34 replies to this topic

[Bench Racer]

That's my point. The ICM setup hangs off of those bumper covers, so I don't understand how you can make accurate suspension settings when it's attached to a part of the car that's not 100% straight.

Even with bumper covers that have been mauled within reason hang your bumper alignment frames front & rear.

You know your strings are per say equal distance apart because you have grooves in your tubes.

Now measure the distance from front tube to rear tube & if the distance is not equal use a shim of what ever is required to make that distance equal.

Now you have a set of parallel strings, or shall I say I would.

You ask, how do I know this to be true. A couple years ago I crewed with a guy that bought a NA car from the South East. The bumper covers had been mauled pretty good. I used the above mentioned guide lines & did camber & toe several times to that car. IIRC qualified 4th at the June Sprints.

[FTodaro]

That's my point. I've got the ICM kit too but have never used it because after my first or second race weekend the bumper covers were already tweaked. The ICM setup hangs off of those bumper covers, so I don't understand how you can make accurate suspension settings when it's attached to a part of the car that's not 100% straight.

The bumpers have nothing to do in the equation relating to getting a square box other than suspending the string parallel to the car. you are squaring the string based off a measurement from the 4 hubs once you have the string equal distant from all 4 hubs you have the square, you could hang that string off the bumpers or jack stands it does not matter. the ICM set up advantage over jack stands as has been stated is that you can roll the car and the strings go with you so unlike jack stands you don't have to re set the strings so a bent front end is not an issue unless your hubs are bent to. In that case you wasting your time trying to align a bent car.

[juliancates]

I'm considering picking up the ICM kit to be able to set this stuff up at home in my garage and at the track if necessary. What are you guys using to get a level platform, especially at the track? I saw a video that showed the "bucket of water" method for leveling the floor and using vinyl tiles to shim the floor to completely level. Seems like this would be OK for at home in the garage where you do it once, but a lot of work for at the track. Are there any leveling solutions out there that don't break the bank? What are you guys using?

[steveracer]

These:

http://www.speedwaym...-Hose,2702.html

Mine needed calibration, and sealing with some RTV, but work great.

FYI, when you pull the stoppers out, hold the tube, not the base!

[juliancates]

These:

http://www.speedwaym...-Hose,2702.html

Mine needed calibration, and sealing with some RTV, but work great.

FYI, when you pull the stoppers out, hold the tube, not the base!

Sorry, I should have been more clear. Thanks for the link. What I was actually curious about was the platform. Mostly what I see are scale levelers and setup racks, which are relatively pricey. For instance:

http://www.pegasusau....asp?RecID=2885

and

http://www.pegasusau....asp?RecID=4596

I was curious to know if there was a middle ground between these and a stack of vinyl tiles. If not, a portable setup solution might be out of my reach at this point.

[steveracer]

Ahhh, I see.

I made a set of the scale pads out of angle iron, with long bolts and feet that I ordered from Mcmaster-Carr.

Some assembly required.

There was a thread about set-up pads ,on the old site. I bet it's in the archive.

[FTodaro]

I'm considering picking up the ICM kit to be able to set this stuff up at home in my garage and at the track if necessary. What are you guys using to get a level platform, especially at the track? I saw a video that showed the "bucket of water" method for leveling the floor and using vinyl tiles to shim the floor to completely level. Seems like this would be OK for at home in the garage where you do it once, but a lot of work for at the track. Are there any leveling solutions out there that don't break the bank? What are you guys using?

Getting the car near perfect level is most important when you scale the car. the ICM kit allows you to calibrate the camber gauge such that you zero it out no matter what angel the car is sitting and it will record an accurate measurement once its zero'ed out. You should try to get as level as you can when you are making toe adjustments but its not a critical for that. I have a 4 post lift so I leveled the lift and when i come in to to an alignment, scaling, its all good to go.

At the track I am only going to make minor adjustments and I will take the best level surface I can get and go with it.

[Zauskycop]

Found these on Ebay last year, and have been using them. Work great...just not a longacre name, and you have to love the price.

