Spec Miata Community   
search | help | calendar | games | forum home

  next oldest topic   next newest topic
» Hello Spec Miata Community » SpecMiata.com » Spec Miata Setup Guide » Back to the basics: string box alignments

 - Email this page to someone! | Subscribe To Topic  
Author Topic: Back to the basics: string box alignments
Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

After paying near 100 dollars for alignments which seem to need to be done constantly, I believe it's time I learn, and try to tackle it myself.

I will be ordering:

The ICM alignment kit which consist of their string box set up and the toe stick.

http://www.ironcanyonmotorsports.com/catalog/product_info.php?cPath=24&products_id=52

And the Longacre CC gauge and adapter from Saferacer.

http://saferacer.com/lodiccgawaca.html


Now... I read JD's set up guide and was a tad bit confused about some of the parts. But, I believe with the string box since it uses an independent string as the control to measure toe from zeroing out one side of the car is unnecessary. Thus making putting the bolts in the rear sub frame to get zero toe is not needed.

So my understanding is this: Hang the string box from the hood and trunk and tie of the strings tight. Once that is completed, use the ICM toe stick and place each ruler on the side wall of the tire. The difference you get is your +/- toe. You do this independently on each wheel in no specific order.

Now back to the basics, which eccentric bolts are for what? Front camber, rear toe? Which side of the eccentric do you want to look off, the silver/gray head of the gold nut? How do you adjust caster, or does that come with the camber adjustment?

As far as scaling and corner weighting goes, I can't budget scales at the moment and will probably have to pay a shop to do that. How often do you corner weight? Before every alignment? After every alignment? Twice a race year? After a big off? Once a year?

Advice please!

Dusty Bottoms Verified Driver Made Donation to Website
99 all the way!

Region: Lone Star
Year : 1990
Posts: 4253
Status: Offline
Icon 1 posted  Profile for Dusty Bottoms     Edit/Delete Post  Report this post to a Moderator

Front: Front camber bolt adjust mostly camber, rear camber bolt adjusts mostly caster. Get under the car and play with it and it will become intuitive...you'll see that knuckle tilting when you move the rear bolt.

Rear: Move both in the same direction, the same amount, to increase camber without changing toe (theoretically, but you must always check toe after). Move in opposite direction the same amount to change toe without changing camber.

(note when I say "in the same direction" I mean which direction it moves the LCA, not which direction you turn the bolt...depending on how they are put in, you could be turning the bolts in opposite directions to move the LCA in the same direction or vice-versa.)

I always look on the head bolt side, not the nut side, and I always note when they start actually pushing the LCA in or out to know how far I've moved it.

You corner weigh after every alignment. On a budget, I'd seriously consider saving the money, time, grief on the string setup and let a pro do the whole thing...a nice neutral setup (like on JD's guide) and check it after big offs or when it doesn't feel right. You can also find a buddy with scales, or find someone who needs them and share the cost.

--------------------
"Your victory is tainted! Asterisk! Asterisk!!!"--Lisa Simpson

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

Sean,

AG is right, you really need scales as well. Alignment and cross are closely related and anything you do to one will effect the other in some way. You also need levelers with the scales. I know it goes on and on.

Make buddies with some one that has scales if you can. The car also needs to be level when you do the alignment as well. Best to do it on level scales IMHO.

One last thing, make sure your tires are at hot pressures and you have the sways disconnected on both sides before aligning or scaling.

Good luck!

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Probably would save time and grief, but after a few alignments I would have already bought the stuff to do it myself.

It can't be that difficult to do once you get the hang out if, I'm young I'll learn fast [Razz]


In all honesty, none of the places I have brought my car to corner weighted it after alignment. So having a "pro" do it might not be the best thing after all.

Steven Burkett Verified Driver
Member

Region: St. Louis
Car #: 26
Year : 2002
Posts: 101
Status: Offline
Icon 1 posted  Profile for Steven Burkett   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Changing alignment does not change corner weights much at all, but changing corner weights changes alignment.

