To lower or not to lower, that is the question...

[carl4x4]

I’ve done a fair bit of late night reading on lowering for my Ghia which is being built for some occasional classic motorsport use as well as a road car. The following information is what I’ve gleamed from various articles (I’m not professing to be an expert so please correct me if I've got anything wrong)...

Starting from basics, why do people lower a car? There seems to be two main reasons, firstly to look good, second to improve handling by lowering the centre of gravity of the car. It seems that 90% of VW’s get lowered for the first reason.

The general concesus of lowering through beam adjusters is that the ride become harsher & bouncy, I tried to find out why this was, after all it can’t be that everyone is forgetting to change their shocks to lower ones or running on the bumpstops can it? When you lower a torsion bar front suspension, it seems that the arc of travel the arms go through changes, they work best when they have the ability to go back slightly when they travel up on hitting a bump. By lowering you make the arms nearer to the horizontal so that in some cases they actually have to travel forward slightly when moving up. This gives more resistance and as a result the ride suffers.
Dropped spindles get over this by leaving the arms in their original geometry, but they also move the track out by ½ to 1 inch, which is a not ideal on a Ghia as the bodywork is a lot closer to the tyres than on a Beetle. People compensate for this increase in track by fitting skinny lower profile tyres which clear the arches.

Trouble with skinny front tyres is that if I want to make my Ghia handle better I want a better footprint of rubber all round, not a smaller one (ie: wider tyres) I could get around this by fitting a narrowed beam to compensate for the wider spindles, but for motorsport you really don’t want to be narrowing the track of a car, if anything quite the reverse.

I’ve looked at the Red9design wishbone front suspension which I must say looks like a great piece of kit and gives the advantage of rack & pinion steering as an added bonus. Twin wishbone setups don’t suffer from the torsion bar arm problems with its arc of travel. But this comes with a 3” drop as standard which means skinny tyres again. I’m told it can be adjusted 1.5” either way so wound fully up it would be 1.5” lower than standard. The question is, would that height give me any clearance troubles if I moved to 185 tyres all round. One other problem with the Red9 setup is that there’s no anti-roll bar, which may not be ideal when on track.

Looking at old magazine articles from car&driver etc from the 60’s & 70’s when these cars were new, very few people mention lowering Beetles or Ghias when they were improving the handling. Stiffer anti-roll bars, different shocks, camber compensators, stiffer torsion bars are all mentioned. Lowering seems to mostly feature in the custom magazines to get the look right.

So the question still remains, to lower or not? There’s no denying that the simple physics of lowering a car’s centre of gravity can improve it’s handling, but on a Ghis that seems to come at the expense of tyre size and suspension performance, so is it worthwhile...

[Marc]

You understand the problem with lowering via the torsion bars (surprisingly few seem to get that).
Most "drop" spindles on the market don't widen the track very much - the old-school welded ones were worse than the modern cast type. If there is a fender clearance problem, there are two things you can do (besides narrow tires) - select rims with more backspace, or narrow the entire beam.
Describe your rear suspension.

[Ol'fogasaurus]

Also, I would describe your budget for the build ("Open you wallet and show me how fast you want to go" is an old racer's statement). We are very good at helping you spend money as people did for us when we were learning.

Lee

[flat_iv]

To add more confusion I ended up using CB Performance dropped spindles with 16 x 6 1/2 wheels. It lowered it way more than I liked. And had a good bit of rubbing. Added a Whiteline sway bar to the front and it was way to harsh of a ride. It beat the front end to death. I ended up removing the Whiteline swaybar and purchasing some HD front torsion bars to raise the front of the car a little and they also act like a sway bar. Its a much better ride now and no rubbing but I have lost some of my turning radius. I have been thinking of sending my front wheels to have the width modified.

[carl4x4]

Thanks for the responses guys, The car is a 1969 UK ghia coupe, with swing axle rear suspension. If I lower the front then the rear will follow suit by a similar amount. It has a Z bar at the moment, (which needs refreshing as the droplinks are very rusty) and I plan on fitting adjustable shocks and a camber compensator to the rear.
As for budget, the Red9design stuff I am considering buying is around £1250 (about $1800)

[Marc]

...The car is a 1969 UK ghia coupe, with swing axle rear suspension...

I suspected as much.

With the swingaxle rear suspension, the rear roll center height is always at the center of the differential - lowering the car will bring it down (and make the camber go negative) so it will handle better, but it'll still be a swingaxle. Slammed to the ground they can be made to work well for parking-lot racing, but the ride will suffer - and you indicated you'd like to avoid that. Putting a sophisticated front suspension on a swingaxle car would not be money well spent, the liability of the rear design is going to be the limiting factor.

IMO you'd be better off spending (some of) your money converting the rear to IRS. Even at stock ride height the handling will be better than you can achieve with swingaxle without a big sacrifice in ride quality.
Lower the car conservatively (~1½"), using torsion bar adjusters on the front. At this height the control arms will still have a little downward angle and bump steer won't be intolerable.

