Yaw???

What tire pressures are you running ?

I can do that with the throttle on my car now. But I doubt that's what you're talking about....

I am running 26 in the back and 22 in the front.  You are right YAW, can't spell and can't drink

I would be looking very closely at my spring plates, spring plate adjusters (I think your car has those stock), transmission mounts, CV joints, wheels, lug nuts and motor mounts.

 

Everything's tight?

Swing arm or IRS rear?

 

Things to look at are different for each.

 

Check that the bolts are tight on the torsion bar end caps, then check the bolts at the other ends of the spring plates.  While it's up on a lift or jack stands, grab each rear wheel and try to move it forward and back to make sure the splines at the front of the spring plates are tight (a mis-match between spring plates and rear torsion bars will allow the plates to move forward and back, thus changing rear wheel toe-in).  You may have to use a suitably long piece of pipe to leverage the wheel/spring plate assy to check for tightness.

 

If it's a swing arm car, check the rear wheel hubs around where the spring plates attach for any cracks.

 

If it's an IRS car, check the forward (inboard) pivot bolt for each diagonal arm for tightness AND that it doesn't have any slop in the mount bushings, especially if they are Urethane (hard plastic, not rubber).

 

As mentioned above, check all three transaxle mounts (nose cone and 2 at the engine/transaxle intersection) to make sure none is cracked.

 

Also, John....More detail on the Yaw condition......Is it a one-shot or a series of oscillations?  If it oscillates, at what frequency (how often)?  Is it steady or does it come and go?  Over what period?

 

Lastly, I hope you have checked ALL of the stuff on the following list on your car as a new owner:

 

https://www.speedsterowners.com...acceptance-checklist

 

gn

I don't know if it's a Swing Arm or IRS.    My guess is Swing Arm. (standard VW)   The part that has me is the intermitted nature of this.  I was hoping that would be a clue.   When this happens it is at about the rate of about once a second.    If it did it all the time it would perhaps be easier to trace down.    

 

An example.  Running down an interstate high way a day or two ago I noticed it.  Got off the interstate stopped and turned around heading back home the other direction on the same road and it seemed to have gone away.   

 

I looked at your list Gordon,  and it's impressive but it's also WAY beyond my pay grade.  A lot of that stuff I wouldn't know what it if I saw it let alone be able to adjust or determine it's condition.    LOTS TO LEARN.    I apologize for my ignorance.   

John,

 

If your type 1 VW pan is from a 74 VW, you have IRS suspension, which was used by VW from 68 onward.  You may want to consider finding a VW shop near you.  Local hot rod or air cooled VW clubs can help you identify one in your neck of the woods.  

 

While all of us are smart enough to learn the mechanics involved, brakes, steering, and suspension are best repaired or modified by a professional, at least for the first time.  If you're lucky, the mechanic you find will show you how things work, and the next round of maintenance or repairs can be done by you.  

If it's a '74 pan it doesn't automatically mean that you have IRS.

 

Many VS (and I bet a lot of JPS) cars with later pans (after 1969) were built up with swing arm transaxles to be more "authentic", even though the pan was originally set up for IRS when it was still a "Bug".  

 

Look under the rear end of the car (it doesn't need to be up on a lift or anything, just get down low and use a flashlight) and see whether it has:

 

a.) a solid, straight, 2" diameter tube (the actual axle is inside of the tube) running from the transaxle to the wheel, with a single rubber boot near the transaxle end or;

 

b.) a short (about 16") axle with a rubber boot on BOTH the transaxle end and the wheel end.

 

"a.)" is a swing arm

 

"b.)" is an IRS

I looked and it is an IRS

Well, I guess it's possible that an owner could stipulate that an IRS pan be swapped for swing axle, but I can't understand why.  I can't imagine VS adding that extra cost on their own, just to decrease handling.  I wonder if that same owner would stipulate 4-wheel drum brakes and bias ply tires for "authentic" handling.

It doesn't make sense to me either, Jim, but I've noticed a number of members' cars here are like that; I think it has to do with pan availability.

John,

 

Do you have castor shims in your front beam? At highway speed, does the car drift left or right with no apparent cause?

 

ALB , (aka Al)  is one of the shim gospels here, what say you Yoda?

