toe-in, just to be sure..
05-15-2018, 09:40 AM
#41
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St. Jude Donor '07
Where you are reading this "spec" may have everything to do with the confusion. So where did you get it? !/32" toe in from center line on each front wheel is correct for a mid year Corvette with radial tires. Add these two numbers for total toe.
Like I said, forget the term total toe
If the front wheels are straight/parallel with the car center line, you have 0 toe. Period!
If you have one tire toed in a 1/32" and the other straight/parallel with the car, you have 1/32" total toe or 1/32" toe on one wheel. Theoretically, in a perfect world, this will throw your steering wheel clear vision off center.
If you have both the left and right wheels toed in 1/32" each from the car center line, you now have a total toe in of 1/16".
In all cases, whatever toe in you have at the front of the wheels should be equally matched as toe outon the back side of wheel unless something is bent. One dimension should cancel the other in relation to car center line.
You are way overthinking something that is very simple.
Like I said, forget the term total toe
If the front wheels are straight/parallel with the car center line, you have 0 toe. Period!
If you have one tire toed in a 1/32" and the other straight/parallel with the car, you have 1/32" total toe or 1/32" toe on one wheel. Theoretically, in a perfect world, this will throw your steering wheel clear vision off center.
If you have both the left and right wheels toed in 1/32" each from the car center line, you now have a total toe in of 1/16".
In all cases, whatever toe in you have at the front of the wheels should be equally matched as toe outon the back side of wheel unless something is bent. One dimension should cancel the other in relation to car center line.
You are way overthinking something that is very simple.
Bill
05-15-2018, 09:58 AM
#42
Melting Slicks
Thread Starter
Where you are reading this "spec" may have everything to do with the confusion. So where did you get it? !/32" toe in from center line on each front wheel is correct for a mid year Corvette with radial tires. Add these two numbers for total toe.
If the front wheels are straight/parallel with the car center line, you have 0 toe. Period!
If you have one tire toed in a 1/32" and the other straight/parallel with the car, you have 1/32" total toe or 1/32" toe on one wheel. Theoretically, in a perfect world, this will throw your steering wheel clear vision off center.
If you have both the left and right wheels toed in 1/32" each from the car center line, you now have a total toe in of 1/16".
In all cases, whatever toe in you have at the front of the wheels should be equally matched as toe outon the back side of wheel unless something is bent. One dimension should cancel the other in relation to car center line.
You are way overthinking something that is very simple.
If the front wheels are straight/parallel with the car center line, you have 0 toe. Period!
If you have one tire toed in a 1/32" and the other straight/parallel with the car, you have 1/32" total toe or 1/32" toe on one wheel. Theoretically, in a perfect world, this will throw your steering wheel clear vision off center.
If you have both the left and right wheels toed in 1/32" each from the car center line, you now have a total toe in of 1/16".
In all cases, whatever toe in you have at the front of the wheels should be equally matched as toe outon the back side of wheel unless something is bent. One dimension should cancel the other in relation to car center line.
You are way overthinking something that is very simple.
05-15-2018, 10:05 AM
#43
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I am not overthinking , and I do agree it's very very simple math indeed. The 1/32" is just an example. All over this forum there are threads about how much toe-in people use/suggest like 1/32", they hardly ever specify what their definition is, so how can I know? Which is the reason of existence of this thread.
I think you have radial tires. Put 1/32" on ea front tire and you're done. About three times that much if you use bias ply.
I'm done.
Last edited by MikeM; 05-15-2018 at 10:09 AM.
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alexandervdr (05-17-2018)
05-15-2018, 10:07 AM
#44
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05-15-2018, 10:37 AM
#45
Melting Slicks
Thread Starter
You could have made your life easier by answering yes/no to my post #33 where I put in a drawing with what I believed you ment to explain to my stupid brain Finally, given that some replies use different definition from yours, it's hard for me (and anyone else) to find out who is right and who is wrong.The background of the thread is that I do have a 2 wheel alignement tool from Tenhulzen Automotive. www.wheelalignmenttools.com/product/toe-plates/. It uses 2 tape measures, going wheel to wheel, one in the frontside , one in the backside of the tire. That is what I can measure. So I simply needed to know how that measurement relates to a toe spec as in table below taken from http://www.tech.corvettecentral.com/...ignment-specs/ (they say it is ....'total Toe'...sorry!)
