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The real issue with the C7 alignment specs, see below, is the +/- Camber range allowed and still be within spec. I had my Grand Sport aligned at 400 miles, free as a warranty item. If I had just said, check alignment, the dealer tech could have just put it on their Hunter Alignment machine and fixed the only item, in Red, out of spec. One toe just slightly out. Then my rear Camber would have been left with the -1.6 degrees (both) as received from the factory. The centerline is -1.1 degrees and allowed range -0.5 to -1.7 degrees. -1.6 is within spec but very aggressive.
I gave the Service Writer a spread sheet with the GM specs spelled out in Min Max columns not just tolerance. And what I wanted in the last column for each item. All of my requests were within the GM spec range but selected for better tire wear. I requested Camber just under centerline for not at the lowest (least amount) of Camber allowed. A compromise between handling and tie wear. Toes were the GM centerline spec, which is close to 0.
Took tech 35 to 45 minutes versus the <10 it could have to fix one toe and ligitimenty say, alls fine.
All done on warranty and in fact the tech invited me into the service bay to watch the Hunter screen as he made changes (I had been standing outside the service bay door, my usual MO.). Gave him a nice tip!
Is this the factory setting for the Z06 mine is a 2019.
When I lived in UpState NY the Chevy Dealership also sold BMWs and had a BMW alignment machine in the shop. When they performed alignments on my Vettes they used the BMW machine which had toe read outs in millimeters. DSC could be using a similar machine since they have done a lot of work on German cars.
After my track incident and subsequent repair which required replacement the entire right rear suspension parts except the spring the body shop did a realignment on my car and I noticed their Hunter machine was set up to read toe in degrees. The mechanic said it might be possible to choose displaying the settings in inches or millimeters but wasn't sure.
When doing this in your own garage the only way to get close to 0.5 mm measurement is by accident. The measurement tools, parallax error and the human eye aren't sufficient to get a measurement less than 1/32 of an inch. The thickness of the string is part of the problem.
Bill
And it's for this reason as you've explained in better detail why anyone posting and suggesting the use of DSC specs should throw them out IMHO.
Are you saying for best tire wear and spirited street driving that I should tell the Service Manager to tell the alignment tech to set the Camber to -1 (degrees?) for all 4 wheels, and the toe to 0 (degrees?) for all 4 wheels?
And then what do I tell them to set the Caster at for front? ...and Caster for the rear?
Also, do they have to have that special bracket mounting piece to align the rear? Is that a must have item to get it correct? What is that piece called or what is that item part number please?
Thank you subieworks
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Subie's post is a reasonable starting point. Then, look at the tread after driving. The tires will pick up sand and dirt and tell you where the contact patch of the tire is for your driving habits. If the dirt pick up indicates the contact patch is not centered on the tread and say, favors the inside corner, then you need to take a little camber out. But for street, even "spirited driving", yes close to 0 toe as possible, whether presented in degrees or inches or mm's. For the street as long as the caster is close to the same, don't worry too much about the exact number. After all there are a lot of fast C5 and C6's out there with no provision at all for changing rear caster. Florida is different than a mountain home in the Rockies! Your tires will tell you what they need with you behind the wheel driving where you drive and how you drive. That is what most alignment shops miss, is dealing with the nut behind the wheel. Most of them are not astute enough anyway. Two racers in the same car will ask for suspension changes to suit the way THEY drive. So after you do a road test show them where wear it taking place and make the shop do it RIGHT. We used to paint white shoe polish on the tread of tires to see where the wear happens, then adjust accordingly.
When I lived in UpState NY the Chevy Dealership also sold BMWs and had a BMW alignment machine in the shop. When they performed alignments on my Vettes they used the BMW machine which had toe read outs in millimeters. DSC could be using a similar machine since they have done a lot of work on German cars.
After my track incident and subsequent repair which required replacement the entire right rear suspension parts except the spring the body shop did a realignment on my car and I noticed their Hunter machine was set up to read toe in degrees. The mechanic said it might be possible to choose displaying the settings in inches or millimeters but wasn't sure.
When doing this in your own garage the only way to get close to 0.5 mm measurement is by accident. The measurement tools, parallax error and the human eye aren't sufficient to get a measurement less than 1/32 of an inch. The thickness of the string is part of the problem.
