I have some street alignment settings for my C6 427 Convertible. Would the same settings apply to my C7 Z06? I I'm getting some new tires.

 

I was curious about my alignment too and when I got back from Spring Mountain I had it checked against the DSC recommended Street/Occasional track settings (https://www.tunerzstore.com/document...-alignment.pdf).

My alignment was almost bang on these exact settings when I got it checked so I left it alone.

Hope this helps.

 

Thanks. This is the one that I have.

 

Dont use PFADT settings for the C7.

Use the DSC settings.

The C7 has adjustable rear caster so make sure whatever shop you take the car to has the proper gauge for it.

 

OK very good. Thanks

 

Funny--I have three Chevrolet dealers within about a half hour's drive of me, with one close by. One of which has a big performance shop run by a long time Corvette expert. They do not have the digital angle meter or bracket and the dealership won't buy one or go to GM Tool Rental to get one.They claim caster is not important. I don't buy that and will not have them do a alignment. My nearest dealer I believe has the tools (I will certainly check before letting them do one) but they do not do too many Corvettes. The third is a higher volume Corvette seller a half hour away and do a lot of Corvette and performance work so I will bet they have the tools. But I would also bet that there are lot of Chevy dealers who just don't check the caster. --Bob

 

I recommend aligning the car yourself. Sure it takes some time and effort, but then you will know it is done right. It is a bit of an investment for some tools, but you only have to buy them once. You don't need a special bracket or special tools for the rear caster measurement. A digital torpedo level works just fine. This one is under $30.

 

Is there a good tutorial you would recommend, especially if it is for this specific vehicle?

 

I have been aligning the suspension on my cars for 35 years. There were no tutorials when I started - or even an internet....

You need a few tools and the better your tools the more accurate the alignment will be. I can tell you that toe in is the most important alignment spec to keep tire wear at a minimum. I can also tell you that your Corvette has the most awesome suspension of any car I have had the fun to align since it is so adjustable!

Camber and caster are a bit tricky because alignment adjustment affects both. Toe in on the front is super easy. Toe in on the rear is a bit trickier because the Corvette has cam adjusters for rear toe plus you have to get thrust angle aligned at the same time.

The first thing you need to decide is what is your intention for the alignment. If you plan to track your car or do autocross, you will be making alignment trade-offs between performance and tire wear. If you only drive on the street, you can optimize the alignment for the least amount of tire wear. You cannot have it both ways unless you want to align your car each time you use it for a different purpose - which is just not practical unless you have unlimited time or money.

I will also tell you that no matter how good the shop is, they will not align the car perfectly. It simply is not cost effective for them to get it perfect. By that I mean, to align the car you need the weight off the wheels, then you have to settle the car back on its wheels and check the alignment you just did. If it is off a bit, you repeat the process. Again and again if you want it perfect. A shop will get it close and then say "good enough." If you are doing it yourself, you can get it perfect. Now I cannot say that perfect is required. Even really good drivers have a hard time telling if the alignment is perfect. But what perfect does do is minimize tire wear for whatever alignment settings you choose.

I started doing alignments with a carpenters square, tape measure and strings. And I could get the alignment just as good as the shop with their laser alignment systems. You might rightly question that, but again alignment comes down to guess and change and the shop is going to call it close enough before they reach the limits of their measurement tools. Those professional tools are also limited not by their inherent accuracy (a laser is a pretty dang accurate beast) but they are limited by the stupid targets they clamp on your wheels (and also tend to scratch your expensive wheels).

I recently made my own laser alignment tools (when I got my C7) to get even better alignments - after all, Corvette tires are expensive so I want the best accuracy I can get!.

I suppose I could make a tutorial the next time I align my C7, but it would be a lot of work and I suspect most people won't bother.

Here are a few alignment spec tips for C7 Corvettes:

Front Camber - If you want to track or autocross your car, you need a substantial amount of negative camber up front. I am using -2.4 deg since i autocross the car. That does two things - it improves your ultimate grip and it reduces tire wear on the outside edge of the tire which gets abused during autocross. If you drive your car aggressively on the street, You can live with -1 to -1.5 deg camber up front. If you want maximum tire life and do not drive aggressively (why did you buy a Corvette?) you will get max tire life at about -.25 to -0.5 degree camber up front.

Rear Camber - For autocross I recommend about -1.0 to -1.5 deg camber. Track use would be higher because you are spending more time with the car hard cornering and putting power down is not quite as challenging since you are moving faster and in higher gears. The more camber you have away from 0 (neg or pos) the less longitudinal grip you will have (tires spin easier when trying to accelerate) since the tire will not have even pressure across the tread. For street driving keep the rear camber at -.25 to 0.0 deg for best tire life.

