I was hoping I could trouble you gentleman for some feedback on a recent alignment job I had done.
Post-alignment, I'm experiencing a darty front end that's impossible to keep in a straight line. The shop is going to take another look, but I know they matched it up to a 1970 VW Sedan already, so if we're looking for different results, I probably need to request a different approach.
Looking at what I'm currently working with, does anyone have advice?
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These are the numbers Danny posted from a Spyder he just worked in for a customer:
“Front: 1/8" total toe-in, -1.0 degree camber. Rear: 1/16" toe-in, -1.8 degrees camber. Caster is not adjustable, the beam is welded in a Spyder. The wheelbase is now even side-to-side, it was a 1/2" different so was dog-tracking a bit before.”
It is “darting around” because it is following the crest of the lane or chasing bumps from “bump steer”. It is doing that because they set it up as if it were a stock VW sedan. Stock VW sedans sit much higher than our cars, which have all been lowered. When you lower the car, you have to add a lot of caster to get the steering geometry back to “normal”. Setting it to the specs for a 1970 VW sedan is fine except for just one thing:
They set your caster to 2.9° and 2.1° (L/R) and it should be set to somewhere in the range of 5° - 7° to eliminate the wandering and bump steer.
They probably won’t have the caster shims in stock to change your front end. The shims are placed behind the bottom torsion tube in the front end. I would suggest that you buy two (2) sets of shims AND a pair of longer mounting bolts, just in case you need them, and bring everything with you to the alignment place.
Perfect @Gordon Nichols, I'll pick those up and bring your info with me. I appreciate you taking the time to share.
In addition to the above, this is what I received w/ my VS when I purchased it from the builder. Hope this helps.
2013 built VS Speedster- Builder Alignment sheet, Hawaiian Garden, CA
- CAR base: 1972 pan, ball joint front, and rear short swing axle (not IRS. Car modified by builder to short swing axle)
Front end Alignment;
16th” on both sides toe in
Rear end Alignment;
@Gordon Nichols posted:It is “darting around” because it is following the crest of the lane or chasing bumps from “bump steer”. It is doing that because they set it up as if it were a stock VW sedan. Stock VW sedans sit much higher than our cars, which have all been lowered. When you lower the car, you have to add a lot of caster to get the steering geometry back to “normal”. Setting it to the specs for a 1970 VW sedan is fine except for just one thing:
They set your caster to 2.9° and 2.1° (L/R) and it should be set to somewhere in the range of 5° - 7° to eliminate the wandering and bump steer.
They probably won’t have the caster shims in stock to change your front end. The shims are placed behind the bottom torsion tube in the front end. I would suggest that you buy two (2) sets of shims AND a pair of longer mounting bolts, just in case you need them, and bring everything with you to the alignment place.
That, right there is the ANSWER ^^^^^
Fully endorse Gordon's advice re caster shims. That's going to make all the difference.
But fwiw...
Camber adjustment with the stock eccentric is limited to about .6 degrees negative, more or less. To get a full 1 degree like Danny you'd need to buy an aftermarket eccentric—but you don't need to do that really. I have my MG set up with about the same camber specs as your guys did: about .3 degrees negative on both sides. I have the Spyder dialed out closer to a half degree. Both handle pretty well—the Spyder especially.
For really aggressive driving, and auto-cross, a bit more might be better, but for a street Speedster just a little negative camber is probably more fitting. Toe in as directed, 1/8, to 3/16 inch all-in in front. A little less in the rear.
Writing your own manual begins with all speedster purchases for what you did 
Ed's right, you don't need that much adjustment range, or that much negative camber in a moderately-driven Speedster.
I believe the Spyder I just aligned has stock adjusters. I have -1.8 degrees on my Spyder, and can dial in more if I want.
Bumping the caster up to 5° - 7° will make a night and day difference in how your car handles.
You’ll need at least 5° for it to be as effective as you want it, but since the shims are a set thickness at about 2° per shim you will use 1 or 2 shims to get you somewhere in that range. Since you already have about 2° in there, then they should be able to get you to 6° pretty easily. They’ll have to decide once the shims are in whether you’ll need the longer beam mounting bolts. They’ll want at least 3/8” - 1/2” of bolt thread engagement once the shims are in and that’s why you want the longer bolts - “Just in case” planning!
I wouldn’t get too hung up on camber adjustment. Unless you’re planning on taking your car on a track to really wring it out, the VW sedan spec for camber should be fine for normal driving. If they had had trouble setting camber then, yes, there are different camber eccentrics available that allow more adjustment. I have a pair of those, too, but I also used to get out on the track from time to time.
All of us (except the Beck folks) adjust our caster with these shims. Beck cars don’t, because the proper caster is built into the frame already (those clever Beck folks!) and the front suspension is a trifle different but the result is the same.
All making sense. I really appreciate you all taking the time to spell this out for me, I'm confident it should get everything resolved.
@IaM-Ray posted:Writing your own manual begins with all speedster purchases for what you did
"All I did" is a very long list of things I spent money on for my Speedster over the 14-15 years I've owned it. Flying my airplanes over the years, I always have kept log books for the engines and air frames so I made a Speedster logbook with everything ever done, to the car and each cost as well as trips' with mileage, mpg and details of performance. Fun to look over but don't add up all the costs! I would imagine that such record keeping would go a long way towards getting top dollar for the sale of a car from a buyer.
I did the same thing, jack, and ran a spreadsheet just for fun. i have to say, it was a revelation of what the true cost of this hobby is and it is a bit shocking for all the unseen invoices and disposable income you spend on toys an their upkeep. Just saying.
I never wanted to tally up all that I spent. Often, it's best not to know, right? Especially during the 90's when spending wasn't an issue, but I wrote a very detailed service manual specific to my car that is a hyper-linked WORD document that is currently 138Mega-Bytes and growing. Whenever someone posts something that you don't want to forget that applies to my car, too, I grab it and add it to my manual (like the bearing part number for my alternator!).
The hyper-links are cool: Bring up the table of contents and click on the category you want and it takes you there, then click on the topic and it takes you there. It's structured just like the Bentley's VW Service Manual for 1970 but is specific to my car with sources and part numbers for just about everything.
We had a three-day snow storm back 7 or 8 years ago and I started this as a way to pass the time and then it snowballed (wicked good pun, there). It's been handy for me and others on here needing info (especially because I can't remember 9-digit part numbers that well anymore!). Just plug in the USB drive and there it is!
If anyone wants to see an example, let me know and I'll post the ToC and one section.
I am on a Mac and I use devonthink which is a filing system overlay on the OS and it allows hyper links but I haven’t made much use of them I guess that would be a good add on.
Post a sheet for fun Gordon, great idea.
If you don't carry a spare, jack and tools the front will be light. The caster shims make a HUGH difference, but the weight is important. It all works together. I built mounts and added 26 pounds to the front beam so that I could use the frunk. Look in the archives for drawings and photos of that project.
You don't have enough caster.
^^^Man of few words^^^ 