Many or most do both simultaneously, but your pros are not wrong - the alignment changes will not effect your corner balance by more than a few ounces.

If I was young and on a budget I would just use four jackstands and a couple of pieces of conduit with parallel eye bolts as my string box....

... oh wait I'm old, not on a budget, and that's what I do...

Steven

--------------------
www.tuxedoparkracing.com

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Steven Burkett:
Changing alignment does not change corner weights much at all

My scales do not agree with that assessment.

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Steven Burkett Verified Driver
Member

Region: St. Louis
Car #: 26
Year : 2002
Posts: 101
Status: Offline
Icon 1 posted  Profile for Steven Burkett   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Maybe we have a different definition of "much"? Seriously, you add a degree of camber or an 1/8 of toe and get a significant corner weight change? Like more than a couple of pounds? If so than I am completely off base on this subject and will go back to my scales and drawing board.

Steven

--------------------
www.tuxedoparkracing.com

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

I can understand why changing corner weights could mess with alignments since you are raising and lower the car which can affect camber. But I'm having a little trouble seeing (like Steven) how changing alignment can change corner weights significantly.

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

To us, .1 in cross is significant. Take a pound out of a tire and you can get that easy. Scary how touchy this stuff is. How much does it matter? Depends on the driver, but it does change things.

One other thing, make sure the tires can slip on the scales. We learned about bind the hard way!

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Dusty Bottoms Verified Driver Made Donation to Website
99 all the way!

Region: Lone Star
Year : 1990
Posts: 4253
Status: Offline
Icon 1 posted  Profile for Dusty Bottoms     Edit/Delete Post  Report this post to a Moderator

Well "significantly" is a loaded word. If you're on a budget, you won't be changing setup every weekend...when you do that is when you change very small amounts. If you bend something or hit something, then you have major changes. OK I change my advice then...on YOUR budget, I would let a pro corner weigh it once or twice a year, I could make SMALL setup changes (toe shouldn't affect corner weights don't mess with camber) and not worry about cross unless the car felt bad (something broke, loose, or bent.)

As far as seeing how much change in camber can change cross, just turn the steering wheel a bit next time you're on the scales. You'll see the change.

I'm all about how the car feels more than worrying about perfect static measurements (good to have as a base to start from though).

When I was racing RC cars, I used to setup the car to the last tenth of camber, toe, caster, cross, shock travel, shock oil weight, springs, etc. Then I'd get to the track, drive a few laps, come back in the pit, and I'd just ask my pitman to "give it a half turn more toe in the right rear" and drive it. [Smile]

I should say this, Kasey's advice of having the scales level (each pad level X & Y) and to each other (water level works great for this) is very important. So unless you have a nice permanent spot that doesn't move (don't you have earthquakes in SFR? [Smile] ), you'll have to setup the scales every time. Once I started spending 6-8hrs prepping my car, the option of having someone else do it started looking real good. Ed does a better job at it than me too. I think I've read that the worst kind of driver is an engineer driver...we're too stubborn. LOL!!

--------------------
"Your victory is tainted! Asterisk! Asterisk!!!"--Lisa Simpson

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

One last word before I go to bed. We can setup the car start to finish in an hour in the garage. It takes practice and the first few times will take forever. Just like anything else you have to practice till you get it right.

Many other things I could say, but you just have to make the effort and learn as you do it. It has paid off for me.

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Dusty Bottoms Verified Driver Made Donation to Website
99 all the way!

Region: Lone Star
Year : 1990
Posts: 4253
Status: Offline
Icon 1 posted  Profile for Dusty Bottoms     Edit/Delete Post  Report this post to a Moderator

One hour? I spend 1hr just clearing stuff from around the car so I can work on it (or used to)! LOL!!!

--------------------
"Your victory is tainted! Asterisk! Asterisk!!!"--Lisa Simpson

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

What exactly are slip/turn plates for? Would those be used if you didn't want to jack the car up and then lower/bounce/roll to adjust camber and ride height?