Front toe in - Keep front toe at 0.0 deg for maximum tire life in any use case. Some people will tell you to use toe out to improve corner turn it for autocross or track use. Don't believe them! They are thinking of what may work on other cars - not Corvettes. Toe out helps other cars turn in better because it enhances the Ackerman affect which then causes the inside tire to scrub and therefore creates a torque vector around the CG of the car. Corvettes (at least the ones I drive, C5, C6 and C7) all have the tie rods in front of the steering spindle. What that means is there is no Ackerman. So setting your front alignment with toe out does nothing to help the car turn in and just causes massive amounts of tire wear.

Rear Toe in - Again keep it at 0.0 deg for max tire life in any use case. Yes - you might gain a slight amount of stability by putting in a tiny amount of toe in, but the trade off for tire wear is a bad one.

Front Caster - The range you can adjust the caster is pretty limited and not very noticeable. I recommend sticking with GM's spec of 7.4 deg but keep both left and right as close as possible. Cross caster (difference between left and right) can cause the car to pull to one side. A bit more caster can help reduce outside edge tire wear for autocross where you have slow, high G corners so you can go up a bit to say 8.5 deg max for that.

Rear Caster - It has been stated by those who have racing experience that setting the rear caster to 0.7 deg will improve stability. Rear caster will have very little effect on tire wear so 0.7 should be good for all use cases. Cross caster should be kept to zero to avoid have less stability when cornering in one direction vs the other. Rear Caster was not set very well from the factory - many have reported factory alignment was way off on rear caster. My own car was 1.0 deg negative caster on the driver side and 0.0 on the passenger side. GM changed the C7 suspension to allow rear caster adjustment for the first time on a Corvette - but they apparently forgot to tell the assembly line how to properly adjust it!

 

Funny...I got ripped off by a Western Auto shop in 1996...and have been doing my own alignments since. When I try to explain how easy it is to do it yourself, I usually get a lot of ignorant guff thrown back at me. Rik, suffice to say i agree with you completely. If you want it right...do it yourself. If the tech miss-attaches a wheel sensor the alignment can show spot on, but is, in fact, off. And based on the crappy alignments I have paid for over the years it happens more often than you would expect.

 

Ive done "redneck" alignment on Jeeps before a bunch... But they will tolerate and you wont notice if things are that precise.

BUT usually follow those up with at least a $20 trip on the laser rack to check the alignment.

Last one on a Jeep I owned, took it to the alignment guy to have him check our work and really dial it in tight because it was a HUGE build and he was super impressed how tight "a bunch of rednecks" got the alignment using a plumb bob and tape measures.

I dont mess with my C7Z suspension ever so paying the $150 I paid right after I bought the car to get the alignment to the "street DSC" specs was good enough for me. The tech spent a solid 2 hours on it and got it really tight. If I was doing track days every weekend and driving the car during the week, that would be different and I would get all the tools, but for me, its not worth the cost to get setup.

 

Have you had any trouble getting shops to do an alignment other than the factory settings?

 

You shouldnt... You are the paying customer after all. If a shop wouldnt align to my specs(as long as they werent some crazy, possibly dangerous spec) I would find another shop.

 

[QUOTE=RacerRik;1601446666]I have been aligning the suspension on my cars for 35 years. There were no tutorials when I started - or even an internet....

You need a few tools and the better your tools the more accurate the alignment will be. I can tell you that toe in is the most important alignment spec to keep tire wear at a minimum. I can also tell you that your Corvette has the most awesome suspension of any car I have had the fun to align since it is so adjustable!

Camber and caster are a bit tricky because alignment adjustment affects both. Toe in on the front is super easy. Toe in on the rear is a bit trickier because the Corvette has cam adjusters for rear toe plus you have to get thrust angle aligned at the same time.

The first thing you need to decide is what is your intention for the alignment. If you plan to track your car or do autocross, you will be making alignment trade-offs between performance and tire wear. If you only drive on the street, you can optimize the alignment for the least amount of tire wear. You cannot have it both ways unless you want to align your car each time you use it for a different purpose - which is just not practical unless you have unlimited time or money.

I will also tell you that no matter how good the shop is, they will not align the car perfectly. It simply is not cost effective for them to get it perfect. By that I mean, to align the car you need the weight off the wheels, then you have to settle the car back on its wheels and check the alignment you just did. If it is off a bit, you repeat the process. Again and again if you want it perfect. A shop will get it close and then say "good enough." If you are doing it yourself, you can get it perfect. Now I cannot say that perfect is required. Even really good drivers have a hard time telling if the alignment is perfect. But what perfect does do is minimize tire wear for whatever alignment settings you choose.

