914-6/904 project begins Options

[veekry9]

http://www.thetruthaboutcars.com/2013/07/o...a-the-manic-gt/

A car you've never heard of,Canadian even.A ton of money that went ffft,and dissipated into nothing.
I acquired two pairs of raw castings for the rear suspension uprights about that time,May '69.Planned to adapt them into a custom mid,lost in a move. (IMG:style_emoticons/default/dry.gif)

http://auto.lapresse.ca/dossiers/dossiers-...t-une-manic.php
https://www.google.ca/search?q=Manic-GRAC&a...igA&dpr=1.5

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[porschetub]

Not sure why mendeola would not work. They have various widths and various hubs for VW wide five and Porsche 944 I believe. I would not pass this by without more thorough consideration.

Just figuring out to weld it in would be the trick. You got the fab/welding skills.

yes but you are buying an engineering jewel designed to bolt on to a beetle floorpan,no separate floorpan in a 914,think you would have to tube it out and build a suitable mounting plate,depends on what Adam has to spend really.

[Mark Henry]

http://eyeball-engineering.net/a-arm.html

This was the response from Bruce at Eyeball, a very honest answer, and much appreciated.

"hi
in a word no,but anything is possible with enough money
the old saying goes speed costs money,how fast do you want to go?
thanks bruce "

No why? Because they don't know how to attach it?
All of the systems I linked you would have to make custom mounting.

Personally I would jig and fab it myself...but I'm cheap and have the skills to copy stuff for my own use.
I'd start by building a front end tube chassis and look at what others do from the VW stuff, sandrails, stock cars/racecars, etc.

[Unobtanium-inc]

No why? Because they don't know how to attach it?
All of the systems I linked you would have to make custom mounting.

Personally I would jig and fab it myself...but I'm cheap and have the skills to copy stuff for my own use.
I'd start by building a front end tube chassis and look at what others do from the VW stuff, sandrails, stock cars/racecars, etc.

The problem I was hoping to solve with the off the shelf stuff was to make the build easier and less unknown engineering. If I have to get out my thinking cap I'm going to try to lower the shock towers in the front and keep the Bilstein Coilover setup, save myself $3000+ on the Dual A-Arm setup. If I can get the existing system to work, that's cheaper, but I was thinking of doing the Dual A-Arm setup if it was more a plug and play thing, but it's not.

[veekry9]

http://www.elephantracing.com/suspension/d...siondiagram.htm

https://www.google.ca/search?q=911+914+fron...UvIjiUsHOgwM%3A

Bill Kirkland,904FF:
"The two Alan Staniforth Books are an absolute God-send to beginners starting out in chassis design and suspension set-up.
At this stage, it was realised that the 914 front Macpherson struts could be modified in the usual manner by cutting off
the top of the tube in the hub,welding in a threaded plug to take a rose (heim) joint which could then become part of the top wishbone.
So now we were into front and rear roll centres, effective swing axle lengths, wishbone angles, chassis mounting points, steering rack
location to avoid bump steer etc etc.Some of the design work around that time is shown below."

A simple approach,in a minimalist method,working from what you have to what you need.
An experiment with some spares you have layin around,the cutting and welding of the tube.
Setting up the chassis on hardpoints,true level and at static ride height,will provide the baseline geometry to work from.
Map the lengths out to scale,drawing on the floor,chalkboard or cad,using the actual numbers.
The effective rolling radius of the tires selected must be accounted for.
Some study of the theory is involved,an improvement of camber gain while minimizing bumpsteer is the objective.
Arbritrary wild ass guesses would result in a horribly handling 904/14,some attempt made at making it better,
not merely hanging it off the chassis.The placement of the top ball or heim is critical,the effective top arm length too.
Many factors that must be made right,some cutting,welding and hacking is involved,the top wishbone's front pivot box inside the sheetmetal.
Measure twice,cut once.Maybe shortening the tube will work dandy,avoiding the unequal length top wishbone,and defining the top attach point.
None of this is plug n play,this is pay your way. (IMG:style_emoticons/default/smile.gif)
Err,play your way. (IMG:style_emoticons/default/biggrin.gif)

Gettin interesting now.
A few examples to peruse,to like,stimulate the inventor juices.
https://grabcad.com/
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[Unobtanium-inc]

I reached out to the guys at Elephant to see if they have any ideas, maybe someone has down this before.

[veekry9]

gimp
View forward,LH side.
Something like this,good camber gain,tie rod arm lowered.
A RH a-arm flipped,shortened,and pivot axis positioned to suit,the parts are all at hand.

Cutting and hacking.
http://www.914world.com/bbs2/index.php?sho...p;#entry1229104

[veekry9]

Heavily modded RH a-arm,shortened,sectioned,reinforced.
Replacing the torsion bar with a gundrilled version on top,the springrate can be raised.
The pivot axis of the top arm is not parallel with the bottom's,in either plane.

https://www.youtube.com/results?search_quer...+arm+suspension
https://www.youtube.com/watch?v=yU2c03KkF6k
https://www.google.ca/search?q=front+suspen...hZXqV8p0k_AM%3A

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[veekry9]

http://performancetrends.com/download.htm#rcc

A few minutes work to derive the numbers.

http://www.planet-9.com/981-chat/103555-do...spension-3.html
The graphs describe the 904/14-6 in motion,desirable attributes.

http://www.shoptalkforums.com/viewtopic.php?t=119846

[veekry9]

A small subframe to carry the torsional loads,welded and or bolted into place in front of the bulkhead on sheetmetal receivers.
Flipping the a-arms side for side,shortened and sectioned.



