a_ahmed

alright good news with the encouragement of 2k2wranglerx, I squeezed my arms through the wheels, thank God I have stock rear rotors lol... and I managed to turn to 6 clicks clockwise in the rear. Went 4 CCW, 6 CW. Scrapes, cuts, dirt and grime and hand burnt... I somehow managed to squeeze through.

Huge difference. Thank God! I went for a spin and I felt a lot better haha... I wanted to try 7 clicks but the rotors were burning hot lol.

Yay... now need to get to a low jack, torque wrench and breaker for the front and to set the fronts to 3 clicks as suggested.

As I was talking to Ryan, I got an email from Gary Nelson from Aldan and he basically said the same thing try 8 in rear and 3-4 clicks in the front. With the rear keep going to even 11 if it doesn't feel still right otherwise if it worsens and doesn't improve back down.

2k2wranglerx

Heck ya man. Glad it's working out

NSFW

Glad to hear you got them working right!

01badvette

I had the Aldans out on Lime Rock Park raceway last week and they performed very well. Even coming up over the hill onto the back stretch where the entire car comes unloaded at the crest it remained very controllable at wot. My only desire moving forward would be under very hard braking coming off the front stretch from 135mph down to 70-65mph the rear would def want to walk a little bit but would grip strong once into the corner. may just need some more downforce on the rear end (spoiler?). Overall impression was very happy and my setup is really close to dead on and not wavering, just my 2 cents from the track.

a_ahmed

Update on my experience.... Still wasn't quite happy... I went up to 8 and then it felt like it was hopping and jacking up over bumps.. but more stable... but there was this strange feeling where at higher speeds (160-240), over bumps the car would shake left to right, not sure how to explain this, like the chassis moved side to side if there was an axis from the front to the back... and if you could spin the car through it... and so the left and right would shake back and forth (rather than front to back) if that makes sense... I don't know how to explain it....

The rear still seemed to wallow some and jack up on harder bumps.... it was still not confidence inspiring, there's no way since the car on stock shocks and slammed (bought it like that...) was able to hit 295 and be rock solid....

I went down to 7 clicks... thinking 8 was too harsh... I still didn't like it at all... it felt worse than 6... or was it in my head but it seemed like 7 didn't feel like 6 anymore... which worried me...

The side to side feeling was present all along it's just that the car was so unsettled front to back that I didn't notice it until I went up higher on the rear rebound...

I contacted aldan and emailed them what I felt... their only answer was others ran 550#/650# and were fine.. they said what i explained may be that the spring rates are too much for me... and in my opinion that is not that heavy of a spring rate considering i ran these kinds of rates on a much lighter car and had more control... and from what I've seen LG's coilovers run 700#/700# or higher... and motion control systems (formerly motons) are also 700# and streetable... it made no sense... I just felt something was wrong with the valving on the rear shocks.... made no sense.......

This morning on the way to work got some wipes and got dirty going in the rear wheel wells... and flipped it to 9 clicks in the rear...

To my surprise... far more stable... and while it is louder 'harsher' it doesn't feel harsher to me... as it's more stable...

I was able to hit 240kph and it felt far more stable. The side to side shake after bumps was reduced but it is still there... I didn't have the space to try and go faster...

Around town sharper bumps are louder but the car is more stable... I didn't drop tire pressure, my other thought was to drop tire pressure... running michelin pilot super sports and they seem to get hot up to 42psi on a very hot day.... was thinking if I drop to 38psi hot...but they are mushy sidewalls to begin with...

Around town on sharp turns the car is better... but now I feel like it has a tenancy to not turn in and seems to be understeering a bit on sharp corners.... all i have is steinjagger swaybars and their metal endlinks (properly installed...)

At this point I want the chassis to be controlled and fine tuning of that sort I am thinking I will get done with better swaybars....

It just bothers me that it's this much of a chore to get the car to feel stable at even highway speeds and obviously 240+ still... if it doesn't feel confidence inspiring... I can't race it... I'll die lol... and I'm not a newbie driver...

So still a work in progress... if I have to switch springs I'll be pissed simply because I wanted a package I could buy and not have to experiment on spring rates... I am not a race or engineering team that'll mean more money spent on a shop that'll have to take them apart, install springs, preload, corner balance, align... im not a race team... just want to enjoy driving fast... and when I buy suspension pieces I tend to expect to be wow'd and not recognize the car from what it was...

So... the bottom line... it's much better... but still not quite right... I don't feel content, having gone through a crappy set of coilovers first (I knew it was a bad decision buying china coilovers -- but I listened to forum members... clearly most people don't drive their cars hard enough and just care to slam them....), then to these which are better, but still not a "omg my car is transformed"... the only thing I'm thinking is maybe the springs I got in the back are something else or the valving on this particular set is not okay... when I was getting mine the rear springs were backordered... I don't know...

I'll do more driving around and maybe even try and see bumping to 10... dropping tire pressures.... nothing else I can really do...

01badvette

A couple things, First Why are you running 42PSI in your tires? That's close to max inflation, you should be closer to 30-32 hot in the rears. You want an uncontrollable rear end run too much tire pressure would do that. There shouldn't be anything squishy about a super sport side wall. Next is what stagger front to rear and what size tires are you running? I have quite a bit experience in autoX / performance driving and I think a lot of your issues may be due to tire pressure and car setup more then the actual shocks. Slamming a car with no suspension (rock Solid feel) is a lot different then having a suspension that works.

a_ahmed

I'm not running 42psi cold, they start at 34psi and get hot to 42psi.... on very hot days and we've had 30-35c weather these days here...