Bill
All machines that I have ever owned have the ability to change units. On my newest Hunter machine I can do degrees (our preferred), degrees and minutes, degrees and radians, mm, inches.
It is not possible to switch between these methods though without recomping the car as the math behind how it is done is performed when the car is setup to the aligner. I prefer degrees as it is an absolute measurement. mm/in is not and cannot ultimately be compared between the alignment machine and what is used on a string setup.
Is this the factory setting for the Z06 mine is a 2019.
Assume that chart is the same as there were no changes in car or tires 2019 that would cause a deviation.. However as I noted the "Factory setting" is whatever it was when it left assuming you have not hit pot hole etc!
As I said my rears were set at -1.6 degrees negative camber where the GM allowed range is -0.5 to -1.7. So they were within spec but more for aggressive driving and not for great tire wear. Only one toe was just slightly out of spec. If using a dealer suggest you go down the list and say what you want, even if you just want to put down the centerline info.
I have a 2017 Corvette Z06 with Z07 package Manual Trans. Everything stock except camber adjusted and corner balanced.
This is my main track car that I would use mostly on the track and occessional weekend driving for about 30-50 miles total in a month.
I drive back and fore to the track as well. Shortest distance is about 140 miles one way and longest is about 550 miles one way, probably 3 times a year on the longest.
I have done 8 track days since April 2018, total about 2,800 miles.
I have scheduled to do about 12-14 this year, already done one for 2019.
My experience: - started April 2018, my first track day and fell in love ever since.
Ron Fellows 2 days school Level 1
Bondurant 4 days racing school
AMG Performance Academy 1 day
8 track days with my own car
I have some question specific for the CORVETTE (not general cars) and hope to get some answers from the experienced one.
I have done the corner balance on this Z06, do I ever need to do it again? If yes, what is the typical interval based on my usage?
If remember correctly, my camber was set to front 2.0 and rear 1.5.
What is the maximum camber I can do with the factory equipment?
What is the interval to have alignment recheck?
What is the alignment recommendation for my application? I am experiencing outer tires wears even with 2.0/1.5 setup.
How much negative camber is considered overdoing?
I ordered new Custom Forgeline wheels 18x11 / 18x12 and hope they will fit.
I am thinking of Toyo R888R. Do you guys think they will fit?
Front 305/35ZR18 or 295/30ZR18
Rear 335/30R18 (only option)
Thank you very much and look forward to learn from the forum.
1. not sure you will benefit from a corner balance if this is your second season. So I think the answer is as long as your ride height is not all screwed up, leave it where it is for now and don't worry about it. otherwise, any time you change something, the corners change.
2. Your rear settings are probably constrained by the OEM toe links. A set of Granetelli's or equivalent will be needed to get all the adjustment you need easily. regarding how often to check, Personally, I check alignment before each track day, just like changing brake pads. I have my own tools so it is just time to me. You can have all the HP you want in a car, but brakes and tires are #1 and #2 respectively.
3. If you are getting outside corner wear, then you probably have a big toe setting problem. Is it the front or rears that are outside corner wearing? With -2.0 in the front, you should wear the inside corners first. So, since you drive so far, you need to compromise a little on settings or just the trip there will wear the tires on the inside. I have two friends that drive their C7's to the track with -2.2 frt,-2.0 rear, a pinch of toe-out front and a pinch of toe in rear. When I say pinch I mean 1/32" total toe max. Shoot for front caster as stated in the Owner's manual, and rear caster 0. With the factory eccentrics and pulling out the shim washers (note the owner's manual has restrictions of removing shims) is what all of us do to get the camber we want. I think with all washers out you can get about -2.6 in the front and -2.4 in the rear with the factory eccentrics. Bottom line, the Owner's manual track alignment settings aren't bad, except for range of allowed toe, which needs to be tightened up to manage tire wear.
4. For your second year, the settings above will be OK and you can drive back and forth with some but not excessive corner wear. Any more camber with the toe settings wrong and a 500 mile road trip will take a set of new tires to the cords.