I started doing alignments with a carpenters square, tape measure and strings. And I could get the alignment just as good as the shop with their laser alignment systems. You might rightly question that, but again alignment comes down to guess and change and the shop is going to call it close enough before they reach the limits of their measurement tools. Those professional tools are also limited not by their inherent accuracy (a laser is a pretty dang accurate beast) but they are limited by the stupid targets they clamp on your wheels (and also tend to scratch your expensive wheels).

I recently made my own laser alignment tools (when I got my C7) to get even better alignments - after all, Corvette tires are expensive so I want the best accuracy I can get!.

I suppose I could make a tutorial the next time I align my C7, but it would be a lot of work and I suspect most people won't bother.

Here are a few alignment spec tips for C7 Corvettes:

Front Camber - If you want to track or autocross your car, you need a substantial amount of negative camber up front. I am using -2.4 deg since i autocross the car. That does two things - it improves your ultimate grip and it reduces tire wear on the outside edge of the tire which gets abused during autocross. If you drive your car aggressively on the street, You can live with -1 to -1.5 deg camber up front. If you want maximum tire life and do not drive aggressively (why did you buy a Corvette?) you will get max tire life at about -.25 to -0.5 degree camber up front.

Rear Camber - For autocross I recommend about -1.0 to -1.5 deg camber. Track use would be higher because you are spending more time with the car hard cornering and putting power down is not quite as challenging since you are moving faster and in higher gears. The more camber you have away from 0 (neg or pos) the less longitudinal grip you will have (tires spin easier when trying to accelerate) since the tire will not have even pressure across the tread. For street driving keep the rear camber at -.25 to 0.0 deg for best tire life.

Front toe in - Keep front toe at 0.0 deg for maximum tire life in any use case. Some people will tell you to use toe out to improve corner turn it for autocross or track use. Don't believe them! They are thinking of what may work on other cars - not Corvettes. Toe out helps other cars turn in better because it enhances the Ackerman affect which then causes the inside tire to scrub and therefore creates a torque vector around the CG of the car. Corvettes (at least the ones I drive, C5, C6 and C7) all have the tie rods in front of the steering spindle. What that means is there is no Ackerman. So setting your front alignment with toe out does nothing to help the car turn in and just causes massive amounts of tire wear.

Rear Toe in - Again keep it at 0.0 deg for max tire life in any use case. Yes - you might gain a slight amount of stability by putting in a tiny amount of toe in, but the trade off for tire wear is a bad one.

Front Caster - The range you can adjust the caster is pretty limited and not very noticeable. I recommend sticking with GM's spec of 7.4 deg but keep both left and right as close as possible. Cross caster (difference between left and right) can cause the car to pull to one side. A bit more caster can help reduce outside edge tire wear for autocross where you have slow, high G corners so you can go up a bit to say 8.5 deg max for that.

Rear Caster - It has been stated by those who have racing experience that setting the rear caster to 0.7 deg will improve stability. Rear caster will have very little effect on tire wear so 0.7 should be good for all use cases. Cross caster should be kept to zero to avoid have less stability when cornering in one direction vs the other. Rear Caster was not set very well from the factory - many have reported factory alignment was way off on rear caster. My own car was 1.0 deg negative caster on the driver side and 0.0 on the passenger side. GM changed the C7 suspension to allow rear caster adjustment for the first time on a Corvette - but they apparently forgot to tell the assembly line how to properly adjust it![/QUOTE]

I have my rear caster adjusted to the DSC's recommendations. However, a few months ago I asked Jim Mero to comment in a thread where rear caster was being discussed. I figured since he was one of the suspension development engineers and the test driver for the C7 he could comment on rear caster and what it should be set at with a lot more knowledge than anybody else. Here is the link to his post:
https://www.corvetteforum.com/forums...post1600456708"This is what he said:
======================================== ======================================
Hello everyone,

A Forum member asked me to provide some in site for the reason we added rear caster settings on the C7, so here goes……

If you recall the camber adjustment on the C6 was done by moving the rear lower control arm rear inboard attachment only. There was no adjustment on the front attachment. So, when the rear attachment is moved outboard to increase negative camber, the rear lower control arm ball joint also moves forward creating rear caster. This also put an undesirable preload on the real lower control arm inboard front bushing.

