VR6 Dropped Spindles/hub

[boost monkey 0]

You filthy slags :norty:

 

If you like the hub, you may get a semi for the new LBJ especially as i did it in chrome (see attached - new server needs filling up!)

 

Also see attached the new current assembly, and for sake of completeness the added spindle! :D

 

Better do some real work now...!

[Kevin Bacon 5]

Oooh lovely mate! I can't believe how real they look, especially the 2nd one down on the left. Amazing! CAD, when I was at college, was 2D flat drawings. This new 3D fangled stuff is the nuts :D

[boost monkey 0]

Cheers fella! I can't claim to be a render aficionado but that one did come out well! I'm much better at 3D than 2D. If I can visualise a problem I can help much more than if someone showed me a problem or told me about it! :lol:

 

Anyways, I think it's about time to get cracking with dropping mount points and all that. Referring back to Kips points, the centre line through the two upper shock mounts on the hub is also the axis of the shock absorber. Therefore, to mod the hub to reduce wheel to arch gap we can move these mounts closer to the centre of the hub by XX mm (measured vertically, so obviously a little bit of trig involved measuring along the centreline!). This would also involve spacing down the LBJ and TRE pickup points for the wishbone and steering rack respectively - I see no need to modify the brake carrier mounting location here. I will try to mock this up visually for you guys this lunch time. Of course it won't be accurate yet as I haven't confirmed my new hub is accurate etc etc etc but it will give us all an idea of what it could look like and we can discuss this further :D

[boost monkey 0]

Ok, so it looks like frankenstein's hub, but bear with me (attached).

 

I haven't bothered offsetting the TRE and LBJ mounts because I have a concern - won't the shock mount on the hub give clearance issues with the shafts in full droop? That's one problem with modding stuff in CAD - you really need to have the whole system of bits mocked up to check for clearance/interference!

 

Anyways this is a simple 40mm drop built into the hub. Happy to hear all thoughts, good and bad :D

 

@quicky1980, is this what you were thinking of Sam? Perhaps something less horrific?! :lol:

[KipVR 1]

Hi Jon, good work there buddy, if you lower the LBJ you don't need to lower the strut mounting position. Lowering the strut mount would have been a nicer way of doing it (you would have kept suspension travel) but for the reasons you've discovered it wouldn't have worked.

[boost monkey 0]

Ok, so we're all agreed that modding the hub so that it reduces wheel arch clearance is a false economy as it doesn't adjust the suspension geometry?

[24V Renshaw 0]

Yep, nothing gained and it's the geometry that's important, well to me anyway :)

Nice work though.

[boost monkey 0]

That's cool, I think modding the hub would be a mission anyways :D

 

btw i'm having this weekend off as it's my birthday :bday: I won't be at Stealth tomorrow but if someone could mope about for me that would be great :lol:

[quicky1980 0]

nice work, but I agree with the others. Have a great Birthday mate!

[boost monkey 0]

Ok cool, I'll be cracking on with the BJE project now then. going to flick back a few pages to Kip's post about wishbone lengths etc :D will post up what I find.

 

---------- Post added at 09:13 AM ---------- Previous post was at 08:39 AM ----------

 

@Kip, when you said that the hub moves in by 1.27mm due to a 30mm drop, won't some of that be taken up by the ball joint? i.e. the ball joint "shaft" will move to counter this inboard motion so that the hub remains in relatively the same place?

[boost monkey 0]

I've been messing around with the LBJ stuff (again), based on a horizontal distance of 355mm, and a vertical distance of 30mm (giving wishbone angle of 4.83degrees above horizontal), I've mocked up a very basic wishbone and attached it to the LBJ making sure the distance between the axis of the LBJ and the inboard pivot end of the wishbone is 355mm. I then rotated the whole lot around the inboard end of the wishbone bolt axis by 4.83deg and this is what I get (attached img 1 and 2). If anyone else can spot some glancing errors in my maths / modelling, please let me know! :salute:

 

AFAIK this is correct. Obviously in real life the 'pin' of the LBJ would tend to stay vertical as it can rotate in its joint, but obviously only up to a point.

 

A drop of 60mm will double this offset, so wishbone angle will be 9.66deg and the LBJ will move further inward again.

[24V Renshaw 0]

Looks spot on. So now we know we need 5 degrees back again how do we do it :)

 

Jay

[boost monkey 0]

This is it! :D Jay do you know off the top of your head what the thread is on the LBJ? I couldn't make it out from that IGES file.

 

We'd need to move it back 5deg for 30mm, but 10deg for 60mm and obviously increments inbetween if people were running 40/50mm.