 

AB

Have no clue on the shims.  Yes it goes left and then back to the right just slightly.   But I sense nothing in the steering.  My guess and it is that a guess is that the cause is in the back of the car.

When I got my car I found out that it "crabbed" a bit, which also made a noticeable yaw.  I fixed it with a good 4-wheel alignment which showed that I had a thrust angle issue - meaning that the rear wheels were not parallel to a line down the center of the car.  I believe that both rear wheels were pointed slightly right, but I could be wrong.  Doesn't matter as it's fixed now.

Yoda say I no clue have!  (on a serious note, my wife will say the same thing, but back to the topic at hand...) It could be so many things, but as has already been mentioned, start by making sure all suspension pieces (including rear torsion bar grommets and irs inner pivots, front ball joints and steering pieces) are in good shape and a proper 4 wheel alignment is done. And if it doesn't have at least 3' of caster then a pair of shims are needed under the bottom beam. With every thing else right it may wander a little at higher highway speeds even with minimum stock ( 2 1/2') caster because of the shorter than stock (beetle) wheelbase. Aim for at least 4'.

My money is on rear alignment.

I have wondered about the short wheel base.   The part that's going to make it a bit of a challenge is that fact that it doesn't do it all the time.    AND it could be a combination of road/wind conditions which causes the it.    Probably another live with it deal.  (unless it gets worse)   

 

In the spring I'll see if I can get a four wheel alignment done.    

Although I talked about the front end (and the need for caster shims) above, I agree with Stan; the problem is probably rear suspension based. Since it's not constant I think you should be replacing the rubber torsion bar bushings before having the rear alignnment checked, and the inner irs pivots may need replacing as well. This is something you don't have to live with; with new rubber suspension pieces (and it being aligned correctly) the car will track properly (and much more safely), even in cross winds at speed.

 

Btw- It would be a good idea to have a set of caster shims on hand (they're less than $20) when you get the car aligned. As I said before, aim for at least 4', 5' is good and I think someone here is running 6' without any ill effects. Low speed steering may be a little heavier, but that's about it. Yoda out.

Hmm,  car has less then 3000 miles on it wouldn't that "stuff" all be new?  Or not necessarily?  

You could ask whoever built the car.

I would spring for the alignment first.  If it comes out ok then start the replacement merry-go-round.

I agree, it sounds like your rear toe settings are out of whack causing the rear oscillations.

Another vote for a four wheel alignment. The difficulty will be finding a shop that can do the job properly.

Alan may know of a local shop.  I could understand how a minor change in the rear tow in could cause this.   Might be as simple as weight distribution and tire pressure as well (?) 

 

Thanks for the information and suggestions.    Sounds like we're about to have some less then speedster weather tomorrow.    

John:

 

All good points up above, especially about getting several different sets of caster shims to take along for the alignment guy - these are old cars that still use shims and wedges to adjust alignment, front and rear.  They will not have them in stock.  Just in case, get a pair of longer lower front beam bolts - they're cheap too.

 

Inadequate caster in the front can cause intermittent "wandering" - exactly that, caused by cross winds and Bump-steer (where the front wheels try to follow the contours of the road surface).  This is amplified by any weird toe-in/camber effects of the rear suspension adjustments.  You don't just bolt an IRS rear end together and expect it to run straight (although it seems that some California Speedster builders do just that).

 

Bottom line - find a good alignment shop that understands that what you have under there is a 1971 VW sedan (use the specs for that year and model, or for a Karmann Ghia that year) with some special twists and can deal with it.  Use the 1971 model year because a 1974 could have had MacPherson Struts in the front end and is set up differently.  You have ball joints, instead.

 

Go for at least 5 degrees of additional caster in the front.  These cars WILL wander at speeds over 60mph unless you have additional caster in the front end.  I am running 6 degrees on one side and 7-1/2 on the other to compensate for strangeness in my chassis and it tracks straight and true up over 100mph.  Different shim needs on each side is common, too, so don't expect that both sides will automatically be equal.   Whatever shop you go to WILL NOT have those shims on hand.  Better, intrepid shops will make a set out of short lengths of pipe (if they know what they're doing) but don't bank on it.

 

As for the rear alignment, On an IRS it is adjusted with wedge shims.  Any good shop will be familiar with wedge shims and shouldn't have a problem installing them and shouldn't be scared away by that big, moose-y diagonal arm back there.  That IRS rear is identical to a Porsche 924/944 so no big deal.

