Bit odd at speed?

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andy198712
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Re: Bit odd at speed?

Post by andy198712 »

Ol'fogasaurus wrote:Andy, when I use a floor jack to do this I also put a chain around to floor jacks front axle something in the car above (I think the URL shows the chain; I didn't go back to the URL to check but I think I did show it in a picture) the jack to keep the floor jack and the car working together. Even with the floor jack tied to the car via the chain the front end of the floor jack will lift up.

Like I said, this is something you want to think and stay a head of. It is fairly easy to do and also fairly dangerous if you aren't prepared for something bad to happen. Like you said: having the car on jack stands is a very good idea also.

As far as the front end goes, I also think it is best to start with dropped spindles then do the hard stuff after. You also might want to replace anything with some time on them so you don't have to do an alignment twice ($$$).

Also remember that if you have too much rake (nose lower than the rear of the car, which I don't think you are planning on but a reminder just-in-case) you might have to use the longer bolts and shim the lower tube to get the proper caster adjustment.

Lee
the only worry of just fitting the dropped spindles is that the tyres will sit on on the wings and i won't be able to get to work :lol: is that the case or does it just rub on full lock ect so the stops needs adjustment?

no worries about nose down, i prefer the look of the car slightly rear down anyways and gather thats better for handling. i'll try and get a picture later to show you how it sits now :)
Ol'fogasaurus
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Re: Bit odd at speed?

Post by Ol'fogasaurus »

Without knowing more (of what you have/are running and add to that what I don't know);\ but simply put:

rim width,

rim off-set,

and the big worry ... "scrub radius" (http://www.racecartuner.com/03/307.html)

are what you need to worry about. The first two can affect the last!

The first two, unless you are running a wider beam, can also affect tire rub on the "wings (we usually refer to them as fenders).

"Rake" (aka a California Tilt) is an old term the Hot Rodders use. In the old days when the early drag racers were running "quick change" rear ends (differentials - http://www.bing.com/images/search?q=qui ... &FORM=IGRE) the rear was raised so you could access the rear of the diff to change the gearing in the "diff" w/o jacking the car up. Looked cool so the look caught on.

About the same time the custom guys were lowering their cars and the easiest part was the rear lowering blocks so the "tail down" look caught on (especially when they had the "continental kits" installed (the continental kits took the spare tire out of the trunk for more room and moved it to the rear bumper which was slid back to accommodate the added tire. To access the trunk the spare could be tilted back using a "release" lever then when access to the trunk was done the tire could be tilted back forward ... "easy peasy" (you hoped).

In the 60's it was figured out that a lifted w/tail down setting transferred the weight to the rear on launch but after a couple of bad "blow overs" at speed that got that banned (the look still is used on replica cars). On a nose up car you are prone to capture/collect under the car. Assuming you do not have a lot of nose up attitude (we are not talking about snobbery here :lol: ) you should be OK.

Lee

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Marc
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Re: Bit odd at speed?

Post by Marc »

I vaguely recall that back in the mid `60s VW did some windtunnel testing on the Beetle which showed a slight improvement in high-speed stability with a slightly nose-up attitude...but it's doubtful that they took it to any speeds extreme enough to encourage "blow-over". IIRC the concern at the time was to see what could be done to reduce aerodynamic lift at highway speeds, and the results were noteworthy since they were counterintuitive.

I remember wondering why they didn't also test the effectiveness of simple aerodynamic aids such as a front dam...going by personal experience, that's a very simple way to increase front downforce at speed.

c1974 a bolt-on aero aid at the rear gained popularity. Got a lot of positive reviews from those who purchased it, but I wondered at the time if they weren't just trying to justify their investment in their own minds. I remember one reviewer who commented after testing that he probably could've achieved the same results using the cardboard box it came in ;) http://ecomodder.com/forum/attachment.p ... 1236821900

Caster shims aren't a new idea - you could get them installed at VW dealers 50+ years ago if you desired better high-speed tracking. My personal car is lowered ~2½" front and rear and I use the ¼" ones with good results. There's a noticeable increase in steering effort at very low speeds, but IMO it's a small price to pay for high-speed stability. Should you choose to try them, don't overlook that tilting the beam back affects the alignment of the steering box with the column, so it needs to be repositioned slightly to save stress on the coupler ("rag joint").
Last edited by Marc on Wed Dec 23, 2015 5:58 pm, edited 1 time in total.
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Piledriver
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Re: Bit odd at speed?

Post by Piledriver »

Ol'fogasaurus wrote:....
In the 60's it was figured out that a lifted w/tail down setting transferred the weight to the rear on launch but after a couple of bad "blow overs" at speed that got that banned (the look still is used on replica cars). On a nose up car you are prone to capture/collect under the car. Assuming you do not have a lot of nose up attitude (we are not talking about snobbery here :lol: ) you should be OK.
...
Those "gassers" not only were nose high, but were very lifted in general, for a very high CG.
(they were typically pretty much level, just jacked up a lot to increase weight transfer on launch, something not needed on an ACVW)
Couple the high CG with huge rubber, very low rear tire pressures and an otherwise screwed up suspension geometry, front end lift could be the least of your problems if the car got the least bit squirrely at speed.

Here's a beautiful example of a gasser:
http://www.onallcylinders.com/2012/09/1 ... he-week-6/
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
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Piledriver
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Re: Bit odd at speed?