Search Ebay for Scale Roll Off Levelers

[juliancates]

There was a thread about set-up pads ,on the old site. I bet it's in the archive.

Yep, found this:

http://forum.specmia...3098;p=0#000000

Thanks!

[NigelStu]

OP
Accuracy of both systems are as good as your initial setup. I spend a lot of time circling the car to get the box right. And after I'm done with the alignment with strings, I usually confirm toe settings with my plates. The ICM or similar systems that hang off the car are MUCH easier to use (compared to the strings on jack-stand method) since you don't have to keep re-setting the strings every time you roll the car to set the suspension.

To help with setup time, I have my bars marked FR/RR and lines where they should be clipped in. I also have visual locators on the car to get the hangers close. Usually only takes me 5-10 min to get 'perfectly' square (I use a 1/64 inch ruler)





CY -
How tweaked are your bumpers? As long as you have the stings in same groove on the ICM bars (I use middle on both sides, FR and RR), and are not missing one side of your bumper you should be fine. Measure to the center of the hubs (make sure your FR hub caps are smooth if you use them) and get the distances equal from side to side on each axle to square up your box.


Figure a VERY, VERY squished bumper (on one side) might give about a 5 degree angle to the bar relative to 'square', you will end up with bars that are approximately 70 mm fore and aft of center (at the ends where the stings go), and will loose about 3 mm of 'square' per side (string will be 3 mm closer to car center line, on each side). That is a LOT, but that would also be VERY noticeable since the bars would be obviously angled compared to the car center-line. At a 2 degree angle, the fore-aft distance is about 28 mm per side, and the 'square' lost is 0.5mm per side. (IF I'm doing my math right...)



So.... what's your accuracy?



For a reality check, put the setup on your car and measure the distance between the bars on left and right side. If the difference is less than 10 mm, accuracy should not be affected (less than 0.1 mm and well within the accuracy of your ruler/hand/eye when measuring the string to rim gap). If its beyond that, adjust with some rubber pads/tape between the hanger and the bumper cover until it is spot on.

[NigelStu]

you are squaring the string based off a measurement from the 4 hubs once you have the string equal distant from all 4 hubs you have the square

Careful with this one. Track width is different front and rear, so unless you KNOW that the measuring points front and rear are exactly the same width, this doesn't work....

[steveracer]

You could also check the squareness of the string using the 3,4,5 method. make a mark 3" in on the bar from where the string intersects, 4" down the string from where it intersects the bar, the distance diagonally between the 2 marks should be 5" if they are square.

Any factor or multiplier of 3,4,5, will work...6,8,10, feet, inches, yards, whatever.

Check one corner of each end, F & R, and you're golden.

[Richard Pressman]

Careful with this one. Track width is different front and rear, so unless you KNOW that the measuring points front and rear are exactly the same width, this doesn't work....

It does work... if you do it correctly.

What you measure is that the strings are equidistant from the hubs in the front and from the hubs in the rear. The front measurement will be different than the rear. But, just so long as fronts are equal side to side, and rears are equal side to side, you will have a perfectly square string box.

[NigelStu]

It does work... if you do it correctly.

What you measure is that the strings are equidistant from the hubs in the front and from the hubs in the rear. The front measurement will be different than the rear. But, just so long as fronts are equal side to side, and rears are equal side to side, you will have a perfectly square string box.

Exactly - thank you for adding the clarification for equaling front axle and rear axle independently.


The way I read Franks post ("equal distant from all 4 hubs") is all 4 measurements would be the same... That doesn't work unless you have some weird hub lengths

[Jim Drago]

The Iron Canyon stuff is very nice and works well. I have used it for a long time. I have started using a laser level and a bracket that we made to fit our wheels. It works as a digital camber gauge and as a thrust/spoke checker when shooting the laser...

Here is why I like the laser for me personally...

-I don't have to spend the time setting up the string box and then fixing it every time I kick it etc.
-I don't like splitting the hairs on the measurements on the string while it is bouncing from moving it etc
-I can do it faster with the laser level

If I only worked on my car, I would use the String box, but since I set up so many I have cars, I have become very good at it, but takes a little explaining. I will write it up at some point...

Jim