They are 275/35/18 front and 285/35/19 rear

01badvette

I would knock the tire pressure down to 34psi hot at most, at 42 psi the tail of your car is gonna bounce and slide.
I have ran close to that exact same setup on re71R tire last year and will tell you that you need very stiff front springs and sway bars and less then an 1/2" of stagger front to rear or your going to have a rear end that will dance around every corner if you want it to or not. But if you have to little stagger your car will push like a dump truck into a corner and have no weight transfer and traction coming out. Its a very difficult setup to get right.

a_ahmed

I will lower tire pressures for sure and try to get lower hot pressures.

I didn't quite understand how you worded your sentence though lol. You had similar tires, swaybars spring rates to what I have? (550#F/650#R, steinjagger F/R non adjustable)

Not sure I understood what you meant by little stagger. A square setup should be more agile per say but may be more loose right? But for a car with this level of torque generally people tend to like a stagger and from the factory it's staggered. It still feels understeery but we'll see... did you mean too little stagger? Sorry rewrite that man It's just me or I'm tired from work lol

01badvette

A_AHMED- Last year I ran an 275/35R18 F and 305/30R18 R setup for autocross part of my season, I couldn't make it handle well, either I had great turn in or great acceleration but couldn't get the rear end to settle under hard cornering no matter what I tried.




Yes, the C5 comes with stagger built in and you do need some stagger no matter what setup I feel to make it handle well. I currently run 315/30R18 square setup and still have around a 1/2 of stagger.



You have a full inch or better difference in wheel size with a 35/18 and 35/19 front to rear combine that with high tire pressure and a mild front sway bar the rear end of the car is gonna be a handful no matter how your driving it. You combine those 2 factors along with alignment settings and you could really have a terrible handling car no matter what shocks/coilovers you put on.I personally had to add around -.25 toe total in the rear to calm my rear end down for my driving style and setup.

I really think the 2 biggest factors you have working against you is the tire pressure and front to rear wheel difference in size. Dropping pressures will help but you are gonna have to spend time adjusting ride heights, Front to Rear stagger of the car and possible sway bar change to get the car dialed in I personally don't think your problem is with the coilovers/shocks but without driving the car its just a somewhat educated guess.

a_ahmed

I like your input you're being helpful. When you say 1/2" you mean wheel height not wheel/tire width? Also aren't we supposed to have a rake on our cars for aerodynamics? From what I remember reading stock suspension dropped 1"-1.25" all around is going to keep roll centers and everything in a good spot... from the factory they just made them higher for the average american joe...

What do you recommend? 305/30/19? It's slightly shorter if I am not mistaken. Or going larger up front? Although with these coilovers... the can't go any higher and it's pretty low... looks nice but yeah... I asked the shop that was setting it up to make it as high as possible...

What would you recommend for swaybars? Mind you I am 550# front and 650# rear

And when you say -.25 toe... you mean 1/4 toe in total?

a_ahmed

I love NT01s... not many people seem to run them on here...

I can't go back to leafsprings... I don't even have them...

What spring rates did you pick front and back?...

01badvette

The stager I am referring to is what you called rake front to rear, if your ride heights or rake front to rear is off it can throw everything out of balance. If you look at my on track picture above you will see my rear fenders have roughly a 1/2" more gap compared to the front fenders with the same size tire. That is what I was referring to front to rear rake or stagger in your ride heights.


Before you buy new tires or spend any money drop the tire pressures to 32psi hot and start playing with your rake front to rear, I think you will see majors changes in the way your car handles.


For sway bars I use Strano adjustable front and rear and really like them, no issues at all with them and Sam is great to deal with for setup questions very straight forward and knows what he is talking about.


And yes my .25 is total of 1/4 toe in for the rear tires with camber maxed on stock adjusters front and rear.

01badvette

I had the same experience the beginning of this year when I put my 315/30R18 rival S square setup on, the car road terrible on the street and just felt off. I needed to change ride heights and rake or stagger as I call it front to back and they dialed in nicely with the ride greatly improved. I have limited experience with GS/z06 C6's. The 2 tracks you described are vastly different I would say try making small changes in ride height and dampening on the coil overs on the street with the NT01's on the car and get it to where your comfortable that way before the next trip to Big Willow and see how it translates to the track. Let us know how you make out and your findings.

a_ahmed

This whole rake ordeal is new to me as I've only ever heard of it on the vette. The other cars I had corner balanced all that was ever mentioned was making the car as close to 50:50 in weight distribution...

The car originally came (laughably) with bmw rims that were too low on offset 19x9.5 all around and 245/35/19 front and 245/45/19 rear. I hit 285 with these tires no problem and the car was stable LOL... so explain me that... and those were like nearly what 28-29" tall rear tires?.... I was so psycho, but the car felt solid so I went at it... then again thoes guys that do salt runs run skinny tall tires for top speed runs...

The problem with height with the aldans is the fact that there is no bottom perch it's just the spring you can adjust for preload.... I was confused initially when buying too because I was told there was a short body and long body version and then I got a new version which was a middle ground, but it's still pretty low...

2k2wranglerx

increased preload will raise your ride height but theres a limit

96GS#007

I have 500 in front, 600 rear. Gives the GS just a touch of oversteer in conjunction with my larger front sway bar.

Just have to get the ride on rough tracks squared away.

2k2wranglerx

Ahmed i had a thought. Is it possible you're experiencing bump steer? I have a little bit right now (although i suspect i may have something worn on the driver side) above 70 mph.

a_ahmed

Installed new moog inner and outers... and in the rear baer toe arms...

2k2wranglerx

Yeah but you can still get bump steer even with all new parts.