Post by Piledriver »

RE "stiction" in urethane suspension bushings and the use of uniballs and such:
There is something in between those two extremes that works well:

On 911s you can get composite urethane-buffered bronze bushes, where the bearing is greased bronze on steel, but it has a squishy urethane around it to allow for some give for vehicle parts//manufacturing tolerances, largely due to the originals parts using rubber and not having to make a perfectly machined hole/surfaces for the bronze bushings to locate in.
http://www.elephantracing.com/suspensio ... shings.htm

Patented, well, OK, they are rubber mounted bushings, which have probably been around since just after the industrial revolution kicked off... Just don't make them for 911s. :twisted:

AFAIK no one makes these for ACVWs. They appear to be pretty trivial to make if you can pour urethane bushings and make round things in a lathe...
Might even be able to DIY mod off the shelf bushings and bond the bronze/steel bits in, or just have them be captured.

I see no logical reason for them to cost $260 a set except for the "Porsche aftermarket" tax.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
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Dale M.
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Re: Bit odd at speed?

Post by Dale M. »

If you guys are on a PC and if you hold down the "ALT" key and type in 0176 you get degree sign...

See >>> ° <<<

IF you guys are not on a PC check "character map" for key strokes to produce whatever sign (character) you want ...

Dale
"Fear The Government That Wants To Take Your Guns" - Thomas Jefferson
1970 "Kellison Sand Piper Roadster"
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Marc
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Re: Bit odd at speed?

Post by Marc »

Dale M. wrote:If you guys are on a PC and if you hold down the "ALT" key and type in 0176 you get degree sign...


Alt 248 also works.

(Use the number pad, not the numbers across the top of the keyboard...make sure that the NumLock is on or you'll be tossed out of your post)
andy198712
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Re: Bit odd at speed?

Post by andy198712 »

Cool stuff!

I had a look at the car today and it's touch the bump stops but this was parked facing down a hill so need to re check and probably trim them!
andy198712
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Re: Bit odd at speed?

Post by andy198712 »

Little cams day pic on a flat surface!

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buildabiggerboxer
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Re: Bit odd at speed?

Post by buildabiggerboxer »

Some good IT tips thank you gents, part of my problem is laziness by using an apple tablet, not my laziness, the freakin tablets! Android leaves it for dead.
Andy, we took the bump stops off our team BBT cars, complete with the holder bracket, try cutting yours in half before hand, we were weight saving obsessed.
Pile, interesting link to those Porsche bushes thanks, I'd rather stay as near VW Supplied parts as possible, I just DONT want to race on some uniball offerings I've seen with just a few welds holding on a mounting block for a rod end, life and a new workshop roof are keeping me from the micro squirt completion for a bit, and now, strangely, after 6 hours racing on the OKRASA Wasserboxer, it has a sticking inlet valve I'm getting into on Tuesday, back to work day...thankfully..
andy198712
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Re: Bit odd at speed?

Post by andy198712 »

I'll get it up on the ramps and see what I can do and post back :)
Ol'fogasaurus
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Re: Bit odd at speed?

Post by Ol'fogasaurus »

Kind of reminiscing about the gassers, they were nose high to start with but were mandated to levl or nose down, I almost posted some Gasser video but decided against it.

Wrinke walls came out probably about the same time. I've still have a pair mounted on some chrome rims and held in place with sheet metal screws ... because they could spin on the rims on a hard launch.

Thank to the subject at hand!

Choose wisely for rims. Wide 5 bolt patterns are good most of the time but I also remember guys going away from the really wide 5 rims that VW used. I wish I could remember why now.

Also steel rims are more prone to bending while AL rims can break with side loads. I am sure there more reasons besides the weight and durability out there.

Lee
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Piledriver
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Re: Bit odd at speed?

Post by Piledriver »

The Elephant racing setup was mostly an example of how simple it can actually be, you could probably fab something far stronger than most of the $$$$ uniball or heim joint setups that works ~just as well while using the factory spring plate.

I'm thinking you could replace most of the torsion bushings with molded in-place high strength epoxy putty with greaseable brass/steel inserts. You would have to initially set it up with no bars to self align properly while it cured.
Refrigerating the epoxy components would give you a bit of working time to assemble it before it cured..
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Steve Arndt
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Re: Bit odd at speed?

Post by Steve Arndt »

Just by trimming the aluminum cover a bit you can fit the 944 torsion bar cover to the beetle torsion housing. The bushing is twice as wide as VWs, and there are many more choices in bushing materials in the Porsche world.

It looks like this
http://www.944turbo.org.uk/images/Image32.jpg
A little band saw work and they fit up. I have a couple sets. Haven't installed them yet.
buildabiggerboxer
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Re: Bit odd at speed?

Post by buildabiggerboxer »

Sorry Andy, bit of a high jack, but just about applies to the topic, Steve, it's not a very clear pic, but you can just make out I have the Porsche torsion covers in use, I've over slung the rear Spax shocks to free up space underneath avoiding all the clutter and allow the Venturi to fit, the a arms are flipped for camber reduction and turrets are done in the wheel arches ready for coil overs if needed, top shock mountings are built into the roll cage.
next I need to come up with something along the lines of piles idea for custom bushes, the Porsche covers certainly offer more scope for better bearings, I know there are some high quality billet uniball set ups out there, but I really want to keep as near the VW original concept as possible, is your car still a VW when it has mendy suspension front and rear??? , not in my eyes, keeping to the VW concept helps win races as it annoys the hell out any opposition, even more so when it's a ball joint car still using a beam...
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