NV Racer Verified Driver
Member

Region: SFR
Car #: 70
Year : 1990
Posts: 768
Status: Offline
Icon 1 posted  Profile for NV Racer     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Sean Allen:
What exactly are slip/turn plates for? Would those be used if you didn't want to jack the car up and then lower/bounce/roll to adjust camber and ride height?

Turn plates are for setting caster. You turn wheels 20 degrees left measure camber then 20 right measure camber than use the reading to determine caster

Dennis

Jason Holland Verified Driver Made Donation to Website
Mediocrity rules!

Region: SouthEast
Car #: 28
Year : 95
Posts: 3756
Status: Offline
Icon 1 posted  Profile for Jason Holland   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

I don't think that's the only thing they are for. they allow the suspension to settle without binding.

this is a good thing.

Jason

--------------------
Jason Holland
Semi-interested civilian

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

As far as the caster goes, a lot of new camber gauges also have a caster reading (bubble). In this case (besides the reason Jason mentioned above) would slip plates be unnecessary?

Jason Holland Verified Driver Made Donation to Website
Mediocrity rules!

Region: SouthEast
Car #: 28
Year : 95
Posts: 3756
Status: Offline
Icon 1 posted  Profile for Jason Holland   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

No, you still need the slip plates to do an accurate caster check. You can get close without them but you can make them cheap so you might as well use them.

Jason

--------------------
Jason Holland
Semi-interested civilian

Steven Holloway Verified Driver Made Donation to Website
Blue Eyes, Aquarius, hates being squeezed to the grass in SowDiv!

Region: Lonestar
Car #: 97
Year : 91
Posts: 740
Status: Offline
Icon 1 posted  Profile for Steven Holloway     Edit/Delete Post  Report this post to a Moderator

You will want 1 set of turn plates at least. Caster is not a static measurement, it's the amount of camber gain through the arc of 20 degrees L/R. They also let you make adjustments freely vs. fighting the flex of the tire sidewall.
Harbor Freight has them for $150.00 + freight.
S

--------------------
If you can't fix it with a hammer, it's got electrical problems.

Jason Holland Verified Driver Made Donation to Website
Mediocrity rules!

Region: SouthEast
Car #: 28
Year : 95
Posts: 3756
Status: Offline
Icon 1 posted  Profile for Jason Holland   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Or you can make your own for about 1.50 per corner!

Jason

--------------------
Jason Holland
Semi-interested civilian

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

Have an alignment shop set the caster then leave it alone. Use trash bags on the scales for slip plates to avoid bind. Works pretty well. Cheap too... [Wink]

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Mike C Verified Driver Made Donation to Website
MegaModerator

Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99
Posts: 3727
Status: Offline
Icon 1 posted  Profile for Mike C   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by JasonH:
Or you can make your own for about 1.50 per corner!

Jason

Yep.

Sean don't let these guys scare you into all of the crap you don't need.

Either buy a string kit or just use jack stands. You make slip plates out of linoleum tiles and grease and then throw them away.

You don't need scales. Make sure your ride height (shock travel) is the about the same all the way around with the driver in the car and you will be fine.

--------------------
Mike Collins
MEATHEAD Racing
http://www.SHEETZ.com
The MEATHEAD Racing 2010 Calendar is up!!!!
www.MEATHEADRacing.com
SMAC Member
WDCR-SCCA SM Drivers Rep.
ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!

B Wilson Verified Driver Series Champ
Gold Member

Region: Oregon
Car #: 68
Year : 91
Posts: 2359
Status: Offline
Icon 1 posted  Profile for B Wilson   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Wow! I finally undersatnd the bumptop type setup... I always wondered how you could possibly get shock travel the same all the way around and still achieve ~50% crossweight.

I've got to try that... Thanks for sharing Mike.

