Wishbone suspension bolt on kit

[volkdent]

Are you working on Martin's car? If your the man, we are glad to have you here. I'm copying you to a degree and just havn't got around to saying Hi yet. I've talked with Martin many times regarding what you guys are building. I have 86+ 928 spindles and a Golf II non-powered rack thus far, I was going to use the 65ET Cup II wheels, but its seems they are a rare item, so I'm going with the 52ET.

To comment on why keep some of the stock beam the Rich is using and keeping it bolt on, it means that someone can actually buy or build one of these things and simply bolt it onto their car. Not everyone has the facility or know-how you do, but they might have the cash, so they can buy a known quantity and bolt it on with little knowledge of what is involved in building a good suspension from scratch. I'd like to see what you came up with if you took this approach, as I'm sure it would be excellent.

While I'm writing, Martin said you used a Volvo top balljoint for the spindle, do you remember which model, or do you know of other balljoints that will fit into that top spot? I'm thinking about using a modified BMW M3 lower control arm on the bottom with the 928 lower ball joint, and then a very custom top arm with whatever balljoint will work.

I have to ask you, will you be reinforcing that front end on Martin's car? It looks pretty torsionally weak right now.

Jason

[Ross Morrison]

Hi Volkdent,
I have done some drawings on the "keeping the frame head" theory. It just wasn't happening. As you will be aware, the 928 upright has a very low mounted steering arm. To get any kind of decent steering arrangement in and around the tunnel part of the chassis was impossible.
I accept that using VW spindles means something could be made to work, but we weren't.........so I didn't!
If I was doing a "bolt-on " assembly, I would still lose the front axle.

Martins' front end still has alot of work to be done to it.
The box frame has to be tied into the cage, the shock supports are part of this, although I was looking into remotely mounting them and using bellcranks.
All the bracketry for the wishbone supports have to be closed
up,steering arms made,petrol tank mounts, inner wing mods, etc..etc...etc.
It will be worth it in the end.


p.s.........I think it was Volvo 340. I will check.

Ross.

[ricola]

Ross, I was trying to have a look at your site, (http://www.rmrrestorations.co.uk/) is it down at the moment? Would love to see progress on that rod with 928 V8 and your Ghia.
That's the advantage for the bug spindle with the high steering arm, although some 928 spindles had a bolt on arm which I would think could be modified although I didn't look into it in detail.
As for using the original centre section of the beam, for making a bug handle you would need some weight up front to get a bigger balance, making it lighter would just make things harder to tune! Picking up on points on the chassis which were designed to take these loads seems an obvious solution to me. Particularly in the case of my speedster, I need all the weight up front I can get, although I won't go as far as actually adding sand bags
Rich

[Ross Morrison]

Rich, yes the site is GONE!
Hard disc failure on the server or something. My mate is going to redo it when he comes up to Glasgow.

The 928 '34 Ford hasn't changed much. I have been concentrating on the Ghia and my new Chevy truck.

I will post pics of the Ghia as soon as I get the new bodyshell.(100% carbon fibre)

Ross.

[volkdent]

Hey Ross,

I can't remember which year 928 spindles you used, but the ones I own have bolt on steering arms. With that in mind, I'm going to have new ones machined that have the pivot point way up high like the Bug ones so I can eliminate bump steerwhile having the rack over the top of the shifter tunnel. I suspect they will be quite expensive, but I do have a couple of master machinist friends that might be able to help me out. I know what you are talking about, using the stock 928 steering arms puts the steering rack right about dead square in the middle of the frame horn.

What kind of ETA do you imagine for finishing Martin's car anyway? How much did those rear bearing carriers cost to machine?

Cheers,

Jason

[Ross Morrison]

Volkdent,
Martin got a real bargain with those rear hubs.The guy quoted on the job without really looking at what was involved! I think it was about £50 each.($80)

ETA on his car? Mmmmmmmmm..............this year.)

I considered unbolting the 928 arms and changing them, but be careful , there are Ackermann issues involved.Depends on which amendment to the principle you work to.
Another thing is to try and use a wheel with the same ET as factory.This helps with the KPI situation.

What rack are you using? How wide is it?


Cheers,Ross.

[volkdent]

I'm using a non-powered Golf II rack that has a rack length of 21" so I suspect 22-23 balljoint to balljoint center.

Correct me if I'm wrong, but if the axis of the outer tie rod ball end stays in exactly the same axis as original, and the tie rod itself is relatively parallel to the control arms, and the inner ball joint on the rack has an axis that dissects the plane between the upper and lower control arm's inner pivot points, things should fall into place OK. I'm just theorizing here, because nothing I've read yet in suspension books deals with creating your own spindleIchanging the spindle steering arm pivot point).

What I have worried a little bit about is the brake caliper thickness causing me to make the new steering arm end pivot axis in a slightly different axis than the original. I don't know what that would do, and though I know moving it toward the the axle will increase my steering rate obviously, I don't know what other stuff will change.

Jason

[Ross Morrison]

Jason,
YES, having all the inboard pivot points co-axial is what you are aiming for to eliminate bumpsteer.
If you are going to fabricate new steering arms for the Porsche hubs, if you put them up high, then you use a wider rack.If you put them low then the rack can be narrower. This is because the axis of the pivots should narrow from top to bottom.
You are making the top arms shorter aren't you???
I would advise making all your arms in scale, or full size, in cardboard, then pin them to a board. Make a very accurate representation of the Porker upright, attach all the bits with pins, and then run it through it's full travel. You should be able to vary all the inner points and see what difference it makes to camber in bounce and droop.
You will notice the steering arms on the hub are very straight(fore and aft). Why don't you try and change them side to side?
We are using S2 arms and hubs.Are yours S4s?They are slightly different.Don't know if that is do-able.I will need to look at our hubs.
If they can be changed side to side,this will put the rack in front. You would then need to find a front steer rack, or get a RHD one and flip it.
With the arms being so straight,I don't think this would have any effect on the Ackermann.
I will look at Martins at the weekend and see if this is feasible.

Cheers,Ross.

[volkdent]

Is there an advantage to front steering? I read in one of the suspension design books that front steer has some advantage when hitting a bump during cornering. It causes understeer for a split second rather than oversteer and makes the corner seem more comfortable. I could make the steering rack I have work as a front steer rack, but I had planned on rear steer. I had already thought about switching the steering arms, but there will be an increase in length if the same bolt holes are used, slowing down the turning rate, I presume. I will have new front steer arms built to have the correct length IF front steer is better, because it will involve getting a new front steer rack or making the other work backwards. If not, I think I'll stick with new rear steer arms moving the joint up high. Any thoughts you have would be greatly appreciated, as you have much more experience in this area than I.

Jason

[volkdent]

Walt has the front end now. Just those new shock towers cost $330. I really couldn't believe it. Anyway, he should have it welded up in a couple of weeks.

Jason

[volkdent]

Picked up the whole works from Walt today. Nice welding! The new shock towers are too tall it seems, and I'm just completely done with the idea of more mods for now, so I may just be getting some new QA1's that are longer and are double adjustable. I gave everything a painjob with hammertone silver. I didn't spend much time on prep, as this whole thing will be sandblasted and powder coated, but at least it will look good and keep the rusting down. I gave the area around the frame head a spray of undercoating. Tomorrow I'll bolt things up and maybe snap some pics.

Jason

[DORIGTT]

Quit teasing us and drive the damned thing! This is worse than going to one of 'those bars'! Yes, I'm worked up about it

[volkdent]

Got her bolted on today. The paint stayed on OK except for a couple spots to touch up. The same can not be said of the undercoating I sprayed on as well. It must be some cheap stuff, because the stuff I've used before has been pretty heavy duty. Getting this thing on and off of a car is like doing one of those wire puzzles from the 80's. So don't get to worked up, as a "for sale" version would need to be modified enough to make it easier to get on and off. Anyway, I'll be ordering up the new shocks tomorrow. Oh, I bolted up one of the wheels. I can't remember the offset, but the tire is 205/40/17. I had to modify the edge of the 2" wider fenders to clear it, so that gives you an idea of how much wider of a track I built into this suspension, again, something that most people probably would want near stock. I'll hopefully get the rear end temporarily bolted up tomorrow to get the car over to Walts.

Jason

[Ross Morrison]

Jason,
I was just throwing ideas around.
I have never read about those benefits of front steer.
Personally, I like the idea of the rack being behind any uprights, so as to offer some kind of protection in a smallish shunt. At least you could drive it home!
I would be interested to see the new arms you get made.

Cheers,Ross.

[volkdent]

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Jason