Mid Engine VR6 Scirocco (update)

[BennyB]

I've started machining parts for the dual-wishbone rear suspension.

Bit of a cross post, but I didn't even realize the Fab forum existed.
I've got a few goodies to work with:
Standard Modern Lathe
Offshore 2HP Mill/Drill, 4" vise, 6" rotary table
Miller Squarewave 180 TIG
Lincoln Migpak 10
Miller Spectrum375 Plasma

Mid Engine VR6 Scirocco

Modified by BennyB at 9:54 PM 2-6-2010

[ftwelder]

nice, I can't wait to view this when I have a bit of time! looks like a great project!

[blackvento36]

That's an interesting hold-down setup you're using on the mill. Did you make that just for the spindles?

[BennyB]

It's pretty much just bolted to a 6" angle plate with standard hold downs. I actually had a tough time getting a reference to make it vertical wrt the balljoint. I temporarily mounted the plate in the vice to make the spindle horizontal. Then centered on the bearing bore and used the lower balljoint hole as the other center. Once I moved it back down and bolted it vertical again, I clamped down the tie rod arm to keep it from rotating.

[GTijoejoe]

This is something very interesting..... I like it....

If you're a baller why not design your own spindle/knuckle and machine it out of Aluminum? I mean we only pay like $10-15k a piece for 'em localy

[BennyB]

yeah, that's on the to-do list, but I want to get the car driving before I commit to a spindle design. You're right though, I billet machined the spindles for my formula car, and it wasn't too difficult. All-out lightness would be 4130 sheet steel, boxed spindles (like F1 or indy). I'd do that if I had access to a waterjet to cut all the parts for a perfect fit. I tried boxed aluminum with the formula car in '04, but the welds cracked because I didn't know how to weld properly then.

Ben

[GTijoejoe]

Quote, originally posted by BennyB »

All-out lightness would be 4130 sheet steel, boxed spindles (like F1 or indy). I'd do that if I had access to a waterjet to cut all the parts for a perfect fit.

Well I didn't know you were going to get all crazy on me. If you do go F1 style you gotta bottom mount your calipers too

Quote, originally posted by BennyB »

I tried boxed aluminum with the formula car in '04, but the welds cracked because I didn't know how to weld properly then. Ben

That's very popular... in baja too.

How difficult is it welding to that iron knuckle???

[RabbitJockey]

i think knuckles are cast steel, i dunno how different they are to weld.

[GTijoejoe]

Quote, originally posted by Trev0rBr »

i think knuckles are cast steel, i dunno how different they are to weld.

We normally call them 'iron', its still an alloy (now I wonder exactly what we really use), very similar to material we use for brake calpers and caliper brkts........

[BennyB]

I'll see how it goes with the welding. I've got a backup plan to bolt the adapter in if necessary.

[GTijoejoe]

Quote, originally posted by BennyB »

I'll see how it goes with the welding. I've got a backup plan to bolt the adapter in if necessary.

I'd be curious.... I mean, I only asked because I have NEVER EVER seen anything ever welded to an iron knuckle (from OE), we have never welded anything to an iron knuckle, if we need something different we get another one casted (or they are billet AL). So my assumption is the weld strength is not very good or difficult to garuantee

[RabbitJockey]

[BennyB]

Compared to that welded lower balljoint adapter, there's a couple things going for me:
- I can get 2x2.5+2x1.25+4*1 = 11.5" inches of weld
- some of the welds are in shear, not tension or compression
- the upper balljoint is about 2x the distance from the hub center than the lower balljoint, so should take only 1/3 of the cornering force
I think I'll put at least one bolt through anyways, just to be safe.

I've read that cast iron can be welded with high nickel content filler so I'm going to try stainless.


Modified by BennyB at 2:55 PM 2-13-2010

[RabbitJockey]

i dunno about audi knuckles but i know vw knuckles are cast steel not cast iron.

[GTijoejoe]

Quote, originally posted by BennyB »

I think I'll put at least one bolt through anyways, just to be safe. I've read that cast iron can be welded with high nickel content filler so I'm going to try stainless. Modified by BennyB at 2:55 PM 2-13-2010

I would do the same thing... on both
I known ppl to use 100% Ni on exh. manifolds, still different than knuckle material.

[ftwelder]

It's steel, not iron..

[BennyB]

good to know. I was pretty sure that was the case, since I was getting some good chips while machining, and cast mostly makes powder and tiny chips.

[GTijoejoe]

Quote, originally posted by ftwelder »

It's steel, not iron..

Well this got me curious so I doubled check today. Most of these 'steel' knuckles in the industry are actually a cast iron alloy. Our knuckles are cast iron, although I can not tell you the material specifically I can guarantee they are iron....(same/similar to caliper material)

Now since the auto industry is not really that big as far as suppliers go, I would certainly think that VW's knuckles are also iron, probably not use to the irons maybe that most of us have worked with. (ie: during maching lots of carbon comes out like dust everywhere and gets all over your hands)...but of course I'm not 100% because I don't work for VW nor their knuckle suppliers.

What does this mean overall? I dunno, take this info as you wish.

[G60syncro]

You could always get your scrap pieces analized for the good of VW science.... I know the university's mechanical engineering dept does it here... Maybe there's a campus in or some shop in your neck of the woods that's able to do the same.

[vortechMK3]

Quote, originally posted by G60syncro »

You could always get your scrap pieces analized for the good of VW science....

is it just me or does this sound painful?

maybe you meant analyzed.

[GTijoejoe]

....I read it as anodized

[BennyB]

For those interested, I'm back working on the project again so have some updates (link to build thread is at the top)

Currently fabricating the hydraulic clutch, so I'm making a few parts for that.

MK4 clutch master pedal clip holder (bolts to pedal)


and I just started on some MK4 master and slave bleeder to -4AN adapters