Effect of ride height on alignment and other queries
12-11-2015, 05:29 PM
#31
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Mark,
Happy to try anything but was struggling to understand your method. If I understand correctly what Jim has just posted your method measures total toe rather than the toe on each side. What I have done to date measures total toe but not each side which I have been eyeballing and used logic to correct.
Now if I can rig my lasers like Bob and Jim have I should be able to get a very accurate picture of what is happening toe wise. Camber is quite easy to read but caster is another matter altogether. I have basic understanding of the concept but how one measures it with the kit we have is beyond me altogether at the moment. I am going to have to study what Bob has written and see if I can get it to soak in.
Lifting the rear passenger side wheel has altered the rear end alignment at tad- camber seems a bit less - have no assessed the rear toe [yet].
Happy to try anything but was struggling to understand your method. If I understand correctly what Jim has just posted your method measures total toe rather than the toe on each side. What I have done to date measures total toe but not each side which I have been eyeballing and used logic to correct.
Now if I can rig my lasers like Bob and Jim have I should be able to get a very accurate picture of what is happening toe wise. Camber is quite easy to read but caster is another matter altogether. I have basic understanding of the concept but how one measures it with the kit we have is beyond me altogether at the moment. I am going to have to study what Bob has written and see if I can get it to soak in.
Lifting the rear passenger side wheel has altered the rear end alignment at tad- camber seems a bit less - have no assessed the rear toe [yet].
12-11-2015, 10:03 PM
#32
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Fred--
There's guidance in the alignment manual that's included in the Morehouse CD set.
While looking at some options for reasonably-priced and reasonably-accurate commercial fixtures, I came upon this SmartCamber gauge that does the camber and caster measurements with an electronic angle gauge. I managed to duplicate the results with the Harbor Freight angle gauge, using the calculation method outlined in the SmartCamber user manual (attached).
To get the 20º or 30º turns just right, I plotted a couple grid sheets with lines at those angles. Taped to the floor and using the beam splitter on the lasers, it's easy to get the wheel angles just right without the need for graduated turn plates. Plastic shopping bag sprayed inside with Pam (vegetable oil spray cooking oil) does the trick under the tires. I've also used gallon-sized zip-lock storage bags with just OK results; if the tire patch isn't centered on the zip-lock bag, it tears. The vegetable oil spray is easy to clean up if it gets loose on the floor or on tires.
The attached manual was downloaded, but is the property of SmartRacing Products.
There's guidance in the alignment manual that's included in the Morehouse CD set.
While looking at some options for reasonably-priced and reasonably-accurate commercial fixtures, I came upon this SmartCamber gauge that does the camber and caster measurements with an electronic angle gauge. I managed to duplicate the results with the Harbor Freight angle gauge, using the calculation method outlined in the SmartCamber user manual (attached).
To get the 20º or 30º turns just right, I plotted a couple grid sheets with lines at those angles. Taped to the floor and using the beam splitter on the lasers, it's easy to get the wheel angles just right without the need for graduated turn plates. Plastic shopping bag sprayed inside with Pam (vegetable oil spray cooking oil) does the trick under the tires. I've also used gallon-sized zip-lock storage bags with just OK results; if the tire patch isn't centered on the zip-lock bag, it tears. The vegetable oil spray is easy to clean up if it gets loose on the floor or on tires.
The attached manual was downloaded, but is the property of SmartRacing Products.
12-12-2015, 06:13 PM
#33
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Thread Starter
I'll take a good look at this. Had the 928 out for a spin this afternoon and the steering was much closer as I expected. The steering wheel now has a very slight bias to the right hand side when you let go of the wheel but you would hardly notice it. About half a turn on both tie rods should rectify that
Rgds
Fred
12-12-2015, 11:14 PM
#34
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Fred--
Generally, pull to one side or the other is caused by some differences between camber and/or caster one side to the other. Toe changes seldom show up as a 'pull' when you let go of the wheel.
In my quest for repeatability and accuracy on toe settings, I made a couple little paper vernier gauges to make tie rod adjustments more predictable. Print the PDF at actual size and it will wrap nicely around the tie rod. There's a left and a right, obviously, so that adjustments towards greater or smaller values have the same effect on toe.
I attach the paper scales using a very hi-tech method -- a wrap of clear packaging tape, after cleaning the area where they will go on each tie rod.