5. I hope you ordered the correct offset (or back-spacing, same thing measured differently). Otherwise, you will not be able to use the wheels. You will learn more about the car if you stick with OEM Michelins, and wait on track tires and wheels. If you run into a rain storm on the way to or from the track, Corvettes with tires like 888's have a proclivity to hit the ditch. Money is better spent on track time.
When you put R888's and an aggressive alignment, it is time to trailer your car and have a spare set of tires or wheels. Chit happens at the track. A couple summers ago, I picked up a pop-rivet that fell out of another car and ruined a tire as it went flat on me. The only place I could have gotten it was the track or the paddock, the tires were slicks and never saw the street.
1. not sure you will benefit from a corner balance if this is your second season. So I think the answer is as long as your ride height is not all screwed up, leave it where it is for now and don't worry about it. otherwise, any time you change something, the corners change.
2. Your rear settings are probably constrained by the OEM toe links. A set of Granetelli's or equivalent will be needed to get all the adjustment you need easily. regarding how often to check, Personally, I check alignment before each track day, just like changing brake pads. I have my own tools so it is just time to me. You can have all the HP you want in a car, but brakes and tires are #1 and #2 respectively.
3. If you are getting outside corner wear, then you probably have a big toe setting problem. Is it the front or rears that are outside corner wearing? With -2.0 in the front, you should wear the inside corners first. So, since you drive so far, you need to compromise a little on settings or just the trip there will wear the tires on the inside. I have two friends that drive their C7's to the track with -2.2 frt,-2.0 rear, a pinch of toe-out front and a pinch of toe in rear. When I say pinch I mean 1/32" total toe max. Shoot for front caster as stated in the Owner's manual, and rear caster 0. With the factory eccentrics and pulling out the shim washers (note the owner's manual has restrictions of removing shims) is what all of us do to get the camber we want. I think with all washers out you can get about -2.6 in the front and -2.4 in the rear with the factory eccentrics. Bottom line, the Owner's manual track alignment settings aren't bad, except for range of allowed toe, which needs to be tightened up to manage tire wear.
4. For your second year, the settings above will be OK and you can drive back and forth with some but not excessive corner wear. Any more camber with the toe settings wrong and a 500 mile road trip will take a set of new tires to the cords.
5. I hope you ordered the correct offset (or back-spacing, same thing measured differently). Otherwise, you will not be able to use the wheels. You will learn more about the car if you stick with OEM Michelins, and wait on track tires and wheels. If you run into a rain storm on the way to or from the track, Corvettes with tires like 888's have a proclivity to hit the ditch. Money is better spent on track time.
When you put R888's and an aggressive alignment, it is time to trailer your car and have a spare set of tires or wheels. Chit happens at the track. A couple summers ago, I picked up a pop-rivet that fell out of another car and ruined a tire as it went flat on me. The only place I could have gotten it was the track or the paddock, the tires were slicks and never saw the street.
Yeah. Corner balance has been performed and front also been lowered, like 1/4 inch only.
Do you happen to know the limit for the rear camber with OEM part? I think as long as I can reach 2.0 or 2.2, it should be good.
Cannot agree more, Tires and Brakes are very important.
The front left outer wore out faster follow by left rear then right side. I ran all CW track and i should have rotate tires left to right to have even tread. All the lefts are gone while right has some left.
I do not have pyrometer but I use laser temperature gun right after every session. My tires temperature were consistently 12-15 degree hotter from outside to inside...such as 200F on the outside, 185F middle and 175 inside. Does it mean outside get more friction? Is this normal or ideally trying to achieve even temperature?
Noted. Thank you.
I ordered the wheels from someone who works with racing guy and he guarantees wheels will fit so I cross my fingers.
Cup2 ZP is sticky but only last me 2 track days and they are expensive!
I hope R888R will last longer, based on the reviews.
The guys sold me wheels recommend me Hoosier because that all his racing guys use. I will try this when i get my trailer!
Yeah. Corner balance has been performed and front also been lowered, like 1/4 inch only.
Do you happen to know the limit for the rear camber with OEM part? I think as long as I can reach 2.0 or 2.2, it should be good.
Cannot agree more, Tires and Brakes are very important.