 

Talk with Alan.  I think his preferred alignment shop also does frame straightening.  If so, THAT is where I would take my car in that area.  

 

Doing this job right on these cars is a bit time consuming.  Bring them brownies.  Say your wife baked them.  Ask them to please do a thorough job as you hand them the brownies.  They will.  (I forgot the brownies for my alignment and after Tony did a STELLAR job on Pearl I went back with a case of Sam Adams Seasonal Brew and dropped it off.  Tony, the young kid with the Mohawk and tattooed arms and '68 VW sedan with a VERY stout 2,110 in it, really understood what needed to be done and even made a pair of un-equal shims from pipe-stock to make it all work.

 

It's the little things that make a difference.

Generally, short wheelbase cars are inherently less stable in a straight line than longer wheelbase cars...........NASA doesn't build short rockets right?

This can be used to their advantage in racing because if the mass of the car is concentrated in the middle, it tends to rotate around that centre of gravity easily. Things like Go-karts and small race-cars such as the Porsche 908 are known to be very "twitchy" and react extremely quickly to every little steering input. The 550 Spyder is mid-engined and this makes it such an agile little "giant killer". These cars have a low Polar Moment on Inertia.

 If you look at something like a Nascar stock car it has a big V8 between the front wheels and around 200lbs of Battery and Fuel behind the rear axle. Such cars have a high Polar Moment Of Inertia. They have a longer wheelbase than say a Speedster, but are pretty stable in yaw due to the weight at either end tending to balance each other out and reduce the tendency to want to rotate around the Centre of Gravity.

 The VW Beetle and Porsche 911 have high Polar Moments of Inertia because the heaviest thing in the car (the engine) is located behind the rear axle. Trouble is, unlike the Stock Car there's not a lot of weight up front to balance it out, so the car's C of G is further back than in most cars. Now the earliest Speedster replicas took VW pans and shortened the wheelbase even further which reduces the tendency of the car to run straight. Every little bump that deflects the rear end sets up a pendulum motion because of all that concentrated weight's effect. Now the driver will feel that and probably make a tiny steering correction that counteracts it. So the car stabilizes, but the weight swings back slightly the other way, so this is possibly what the driver feels as a kind of "tail wagging". Even tire sidewall flex from a bump deflection could cause this.

 

 None of what I've written negates anything others have written, but more adds to what they are saying. Check everything, because any slight fault or play in the rear suspension can add to the design's limitations and natural yaw tendencies.

 Increasing the front castor from standard VW Beetle specs will help counteract the reduction in wheelbase and give more natural tendency to run straight.

 

I'm NOT a Speedster owner, so I can't speak from specific experience, but I messed around with modified Beetles enough in the 80's to have explored their handling quirks and tendencies. Go test the car again on the same pieces of road and see if you get the same feelings. It could be something in the road surface or a combination of that, plus wind or whatever. See if it does it again or if it happens somewhere that it didn't before.

 

Everyone's "through the seat of the pants" feelings are different. You might just be experiencing the "feeling" more than others would perceive it, BUT it could be something peculiar to the car so get a good shop to check things out.

 

Peace of mind is good.

This probably will not get attention until spring.  I hope to be able to drive the car a little over the winter but certainly it will be only on unusually nice days.   

 

I appreciate ALL of the help.   I expect this will be a bit of a challenge to sort because it's not to this point at least easily repeatable.   

 

I DO understand that my perceptions could be entirely wrong as well.  Only thing I can say is that when I've noticed this I've very carefully tried to hold the steering dead still and what I feel is this left to right yaw or oscillation left to right and then back right to left which SEEMS to be coming from the back of the car.   I am not correcting this movement by putting in steering corrections.   It just as if the back end of the car is wagging it's tail just slightly.   I am of the opinion that it's some issue with the rear suspension and the rear tow in makes sense to me as a first place to check.    Or it's just conditions, wind and road relative to the very short wheel base and the heavy engine.  I'll report back when I know more 

If I had your provblem and lived in Shippensburg, I'd contacy Alan Merklin, "the wizard" and pay him shop rates to straighten that issue out.  period.

 

I wish you success in fixing that yaw or "seeking" problem because it won't be much fun to drive at highway speed.

