Caster Shims and Shock absorber options for street Ghia

[Evil_Fiz]

I am buying parts for the suspension on my street-only 1970 Ghia convertible and am looking for guidance on the best options for the application. The goal is a compliant and predictable suspension on zippy curves and <90 MPH highway driving.

The plan so far:
- OEM standard-width beam.
- 2.5" drop spindles with beam adjusters
- Total static lowering = 2" - 2.5" front and rear and a level stance
- 16x6" or 16x7" wheels with lower profile 195/205 series tires (possible additional drop)
- Wilwood front disk (EMPI kit or Dynalites on drum spindles)
- Wilwood rear brakes with e-brake
- Appropriate brake master cylinder and proportioning valves as needed
- 19mm front sway bar
- 15mm 924/944 rear sway bar
- Bearings with Delrin inner bushings or Full Delrin bushings on the front beam (undecided)
- Delrin IRS trailing arm pivot bushings
- Delrin IRS spring plate bushings
- possible chassis stiffening by tieing the front beam, body, and rear tortion tubes together with 2"x.125" longitudinal round tubing and outriggers to A 1.5"x.125"aquare tubing frame attached to the side body mounts/heater channels. (still in R&D)

Questions:
- caster shims; 1.25*, 2.6*, 4*, or 5.25*?
- Shocks; KYB Gas-A-Just, KYB Excel-G (GR-2), KONI Red, other?
- Any additions or substitutions to the list above?

I want to get this right but don't fully understand it yet. I have read the Ghia Road Course Setup thread several times and am following the advice closely.

Cheers,
Emil

[Ian Godfrey]

Emil, I like about +6 deg caster, so for me with a slight rake, 3.4 deg caster shims (Berg) got me there. The more caster the more stable in a straight line and better turn in. The down side is heavier steering at slow speed and parking, and the feeling of pulling the steering over the centre. +6 deg is about what a 70's Porsche had, and a 356 around 5 degrees. I don't think you'll really know until the car is set up and you can measure what you've got. At least is is pretty easy and cheap to change caster with different shims. Don't forget to use 100mm bolts on the bottom with the shims, as the stock bolts are a bit short.
I'd also suggest camber eccentrics to help get your front camber into the 0 to neg 1 degree territory. The camber eccentrics also effect caster on our cars which is why it is very hard to predict how the alignment numbers will come out. So I adjust the camber with the eccentrics the use the caster shims to get the caster number I want. As you go into neg camber territory you may need to trim the top of the front shock towers for clearance. The top of the front wheels are now tipping inward a bit so they are inclined to hit the shock tower on full lock.
Lastly, 1/8" (total) toe in works well to enhance stability.
Re shocks, I have tried Bilsteins but they were quite harsh so I wouldn't recommend them.
re tyres, I think 195 is plenty in the front, again thinking 70's porsche and Lotus Elise. They will go on a 5.5 or 6 inch rim and you will still have a decent turning circle.
broadly, I think your plan is excellent

[Bruce.m]

Not sure if they are available in your area but I use Gaz dampers. Koni reds are good on stock torsion bars, with the front rebound set about 1/2 way.

If you dial in any rake, as a minimum, reverse the effect of that on the caster.

[Evil_Fiz]

I see the KONI Reds referred to by several names. Does anyone have the recommended part numbers I should get?

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Cheers,
Emil

[Bruce.m]

[Evil_Fiz]

Thanks for the details.

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Emil

[Bruce2]

The Koni 80-1787 is a bit too long for a stock Beetle. If you adjust the front down with adjusters, then that shock is going to be almost fully compressed all the time.
The bump stop Koni uses is a high density foam sleeve tucked up around the shaft inside the splash shield. Push it out through the provided holes, then cut it in half. By reinstalling half of the bump stop, you will gain the range you need.

Castor:
Everyone says steering gets difficult in a parking lot if you have too much castor. One of the local VW guys works at a Merc Benz dealer. Those cars spec with very high castor numbers, so he copied that in his VW. To achieve 11° of castor, he stacked up FOUR sets of castor shims under the bottom tube. I have driven this car, and at slow parking lot speeds I noticed nothing different from my own car that has only one set of shims.