When I first had a track alignment done on my 2015 Z the dealership didn't have the tools to set rear caster. The mechanic set the front camber at -2.0 and rear camber at -1.9 without removing any shims and let rear caster fall where it fell. I marked the LCA cams so I knew the original settings and the after settings. I ran that way for a year. The following season I went over to k24556's house and worked with another forum member to set a DSC track alignment on both of our Z06's. When we went to do my car we found that rear caster was +0.4 degrees on the left and -0.5 degrees on the right which is where it fell after the previous year's alignment. The rest of the numbers were pretty much in line with the sheet I had from the previous alignment so that showed us the alignment doesn't change much with hard track usage and some curb pounding. While trying to get the DSC recommended -1.7 degree rear camber and +0.7 degree rear caster was the toe links lacked sufficient adjustment range to get the toe setting we wanted. If we reduced rear caster close to zero or at 0 like GM recommends or to negative caster there was plenty of adjustment but not at +0.7 degrees. We also noticed that we could easily achieve over -2.0 degrees rear camber but didn't push it to see how far we could go. This was with the single rear shims in place (Z06 comes with only 1 rear shim Vs Z51 2 rear shims and GM says to have at least one shim behind the UCAs. Don't know why but I decided to go with their judgement which may have more to do with wear/durability issues than alignment.
With the cars on k24556's 4 post lift with home made toe plates at each wheel it took us two complete days to get the alignment done on both cars. We learned a lot about how to do it and the main point is the rear camber/caster/toe adjustment is very touchy very slight movements of the cams can suddenly take you a long ways from the setting you are trying to achieve. It takes a lot of time to do the rear correctly. If you don't worry about getting caster set the same on each side and apply GM's +/- 0.8 degree tolerance to the caster setting it doesn't take any time at all but if you want to zero rear cross caster and go with a positive rear caster near the upper tolerance limit it will take a lot of time. When you pay somebody to do this they will expect to be paid appropriately since it can add 3 or 4 hours to the length of the job. That may be why DSC gets $400+ to do an alignment.
The front left outer wore out faster follow by left rear then right side. I ran all CW track and i should have rotate tires left to right to have even tread. All the lefts are gone while right has some left.
I do not have pyrometer but I use laser temperature gun right after every session. My tires temperature were consistently 12-15 degree hotter from outside to inside...such as 200F on the outside, 185F middle and 175 inside. Does it mean outside get more friction? Is this normal or ideally trying to achieve even temperature?
Noted. Thank you.
I ordered the wheels from someone who works with racing guy and he guarantees wheels will fit so I cross my fingers.
Cup2 ZP is sticky but only last me 2 track days and they are expensive!
I hope R888R will last longer, based on the reviews.
The guys sold me wheels recommend me Hoosier because that all his racing guys use. I will try this when i get my trailer!
The 18s should work. I run 18x11 front CCWs and either 18x13 rear CCWs or 18x12 OZ racing wheels all of the wheels were built to run on C6Zs and have the offsets for those cars. They do fit on the C7Z06. The only issue with the ceramic brake cars is the front rotor hats. On both the C6 ZR1 and the C7 Z06 the hats have a depressed center area to get the correct rotor offset so the rotor is located in the center of the caliper. The stock wheels and some aftermarket wheels have hub faces that will fit in the depressed area. However, the CCW wheels don't fit. They have hub faces that are a few thousandths too large in diameter and the edge of the hub face rides on the radiused edge of the depressed area in the rotor hat. This means the wheel can't be torqued down properly and will move around on the hub while running. That may cause the lug studs to fail (been there and done that on my C6Z with resultant breakage of all 5 studs and loss of wheel after 7 track days). The solution that CCW provides is a thin spacer that fills the depressed area so the wheel will ride flat on the rotor hat. I use Extended Thread lug nuts to provide sufficient thread engagement when using the spacer. If you are using the stock ceramic brake rotor hats or something similar from an aftermarket supplier make damned sure you don't need the spacer between the hat and the wheel. I have since changed over to the AP Racing brakes and that rotor hat is flat so no spacer is required.Not a big deal as long as you know you have to use the spacer but if you don't know it can bite you badly. It only cost me $4000.
