freeway handling

[craigvwdude]

Fellas,
when i drive my 67 bug down the freeway, i get blown all over the place.
Everything is new, 145 tires, fresh alighnment, caster shims, ect. ect.
The car is lowered also.

Any ideas? Bad tires? Tires too skinny?

Let me know your ideas!

Thanks!
Craig

[helowrench]

Lower profile tires would help (stiffer sidewall).
And if you are lowered a lot, then you might consider adding a second set of the caster shims.

Unfortunately a lot of it is due to it being a beetle, with a side aspect of a sheet of plywood.

Rob

[Brent Bousman]

As Helo said you do have a Bug........and the car is pretty light.

Extra caster shims are only needed if your rake is off (tail up) because you did not lower the rear according to how you lowered the front. Your alignment spec sheet will show if you are off or not.

145s? Hopefully they have the same loading rating as a stock tire. Put some wider quality tires on it if you can. Personally I would not run a VW with something less than a 165.

For a lot of highway driving and in windy conditions you could always make a front spoiler and attach to the bumper supports to block some of the air getting under the car at highway speed. You would be surprised at how much lift the bug can generate at highway speed.

[Marc]

If the front is lowered more than an inch or two by any means other than drop-spindles the steering geometry starts to get pretty poor. It's a primitive setup that works surprisingly well so long as you stay within the ride-height range that it was designed for. Specifically, the further away from horizontal the tierods get the more "bump-steer" (a wheel turning by itself in reaction to suspension travel) you'll have. With the tierods angled up away from the steering box, their effective length gets less whenever a wheel goes up in response to road surface imperfections which makes the wheels toe out - that may have something to do with your symptom. If you still have the original `67 small-stud spindles they could be reamed to reverse the taper, then late ends installed; if they're already large-stud, they can be bored straight and tapered-I.D. sleeves installed (called a "flip kit"). I would address this before fitting any kind of air dam - if you don't the added downforce will cause toe-out.
Another potential cause of dartiness is rims without enough offset. That increases the "scrub radius" (difference between the center of the tire contact patch and the axis about which the wheel steers) and directional stability suffers. No fix for this (other than changing rims) although a little extra toe-in will reduce the symptom at the expense of faster tire wear.

Are all the tires 145s or just the front? The rears are radials, though, right? Has the transaxle been out/was the rear toe checked too?

[FJCamper]

Hi Craig,

Was there a time and setup when you felt your Bug was stable? Or at least more stable than now?

Remember the rear end steers you, too. Have the rear toe checked.

FJC

[craigvwdude]

Fellas,
thanks for the ideas!
The car is lowered pretty good. Just weld in adjusters. No drop'd spindals.
The car was fine before. It used to have 165's all around. Now i have 145's in front, and 165's back. All tires are new and are radials. All suspension is new.
The only thing i can think of is, it has to be the skinny 145's. Going over bumbs does'nt make any differece, so i know it's not bump steer. It's just if it's a windy day or if a truck passes me, i'm all over the place.

Any more ideas?

Thanks again,
Craig

[1303wasserbug]

a cal look bug that doesn't handle at speed? never heard of that before . i think the first thing you should be doing it putting in some castor shims, even if you've not got masive nose down rake, they'll still be a good idea.

[Marc]

....Everything is new, 145 tires, fresh alighnment, caster shims, ect. ect....The car is lowered also...

Not to say that additional caster shim thickness might not improve the high-speed stability - we don't know how much rake the chassis has. If the rear's lowered a bunch too I'd look at the rear toe first.

[1303wasserbug]

ah didn't notice craig mentioned castor shims in the first post . but if it's running a lot of rake two sets might be a good idea. any chance of a recent side on pic? front spoiler/spliters seam a good idea too and a lot of people say they improve stabiltiy at speed/windy days etc. thou getting one to look right on an early bug is a tuffy. but anything that stops air going under the front of the car/up under the wings is a bonus.

[turbobaja]

I'd go with the alignment RECHECK. Once you've got it all set, go and sit in the car, and someone else in the pass side too if possible. Now take a look @ the alignment. I gaurantee your front toe goes negative.

Make sure you get an accurate measurement of both CASTER and CAMBER in the front. And front and rear toe in/out.

Are you able to do the alignment yourself or are you taking it to a shop?

With all new suspension components and a good alignment, your tire combo should be fine. However, these cars are light, so cross winds and following semi trailers will always be a little more interesting.

Karl

[craigvwdude]

Thanks for the replys fellas.
Put some 195/50's on the front. Seem to help quite a bit.
The car has just a slight rake. It's lowered pretty good. Now it seems a little squirly in the back. I'm thinking it's because it has a lot of negative camber from being lowered and causing some toe in. Not really too much i can do about that unless i raise it back up.
The car also seems to be real "touchy" on the steering wheel. It's got a brand new steering box in it and a buddy suggested i loosen up the box just a little. It worked on his. Just a thought..
Anyways, thanks for all your ideas!
Craig

[FJCamper]

Dear Craig,

On our VW's, the rear roll center is already higher than the front, and when we lower the front, the car can take on a very unstable feeling.

The extra castor shims behind the lower axle beam tube help by making the front end track straighter, but we still have the buttend in the air creating the feeling that the rear end wants to pass the front.

We got into the same problem when we put a Puma axle on our racing Ghia. Our fix was to add the castor shims, and remove the rear sway bar. The car was then stable.

I know you don't have a rear sway bar to remove, but with bigger front tires, and castor shims, the car should be okay.

FJC

[Marc]

Will this help any?

[FJCamper]

Was that caster or castor?

Only the spellcheck knows for sure.

I stand caster-corrected.

FJC

[Marc]

I've never slammed the back of a swingaxle enough that the rear toe couldn't be adjusted using the stock slotted holes in the springplates (at super-low heights the wheel bearings get starved for lubrication, a lack-of-function which I'd never accept in the name of fashion).
But if you choose to do so, the holes may need to be elongated or in extreme cases it might take these to correct the rear toe:
http://www.thesamba.com/vw/classifieds/ ... ?id=347713