Suspension and Handling

[DeathBySnuSnu]

Several questions.....hoping for some experience.

I a building a kit car and as per my usual self.....things get a bit out of hand.
So now it is a full tube chassis, close to beetle wheel base length, v6 mid engine (all aluminum not very heavy).
901 side shifter 5 speed.
Cut some more castor in the head (pie cut)
Drop spindles.
Ball joint front.
19mm sway bar
Bent the top arms so with the extra offset bushings I can go +1 to -2 on front camber.
IRS rear.
Reinforced arms
Poly bushing
28mm spring (short swing type)
NO rear sway bar (yet)
-2 rear camber (trying to tweak this down to a -1)

So here are the question.

I plan on splitting at least one of the front spring packs and doing a double adjuster.
Which beam ? Top or bottom?

When adjusting a different pre load top vs bottom.....
Which is the primary load?

On the rear....
I have double spring plates.....are the adjustable plates robust enough for a 200hp sport about (not a drag racer)?
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[Alstrup]

[DeathBySnuSnu]

Thanks.

Yeah I did think of the top ball joint load.

I guess the double adjuster/split spring can be the top also.

I do not know if I actually need the rear adjustable plates or not. Original plan was the early double plates (and I have them already).
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[oprn]

It has been my impression that due to the roll steer and bump steer problems built into the VW front beam, they handle best when they are sprung stiff. In fact I have heard guys express the opinion that the ONLY reason they work at all in autocross is because they are stiff. That I believe is why VW and Porsche abandoned them and went to struts on the front. The trailing arm system does go through a number of complex angle changes in it's travel.

I have often thought that a center mounted steering box and equal length tie rods would make a big improvement.
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[modok]

That bump steer is mostly in their imagination or of their own doing from not positioning the pitman arm correctly.
it's not a great system.... all parts have a lot of of flex for how heavy it is, but there is not much bump steer and no speed wobble. Grass is always greener

[nextgen]

First I agree with Modok, bug steering is archaic, Ok but privative.

Kit car, most likely lighter then a bug. I am going to save you some money and maybe your life.

Have my bug since 1988, here is what I did and got rid of.

Stiff Gas shocks, did work lower the bug and they raised it, ride was bad. Went for stock shocks.

Rear Sway bar, it is ok for handling but really not that much better and puts a lot of stress on the car when making turns.

My car now has HD front sway bar, 2 1/2" dropped front spindles. 4 wheel disc brakes ( with emergency brake ).


195 60 15 rear tires and 195 50 front racing tires, they dropped the front another inch.

My main point. My bug is heavier then your kit car. I have a 914 2.0 engine.
from a 914 that had a top speed of 127 mph.

Tried that and got from 60 to 100 in seconds but my steering got real light and I felt I was going to lose control of the car.

Forget the front torsion bars.

Below is front drop and rear is stock.

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[spencerfvee]

[nextgen]

Spencerfvee,
Thanks !! the bumpers were nick named the Sliced Cali Style! I took a set of late 74 big bumpers with the 1' Rubber strip in the middle and sliced out the 1" then overlapped the top on the bottom with some Stainless steel Bumper bolts.

The floors are stainless steel and nothing that will hold moisture like rugs or sound deadening and headliner.

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[DeathBySnuSnu]

[nextgen]

Did not know you were as old as I am and the experience. Mine started in 1967 when I raced MGA Roadsters. Photo is that year in the Bronx I was 18 in the photo, do the math. BTY the women shown after a snow storm became my wife.

The only things I was not recommending was screwing with the front beam.
Hey you did it before. Also the The rear sway bar but seeing it is mid engine, it is up to you.

_________________
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The TYPE IV UPRIGHT CONVERSION MANUAL
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[Wreck]

back in the late 80's I had a 68 bug which I converted to IRS , it had a 3.88 box , 2lt upright type 4 . front and rear sway bars and good oil shocks .lowered a little front and rear with no rake. On one or two occasions I had the speedo needle firmly on the wrong side of the stop !

I then had a moment brain fade and bought a Eureka /Sterling kit car and rebuilt it swapping the pan/running gear with the bug . 265/50r14's on the rear and 245/50r14's on the front . It could do 180km in 3rd gear and I did that often.

[modok]

Not sure what he was rambling about but I agree as far as...If there was any wild idea that makes it all work better we've all been looking but never found it. For instance...
Lets space the front wheels out and run a lot of caster and maybe that would help low speed understeer?..... and it could in theory, but at least IMo, just doesen't feel right.
I rather keep the scrub radius to a minimum so the flex in the arms just causes the wheel to tilt instead of flopping around up and down.

Front springs aren't adjustable, but it may end up about the same front end weight as a bug anyway, so that'll work itself out. IMO the main reason the front torsion bars were at different angles was to get over the bump stop, on the early beam.... but then why is it also like that on ball joint beam? Maybe just to make it easier to assemble the ball joints into the knuckle. If there is any other functional reason I never found what it is. Both arms are pushing down unless you are flying. Kinda like the three shims. Must be the magic number, but it isn't really. I've set them at both the same angle, never found any difference. Tires make the most difference. Always looking for a REAL tire small enough for the front end, which seems to be determined by whatever the smallest new car happens to be lately.

[DeathBySnuSnu]

The old beam front works amazingly well......for what it is.

One thing to consider.....I am trying to make a psuedo euro racer.....it will be a lot of yester-tech.

Not running a huge tire.....but not small.....205's on front and 215's on back. Front is 23.5 tall. The disc brake drop spindles pushed the wheels out.....but I have heavy offset wheels. With the offset camber bushings, and bending the top arms.....I got the scrub back within reason and the camber adjustable from +1 to -2
I pie cut 6 added degrees in a head. That might be a bit much but not to sure....can always tweek from there with shims.
I am splitting one of the springs.....I will lose an inch of spring each side which will stiffen it up a bit. I have a basic 3/4 front sway bar. The back has 28mm torsion bars. I do not have any rear sway as of yet.....I was hoping the stiff bars would take care of that. Of course you know center of gravity of the engine is higher than the flat four.

The engine is not all that powerful...... little 2.5L around 200hp....but is an 8000rpm screamer.
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[nextgen]

I better brush up on my Australian,,

Wreck Nice Car, in 80's at that time Mike Sharp and myself were communicating on snail mail and a Film Camera that belonged to his Grandmother..

Oz was way ahead of us in the 80's with T-4 engines.
_________________
email: [email protected]
The TYPE IV UPRIGHT CONVERSION MANUAL
BEETLE MAGNETIC DEFLECTOR SHIELDS
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[earthquake]

I was working on making a aluminum front beam for a saltflat car that I never went to far with, it was going to have a lot of castor adjustment I wonder if you could do something for a handling car for Auto X or road racing.

I also have been thinking about making a pitman arm for the pass side of the beam and using two equal length tie rods.

eQ
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74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
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DEATH TO CHINGERS!
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