TraviZ06

Thanks for the advice. If it is out more than an 1/8th, i correct that by adjusting the rear tie rods equally until the distance is near equal?

froggy47

This is almost good enough for an old truck, but seriously, you ARE on the right track to learning alignment. Keep it up. You don't need Smart Strings like I use, jack stands (heavy) will serve to let you set a string off the axles. Remember when you set toe the wheels cannot be bound up, turn plates or the equivalent MUST be used.

Joshboody

For toe I'm not sure if jack stands work unless we have equal width wheel base front and rear, but even then without ridged axle there is error. You really need the sides connected to get parallel... Prob doesn't have to be perfectly square, but at least quadrilateral tying the 2 sides together so they move together. Hopefully this makes sense. I tried to get as square as possible with 2 metal rods.

Camber is easy, but make sure you are level. The other day I was quickly checking it on 1 garage slab "assuming" should be fairly level. I was wrong and 1/2" diff put me 0.7* off... little surprising. When I leveled the car, I was dead even side to side.

froggy47

Here is a very good recent thread by guys that all do their own alignment:

https://www.corvetteforum.com/forums...-contrast.html

We do have equal wheel base on our cars of course, I think you mean track. It is NOT necessary to have equal track to do a string alignment.

Some pictures of race teams (F1) setting toe with strings (different track for sure):

https://www.google.com/search?q=f1+t...w=1280&bih=721

Joshboody

What I was saying is that square strings is best. Unless both sides of your strings are connected (square best) there's more room for error. In my thinking anyway.

I've read through that thread... very informative!

froggy47

Oh, sorry, didn't get that from the post. My bad. Actually squared off strings (parallel) is the only way I know of doing it. If you look at the pics, jack stands and a precision straight bar is how they get there.

The F! cars have an attachment to the frame of the car that holds the straight bar, eliminating the jack stands (similar to how smart strings attaches).

Xian

Everyone here talks about stringing their cars a DIY alignment; curious why that's the trend vs. using Toe Plates. As long as you have a base alignment that's got the front and rear wheels pointing straight (or with equal toe), it's easy enough to add/remove toe via toe plates vs. setting up a string box with sliders.

My method assuming a decent baseline alignment:
#1- Measure total toe on an axle
#2- Jack up car & turn both sides the same #'s of flats
#3- Lower car
#4- Roll car back and forth, bounce it some
#5- Re-measure total toe
#6- lather, rinse, repeat

I adjust camber separately from and before doing toe (i.e. do camber first, get it equal, then futz with toe) since camber impacts toe anyway.

Christian

tmtraylor

Very impressed with those that do your own alignments. I'm not there yet but interested and curious about how I would avoid my current issue if I did do my own alignments.

I just got sent home from my shop because there is too much "slop" in the rear toe of my C5Z. I picked up new rear outer tie-rod ends and will go back tomorrow, but curious how you guys handle that situation. The shop has the newest Hunter machine and when they pressed on the rear suspension the toe would change up to a 1/4" on each side. By yourself with the string technique I guess that is not do-able? Do you check/feel for movement and decide based on that? This shop is probably the most capable shop in Atlanta, all the track guys I know use them...They know their stuff.

froggy47

Nothing wrong with that basically, my three small issues are (depending on the tires) your toe plate is up against a piece of rubber that has a lot more possible runout than my rim.

2) With my car already in the air on "turn plates" I can get the toe I want & straight steering wheel in one shot. Done & done.

3) You measure with a carpenters tape vs. machinist ruler (I set toe to 64th's)

It does take longer to set the strings, but if you do it enough & mark lines on the frames where to do your prelim setup it's not that bad. I imagine with jack stands it's even quicker than the Smart Strings frames.

I am in a testing period and doing a full alignment a month so far this season.