-Bruce

--------------------
Bruce Wilson
2010 Oregon Region Champ
2010 Monte Shelton Driver of the Year
2010 25 Hours of Thunderhill E3 and Under 2 liter Overall Champion
Oregon Region SM Class Advisor

disquek Verified Driver Made Donation to Website
Veteran Member

Region: New England
Car #: 92
Posts: 1993
Status: Offline
Icon 1 posted  Profile for disquek     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by El Guapo:
Have an alignment shop set the caster then leave it alone. Use trash bags on the scales for slip plates to avoid bind. Works pretty well. Cheap too... [Wink]

When you change camber, you will change caster.

Depending on your mindset, you don't have to have degreed turn plates for caster. You can just turn the steering wheel 1/2 a turn in either direction and measure the difference in camber. If you're going for the tried and true "max and equal" caster setup, you just drop the larger side to match the smaller, and you're all set.

For a guy that all about rescaling in every setup, I'm surprised to see you skip simple ol' caster. [Razz]

-Kyle

Casey Z Verified Driver Made Donation to Website
MegaModerator

Region: MidDiv
Car #: 13
Year : 92
Posts: 2873
Status: Offline
Icon 1 posted  Profile for Casey Z     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Kyle Disque:
When you change camber, you will change caster.

I have found that caster changes very little with the camber adjustments that are within the normal range we use. For the record, we played with caster a lot earlier this year based on some of JD's posts and ended up always being happier back up in the 4.5 range. YMMV

You are correct that it does change, I just don't find the change to be appreciable. At least not where I am as a driver. You would have to be one hot shoe to tell the difference between 4.5 and 4.4. Toe, camber, cross, and pressures are a different story. IMHO

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
MidDiv National #13

Slow Ride
Member

Car #: 54
Year : 91
Posts: 333
Status: Offline
Icon 1 posted  Profile for Slow Ride     Edit/Delete Post  Report this post to a Moderator

Wow, I guess I should check my alignment! Its only been three years. I have adjusted the toe a little so that the tires point in the same general direction. Maybe if I pay attention to the alignment a little more, I might be able to pass the guys with the high dollar cars at my local track instead of only sticking my nose in on them.

Maybe I can just add more weight too. The last time I did, my car handled better. Its amazing how good a $450 motor and trans with 120k on it can run.

--------------------
No matter where you go, there you are.

JordonMusser Verified Driver
Member

Region: SW
Car #: 06
Year : 1990
Posts: 110
Status: Offline
Icon 1 posted  Profile for JordonMusser   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

"add weight to make it handle better"

man.. you got issues [Wink]

--------------------
------------
Jordon Musser
#06 MRE Spec Miata!

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Well for an update:

I tired to do this, and well... didn't turn out so well. I got it all set up, but once I got my readings I was lost as to how to change them.

Looks like I will be going back to the shop to get someone else to do it for me! I may still keep the stuff I purchased. Considering I might learn how to do it down the road.

Jim Boemler Verified Driver
Veteran Member

Region: NWR, OR
Car #: 30
Year : 1992
Posts: 8523
Status: Offline
Icon 1 posted  Profile for Jim Boemler     Edit/Delete Post  Report this post to a Moderator

Definitely keep the "stuff" -- pro alignments will drive you to the poorhouse. What were you trying to change, and what are you "lost" about?

jim

--------------------
Just a clown

38BFAST Verified Driver
Member

Region: Waterford Hills
Car #: 38
Year : 96
Posts: 348
Status: Offline
Icon 1 posted  Profile for 38BFAST     Edit/Delete Post  Report this post to a Moderator

Dont give up. Set up is a great thing to learn and know how to do.

