[Z06] Track Alignment
06-18-2007, 03:20 PM
#1
Race Director
Thread Starter
Track Alignment
this is not for the guy that runs on the street, and does one or two HPDE's per year, but I dialed in -2.2deg front and -1.5deg negative camber on the Z06, and it is perfect. On OEM street tires, we're getting perfect tire temps and wear, and the car is extremely balanced. We were at Roebling this weekend, and I figured -2.2 would be a bit much for street tires, but I happy enough that I'm going to leave it. Will be at VIR for the NCM event in a couple of weeks, and will try the alignment out with some sticky tires.
btw, I really like the new upper control arm mounts on the Z06 rear. It's nice to be able to make adjustments at the upper and lower control arm, unlike the C5 and C6 where you can only adjust the rear on the concentrics.
Hope to see many of you at VIR July 1-2!
btw, I really like the new upper control arm mounts on the Z06 rear. It's nice to be able to make adjustments at the upper and lower control arm, unlike the C5 and C6 where you can only adjust the rear on the concentrics.
Hope to see many of you at VIR July 1-2!
06-19-2007, 02:05 PM
#3
Melting Slicks
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You can get better than -2 degrees front and rear with both washers out.
Enjoy...
Frank Gonzalez
06-19-2007, 03:08 PM
#4
Race Director
Thread Starter
Our car had 4 washers in front, and 2 washer in the rear. Each washer is almost exactly 1/2 deg, so I took 1 out of the rear and 2 out of the front.
Be doing it this way, you don't have to touch the concentrics on the bottom, and that way you don't mess the castor up.
I left the ride height stock, where it works best. I may drop it a tiny bit later, but the suspension is in it's "sweet spot" at OEM ride height.
Will have RB rotors and ducts for the NCM event coming up, and likely stick some slicks on.
Be doing it this way, you don't have to touch the concentrics on the bottom, and that way you don't mess the castor up.
I left the ride height stock, where it works best. I may drop it a tiny bit later, but the suspension is in it's "sweet spot" at OEM ride height.
Will have RB rotors and ducts for the NCM event coming up, and likely stick some slicks on.
06-19-2007, 06:28 PM
#7
Wow David! That's a great discovery! Do you think it would be practical to simply remove the washers for a track set up then replace them for the street? That would sure solve alot of my problems running R6's and runflats.
(I left you a voice message)
06-19-2007, 07:50 PM
#10
Our car had 4 washers in front, and 2 washer in the rear. Each washer is almost exactly 1/2 deg, so I took 1 out of the rear and 2 out of the front.
Be doing it this way, you don't have to touch the concentrics on the bottom, and that way you don't mess the castor up.
I left the ride height stock, where it works best. I may drop it a tiny bit later, but the suspension is in it's "sweet spot" at OEM ride height.
Will have RB rotors and ducts for the NCM event coming up, and likely stick some slicks on.
Be doing it this way, you don't have to touch the concentrics on the bottom, and that way you don't mess the castor up.
I left the ride height stock, where it works best. I may drop it a tiny bit later, but the suspension is in it's "sweet spot" at OEM ride height.
Will have RB rotors and ducts for the NCM event coming up, and likely stick some slicks on.
06-19-2007, 08:09 PM
#11
Race Director
Thread Starter
yes, 1 washer should take you from -1.6 to -2.1. That is one washer PER BOLT, obviously. It may vary by a 1/10 deg or so, but mine came out to almost exactly 1/2 deg per washer, front and rear.
btw, I do not recommend modifying the alignment back and forth, as you ultimately risk damaging or stripping one of the upper control arm mounts. I always recommend finding a compromise, and leaving it alone. For our car, -2front and -1.5rear is just fine. Drove 225miles each way, plus 4 guys driving at the track, and the wear and tire temps were perfect.
btw, I do not recommend modifying the alignment back and forth, as you ultimately risk damaging or stripping one of the upper control arm mounts. I always recommend finding a compromise, and leaving it alone. For our car, -2front and -1.5rear is just fine. Drove 225miles each way, plus 4 guys driving at the track, and the wear and tire temps were perfect.
Last edited by davidfarmer; 06-19-2007 at 08:12 PM.
06-19-2007, 08:29 PM
#12
Instructor
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I didn't know about the washers; I turned the bottom adjusters to full negative on the front, reset the front toe to zero, and left the back alone, and it seemed pretty good to me. I don't have any of that high falutin stuff to measure camber or tire temperatures.