Last edited by alexandervdr; 05-15-2018 at 11:47 AM.
05-15-2018, 11:35 AM
#46
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Mike is right. I know this because I have and still do align cars. Started with a John Bean unit, moved to Hunter A-111, then the c-111 and now it's the Hunter Hawkeye. Been doing 4 wheel alignments since 1983. But what do I know. And what does Mike know. You want to align a car right, get a piece of string and get on the internet! Woo-Hoooooo!!!
05-15-2018, 11:49 AM
#47
Team Owner
Mike is right. I know this because I have and still do align cars. Started with a John Bean unit, moved to Hunter A-111, then the c-111 and now it's the Hunter Hawkeye. Been doing 4 wheel alignments since 1983. But what do I know. And what does Mike know. You want to align a car right, get a piece of string and get on the internet! Woo-Hoooooo!!!
05-15-2018, 11:52 AM
#48
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Total Toe-in is A-C, but from a practical standpoint, it's usually measured between the centers of the tread, and it's important to have total rear toe equally divided between both wheels for stable handling. Front toe will automatically "center" to be equal on both sides driving down the road, but if the steering wheel is cocked at an angle the tie rods must be tweaked to center the steering wheel, while maintaining total toe to the original dimension.
Modern alignment equipment uses lasers to determine true vehicle center line and measures toe per wheel, but they often measure toe as an angle, which can be converted to a linear measurement by the following formula for PER WHEEL toe.
toe (per wheel) = angle (in radians) X tire radius.
360 deg. = 2Pi radians is the angle conversion formula.
Total toe is the sum of left and right.
Radial tires need less toe-in than bias plies because radials have more self-aligning torque. As a general rule, toe per wheel should be about 1/32", which is 1/16" TOTAL. For bias ply tires use the shop manual values.
Different side to side toe at the rear will show up on the alignment report as a thrust angle. You want the thrust angle to be as close to zero as possible, but 0.1 or 0.2 deg. is probably okay for normal road driving.
In the diagram, if A-C is 1/16" and the distance to the front face of the tread to vehicle centerline is the same, then the toe is equally divided between both wheels at 1/32" per wheel, and the thrust angle should be zero.
Duke
Modern alignment equipment uses lasers to determine true vehicle center line and measures toe per wheel, but they often measure toe as an angle, which can be converted to a linear measurement by the following formula for PER WHEEL toe.
toe (per wheel) = angle (in radians) X tire radius.
360 deg. = 2Pi radians is the angle conversion formula.
Total toe is the sum of left and right.
Radial tires need less toe-in than bias plies because radials have more self-aligning torque. As a general rule, toe per wheel should be about 1/32", which is 1/16" TOTAL. For bias ply tires use the shop manual values.
Different side to side toe at the rear will show up on the alignment report as a thrust angle. You want the thrust angle to be as close to zero as possible, but 0.1 or 0.2 deg. is probably okay for normal road driving.
In the diagram, if A-C is 1/16" and the distance to the front face of the tread to vehicle centerline is the same, then the toe is equally divided between both wheels at 1/32" per wheel, and the thrust angle should be zero.
Duke
Last edited by SWCDuke; 05-15-2018 at 11:58 AM.
05-15-2018, 12:12 PM
#49
Safety Car
I do my own alignment in my garage using levels, string, bob weights, tape measure and 2 long straight sticks.
Setting Toe-In
First, I level the car using rubber mat as needed under each tire because the floor is not perfectly level.
Next, I tie the 2 long, straight pieces of stock onto both front wheels, about 6" off the floor and set the steering wheel centerline such that the wheel is dead straight with both straight sticks oriented the same way on both sides of the car.
Then drop a plumb bob from fattest tire section both front and rear section of both tires and mark the floor.
Finally, I measure distance across front track and rear track of both tires. Subtract and adjust for 1/16 - 1/8" toe in. I convert these measurements to toe angle on each side using trig.