If you do stay swingaxle, be advised that both the Z-bar and the camber compensator have the same effect, reducing oversteer and swingaxle "tuck". They work the opposite of an anti-sway bar, actually reducing rear roll stiffness. Safer on the street, but often one of the first things to go when setting up for track work. Z-bar equipped cars have the smallest rear torsion bars ever fitted (again to reduce rear roll stiffness - also the Z-bar functions as an overload spring).

Stock Beetle/'Ghia IRS torsion bars will be somewhat stiffer, but for track work you'll probably want more...I'd look for a Squareback donor for the IRS parts if those exist in the U.K., you'll get bigger t'bars and the stiffer double springplates.

[FJCamper]

RetroRacing's 1965 swing axle Ghia on stock 15" wheels with 50-series 165mm Federal Formoza tires. Or tyres, if you prefer.

Hi Carl,

A Ghia at stock ride height is more than okay for the street. For competition work, our experience is the practical lowering limit is two inches.

I've have futzed around with all manner of lowering, and come to the conclusion that you should leave your street car at stock ride height, but get those two inches of lowering for racing by simply using low profile (50-series) tires.

FJC

[carl4x4]

It has crossed my mind to convert to IRS, not sure if it's best to get someone to do the conversion, or just use an IRS pan. There's a Karmann Ghia breakers yard here that is selling IRS chassis including the rear suspension components for £400.

I'm guessing that it'd cost me about that or more to get someone to do the conversion welding for me?

[Ol'fogasaurus]

It would leave you a lot of budget for a bunch of updates.

Lee

[carl4x4]

There's a couple of bits of welding in some tricky to get to places in the back arches around where the body mounts to the pan, I have toyed with the idea of removing the body from the pan, but a bit worried the body will distort if I do that...

On the plus side starting with a separate pan means I can refurbish the running gear a lot easier before I fit the body back on...

[Ol'fogasaurus]

If you are worried about the body off the pan, building your replacement pan first also means that the body has to spend less time off the pan old before the switch. It would also let you do any beefing up of the pan if you feel a need to and check the tunnel enclosed parts (including checking on the fuel hard line in the pan) and brake lines before you paint it and get it ready for the body swap; a lot of advantages to going this direction.

You get the pan done the way you want it, make new body to pan seals/gaskets, and then you could start to make the switch. With the body off the pan you then could do the body fixes you are talking about, when they are more exposed and you (possibly) have better access to them. The body to pan turn about should be able to be done in a very short time if you plan ahead.

Lee

[carl4x4]

If you are worried about the body off the pan, building your replacement pan first also means that the body has to spend less time off the pan old before the switch. It would also let you do any beefing up of the pan if you feel a need to and check the tunnel enclosed parts (including checking on the fuel hard line in the pan) and brake lines before you paint it and get it ready for the body swap; a lot of advantages to going this direction.

You get the pan done the way you want it, make new body to pan seals/gaskets, and then you could start to make the switch. With the body off the pan you then could do the body fixes you are talking about, when they are more exposed and you (possibly) have better access to them. The body to pan turn about should be able to be done in a very short time if you plan ahead.

Lee

This had gone through my head as well, just need to find somewhere to store the car whilst it's new pan is in the garage perhaps...

[carl4x4]

Ok so here's a thought, how about a setup like this for some spirited driving and occasional track use, it's a link to a roadtest of an 'Empi Ghia' from a 1967 issue of Motor Trend magazine.
http://www.karmannghiaconnection.com/67mt_roadtest.html

They mention: rear camber compensator + bigger front anti roll bar + stiffer shocks on the test car transforming the way it handled.

[Ol'fogasaurus]

carl4x4, it takes great bravery to break a car apart; bravery to do it in the first place and bravery that it will get put back together at all. If you decide not to do it, no biggie, you still can have a car that will do dual duty very nicely and it will still be a cool car. The drawback: it that it may not be the car of your dreams. Be careful on you choice and no matter which way you go, you can count on us to be here for you.

Lee

[Marc]

Ok so here's a thought, how about a setup like this...They mention: rear camber compensator + bigger front anti roll bar + stiffer shocks on the test car transforming the way it handled.

Those mods will definitely improve the handling compared to stock, if you're after a period piece and state-of-the-art from over 40 years ago. I'd wager that a bone-stock IRS car would still handle (and ride) better, but those weren't around for comparison when the article was written. These days the most popular replacement shocks are from KYB - they aren't adjustable, rebuildable, or as sexy as Bilsteins or Konis, but they're dirt cheap in comparison. The "Gas-a-Just" model is one stiff puppy, too stiff for almost any application but off-road IMO...but their "GR-2" model still retains decent ride qualities, and there are slightly shorter ones readily available for lowered suspensions (stock-length are OK at ~1½" drop, however).
I'm all in favor of you trying these relatively inexpensive modifications, they could be enough to make you happy...I just didn't want to see you blow $1800 on a trick front suspension only to still have an ill-handling pig.

Straightening-up in the garage last week we found a vintage EMPI camber compensator. Don't have the center bracket that bolts up to the trans, but the rest of it's there. Anyone who'll give it a good home can have it for the cost of shipping, I know I'll never run swingaxle again.