Generally, pull to one side or the other is caused by some differences between camber and/or caster one side to the other. Toe changes seldom show up as a 'pull' when you let go of the wheel.
In my quest for repeatability and accuracy on toe settings, I made a couple little paper vernier gauges to make tie rod adjustments more predictable. Print the PDF at actual size and it will wrap nicely around the tie rod. There's a left and a right, obviously, so that adjustments towards greater or smaller values have the same effect on toe.
I attach the paper scales using a very hi-tech method -- a wrap of clear packaging tape, after cleaning the area where they will go on each tie rod.
12-13-2015, 03:55 AM
#36
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Thread Starter
Gents,
Apologies if my "Middle of the night" English was a bit misleading- the 928 is not pulling to one side it is just the steering wheel taking a very slight offset to the right when I let go of the wheel- it is driving as straight as an arrow.
Rgds
Fred
Apologies if my "Middle of the night" English was a bit misleading- the 928 is not pulling to one side it is just the steering wheel taking a very slight offset to the right when I let go of the wheel- it is driving as straight as an arrow.
Rgds
Fred
12-13-2015, 05:04 PM
#37
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Fred--
Print out those scales I shared, and tape them around the tie rods and ends. With matching scales on both tie rods, you can adjust both tie rods the same amount to center the steering wheel without affecting your total toe numbers.
Print out those scales I shared, and tape them around the tie rods and ends. With matching scales on both tie rods, you can adjust both tie rods the same amount to center the steering wheel without affecting your total toe numbers.
12-14-2015, 02:54 PM
#38
Rennlist Member
just do a quarter turn on both adjusters and you will probably be good
12-14-2015, 03:48 PM
#39
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Thread Starter
I have printed Bob's vernier scale so will probably give that a shot tomorrow morning all being well. was thinking of half a turn both sides but will try your suggestion first. Drivers side needs to be a tad longer and passenger side a tad shorter to ensure both wheels change the same amount in the same direction to the right.
Rgds
Fred
12-14-2015, 04:05 PM
#40
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Fred--
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure. It's a lot more predictable and repeatable than 'just do a quarter of a turn on both adjusters and you'll probably be good', because you can turn each the same precise amount, and gauge how that affects wheel centering.
Mark, you might consider putting these on your tie rods and sleeves. Should you decide that some particular track or a particular tire deserves a slightly different toe setting, you can make the adjustment, then return to your previous settings quite easily without having to get out the stick and the marker.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure. It's a lot more predictable and repeatable than 'just do a quarter of a turn on both adjusters and you'll probably be good', because you can turn each the same precise amount, and gauge how that affects wheel centering.
Mark, you might consider putting these on your tie rods and sleeves. Should you decide that some particular track or a particular tire deserves a slightly different toe setting, you can make the adjustment, then return to your previous settings quite easily without having to get out the stick and the marker.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
12-14-2015, 05:06 PM
#41
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Thread Starter
Fred--
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
How very true- I found this when I did the alignment personally on a local Hunter machine. I was quite surprised as to how sensitive the measurement was to small adjustments- even locking the nut can result in a slight change of toe presumably caused by bolt stretch.
I have even seen alignment changes on the Hunter on a windy day on a rig that was in an "open shed" type of situation.
Rgds
Fred
12-14-2015, 06:41 PM
#42
Rennlist Member
Fred--
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure. It's a lot more predictable and repeatable than 'just do a quarter of a turn on both adjusters and you'll probably be good', because you can turn each the same precise amount, and gauge how that affects wheel centering.
Mark, you might consider putting these on your tie rods and sleeves. Should you decide that some particular track or a particular tire deserves a slightly different toe setting, you can make the adjustment, then return to your previous settings quite easily without having to get out the stick and the marker.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
The reason for the vernier scales is that the threaded end at the outside will rotate some as you tighten or loosen the nut, independent of the adjustment itself. Using the vernier scales, with the 'pointers' on the threaded portion just outside the nut by a thread or two, takes that unintended rotation off the list of wildcard variables in the adjustment procedure. It's a lot more predictable and repeatable than 'just do a quarter of a turn on both adjusters and you'll probably be good', because you can turn each the same precise amount, and gauge how that affects wheel centering.
Mark, you might consider putting these on your tie rods and sleeves. Should you decide that some particular track or a particular tire deserves a slightly different toe setting, you can make the adjustment, then return to your previous settings quite easily without having to get out the stick and the marker.