PM sent

--------------------
Ralph Provitz
#38
2008 WHRRI SM Champion
2008 WHRRI Top 10 Overall
V2 Motorsports, Race support, Data Dude

Sean Allen Verified Driver Made Donation to Website
Veteran Member

Region: SFR
Car #: 54!
Year : 90'
Posts: 1907
Status: Offline
Icon 1 posted  Profile for Sean Allen   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Jim Boemler:
Definitely keep the "stuff" -- pro alignments will drive you to the poorhouse. What were you trying to change, and what are you "lost" about?

jim

I replaced the right LCA so I need to re align. Basically I am confused about which bolts and which direction to turn to change camber/caster/toe.

Jim Boemler Verified Driver
Veteran Member

Region: NWR, OR
Car #: 30
Year : 1992
Posts: 8523
Status: Offline
Icon 1 posted  Profile for Jim Boemler     Edit/Delete Post  Report this post to a Moderator

I never think about which direction the bolts turn. Instead, think about what direction you want the arm to move. Remember that the top of the "kingpin" (the line between the top and bottom ball joints) is fixed, and you're moving the bottom. So to change camber, you need to move the lower joint inward/outward -- the forward arm does most of that. For more caster, the bottom needs to move fore/aft -- the rear arm does most of that.

Just move the lower ball joint the direction you need it. Forward for more caster, back for less. Inward for less camber, outward for more.

Toe is affected by any movement of the ball joint, but don't ever move the joint to adjust the toe -- use the steering rods, because they ONLY affect the toe. Do that last.

It's really not as complicated as it looks at first; it's all about visualizing what you're going. I'd suggest NOT trying to memorize that this bolt in that direction does that -- instead, think about the angle of that imaginary kingpin, and how you want it to change.

jim

--------------------
Just a clown

Tom's Double O Verified Driver
Member

Region: Oregon
Car #: 00
Year : 1992
Posts: 294
Status: Offline
Icon 1 posted  Profile for Tom's Double O     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Jim Boemler:
I never think about which direction the bolts turn. Instead, think about what direction you want the arm to move. Remember that the top of the "kingpin" (the line between the top and bottom ball joints) is fixed, and you're moving the bottom. So to change camber, you need to move the lower joint inward/outward -- the forward arm does most of that. For more caster, the bottom needs to move fore/aft -- the rear arm does most of that.

Just move the lower ball joint the direction you need it. Forward for more caster, back for less. Inward for less camber, outward for more.

Toe is affected by any movement of the ball joint, but don't ever move the joint to adjust the toe -- use the steering rods, because they ONLY affect the toe. Do that last.

It's really not as complicated as it looks at first; it's all about visualizing what you're going. I'd suggest NOT trying to memorize that this bolt in that direction does that -- instead, think about the angle of that imaginary kingpin, and how you want it to change.

jim

Jim,

That is a very clean and clear explaination of what needs to be done. Visualizing the adjustments is so much easier. Thanks.

Tom

Jim Boemler Verified Driver
Veteran Member

Region: NWR, OR
Car #: 30
Year : 1992
Posts: 8523
Status: Offline
Icon 1 posted  Profile for Jim Boemler     Edit/Delete Post  Report this post to a Moderator

For those doing very manual string alignments (as I do), the spreadsheet in here may provide some help. You enter the raw measurements (from string to wheel) at each corner, both from the "box" and from a dangling string. You also enter your desired alignment settings (in degrees). The spreadsheet will give you the changes you need to make at each corner, in thousandths. I use a dial gauge on the arm to adjust, completely ignoring the bolt markings.

With this setup you'll get very close to your desired settings the first time around. It's a big help for me, since I don't have platforms and turn plates, and a second person.

The file is at http://forum.specmiata.com/files/00000371/MiataAlign.zip


jim

--------------------
Just a clown

Jim Boemler Verified Driver
Veteran Member

Region: NWR, OR
Car #: 30
Year : 1992
Posts: 8523
Status: Offline
Icon 1 posted  Profile for Jim Boemler     Edit/Delete Post  Report this post to a Moderator

BTW, I should mention that the program does have some bugs, but they're second-order stuff that doesn't keep it from working reasonably well.

jim

--------------------
Just a clown

John Wymore
Member

Region: Oregon
Posts: 225
Status: Offline
Icon 1 posted  Profile for John Wymore     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by El Guapo:
Use trash bags on the scales for slip plates to avoid bind. Works pretty well. Cheap too... [Wink]

This is one of the best and cheapest alignment ideas I had heard in a long time. Just fold the bags into forths and place one under each tire. No suspension bind and setting castor is a breeze because you can turn the front tire by hand, no need to keep reaching for the steering wheel.

