Question: what needed for Bugeye alignment?

[drooartz]

So I'll be in town today, near shops where I can pick up extra tools and such. I need to set the alignment on the Tunebug, and I've never done that before. What do I need?

I've been researching methods for DIY toe-in setting, and there seem to be quite a few. Thoughts on the best one to use?

Thanks!

 

[JPSmit]

string, a wrench and maybe some tacks. Nothing else that I know of. I hope to do mine tonight also

 

[drooartz]

What's your method, JP?

 

[aeronca65t]

First thing: make sure the steering is at mid-point. This means, that you turn the wheel all the way one way to full lock....then count the exact number of turns to the other full lock.......then turn exactly half way back. Then somehow, lock the steering wheel in this position ( with rope, bungy cords or whatever). If you don't start from the center of the steering rack position, you may end up with "toe-out on turns" errors in the steering geometry. If the steering wheel doesn't end up <span style="font-style: italic">straight</span> when you are at mid-point on the rack, you can remove and correct it at that point (if you find this, it probably means someone installed it wrong once before).

~HERE~ is decent explaination of the "string method".

~And Here~ is another.

For a <span style="font-style: italic">quick and dirty</span> method, you can do do what I sometimes have done to get things "close".
Since Sprites have flat, parallel rockers, you can actually get pretty close buy using a flat, straight board spaced away from the rocker. Turn the tie rod until the tire/wheel is parallel with the board. Do this on each side. After adjusting the tie rod, always bounce the car up and down a bit to let the tire "set" and then re-check.

Obviously, before you start, make sure the lock nuts on the tie rods are loose and that you can turn the tie-rods a bit.

 

[Jim_Gruber]

Drew, I used the string method, you could also incorporate a Laser Pointer placed against the rear tire to establish some baseline marks and keep things straight and to make sure front wheel is centered correctly to begin with. I quickly discovered why my inside treads were wearing far quicker than the outer. Maybe not as precise as an alignment machine but then again trying to find an alignment machine where a BE will even fit on the rack is even more challenging.

 

[drooartz]

Thanks all for the tips. That was what I needed.

I hadn't thought about using the sills as a rough flat point -- that will certainly help in getting close.

 

[nomad]

Drew,I have used couple of 1by4's 8ft long for years on several brit cars. Set them up on blocks against the tires. Measure the distance immediatly in front of the tires and at there ends several feet in front of the car. Flip them over and do it again to get a average to compensate for any warp in the boards. Longer radius makes the measurement more accurate and is simple to do.

Kurt.

 

[jlaird]

No big deal Drew, should only take a half hour by your self. We use the string methoid on the race cars as well. It is pleanty close.

Keep in mind the rear and the front of the car, the wheels, are not the same width.

 

[Guest]

If you don't start from the center of the steering rack position, you may end up with "toe-out on turns" errors in the steering geometry.
.

O.K, you're gonna have to explain that to me as I can't make any sense of it. Unless a difference of tie rod angle will build more ackerman into it, which it shouldn't.



I alwaysed used a tape measure across both tires to the same tread point, or a common edge on both sides (pinch rail, radius arm bolts).

 

[jlaird]

Tape works as well. Lets just say that you need to center the wheel so you can turn around either direction in the same space.

The other comment is in error as to my knowledge. Makes no difference where you start on the turn as long as the wheels are aligned for straight ahead.

 

[Jer]

My method involved making an appointment at a local alignment shop (which happens to be owned by a ol car nutt, so I knew my car would get the proper care that most other shops don't have) I left my hanes manual on the seat with a post it note on the page with alingment specs & they called me back a couple hours later, gave them 60 dollars & been happy ever since

 

[drooartz]

My method involved making an appointment at a local alignment shop

I'd do that, but my car isn't running, and to get it there once running the wheels should be at least *sorta* pointing in the same direction.

 

[Gundy]

While the quality was crap and a dremel was needed to make the
crappy thing work at all, the Moss type alignment gauge did
the job for me. Now it tracks straight and isn't too twitching when tugging on the wheel. Made a big difference in how the car handles. I should have used string. Live and learn.

 

[JPSmit]

If you don't start from the center of the steering rack position, you may end up with "toe-out on turns" errors in the steering geometry.
.

O.K, you're gonna have to explain that to me as I can't make any sense of it. Unless a difference of tie rod angle will build more ackerman into it, which it shouldn't.



I alwaysed used a tape measure across both tires to the same tread point, or a common edge on both sides (pinch rail, radius arm bolts).