This is exactly what your machine is having you do. That is why they give you a generic number for toe, and the only way to get an OEM spec, is to convert your measurements using trigonometry: ie: sin/cos/tan. Toe ANGLE doesn't lie, and that's the only way you can get an accurate adjustment using your handy tool, or my much more cumbersome (but very effective) method.
Without an explanation of what any particular toe spec refers to (A-C; B-C, [A-C]/2; [B-C]/2) then you're flying blind. The only true measure, without an explanation of a toe spec, is toe angle.
I set camber is a similarly cumbersome fashion using levels on each tire. I effectively eliminate all guesswork by setting for ZERO bubble (zero degrees camber).
Your tool is a very handy one and if you refer to the video on the link page, go to 0:58 of the video and the narrator tells you exactly what they mean for toe-in setting: the difference between the two tape measures............which is A-C in your first diagram. Convert that to toe angle using the formula/chart supplied with the tool to get toe-in ANGLE. The toe angle means: FOR EACH WHEEL, INDEPENDENTLY.
Nice tool, but according to the video, the measurements are taken at arbitrary points fore-aft (unless the video doesn't show entire procedure). I'm curious just what those 2 slots with the movable buttons are in both of the measuring stands.
What I CAN tell you about my procedure...............which is very time consuming...............is that the steering wheel is dead straight, the car tracks straight and does not wander if I let go the wheel on a flat, level road, will drift very slightly down a crowned road as it's supposed to, shows ZERO tire wear after 20,000 miles on radial tires and best of all, handles like a sonofabitch with neutral handling and zero tire squeal around turns.
Setting Toe-In
First, I level the car using rubber mat as needed under each tire because the floor is not perfectly level.
Next, I tie the 2 long, straight pieces of stock onto both front wheels, about 6" off the floor and set the steering wheel centerline such that the wheel is dead straight with both straight sticks oriented the same way on both sides of the car.
Then drop a plumb bob from fattest tire section both front and rear section of both tires and mark the floor.
Finally, I measure distance across front track and rear track of both tires. Subtract and adjust for 1/16 - 1/8" toe in. I convert these measurements to toe angle on each side using trig.
This is exactly what your machine is having you do. That is why they give you a generic number for toe, and the only way to get an OEM spec, is to convert your measurements using trigonometry: ie: sin/cos/tan. Toe ANGLE doesn't lie, and that's the only way you can get an accurate adjustment using your handy tool, or my much more cumbersome (but very effective) method.
Without an explanation of what any particular toe spec refers to (A-C; B-C, [A-C]/2; [B-C]/2) then you're flying blind. The only true measure, without an explanation of a toe spec, is toe angle.
I set camber is a similarly cumbersome fashion using levels on each tire. I effectively eliminate all guesswork by setting for ZERO bubble (zero degrees camber).
Your tool is a very handy one and if you refer to the video on the link page, go to 0:58 of the video and the narrator tells you exactly what they mean for toe-in setting: the difference between the two tape measures............which is A-C in your first diagram. Convert that to toe angle using the formula/chart supplied with the tool to get toe-in ANGLE. The toe angle means: FOR EACH WHEEL, INDEPENDENTLY.
Nice tool, but according to the video, the measurements are taken at arbitrary points fore-aft (unless the video doesn't show entire procedure). I'm curious just what those 2 slots with the movable buttons are in both of the measuring stands.
What I CAN tell you about my procedure...............which is very time consuming...............is that the steering wheel is dead straight, the car tracks straight and does not wander if I let go the wheel on a flat, level road, will drift very slightly down a crowned road as it's supposed to, shows ZERO tire wear after 20,000 miles on radial tires and best of all, handles like a sonofabitch with neutral handling and zero tire squeal around turns.
05-15-2018, 12:24 PM
#50
Melting Slicks
Thread Starter
Total Toe-in is A-C, but from a practical standpoint, it's usually measured between the centers of the tread, and it's important to have total rear toe equally divided between both wheels for stable handling. Front toe will automatically "center" to be equal on both sides driving down the road, but if the steering wheel is cocked at an angle the tie rods must be tweaked to center the steering wheel, while maintaining total toe to the original dimension.
Modern alignment equipment uses lasers to determine true vehicle center line and measures toe per wheel, but they often measure toe as an angle, which can be converted to a linear measurement by the following formula for PER WHEEL toe.
toe (per wheel) = angle (in radians) X tire radius.
360 deg. = 2Pi radians is the angle conversion formula.
Total toe is the sum of left and right.
Radial tires need less toe-in than bias plies because radials have more self-aligning torque. As a general rule, toe per wheel should be about 1/32", which is 1/16" TOTAL. For bias ply tires use the shop manual values.
Different side to side toe at the rear will show up on the alignment report as a thrust angle. You want the thrust angle to be as close to zero as possible, but 0.1 or 0.2 deg. is probably okay for normal road driving.
In the diagram, if A-C is 1/16" and the distance to the front face of the tread to vehicle centerline is the same, then the toe is equally divided between both wheels at 1/32" per wheel, and the thrust angle should be zero.
Duke
Modern alignment equipment uses lasers to determine true vehicle center line and measures toe per wheel, but they often measure toe as an angle, which can be converted to a linear measurement by the following formula for PER WHEEL toe.
toe (per wheel) = angle (in radians) X tire radius.
360 deg. = 2Pi radians is the angle conversion formula.
Total toe is the sum of left and right.
Radial tires need less toe-in than bias plies because radials have more self-aligning torque. As a general rule, toe per wheel should be about 1/32", which is 1/16" TOTAL. For bias ply tires use the shop manual values.
Different side to side toe at the rear will show up on the alignment report as a thrust angle. You want the thrust angle to be as close to zero as possible, but 0.1 or 0.2 deg. is probably okay for normal road driving.
In the diagram, if A-C is 1/16" and the distance to the front face of the tread to vehicle centerline is the same, then the toe is equally divided between both wheels at 1/32" per wheel, and the thrust angle should be zero.
Duke
05-15-2018, 12:32 PM
#51
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I'm not sure I understand your post. If the thrust angle is a whooping quarter-degree, then you have significantly different per wheel toe at the rear.
Then you said " Toe is now spot on 0°". Which corners?
If you have an alignment report, post it.
If your own measurements, post them and how you made them.
Duke
Then you said " Toe is now spot on 0°". Which corners?
If you have an alignment report, post it.
If your own measurements, post them and how you made them.
Duke
05-15-2018, 12:33 PM
#52
Melting Slicks
Thread Starter
I do my own alignment in my garage using levels, string, bob weights, tape measure and 2 long straight sticks.
Setting Toe-In
First, I level the car using rubber mat as needed under each tire because the floor is not perfectly level.
Next, I tie the 2 long, straight pieces of stock onto both front wheels, about 6" off the floor and set the steering wheel centerline such that the wheel is dead straight with both straight sticks oriented the same way on both sides of the car.
Then drop a plumb bob from fattest tire section both front and rear section of both tires and mark the floor.
Finally, I measure distance across front track and rear track of both tires. Subtract and adjust for 1/16 - 1/8" toe in. I convert these measurements to toe angle on each side using trig.
This is exactly what your machine is having you do. That is why they give you a generic number for toe, and the only way to get an OEM spec, is to convert your measurements using trigonometry: ie: sin/cos/tan. Toe ANGLE doesn't lie, and that's the only way you can get an accurate adjustment using your handy tool, or my much more cumbersome (but very effective) method.
Without an explanation of what any particular toe spec refers to (A-C; B-C, [A-C]/2; [B-C]/2) then you're flying blind. The only true measure, without an explanation of a toe spec, is toe angle.
I set camber is a similarly cumbersome fashion using levels on each tire. I effectively eliminate all guesswork by setting for ZERO bubble (zero degrees camber).
Your tool is a very handy one and if you refer to the video on the link page, go to 0:58 of the video and the narrator tells you exactly what they mean for toe-in setting: the difference between the two tape measures............which is A-C in your first diagram. Convert that to toe angle using the formula/chart supplied with the tool to get toe-in ANGLE. The toe angle means: FOR EACH WHEEL, INDEPENDENTLY.
Nice tool, but according to the video, the measurements are taken at arbitrary points fore-aft (unless the video doesn't show entire procedure). I'm curious just what those 2 slots with the movable buttons are in both of the measuring stands.