Scott Malbon Verified Driver Made Donation to Website
Member

Region: Blue Ridge Region (103), SEDiv
Car #: 52
Year : 94
Posts: 314
Status: Offline
Icon 1 posted  Profile for Scott Malbon     Edit/Delete Post  Report this post to a Moderator

Jim,

The Excel spreadsheet is nice, thanks for sharing it. As I think about using it I have some questions.

I measure to the lip of the rim rather than the tire, assuming the rim is straight and more consistent than the rubber, flexed, tire. Why measure to the tire? How do you ensure you always measure out (radius) to the same spot on each tire?

I use a ruler and figure the difference between front and back (for toe). How do you measure absolute distance with a dial and ensure the dial is exactly on the box?

I guess you use a digital camber gage. My bubble gage doesn't give that degree of precision.

How do you set up your box? I have a friend with an ICM style box kit which I plan to use (probably better than my jack stand method).

I'd appreciate any guidance.

Scott

Jim Boemler Verified Driver
Veteran Member

Region: NWR, OR
Car #: 30
Year : 1992
Posts: 8523
Status: Offline
Icon 1 posted  Profile for Jim Boemler     Edit/Delete Post  Report this post to a Moderator

I measure to the wheel lip as well, for the same reasons. That's why you'll see a value for the "Wheel lip diameter" in the upper left corner, and a tire circumference value as well. That ratio is used to extend the lip measurements (in the top block) to the tire values shown in the second block. The only reason to extend the calculations to the tire circumference is so you can compare values with others who use more traditional numbering.

I use a ruler too. Actually it's a steel rule, marked in decimal inches, which is why the spreadsheets take values to the nearest 0.010". But that's for measuring, at the wheels. The dial gauge is used on a single suspension arm, because the movements can be pretty small. I have a small magnetic guage mount that I put on the arm. The dial gauge is never used on the string box.

I don't use a digital camber gauge, although I do have one. Instead, I drop a string from the fender, and measure (using the steel rule) from the vertical string to the wheel lip at top and bottom. It's those measurements which go into the "Top" and "Bottom" cells in the top section of the spreadsheet. I did at one time plan to start using the digital gauge, which is why the input can also be done that way, but I never got around to building a jig for the wheels.

I also use the ICM tool to create the box, although I'm still hoping to build a better system "some day". I've also used jack stands, which are more stable. But when you move the car after an adjustment, the ICM tools are much easier to set up the second time.

Thanks for the note, Scott -- hope this helps. Always keep in mind what you're trying to accomplish at each wheel; there are lots of ways to skin this cat, and this is just one that works for me.

jim

--------------------
Just a clown

Scott Malbon Verified Driver Made Donation to Website
Member

Region: Blue Ridge Region (103), SEDiv
Car #: 52
Year : 94
Posts: 314
Status: Offline
Icon 1 posted  Profile for Scott Malbon     Edit/Delete Post  Report this post to a Moderator

After reading this thread I got a digital level at Sears. About $50. So as I realign after installing the 99 shock hats I used the digital to verify my bubble level when setting up the scales. (Bubble was good.) To my surprise my camber was < 2 deg. measured with my trusty bubble camber gage. But the digital level shows > 2. My trusty bubble gage was off ~1 degree! I now have a simple method to measure camber with the digital level.

Scott

   

   Close Topic   Feature Topic   Move Topic   Delete Topic next oldest topic   next newest topic
 - Printer-friendly view of this topic | Subscribe To Topic
Hop To: