Macpherson struts, a-arms, front suspension brainstorm

[shuie]

I really want to build a hotrod T1 based car with a great suspension and brakes.

I've read over volkdents bolt-on A-Arm threads and Hugo's mid engine build with the Z06 suspension. Impressive, inspiring stuff. I've looked at the Rorty chassis threads here, and on other forums. I've read countless Mustang II conversion threads on other forums. I've seen the Red9Design and Eyeball Engineering stuff that's been posted on the forums. I drool over the Mendeola photos that have been posted online on a daily basis.

I don't know enough to actually calculate correct suspension geometry myself, but I have a high level understanding of how an unequal length dual a-arm wishbone suspension works vs. a Macpherson strut setup.

The dual A-arms setups adjust camber well under load, but are complicated to design and build. Bolt-on and Weld-on A-Arm units are available commercially. They are dead sexy to look at online, but have a lot of parts that can potentially fail, and are usually untested. Macpherson struts are simpler, very durable, but provide less dynamic camber adjustment. They were also good enough for Porsche for a long, long time.

Anyway, back to my brainstorm. I want to build a T1 based car with a great suspension and I'm struggling with whether I should try a dual A-arm setup or a Macpherson/coilover setup with shock towers tied into a tube frame.

Any thoughts? Are the A-arms the right way to go? Has anyone built a T1 hotrod with MacPherson style struts in the front?

Any thoughts? Advice?

TIA

[evilC]

I like the Macpherson strut design especially with long track contol arms as you have the potential with a super chassis. My current super has my own fabricated track control arms with 944 struts. The arms have camber adjustment at the inner end as well as the adjustment on the 944 strut giving at least twice as much camber adjustment as normal and twice as much thatt Porsche felt necessary for the 944 that is quite successful in racing. In normal circumstances if the suspension design is properly sorted the maximum amount of adjustment you should need is 2-3*, if it needs more then something is seriously wrong with the layout.
Whilst the double wishbone design is the ultimate it needs long arms that the Red9 design and some of the others don't have. Whilst you could fabricate a long arm double wishbone suspension in a bug forget having any boot (trunk) space especially if you go for a inboard horizontal monoshock unit.
I have been working on the design of a macpherson strut front with fabricated track control arm and a compression strut that will give adjustment for camber, caster, roll centre and anti-dive. That will perform as well IMO as any other system, be simple to install and still give a package that provides a reasonable amount of space in the boot.
The late Colin Chapman was reknown for his suspension prowess and the development of the 'Chapman Strut' that was a macpherson strut for rear suspension. Also, many of the very best rally cars over the last 5 decades have used the macpherson strut to win international events and world championships. Some manufacturers even adopting the strut instead of of double wishones for their cars - the Metro 6R4 comes immediately to mind.

Clive.

[volkdent]

You mean like this?



The whole build is here:

Project No Budget

I think this is the best thought out strut setup I've seen to date, but it hasn't seen the road yet so who knows.

I really enjoy mine, no complaints except I need to introduce sway bars. Both this setup and mine require major width increases to get decent length arms, as Clive sort of mentioned, the Red9 has REALLY short arms and is kinda useless IMO. My front end was built to be under 3" wider fenders and the Aussie guys is probably 4 or 5" wider.

Here's what Audi is using on the R8 just for some drooling...



Jason

[Steve C]

Hi

There was a post on Shoptalk about an off roader using A arms on a Super pan.

Ignore the 2nd photo, I uploaded it by mistake and I cant delete

Steve

[shuie]

Originally Posted by volkdent

You mean like this?


Jason

YES! That is absolutely insane. Thanks for posting it. That will keep me busy for a while

[STIDUB]

ahh good old avd, we aussies are useful sometimes :P

[spannermanager]

Hi guys, that's the future for me too. I've done a number of these over the years, using A80 or Passat sub frames, and loosing
all the heavy super beetle front end, and axing the frame head, saves a good 20 kg plus and opens it up to all the golf etc rang of brakes , wheels, struts etc, plus more room for whatever you want, p/s racks, tanks you name it, I did a 4x4 super back in the mid '80s, so the ideas nothing new, but times move on, I'm doing a ball joint 1200 for my next, and probably the last of this type, they're old and hard to find in the scrappy yard now, but i do have plenty of the 'a' arms as spares, this one will be a circuit car, with wasser power and less than 800kg wet, roll out in 2011 with luck.

[Xellex]

Hi! Now that you have our full attention, can we get a few more pictures of how you used the audi/passat sub-frame? Did you only cut up the beetle frame head, and somehow replaced it with the other, or ditch the entire beetle pan?

[evilC]

Perhaps I am missing something but there's no logic in cutting out the front of a super or any bug and substituting a heavy front engined suspension and steering that was designed as best it could to be located outside the line of the engine giving relatively heavy short bottom arms. If you are going to cut the front end out then surely long fabricated arms are the way to go, there is no more engineering to do than trying to fit in something that was design for a totally different application. Given a choice all suspension designers will be using suspension arms as long as possible. When did you last see a Formula race car with anything other than long front A arms?

Clive

[spannermanager]

evilc, i know all about your theories, and im a theory buster! i worked for GA motorsport in the '80s, top team, long arms and all, but this is about beetles, not fairy land FI and single seater b/s...
i do this for fun and build prolifically, i do what i like, and what i fancy, ive done all your fabricated long arms, i race to bend things, push and shove is where its at, thats not my fault, its the others, and i win races, you can work the rest out. i'm to modest, i dont want to be stood making special parts and a few dozen spares, in case you didn't think of it, short arms are good in a contact sport, and if you read my post properly you will see i had to squeeze in my 4x4 system, i adapted the A80 method after my 6mth fabbing wishbones etc came to a crunching expensive end. special parts? i done 'em, 1500 hrs worth of em, I've learnt to adapt ready built kit, you obviously havent bent your special parts yet, i suppose you mean volkdents
build as being too heavy, as the post says, mine is very light, or perhaps the A8 system with its short arms? that looks clumsy, whats the logic you cant see for it all then? could it be fun?
xellex, they go in a super easy, some i modify and bolt in, some i modify more and weld in, tilt them for anti dive if you want, not for me , too much on power lifting. get rid of all the heavy old super right back to the bulkhead. no pics, maybe later when the new ones looking good. have fun, i do...

[coolrydes]

Check this out for the Super Beetle guys now....
Only one Super beetle was sacraficed in the test fitting of our performance front end. Wow Super beetle and performance in the same sentence.... LOL









First please excuse the quick plazma cut sheet metal, however for the sake of time it was the quickest way.

The good news:
You only lose half of the spare tire well.
If you want to close the spare well back up its as easy as cutting some flat sheet metal and putting a bend in it. If you do it right you can put the spare back in like an early beetle standing up.
You can retain the stock steering colum and u-joints
You can keep the stock gas tank.
And there is very moderate cutting in the quarter panel area.

It is as if this kit was designed around putting the stock body back on. Honestly we never thought of it, but here it is......

[Humble]

Now I need to save a couple of pay checks to get this setup on my car! I think I found my winter project for next year