For me toe plates are for a Q&D trackside adjustment.

froggy47

I check those parts (and more) every event. I agree with your shop it's pointless to align a car with worn out suspension parts. Surprised you did not feel the issue in the back? That's a lot of slop.

froggy47

Good discussion, I wish it were on fatbillybob's thread to keep stuff all together.

tmtraylor

I'm new, Froggy with a year in this car and the sport (Don't know what I don't know yet). The car was pretty loose at my January track day. I assumed it was just 35-40 degree temps and tire issues. Maybe it was both? Hopefully I notice a difference this weekend, but I have new tires too.

Alignment guy said he's OK with 1/16th of movement beyond that he wants the tie-rod ends replaced.

So much to learn!!!

AND0

When my rear tie rod went bad it made a very distinctive wiggle in back when downshifting. Only a small amount of play in the tie rod, hard even to tell, but it was enough to loosen up the whole rear end.

AND0

My current alignment method

Race ramps on under the front tires
Hollow tile blocks under the rear tires
Jack up the car and level the wheel pad areas with the 6' carpenter's level using Flooring tiles as spacers and turn plates
Run strings along side of the car from jackstands at the hub height measuring equally from a flat spot in the center of the rim
set camber with SPC camber gauge
set toe with the strings and either a machinist's ruler or calipers measuring the difference between the flat edge of the front and rear of the rim.

This way, I have enough room to work under the car and make adjustments and measure immediately.

I don't use a toe bar, as this system allows me to check thrust angle. If I was only concerned about toe, a toe bar would be way easier since this system takes about 1-1.5 hours depending on how many adjustments I have to do.

With the stock rubber bushings there was a huge amount of play in all the settings. I had to switch to polyurethane.

froggy47

So you still have the eccentric bolts for alignment?

AND0

I do, though if they slip one more time, I'm going to work up a camber kit.....
or buy one I suppose ......

froggy47

Slicks will make them move, don't care how much you torque them.

I think you have a very decent alignment system, way to go!

Xian

Fair enough and everyone has their "preferred" method of doing stuff. I admire your attention to detail. Seriously impressive!

My approach to alignment is a little more "pragmatic" In my experience/opinion, trying to nail an alignment down to 64th's is more effort that it's worth. Is there a difference in how a car drives with or without 1/64" in toe difference? Probably. Is it something that I'm going to be able to identify in a blind test drive? Very doubtful. Is it something that will make a quantifiable difference on an autoX course? I'm going to say probably not. I've got a reasonably well tuned backside when it comes to handling dynamics but I really think that anything less than a 1/16th gets lost in the noise. Same sort of thing with camber; a tenth difference from side to side really isn't perceptible to me.

For autoX, since every course is different and you carry enough slip angle through the course it's tough to attribute these small, incremental adjustments to balance or handling differences. For track use where you've got more sustained loading and can spend more time balancing the car at the limit, I *prefer* to get within 1/32nd but even that to me is slight overkill.

And all this ^^^^ is assuming that you've got dead weight in the car when you're doing the alignment and that you've already scaled/cross-weighted the car. IMO, it's good to remember that these are tin top cars with rubber bushings and factory tolerances throughout them. They're better than many cars but, unless you're running full sphericals, still have compliance built into them. That stuff starts to deflect before you've even left the line.

TL;DR- Froggy's way is better but (to me) the juice isn't worth the squeeze for this application.

froggy47

I'll bet we are both getting a better alignment than almost everybody else who pays a shop to do it for them.



As for 64th's I agree, I doubt I feel it or it makes a difference vs. 32nd's. It's just sort of a "goal" or a "standard" I set for myself.

If it can be done, why not? And it's not that much extra work, one or two trips underneath the car to turn the flats a bit.

I love it when I test the car afterwards & I can take my hands off the wheel for a 1/4 mile or more on a good level piece of freeway and it tracks like an arrow.

I have half a dozen machinist rulers just trying new one to see if they "read" better. And different strings. It's all in the fun. Then the win.

Xian

Agreed! Especially given the OP's "special" alignment.

Very true. If you've got the tools, the setup, and you're already there then it makes more sense to sweat the details.

Testing rulers now? You're crazy... but in a good way!!