I track the car pretty often and I also put Street miles on it, are my toe numbers way off? I told the guy it's,supposed to be -.5 mm and he told me that converts over to -.028 degrees. After reading I think this guy was incorrect and it should be set at .06 degrees for toe, what do you guys think?
ELI, The sheet you show in your post and the verbal report from your alignment technician don't seem to agree. The sheet shows 0.28 deg toe out at each corner. That is a lot of toe out for the street, and maybe not the right setting for the track either. Just because the Hunter alignment machine shows a green highlight on a setting does not mean squat. If merely means the settings are within the OEM specs. Most folks here will say that the OEM specs can lead to some really bad wear and poor handling.
What you are saying is that you drive the track and street, so the settings on the sheet will lead to quite a bit of corner wear when street driving. Those settings aren't particularly great for the track either. You will either need to change back to street settings for the street, or come up with a compromise solution.
As a compromise, shoot for the settings given on pg 166 of your owner's manual. Assuming you have the OEM rear toe links, you will not be able to get the rear camber to -2.0, caster to 0 and get toe set properly. Give up on camber/caster to get the toe close to 0. you will probably get -2.0 camber on the LR and -1.9 on the RR but that will be close enough. shoot for 0 toe both front and rear, and 0 total toe. You should have no trouble getting -2.0 camber in the front, and no problem getting +7 or greater front caster. the trick is to make sure the cross-caster is close (both front caster measurements are close to each other). the key to the COMPROMISE setup is 0 toe front and rear.
Many here will reply 0 toe is bad for driving on the track. Well, there are a bunch of depends-ons. Depends on what you are doing at the track. If you are doing HPDE's, this compromise will allow you to drive on the street with this setting, and give you decent performance on the track. If you are doing time trials, then this compromise is not for you.
Another depends-on is your driving style both on the street and the track. On the track if you turn into corners early or are too hot at turn in, then you are going to scrub the crap out of the corners of the tires. No amount of toe change or camber change will correct for such driving habits on the track. Ditto for the street. Make your turn late in the lane. This will mean more steering input, but for a shorter time. A further benefit is you are in oncoming traffic for less time, therefore in harm's way for a shorter time. Among the many other depends-ons is the track condition. Some are just plain harder on tires than other tracks. Oh yea, don't forget tire pressure. This is something you can fiddle with and help your tires.
Please do not think I am critiquing your driving style. I'm just pointing out possibilities for consideration.
Front toe on a C7 ZO6 for a lot of track Duty 4 times per month
Okay so the .028 is definitely way off, so what should it be? should it be negative .01 for track Duty instead of the 0? Thanks for your input it's much appreciated! And what does the .5 mm toe convert to in degrees
Okay so the .028 is definitely way off, so what should it be? should it be negative .01 for track Duty instead of the 0? Thanks for your input it's much appreciated! And what does the .5 mm toe convert to in degrees
In my humble opinion it would be great if people stop using mm measurements
Okay so the .028 is definitely way off, so what should it be? should it be negative .01 for track Duty instead of the 0? Thanks for your input it's much appreciated! And what does the .5 mm toe convert to in degrees
0.028 is probably between 1/32 and 1/16. If you have this both sides, then you may have almost 1/8" total toe. That is too much for the street and you will probably get a lot of corner wear with that much toe. If you are sticking with your Hunter guy, insist on 0 toe. Then it does not matter if it is an angle or a dimension. Zero is Zero. You will have a good compromise for street and track (camber and caster per OM, page166).
Answer to your second question is since the steering rack is in front of the knuckle on a Corvette, an optimum TRACK alignment, start with with toe out. In the back since the toe link is behind the knuckle, you would start with toe in. Alignment settings are at a resting condition of the car. When you load the suspension in a turn at the track, the front toe decreases as a function of suspension movement from the resting condition. Since toe is constrained by the steering rack, you increase toe in for the front when the suspension is moved from rest. The back is the opposite, suspension loading from the resting condition will increase toe out. So to compensate for this you start with a toe "offset" at each end. It is a lot more complicated than that, but maybe that will help with the understanding a bit.
Back to the issue at hand. If you expect the Hunter alignment tech to understand the implications of the alignment settings you desire, good luck. Not many techs are racers too, so what you may have is a person well trained to be able to turn the little boxes green on the printout. So the printout is good to start a fire in the fire place, not much else.