Rocker stiffener rib,another added to the pivot tube,if necessary.
Something to hang your Bilsteins from.



A two piece subframe,bolts to the bulkhead and bottom factory tube.
Minimal approach,the top tube positions the top a-arm bushing receiver.
Tubular.

[Mark Henry]

Shortening the strut is not going to work unless you can find a shorter strut/shock insert.

Veeks idea I though of as well, but it still needs shocks and may end up a poor working design. I don't know how well torsion springs will work on an A-arm suspension.
But the plus side would be the bottom arms would use the stock alignment points.

Personally I'd look into the Mustang II front end, a lot of the rod guys use the Mustang front end so parts are plentiful and cheap.

[mgp4591]

Shortening the strut is not going to work unless you can find a shorter strut/shock insert.

Veeks idea I though of as well, but it still needs shocks and may end up a poor working design. I don't know how well torsion springs will work on an A-arm suspension.
But the plus side would be the bottom arms would use the stock alignment points.

Personally I'd look into the Mustang II front end, a lot of the rod guys use the Mustang front end so parts are plentiful and cheap.

You don't use a strut insert- it looks like it's only the housing that gets used as making the knuckle for bolting to the upper and lower ball joints. The shock would be installed on a separate mount taking into consideration of the total travel of your new components. And torsion bars work fine with an Short/Long Arm type 1 or type 2 suspension- all of the Chrysler A and B body musclecars had torsion bars on their SLA Type 2 suspensions.

[Mueller]

Shortening the strut is not going to work unless you can find a shorter strut/shock insert.

Veeks idea I though of as well, but it still needs shocks and may end up a poor working design. I don't know how well torsion springs will work on an A-arm suspension.
But the plus side would be the bottom arms would use the stock alignment points.

Personally I'd look into the Mustang II front end, a lot of the rod guys use the Mustang front end so parts are plentiful and cheap.

You don't use a strut insert- it looks like it's only the housing that gets used as making the knuckle for bolting to the upper and lower ball joints. The shock would be installed on a separate mount taking into consideration of the total travel of your new components. And torsion bars work fine with an Short/Long Arm type 1 or type 2 suspension- all of the Chrysler A and B body musclecars had torsion bars on their SLA Type 2 suspensions.

Yep, plenty of Locost builds go this route.

[Dave_Darling]

Shortening the strut is not going to work unless you can find a shorter strut/shock insert.

Guys, I think he is referring to the original idea, not Veeks' design here.

I don't know how well torsion springs will work on an A-arm suspension.

It's a spring, why might it not work? This layout, at least, seems to be keeping the torsion bar in the same location with the same mounting points. I could see issues if you wanted to have different mountings for the A-arms, but that doesn't seem to be the case here.

--DD

[veekry9]

What's great about these struts is the method of fabrication,allowing much leeway in the modifications to suit the UELW geometry.
A narrow tire,as per the genuine article,poses no problems,fitting a wider front tire to a 904/914 makes for a more acute kingpin angle,setting the scrub radius.
Cutting and prepping the strut must be done carefully,working to < 0.25mm/.01".The balljoint's pin and clamping bolt bores make for convenient references.
Jigging up is a simple matter,so must be done as a matter of course,ensuring dimensional equality side to side and repeatability.
Setting your ride height,maintaining a horizontal lower arm,is a matter of moving the axle forging up the tube,the axle centerline the datum.
Butt welding the tube is less strong than a lap joint,a tubular doubler inserted internally,real strong,to resist fatigue in the heat affected zone.
The same approach when welding the top a-arms and pivot tubes,these welds must pass penetration and porosity tests,crack free.
The placement of the damper end must be considered carefully,the lower arm not designed to carry the load,so must be reinforced if doing so.
A pushrod,rocker or lever arrangement would be possible with a heavily ribbed upper arm,the shock positioned inboard of the pivot.



The objective is to use what's at hand,cutting,grinding and welding,to close tolerance.
Care must be taken that the joints have freedom of movement throughout the full travel.
A better mousetrap might be out there,such as adding or moving the top front bushing closer to the lateral beam of the control arm.
Tweak the idea to suit your installation,904 or 914,measuring and calculating the front and rear roll centers and cg's.
(IMG:style_emoticons/default/smile.gif) Play away. (IMG:style_emoticons/default/biggrin.gif)

[mgp4591]

Yeah, what he said... (IMG:style_emoticons/default/blink.gif)

[Mark Henry]

Shortening the strut is not going to work unless you can find a shorter strut/shock insert.

Guys, I think he is referring to the original idea, not Veeks' design here.

Yes that is what I was referring to. (IMG:style_emoticons/default/shades.gif)

I don't know how well torsion springs will work on an A-arm suspension.

It's a spring, why might it not work? This layout, at least, seems to be keeping the torsion bar in the same location with the same mounting points. I could see issues if you wanted to have different mountings for the A-arms, but that doesn't seem to be the case here.

--DD


Didn't say it wouldn't work, I was just questioning if it would be the best solution.

[Unobtanium-inc]

I'm going to play around with the towers next week, we'll see what works. (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/sawzall-smiley.gif)

[veekry9]

CG is on this vertical line,laden.



CG height tbd,min/max

[veekry9]

3/4" plate-crs,jig for both axis level.Location pins (ball dim)variable.
Tack heavy,remove location tube,pins before final passes.
Adjustable ball to ball dim,(blue),and spindle height.
M10,M12 shoulder bolts.