Front sway bar:
IMO, a 19mm (3/4") front bar is way too stiff. But that's all you can buy. Back in the 70s, EMPI sold a 5/8" bar. This is the ideal bar for the street.
Some numbers: The 3/4" bar is 6.3 times stiffer than the stock coat hanger. A 5/8" bar is 3 times stiffer than stock. A Thing bar (14mm) is 85% stiffer than stock (hardly noticeable).

[Bruce.m]

I have a 15mm bar from whiteline but it is NLA. However CSP are now making 14mm link pin and 15mm ball joint bars but they might be a pain to source outside Europe

[Piledriver]

He's using drop spindles.

Too bad Koni doesn't make orange ST.Rs for older vehicles... Supposedly same valving as yellows on softest setting.

Having said that I bought Bilstein and just revalved (and converted to ex-KYB as remotes), super easy to convert to take-aparts.

Many of the local race shops can provide parts, used the calculator at http://farnorthracing.com/autocross_secrets.html and went to digressive valving.
Its not expensive if you can DIY. I run modified 38mm front Bilstein racing shocks with proper welded on kevlar heim joints and Fox 2" "truck" shocks converted to coil overs out back (hard anodized very thick wall shocks) Tommy at Day motorsports in Tyler Texas set me up with my valving.

The 38mm shocks were 6" stroke, by physically too long. Took the body down and inch and moved the gas piston to a remote made from a KYB front shock... Will never use KYBs as shocks again after seeing how they are made.

[Bruce2]

However CSP are now making 14mm link pin and 15mm ball joint bars but they might be a pain to source outside Europe

CIP1 already sells CSP parts over here, so maybe they might be interested in adding these bars to their inventory. I'm going to send a message to my contact at CIP.

More numbers:
The CSP 15mm bar is 2.4 times stiffer than the stock 12mm bar.
So here's the lineup:
14mm "Thing": 1.85
15mm CSP: ___2.4
5/8" EMPI: ___3.0
3/4" : ________6.3

[Piledriver]

Apples to oranges, but the 3/4" Bugpack front bar on my sons 71 SB combined with a 2" F&R drop and std 5.5x15 steelies with short fat rubber worked a treat. (+ DIY kafer brace, black self lubricating urethane bushings etc)

I still miss my 64 Ghia.

[Steve Arndt]

Disc kit plus drop spindles and 6" wheels on a Ghia I would go with a 2" narrowed beam. They will likely stick out beyond the fenders otherwise.

[Evil_Fiz]

Thank you all for your contributions to this thread. I understand the concepts and tactics being discussed but am lost on how to go about implementing them. I've got the caster shims sorted, will be going with Koni Red's as a starting point, and have a set of Energy Urethane spring plate grommets and IRS pivot bushings on the way.
I see a mention of self-lubricating urethane bushings above. Is there a brand that I should be looking at?
Inspired by Ian Godfrey, I am also contemplating having some oil-impregnated bronze bushings turned and fitting them inside the urethane grommets; some assembly required. The front beam will have OE style outer bearings and Delrin inner bushings.

Off on a tangent here:
Is there a reason, other than cost, why the inner BJ beam bushings can't be replaced with 46mm OD x 37mm ID upper BJ beam bearings? My research leads me to believe that the dimensions of the inner beam bushings (Micata+sleve or Delrin) and the outer-upper BJ beam bearings are the same. Please correct me if I am misinformed.

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Emil

[V8Nate]

The "self lubricating urethane bushings" are the black polyurethane bushings. They have graphite in them if I remember correctly so they won't squeak like the red ones. If it's a moving part like the spring plate bushings make sure to use the correct grease that is supplied

Sent from my SM-S918U using Tapatalk

[Piledriver]

Energy and others make them. Most other companies sell Energys bushings as their own.
You can also get MoS2 loaded plastic machined bushings, but probably too rough for street, no idea how long they last.
(not specifying kynar, but its one of them, also works by itself)

I suspect the greaseable ones with a brass or steel wear surface stuffed into deformable urethane outer area are more ideal, but I have not seen then for VWs. They really should be a thing. Biggest downside is you would have to have a decent matching surface on the trailing arms to work reliably, use of new, adjustable trailing arms might be advised. (for rear of course)