Now for your question about what does 5 mm mean in terms of an angle. Well again, depends. I don't know much about Hunter alignment systems, but it is measuring dimensions and converting to angles by computation. The trig equation is:arctan y/x . in plain English the expression is stated "angle whose tangent is y divided by x.
So let's make the value for y be your .5mm, and the x value be the diameter of the front wheel, 19 inches. For simplicity sake, call .5mm 0.020 inches. Open up your EXCEL spreadsheet. The EXCEL formula for arctany/x in degrees: =DEGREES(ATAN.02/19)) You should get 0.06 degrees. Now for the DEPENDS. If you look at pictures of the hunter system, a cylinder that is about 10 inches in diameter is bolted to each wheel. If 10 inches is the x value for their calculation, then the result will be reported as 0.114 degrees. So, unfortunately, unless we can find something on how Hunter computes the angles they report in the little boxes, it is a guess (at least for me).
The nominal convention is to calculate angles based on wheel diameter. This goes back to the history of alignment measurements where toe plates were the norm. They were made to be about the diameter of the wheel. Then a toe plate was placed on either side and a tape measure used to measure the difference between the front and back of the two toe plates. A simple but very effective way to set toe. After all, if you get to less than 1/32 inch you are in the grass as far as accuracy goes. You can get that close with a tape measure no problem. For that matter, you can stretch a tape measure from side to side , measuring a tire tread feature like a groove and get really close. In fact, that is all I use at the track if something comes up loose and I have to re-adjust. Not going to waste an entry fee just because there isn't an Hunter machine handy.
yea my 71 YO brain thinks in inches. Thinking about it, the only thing on today's cars that is not metric is wheel size. I don't ever recall seeing truly metric sizes in wheel diameters. Now this is straying from the purpose of original post, but it does cause us to think before making a measurement. I still do all my alignment measurements in inches.
In my humble opinion it would be great if people stop using mm measurements
Originally Posted by subieworx
I agree. It's a stupid form of measurement for toe.
Hmm, "back-in-the-day" it was easy to measure toe in "inches." Didn't need a fancy machine- just a tape. It fact, when I spent a year building my '34 street rod, had to drive ~100 miles to and from the interior shop before it was finished (just two seats with foam no other interior) and I could get it "on an alignment machine." Used a tape for toe and a level on the rims with feeler gauges to set camber. Just needed a Tri table! It was very close, when checked!
Leave you with another thing to contemplate. Set my 1967 Corvair rear toe with a tape. It was set at 1/4 up to 3/8 inch toe-in! That was the GM spec- for a good reason!
In my humble opinion it would be great if people stop using mm measurements
Some alignment machines show toe in mm not inches or degrees. Before I moved South I used to take my Vettes to a Chevy dealer in upstate NY for for some alignments. They were also a BMW dealership and the alignment machine they used was a BMW recommended machine. While I was watching the mechanic set my specified alignment I noticed the toe readings were all in mm. I had given him the specs in degrees but all he could see on the read out was mm and he said there wasn't any way to change it. Guess what? I had to get out the calculator and convert the readings to degrees. Degrees are the only constant way of measuring toe since 1/8 toe on a 20 inch wheel isn't the same angle as 1/8 toe on a 120 inch wheel.
Some alignment machines show toe in mm not inches or degrees. Before I moved South I used to take my Vettes to a Chevy dealer in upstate NY for for some alignments. They were also a BMW dealership and the alignment machine they used was a BMW recommended machine. While I was watching the mechanic set my specified alignment I noticed the toe readings were all in mm. I had given him the specs in degrees but all he could see on the read out was mm and he said there wasn't any way to change it. Guess what? I had to get out the calculator and convert the readings to degrees. Degrees are the only constant way of measuring toe since 1/8 toe on a 20 inch wheel isn't the same angle as 1/8 toe on a 120 inch wheel.
Bill
Agreed, degrees are the only constant as mm is arbitrary and subjective. If there were a specific location and spec for a mm or fractional measurement we could all reference so that we could make it a standard we could all live with it, but there isn't one.
11-29-2018, 02:24 PM