Someplace I have pictures of those installed on my tie rods, but the pic isn't handy to where I am now.
I dont think toe, on the race car matters too much other than wear problems due to bump steer issues. However, i do bet that if i was able to toe in a lot at willow springs, it would help the lifting tire from scrubbing down the inside edge. no other track does that out west.
Mark,
I have printed Bob's vernier scale so will probably give that a shot tomorrow morning all being well. was thinking of half a turn both sides but will try your suggestion first. Drivers side needs to be a tad longer and passenger side a tad shorter to ensure both wheels change the same amount in the same direction to the right.
Rgds
Fred
I have printed Bob's vernier scale so will probably give that a shot tomorrow morning all being well. was thinking of half a turn both sides but will try your suggestion first. Drivers side needs to be a tad longer and passenger side a tad shorter to ensure both wheels change the same amount in the same direction to the right.
Rgds
Fred
Bob,
How very true- I found this when I did the alignment personally on a local Hunter machine. I was quite surprised as to how sensitive the measurement was to small adjustments- even locking the nut can result in a slight change of toe presumably caused by bolt stretch.
I have even seen alignment changes on the Hunter on a windy day on a rig that was in an "open shed" type of situation.
Rgds
Fred
How very true- I found this when I did the alignment personally on a local Hunter machine. I was quite surprised as to how sensitive the measurement was to small adjustments- even locking the nut can result in a slight change of toe presumably caused by bolt stretch.
I have even seen alignment changes on the Hunter on a windy day on a rig that was in an "open shed" type of situation.
Rgds
Fred
the main thing, is does it pull... if not . you are good. is the toe near 0. if so, your tires will last a long time. on the rear, its much more critical for handling. rear toe is a tough one to find the best mix of handling and wear.
12-14-2015, 06:49 PM
#43
Chronic Tool Dropper
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Bob,
How very true- I found this when I did the alignment personally on a local Hunter machine. I was quite surprised as to how sensitive the measurement was to small adjustments- even locking the nut can result in a slight change of toe presumably caused by bolt stretch.
I have even seen alignment changes on the Hunter on a windy day on a rig that was in an "open shed" type of situation.
Rgds
Fred
How very true- I found this when I did the alignment personally on a local Hunter machine. I was quite surprised as to how sensitive the measurement was to small adjustments- even locking the nut can result in a slight change of toe presumably caused by bolt stretch.
I have even seen alignment changes on the Hunter on a windy day on a rig that was in an "open shed" type of situation.
Rgds
Fred
I'm pretty sure that the relatively casual torque on the locknut isn't actually stREtching the threads on the tie rod end. Much more likely is that tightening the lock nut takes all the play out of the threaded junction, preloading it in the stretched/tension direction.
I haven't figured out how to 'accurately' torque the locknut with the car on the floor. There isn't much room at all for a torque wrench and a crowfoot under the tie rod locknut, although it would be relatively simple with the car on a 4-post 'alignment' rack with room underneath. For sure the effort needs two hands to hold the 15mm spanner on the sleeve and the 21mm wrench on the nut. Once the wrenches are set correctly, I just squeeze them together to get them good and tight. It's worked well for me so far.
12-14-2015, 07:05 PM
#44
Rennlist Member
I'm pretty sure that the relatively casual torque on the locknut isn't actually stertching the threads on the tie rod end. Much more likely is that tightening the lock nut takes all the play out of the threaded junction, preloading it in the stretched/tension direction.
I haven't figured out how to 'accurately' torque the locknut with the car on the floor. There isn't much room at all for a torque wrench and a crowfoot under the tie rod locknut, although it would be relatively simple with the car on a 4-post 'alignment' rack with room underneath. For sure the effort needs two hands to hold the 15mm spanner on the sleeve and the 21mm wrench on the nut. Once the wrenches are set correctly, I just squeeze them together to get them good and tight. It's worked well for me so far.
I haven't figured out how to 'accurately' torque the locknut with the car on the floor. There isn't much room at all for a torque wrench and a crowfoot under the tie rod locknut, although it would be relatively simple with the car on a 4-post 'alignment' rack with room underneath. For sure the effort needs two hands to hold the 15mm spanner on the sleeve and the 21mm wrench on the nut. Once the wrenches are set correctly, I just squeeze them together to get them good and tight. It's worked well for me so far.
yeah, strong tight is all you really need there.