On the tires, I think the grip level of the factory tires is pretty well matched to the suspension tuning, but I wonder if putting on sticky R compound tires might not reveal some shortcomings in the factory suspension?
On the tires, I think the grip level of the factory tires is pretty well matched to the suspension tuning, but I wonder if putting on sticky R compound tires might not reveal some shortcomings in the factory suspension?
06-19-2007, 08:53 PM
#13
Race Director
Thread Starter
The Z06 suspension is darn close to T1 stiffness, and should work great with sticky tires. There are tons of C5Z06's running racing tires, and the C6Z is significantly stiffer IMHO.
The problem with maxing out all of the bottom adjusters is that they are all at different places from the factory, and you never know where you end up withou measuring. I've done exactly what you did, and it's great for track only, but if you want to keep the car on the street you really want to have even castor on both sides.
my DIY guide can help measure camber, castor, toe and thrust angle with simple tools most of us have already.
http://www.davidfarmerstuff.com/align.pdf
The problem with maxing out all of the bottom adjusters is that they are all at different places from the factory, and you never know where you end up withou measuring. I've done exactly what you did, and it's great for track only, but if you want to keep the car on the street you really want to have even castor on both sides.
my DIY guide can help measure camber, castor, toe and thrust angle with simple tools most of us have already.
http://www.davidfarmerstuff.com/align.pdf
06-19-2007, 09:12 PM
#14
Le Mans Master
06-19-2007, 09:32 PM
#15
Le Mans Master
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I am certainly confused. He did say the car would have to be lowered to get more negative camber.
I guess a second opinion may be an idea. I do have an enormous amount of trust in my guy but he told my other friend the same thing with his Z51.
I guess a second opinion may be an idea. I do have an enormous amount of trust in my guy but he told my other friend the same thing with his Z51.
06-19-2007, 09:48 PM
#16
Le Mans Master
David,
Which slicks?
Do you not feel there will be damage to the other parts taking the grunt from slicks? With such a grippy tire, something has to give.
Even with my coil-overs I have been hesitant to run anything more than a Hoosier R6.
Thanks for your thoughts!
Mike
Which slicks?
Do you not feel there will be damage to the other parts taking the grunt from slicks? With such a grippy tire, something has to give.
Even with my coil-overs I have been hesitant to run anything more than a Hoosier R6.
Thanks for your thoughts!
Mike
06-20-2007, 02:32 PM
#17
Race Director
Thread Starter
The C6 and C5 architecture are exactly the same, and we've been running R and slick tires on them forever and ever. I'm running scrubbs that I buy from Bob Chick, but I wouldn't hesitate to run any tire I could find. Remember, the upper and lower control arms take ALL of the later load, not the springs or shocks.
That being said, Hoosier A6's are pretty much the stickiest tire in the world, and the R6's aren't far behind. I use cheap, scrub slicks as practice tires, simply because they are cheap. I may take my Kumhos to VIR as well, but they may be too wide for the OEM brake ducts (haven't tried them).
Outnumbered, did you're alignment guy pull the wheels off....I bet he didn't. You certainly are limited in the amount of camber you can get without pulling the wheels, and removing washers, and alignment shops don't usually pull the wheels for alignments. My car had over a degree front and rear camber from the factory.
That being said, Hoosier A6's are pretty much the stickiest tire in the world, and the R6's aren't far behind. I use cheap, scrub slicks as practice tires, simply because they are cheap. I may take my Kumhos to VIR as well, but they may be too wide for the OEM brake ducts (haven't tried them).
Outnumbered, did you're alignment guy pull the wheels off....I bet he didn't. You certainly are limited in the amount of camber you can get without pulling the wheels, and removing washers, and alignment shops don't usually pull the wheels for alignments. My car had over a degree front and rear camber from the factory.
06-20-2007, 03:23 PM
#18
Melting Slicks
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If you add or remove washers (same in the front and rear of each A-arm) for camber adjustment you need to reset the toe. Caster will remain unchanged.
Frank Gonzalez
06-20-2007, 03:28 PM
#19
Melting Slicks
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06-20-2007, 04:12 PM
#20
Le Mans Master
I posted another post about this per Frank's advice at the track the other day (thank you), before I got a chance to read this post. Just a quick (stupid) question...if I losen the bolts competely (2 per link 4 per wheel), are there any bolts in the frame plates that need to be held so they don't fall away into the abyss when completely loosened? Or are the bolts permanently threaded into the frame and you can just pull out the studs and take out the washers without any concern?
Last edited by 95jersey; 06-20-2007 at 04:25 PM.