The further we moved the rear lower control arm rear attachment outboard and the rear lower ball joint forward to increase negative camber, also increased rear caster, and produced ride and roll curves that were undesirable. I no longer have access to these curves, but I do remember we wanted/needed to improve them for the C7. The toe change in ride and roll on the C6 when the rear negative camber/caster was increased produced some motions that were subjectively unfavorable.

So, for the C7, we made both inboard attachments on the rear lower control arms adjustable. This kept the ride and roll curves linear. However, there was a biproduct of adjusting both lower control arm inboard attachments which was a rear caster setting that needed to be monitored as we increased rear negative camber.

Therefore, the rear caster adjustment was never included to be some kind of tuning setting, but it was necessary to maintain 0 degrees as rear negative camber is increased.

When we were at the Nürburgring, several times I worked with our technicians doing alignments on C7’s. Maintaining 0 degrees caster in the rear was not that difficult when increasing rear negative camber. An extra set of hands helped but was not necessary. I believe there is a special tool that goes into holes in the rear knuckle, but all we used was a digital level. There are 2 machined surfaces on the inboard side of the knuckle that the level can be placed against. As we adjusted rear negative camber, we always ensured the rear caster was 0 degrees.

Because of the undesirable toe curves generated when the rear caster was not 0 degrees, we never deviated from that setting.

Finally, I know there are production tolerances on the alignment settings that are way more than I like. Decreasing them was a battle I continually lost. Also, I recently was been told dealers do not monitor rear caster when performing an alignment, I never knew that, but this is also unfortunate.

I’m not sure there is much more I can add, but I hope this helps.

Thanks, Jim"
======================================== ======================================== =
One thing I found out when I was trying to get a track alignment done on my C7Z in March of 2016 was the lack of knowledge of the rear caster setting even though it is called out in GM service documents and the documents tell the mechanic what tools to use and how to use them.

So my first track alignment was done by a dealer that didn't have the equipment and by a Corvette Specialist who had no idea what rear caster was or why it was spec'd on the C7. I rode with that alignment for a year until I had the tools to check it myself. At a friend's house I checked my rear caster. The left rear caster was +.05 while the right rear caster was -0.4. Both within GM's specification of 0.00 plus or minus 0.8 degrees at each wheel with no cross caster spec.

Bill

 

RacerRik,

I am in the Wentzville area and just purchase my first corvette. I see you are in St Louis. I tried to DM you, but system won’t let me yet.

I just purchased a 2017 z06/z07 and need to replace the tires due to very bad inner wear. I’m suspecting it’s due to the track alignment. I get new tires next week and want to change to a street alignment. The car won’t be tracked, for now, but may be some day. I’ll use different tires when I track. I am putting in Michelin pilot Sport All Season 4 for my street driving.

is there an alignment shop you know does good work you’d recommend in our area. I am not able to do the alignment myself due to experience, space and tools. Maybe some day. Anyway, any direction would be helpful. I want to make the alignment change shortly after the new tires.

Thanks!


anyone else I the Wentzville-ish area. Feel free to chime in.

 

I noticed exactly the same tire wear at about 20k miles on my 2016 Z06. As noted my my 2020 post in this thread, I took it to a dealer who had a digital angle meter and had them do a street alignment using the Pfadt specifications. As I recall there was one item they could not do precisely to those specs but since then (five years and 33k now) I have no indication of inside shoulder tire wear on the replacement Michelin Pilot Sport A/S tires. --Bob

 

Gadget,

Beautiful car you have there!

For anyone in the St. Louis area, I recommend contacting Dave at Solo Performance Specialties, https://soloperformance.com/.

Text: 636-343-5095

Voice: 636-343-5095 / 877-614-7656

He does excellent work on performance car precision alignments as well as tire and wheel work. Tell Dave that Rick Wingerter sent you. I don't get any kick backs but Dave will appreciate that I am sending people to him. Dave autocrosses with us and he is a great guy as well as excellent mechanic.

 

I'll be in touch with Dave. Will need tires and a street alignment

 

Dave specializes in high performance cars and race cars. He knows how to properly handle low profile tires and will not damage your tires, wheels or any part of your car unlike many tire shops that mostly work on regular cars. If I did not do all my own work, Dave is the only one I would let work on my car.

 

Thank you, Rick! I appreciate the direction and will hang onto his number for when I’m ready. Current conversation with my wife was we’re going to keep the track alignment. See how we do with the first set of tires. If they are wearing too quickly, then our budget allows, then we may switch to the street alignment. However, we’re gonna drive it and have lots of fun with it.

The first set of tires were included with our purchase.