I'm not an engineer but, I presume it is because you can set up a toed in parallelogram if you haven't also set the tires straight relative to the car itself.

 

[Guest]

He's talking about rack position though. If you set zero toe with the wheel turned a 1/4" turn, toe is going to stay the same in a turn as it would if the wheel was set straigh and toe set. The tires don't know where the steering wheel is, and nor do/should they care as tire toe is relevent to each other. I can see where overall tierod lenth/angle may make a difference on full lock possibly, but shouldn't be enough to make a difference in my mind.

I know Nial has allot more knowledge on this then I do. I just can't figure out why it would.

 

[Jer]

My method involved making an appointment at a local alignment shop

I'd do that, but my car isn't running, and to get it there once running the wheels should be at least *sorta* pointing in the same direction.

True Enough ;-) ha ha

 

[aeronca65t]

If the steering rack is "centered" (ignore the steering wheel position....I'm talking about the actual rack), then the tie rods will be at the same relative angle to the front axle centerline (as you look down on it).

If, for example, the rack is turned so that it is sticking out 1" more on the left than the right, then the left-side tie-rod will need to be shortened to make toe adjustment correct. But the left tie-rod will now be at a different angle than the right-side tie rod when driving "straight' (because the inner ball attached to the rack is closer to the left tire than it should be). Steering geometry will suffer as a result.

Those old BMC engineering spent a lot of time on slide-rules getting it all right and it's a pity to spoil it.

What often happens with older cars is that a PO will adjust only one tie rod to set the toe-in. Then, if the steering is "off", they will remove and re-set the steering wheel to be "centered". This is incorrect and will cause the steering problems I've mentioned.
In some cars, it can also prevent "full lock" on turns on one side (but not on Spridgets as far as I can see).

Of course adjusting only one tie rod to set the toe-in has no effect on "straight ahead" driving and if you drive gently, you'll never notice it. But then, why buy a sports car at all?

I'd say that with an older car that's been played around with by many POs for 40+ years, it's a good idea to start by re-centering the rack.

Most modern cars do not actually use "pure" Ackerman geometry. If you do a K-turn in a Miata at low speed on gravel you can feel it "scrub" because the bias for less Ackerman at low speeds when suspension does not deflect so much. Many roundy-round Sprint cars use "reverse-Ackerman" to improve left turning.

Of course the question of toe-in can also be interesting. I set my Spridget at "0" toe for racing and when I was auto-crossing it, a little toe-out. I always set my NASA racer (fwd Escort GT) at about 3/16" toe-out. My old street Mini was always set 1/16" toe-out.

 

[Hap Waldrop]

Most DIY methods and tools are only toe setters, which can allow the car to crab because the entire car was not squared in strings. the biggest error in doing a string alignment is assuming both your front and rear track is the same, it is not, the Spridgets have a wider front track, different wheels, spacers of course can change all this, so if front and rear track are not measured, all this will be in void. The easiest way to measure track is measure from where the tire makes contact with the ground on the outside of one axle to the inside of where the tire makes contact on the side of the same axle, this mean to be squared in the strings the hub center will be further away from the strings in the rear than than in the front, if correct it should be in the rear exactly a half of the track difference away for the string in the rear, this is big time important if this is not taken into account, then the strings will run at a angle and the measurements are useless. Aslo you need some sort of turn table for the front wheels so as you make adjustment and the wheel and tire can turn freely during those adjustments, now here a trick on a super cheap set of turn tables for home use, racer do this all the times, get 4 pieces of commercial tiles, use two for each front wheel put some wheel bearing grease and WD40 between the two tiles for each front wheel and tire, this will alow a friction free surface for adjustng the toe. The string alignment I have just described to you work exactly like a high dollar aligment machine using lasers and computers to do all this, exactly. Modern alignment machines are like X boxes with wrenchs these days, it allowed the tech to no longer engage his mind, the machine tells him everything he needs to know, while it doesn't make for smarter techs, it allows you to train a lesser than smart tech to do the job, if you are willing to think about this, fiquire out the method, the string aligment does the exact same thing, and you can do as good as a job as home as $100K machine can do.
Drew the only adjustment you have on your Bugeye is toe, all others have to be done with add on devices as for camber and castor. Hope this helps, call me if you need to.

 

[drooartz]

Does help, Hap (and all of you). I think I've got the concept clear in my mind, just need to drum up some tiles or plates of some sort for the turn tables.