Measuring Ride Height?

[andy198712]

Where do you measure ride height from? i've seen it written about in books to be an inch lower in the rear, but where do you measure this from?

Cheers

Andy

PS its in a beetle

[FJCamper]

Hi Andy,

Usually, people measure ride height from the bottom of the floorpan, under the "backbone" hump area.

The information that the rear ride is supposed to be a half inch lower than the front is true, but pertains to swing axle cars and is more of a handling adjustment than a factory spec.

FJC

[buildabiggerboxer]

Andy, reading books is dangerous , they date together with our old air cooled motors, now so old and worn the makers o/e specs don't apply to much, but any measuring has to be done on a flat surface, ideally, it should be level too, establish your own datum points and stick to them, ideally, don't use bodywork or jack points etc, under the rear torsion tube housing at the rear is good, under the lower shock tower at the front axle tubes is ok, but check they're not ground away or damaged as mine are, in that case use the torsion tubes.
Now you can scare yourself shirtless as they never sit level at this great age they all are, my take on the 'down at the back' fable' that is as old as the CRI mono grade oil tales, they were never 'down at the back' but they, they being coil sprung 1303 and 411/12 models, were 'up at the front', it was done for load carrying in the US Market with the cavernous front luggage capability they had, nothing to do directly with handling, but it did, coincidently, just happen to add castor to complement the IRS System they also had, I've not seen it like that on our stock swing axle models, they already had a rep for bad handling, although lowering the rear can reduce oversteer, it de cambers as its lowered, and also adds some castor at the front, And Making the rear track wider will lower the car slightly, you can work that one out incidently, the USA market went IRS well before we got it in Europe, Ralph Nader made that possible at least. Happy reading lol.

[FJCamper]

Gentlemen,

Yes, ride heigth is where you measure it from. But the bit about a swing axle car handling better if half an inch lower in the rear is true. Even an inch.

We have a swing axle road racing 1964 Ghia with adjustable rear spring plates. Starting from level, if you raise the rear suspension (from level), it promotes oversteer. Lowering the rear (from level) promotes understeer. It seems like we get the closest to neutral steer in this configuration by very slightly lowering the rear end.

My guess is having a slighly lighter front end means less grip -- less understeer.

FJC

[andy198712]

Cheers for the replies gents,

are the torsion tubes level do you think? i'm interested to see how level my cars sits at the minute, or the spine as FJ mentions,
the torsions are easy to get to.
my bug is standard height and it does handle well with KYB GR2 front shocks, HD roll bar, caster wound in, and at the rear a camber comp, stock oil shocks (removed the KYB's at the rear and its better) and flop stops with no spacers.

in the future when money allows i was some nice shocks on all 4's like the Koni's or some custom made ones from here in the UK.

What effects does adding castor shims give? more stable at speed but heavier slow speed steering is that right? ( kicks the beam out at the bottom yeah?)

i would like to lower the car a little but worried if i go with drop spindles i'll need silly tyres to clear as they give quite a drop, where as adjusters, not as good for geo but more adjustable, so could drop it an inch or 1.5 ect...
narrowed front beam is the anti christ for good handling so it seems.

then the rear one outer spline maybe, or if i'm feeling flush, adjustable plates!

i'll try and measure the car on the flat today if i can (i live on a slope)

cheers guys!

[FJCamper]

Hi Andy,

Yes, caster shims make you go straight. If you intend to run 75 MPH up to 110 straight and true, you need an extra set of shims. More for the Bug than the Ghia.

The extra shims slightly increase turning resistance. You'll feel it more with a smaller diameter steering wheel.

Adding caster does not cause tire/tyre wear. You run no caster shims for autocross, to be able to throw the car around, and run one to two sets for road racing, depending on your suspension setup. We run one set on our IRS Ghia, which works well with the rear suspension for steady-state understeer at high speeds, but none on our swing axle Ghia, which is straight-line stable up to approx 125 MPH.

Our IRS Ghia has a quick-steer kit in it, and the added caster seems to counteract the twitchy (how's that for a technical term?) feel a quick steer kit can cause.

FJC

[andy198712]

Cool thanks I plan to build replacement beam then do the switch on a weekend as its my daily! Only snag I for see is the bolts snapping!

[buildabiggerboxer]

in the future when money allows i was some nice shocks

Go for protec shox, UK made too.

What effects does adding castor shims give?

As well as added stability, castor adds camber with increasing steering angle.


i would like to lower the car a little but worried if i go with drop spindles i'll need silly tyres to clear as they give quite a drop, where as adjusters, not as good for geo but more adjustable, so could drop it an inch or 1.5 ect...

Drop spindles are the way, sort out any tyre rubbing as required, roll the wheel arch lip etc, don't take the easy way out.

narrowed front beam is the anti christ for good handling so it seems.

It can work, or put another way, you can get out of jail free with one, just about, but you would never narrow any track width for handling, it's a posers paradise, even think about going red 9 through rod and coil over on a stock width beam, that's the way forward, very good front wheel control especially under braking, I was a sceptic, but after driving a bus and several bugs with it, I'm swayed, even from me being cussed about keeping it VW with logo' parts, I believe it's a legitimate move and still in concept, why have I mellowed to this? The driving I mentioned above, and I've realised Probably the quickest German spec kafer cup car of the day is so equipped...

then the rear one outer spline maybe,

Yes, that is standard BBT CUP Beetle challenge setup, low but street able and with good traction, which reduces with extreme lowering, curtesy of less contact patch.

cheers guys!

[andy198712]

interesting, so they just run through rods instead of torsions and then use a coil over.... are the damper mounts man enough?

[buildabiggerboxer]

interesting, so they just run through rods instead of torsions and then use a coil over.... are the damper mounts man enough?

Given that the spring rate for the street would only be around 100 lb in, the mountings are plenty strong enough, for racing, I always seam weld the towers using conventional shocks anyway, in theory, it would be the bus setup with coil overs that would be on the limit with a full load and slammed to the max, I've had to raise them just to pass the MOT, then drop them back to suit the customer after, they definitely bottom out, but I've not heard of a failure.

[andy198712]

Thanks buddy