car, however I have hit 175. a few times. I havent noticed any ill movement. She was very steady.


Garry

Heber Guy

I had a 2006 that just was a hand full to drive. Two hands at the ready all the time and needing absolute attention. Tried all the usual stuff but to no avail. It got to the point that I did not want to drive the car. Traded for a 2008 and all the problems are gone. When my 2006 was being prepared for the new owner the mech took it out for a test drive and crashed it. Said he just lost control. This at least let me feel perhaps I wasn't completely crazy. How can these cars be so different one from the next?

jerseydrew

how did you lower your car? if you turned the bolts down and eyeballed it you may have thrown the corner balance out of wack. corner balance and alignment would be my first method of attack.