What I CAN tell you about my procedure...............which is very time consuming...............is that the steering wheel is dead straight, the car tracks straight and does not wander if I let go the wheel on a flat, level road, will drift very slightly down a crowned road as it's supposed to, shows ZERO tire wear after 20,000 miles on radial tires and best of all, handles like a sonofabitch with neutral handling and zero tire squeal around turns.
Setting Toe-In
First, I level the car using rubber mat as needed under each tire because the floor is not perfectly level.
Next, I tie the 2 long, straight pieces of stock onto both front wheels, about 6" off the floor and set the steering wheel centerline such that the wheel is dead straight with both straight sticks oriented the same way on both sides of the car.
Then drop a plumb bob from fattest tire section both front and rear section of both tires and mark the floor.
Finally, I measure distance across front track and rear track of both tires. Subtract and adjust for 1/16 - 1/8" toe in. I convert these measurements to toe angle on each side using trig.
This is exactly what your machine is having you do. That is why they give you a generic number for toe, and the only way to get an OEM spec, is to convert your measurements using trigonometry: ie: sin/cos/tan. Toe ANGLE doesn't lie, and that's the only way you can get an accurate adjustment using your handy tool, or my much more cumbersome (but very effective) method.
Without an explanation of what any particular toe spec refers to (A-C; B-C, [A-C]/2; [B-C]/2) then you're flying blind. The only true measure, without an explanation of a toe spec, is toe angle.
I set camber is a similarly cumbersome fashion using levels on each tire. I effectively eliminate all guesswork by setting for ZERO bubble (zero degrees camber).
Your tool is a very handy one and if you refer to the video on the link page, go to 0:58 of the video and the narrator tells you exactly what they mean for toe-in setting: the difference between the two tape measures............which is A-C in your first diagram. Convert that to toe angle using the formula/chart supplied with the tool to get toe-in ANGLE. The toe angle means: FOR EACH WHEEL, INDEPENDENTLY.
Nice tool, but according to the video, the measurements are taken at arbitrary points fore-aft (unless the video doesn't show entire procedure). I'm curious just what those 2 slots with the movable buttons are in both of the measuring stands.
What I CAN tell you about my procedure...............which is very time consuming...............is that the steering wheel is dead straight, the car tracks straight and does not wander if I let go the wheel on a flat, level road, will drift very slightly down a crowned road as it's supposed to, shows ZERO tire wear after 20,000 miles on radial tires and best of all, handles like a sonofabitch with neutral handling and zero tire squeal around turns.
05-15-2018, 12:41 PM
#53
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St. Jude Donor '07
So I simply needed to know how that measurement relates to a toe spec as in table below taken from http://www.tech.corvettecentral.com/...ignment-specs/ (they say it is ....'total Toe'...sorry!)
Bill
05-15-2018, 12:41 PM
#54
Melting Slicks
Thread Starter
I'm not sure I understand your post. If the thrust angle is a whooping quarter-degree, then you have significantly different per wheel toe at the rear.
Then you said " Toe is now spot on 0°". Which corners?
If you have an alignment report, post it.
If your own measurements, post them and how you made them.
Duke
Then you said " Toe is now spot on 0°". Which corners?
If you have an alignment report, post it.
If your own measurements, post them and how you made them.
Duke
When I'll actually do the alignment I'll post the numbers and the set-up
05-15-2018, 03:21 PM
#55
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05-15-2018, 03:48 PM
#57
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05-15-2018, 03:59 PM
#58
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05-15-2018, 04:29 PM
#59
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05-15-2018, 04:34 PM
#60
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Rear 'Total Toe' is 0°, in my set-up that means the wheels are parallel to each other, but not parallel to the centreline cause there they are .25° off as reported. All those measurements are as accurate as one gets using tape measures.
When I'll actually do the alignment I'll post the numbers and the set-up
When I'll actually do the alignment I'll post the numbers and the set-up
I can get very accurate individual wheel toe measurements, in inches, but the key is to measure the center points of all cross members, then draw a string with plumbobs as necessary to keep the string as close to axle centerline as possible without interfering with any part of the car.
Duke