Ghia Road Course Setup

For road racing, autocrossing, or just taking that curve in style. Oh yea, and stopping!
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FJCamper
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Re: Ghia Road Course Setup

Post by FJCamper » Sat Nov 30, 2013 3:22 pm

Image

Hi CobraJet,

No build-link yet. We have the donor 1969 VW Sedan, three 914 engines, a pile of new and used parts. The big issues are coupling the engines, and we think we have that solved, plus having access to all the right places with a body on the car.

FJC

helowrench
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Re: Ghia Road Course Setup

Post by helowrench » Sat Nov 30, 2013 4:03 pm

I am assuming that you will be converting those to upright cooling?

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FJCamper
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Re: Ghia Road Course Setup

Post by FJCamper » Sat Nov 30, 2013 4:22 pm

Hi Helowrench,

Yes, upright. Can't couple a flywheel to a fan.

The original bi-motor was coupled wih elastromeric rubber donuts, which failed. We've got a few good coupling options, all rigid or semi-flexible. This means a very strong engine subframe that supports them both.

Two engines, one starter. And we will be swing axle, hydraulic clutch.

FJC

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Bonemaro
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Re: Ghia Road Course Setup

Post by Bonemaro » Sat Nov 30, 2013 4:51 pm

Kinky...
Jim
My 1973 Karmann Ghia---> http://www.73ghia.com

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Marc
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Re: Ghia Road Course Setup

Post by Marc » Sat Nov 30, 2013 5:36 pm

FJCamper wrote:...we will be swing axle...FJC
(Shuddderrr) I know you've done well enough with swingaxle to date, but if I was to set about building an entire new subframe I'd be trying to incorporate something better...which IMO is just about anything. Have you looked into DeDion? Caterham, Locost, et al have shown that it can work with outboard brakes. In a transaxle application I would envision the DeDion tube needing to go over the trans in order to maximize ground clearance. It'd be heavier than swingaxle, but depending upon the materials used it shouldn't be worse than IRS, and it would avoid the diagonal-arm clearance problem inherent in IRS. You'd have no evil swingaxle-tuck, and the rear roll center could be significantly lower. Springing could be stock torsion bar, coil-over, or a combination of the two.

lcvaldetaro
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Re: Ghia Road Course Setup

Post by lcvaldetaro » Sat Nov 30, 2013 5:54 pm

Here is a link to pictures and magazine articles:

http://valdetaro.ploinks.com/vintage/Fitti-Fusca

FJ, I'll be honored to help you in any way I can. My brother has seen the original and is friends with one of the designers. We have ties to the Fittipaldis.

They have built a replica new one , with diferences:

http://valdetaro.ploinks.com/vintage/Fi ... ors.02.jpg

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Re: Ghia Road Course Setup

Post by lcvaldetaro » Sat Nov 30, 2013 5:56 pm

Indicentally, they didn't use swings or IRS; they built it from scratch based on a Formula Super V chassis:

This design shows it well:

http://valdetaro.ploinks.com/vintage/Fi ... utaway.jpg

FJ, let me know if you need help translating those articles and PDFs on my link.

LCV

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FJCamper
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Re: Ghia Road Course Setup

Post by FJCamper » Sat Nov 30, 2013 6:06 pm

Gentlemen,

I think we all agree the only way to make a swing axle handle is to keep it from swinging.

We'll call this a modified swing axle.

The main reason we're using the swing axle is ease of adaptability and lots of parts available. The axles will be on coilovers, and have limited downward movement (no tucking under) but fairly soft rear roll so as to make the front end work harder, and some wide tires.

FJC

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Marc
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Re: Ghia Road Course Setup

Post by Marc » Sat Nov 30, 2013 6:31 pm

Tuck isn't the only issue; with swingaxle the rear roll center height will always be at the center of the differential. Nothing you do with the suspension can change that. Combined with a trailing-arm front end (which has a roll center height of zero) the roll-center axis is pitched downward; since the car's mass must rotate about the RCA, the rear will always be "hiking up" under body roll. It's a hopeless arrangement, at its very best it can only be mediocre.

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FJCamper
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Re: Ghia Road Course Setup

Post by FJCamper » Sat Nov 30, 2013 9:42 pm

Dear Marc,

Yes, everything you say is true. I'm minimizing rear roll center lift by physically limiting downward axle movement. I know that if I give it two inches of downward axle movement, it will try and take three.

To keep control of what may be a 300 HP racer, the rear axle is restricted so it is almost a straight axle, with just a couple of inches of upward suspension movement before it hits the bump stops.

By keeping this chassis low and the tires wide, we have a smooth-track go-kart.

Remember, if we were doing all this for any reason other than we love it, we wouldn't be racing cars with basic 1930's technology!

FJC

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CobraJet
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Re: Ghia Road Course Setup

Post by CobraJet » Sat Nov 30, 2013 11:28 pm

I want to see what you'all come up with as a rear frame set.

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Re: Ghia Road Course Setup

Post by sideshow » Sun Dec 01, 2013 11:05 am

A swing axle is more true to the era, same goes for a lack of radiator, same goes for points, same goes for carburetors, I don't see why internet keyboard experts insist it can't be done.

Let them type furiously...while you do. It will just make them more mad.
Yeah some may call it overkill, but you can't have too much overkill.

lcvaldetaro
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Re: Ghia Road Course Setup

Post by lcvaldetaro » Sun Dec 01, 2013 11:39 am

Fj, later i will try to write a small reader's digest of what i know of the twin engine, aka 'fitti-fusca'...

Some small things..
-it was based on a formula superv chassis and suspension.
-body was in plastic, weighted 17 kg
-it weighted 550kg in total.
-was named fittipaldi vw 3200, but at the end it had 2200cc in each engine, very hot cams designed by ricardo divilla. Approx 400hp total
-in rio it outqualified much more famous cars, such as lola t70
-was inspired by the movie love bug
-it actually handled extremely well.

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CobraJet
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Re: Ghia Road Course Setup

Post by CobraJet » Sun Dec 01, 2013 11:59 am

You'd only need one generator/alternator so one of the two from the engines could be eliminated. You could then couple the two fan shafts together and run them from one belt.

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FJCamper
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Re: Ghia Road Course Setup

Post by FJCamper » Sun Dec 01, 2013 12:22 pm

Hi lcvaldetaro,

Thank you. I'd really like to know details of the original engine coupling.

We're not trying to build a reproduction of the original Bi-Motor, but a similiar type car with a steel body, keeping the original wheelbase. Our original plan was a fiberglass body with the rollcage bonded to the body. This has evolved to an extremely lightened steel body shell on a tube frame so we have some repairability.

The rear suspension is a copy of a FV, but made stronger, especially so we can bolt in twin engines.

And CobraJet, yep, we're aware we can get by on one starter and one alternator. Anywhere we can cut weight we're happy. Two engines weight twice as much, and you have to carry twice the fuel.

We call our Bi-Motor the XCAR.

FJC

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