I think Alan's up to his elbows right now.    This can wait. 

Your call.  You won't be driving much in your part of the world until spring anyway.  

John,  We'll address this in Feb.  after I can move the project off the lift and out of my shop.....There  are many good suggestions made here....Starting with tire pressure, 4 wheel alignment, checking rear hubs are tight ...........Hey maybe it's just a case of too much HP :~)

See?!

True story:

In High School, I had a '65 Pontiac Catalina that did have a similar yaw to it "under load" coming through the Lincoln Tunnel...that is, it turned out that the Clifton New Jersey Officer said it was due to the trunk full of 36 cases of... "Old Bohemiam White Beer" .

Officer say's: " Hey kid, you clowns drink that sh*t ?"  

Me:  "Just me and my buddies, Sir"

Officer: " Any open containers ?"

Me: " NO Sir "

Officer: Get the hell out of my town"

 

 

You gotta love cops like that.

 

I wrapped my mother's Ford XL (351) around a phone pole. As kids, our dare was to light the car off at the top of the hill and lock it up just before the phone pole. When we were really having fun someone would lie spread eagle on the hood during the process. One night I stood on the brakes before the pole and the rear lines blew (rusted) -to this day I'm glad no one was on the hood. Had to put a new front end on the car but it never went straight again. It would sidewind down the road like a snake. My dad gave me the headlight cover one year for Christmas (He pried it off the rotting corpse in the dump). One of the funniest gifts I've ever gotten.

Our son is 40, our daughter is 38.  Every once in a while, they will let the other show drop, and tell us the real truth about an incident that occurred when they were teenagers.  It's reassuring to know that some things never change.  I was too young when my folks died to cop to anything.

You transport large quantities of beer in your personal vehicles don't you Doc?  I think your pickup fits about 65 cases of Guiness doesn't it?

To this day, I don't know me or any of my high school buddies didn't get a DUI or worse (die?).  We did a lot of dumb **** growing up in Chico,CA.  Some of the best times we had were drinking beer up on old Highway 32.

 

One night we had to scramble from the cops. Someone had the bright idea to put a partially full keg of Coors Light in the 'back seat' of my Ghia. Imaging being bombed, bombing down a old twisty high way with a keg of beer basically strapped to your back.  At one point we had people telling me to pull over so they could refill their cups. Running from the cops...

 

Oh... and... yeah:

 

Thread drift...

Back in the 60's in New Jersey, you could not buy package goods after 9:00PM so Bars decided to skirt the law by selling draft beer in wax coated paper quart containers that were used for potato salad etc. in grocery stores.

 We would head to the Bar and get a few dozen " Tainers" as they were called.....to go...

  Bars would set them into various beer ( bottle) cartons for secure travel....

"Where there's a will there was always a creative way...."

 

BTW It's strongly suggested as a kid  not to be a wise ass and do a burn out in front of the local Police Chief's home. Result was a court appearance..When the Judge asked the Chief about the " note affixed to the back of my Careless Driving Summons that read: "Excessive acceleration from a stand still"

Said Chief replied "150' of rubber in front of my house your Honor"

The courtroom broke in laughter however, in a split second the gavel met the bench " 30 Days suspended license"

 

...........and now back to the yaw thread.

I'm one of those folks who never gets away with anything.   I read some of these tales and listen to my friends describe their some what wayward youths. My parents kept a close eye on my brother and I.   I have nothing to tell you other then if it had been me I'd not be here to tell you about it.    When I was about 21 I rolled my Dad's 1965 Saab over on it's side.  (At the bottom of the Timmon's Mt Alan) going too fast around a turn on slightly wet roads.   That's the worst that I've done.   Had to hitch home to Boiling Springs and explain to my Dad what I had done.   He was nice about it and I've been eternally grateful for his understanding because I deserved a kick in the ass.  I was old enough to know better.  That and a couple minor traffic violations are the sum total of my sins.   My brother is absolutely lilly white.  I don't think he's had more then a parking ticket.    

 

BUT, it seems to me that bad luck will claim the innocent as well as the guilty.   Being at the wrong place at the wrong time can get you just as easily as tempting fate or so it seems.   

 

Regardless be careful out there in speedster land.  These little cars are not the things to run into tree's with. 

 

Drinking and driving???  Well there is no excuse at any age.