 

What do we think? Develop a BJE that corrects for a 30mm drop? I'm starting to think it wouldn't be too hard (too much of a design change) to do a few of them. Perhaps take a poll of who uses what ride height as someone people like slightly low with bigger wheels and some people like scraping sills on standard 15s.

[24V Renshaw 0]

A correction based on 30mm would be a sensible start. That would be a massive help even to those running bigger drops.

Lots of other things come into play the lower you go too..

 

Jay

[boost monkey 0]

Good point. I've started mocking up the 30mm one. As per the screenshots, the the LBJs are quite close so designing a piece that will fit both positions is a little tricky but I'm sure we will get it done.

[boost monkey 0]

Ok, so I did a fair bit of work on this yesterday, continuing when I got home. This stage is what I call "The Dilemma". You know what needs to be done,b ut it's just the design process of making something useful, strong, safe, cheap and successful. I've offset the actual hubinto the "lowered 30mm" position just the same as the upper LBJ in the pics I posted above, whilst I left the LBJ and wishbone (for want of a better word!) in the standard position - dead flat to the ground.

 

I have attached the pics.

 

Basically the gap between the LBJ and the hub is where our designed BJE will go. As you can see it looks like a mission. Don't worry too much about the fact that the LBJ "cuts" into the hub - the joint will rotate around in real life of course but I've not modelled it as a joint in the computer (may pay me to do so in fact). At a 30mm lowered height, you can see there is really not much space at all to fit between the standard position LBJ and the lowered hub.

 

I am starting to wonder whether using a 4-cyl LBJ with the waisted section (and base the bottom of the BJE around this instead of the VR LBJ) would be a much better idea. AFAIK, the 'pin' of the 4cyl LBJ is nowhere near as long as the pin on the VR LBJ, so this may give us more room. I had to remind myself that you VR boys not only have to get an M12 locknut in there but you have to put in a 6mm(?) allen key into the top to tighten that nut up and secure it in place. This leaveas us with more clearance issues.

 

Anyways, have a look at the pics and have a think and let me know what you come up with :D I know someone (probs Sam?) was thinking about using a 4cyl LBJ previously so maybe this would work. We obviously have to consider the impact this would have on the suspension geometry and whether it will be viable to replace the LBJs for one another.

 

My 2p for today :salute:

[boost monkey 0]

Just looked for the standard 4cyl BJEs on the market. One set is £150 a pair :suprised: and the other is £80 a pair but show use only! Shows how confident they are in their own design really.

[24V Renshaw 0]

Great way of demonstrating why its not totally straight forward. Nice work as always and the stuff I wanted to always do but never had the time.

 

Jay

[boost monkey 0]

Cheers Jay :D Ironically, it looks like it will be easier to create a BJE for a larger amount of lowering purely due to the greater clearance between intended LBJ position and lowered hub.

[boost monkey 0]

60mm drop - approx 12mm clearance at closest points. Pics for comparison

[24V Renshaw 0]

The stresses in that would be massive though...

[boost monkey 0]

True. I can stress analyse it here, even leave it running ni the background whilst I work on something else.

 

What do we think a reasonable stress level would be? How about fully bottoming out suspension and modelling 1/4 car weight through the BJE? Say, equivalent of 350kg?

 

We can always make it out of really thick metal. There should be space with the 60mm clearances to get some real steel in there! :D

[quicky1980 0]

I think I may have lost track a while back on this, but is the model of the hub a modified version or a copy of the original setup? If its a modified version I would kindly ask for an overlay to see the difference as Im struggling to visualise the modifications.

 

I thought the direction being taken was to effectively raise the position of the bearing and hub flange in relation to the hub itself, or did this cause packaging concerns? This would avoid the requirement for BJE.

 

Sorry again if Im being dull.

[boost monkey 0]

Sam, i've uploaded all the pics as I've gone along. If you flick back a few pages you'll see that the hub is currently a replica of standard.

 

Again, we've covered that already in the last 2-3 pages. We decided that modding the hub would cause interference with the outer cv / driveshaft when suspension is in droop, and possibly other issues too so we are currently looking at the BJE again.

 

 

For those interested, I've attached a few pics of a basic concept BJE i knocked up for the 60mm lowering setup. It's kind of primitive and a first attempt at a design that meets the requirements. It was tricky trying to keep clearance around the nut to allow for a spanner and also keep strength in the component, but i'm sure the design will evolve. The tapered section is based on IGEs data for the LBJ, approx 18mm long with an inward draft of 5.6 degrees. The upper pin section doesn't actually need the allen key slot in the top as it won't twist like the original LBJ does, but it's all just a mock up for now.

 

If anyone can see how the BJE could be better designed whilst meeting all requirements for tool clearance, strength, and geometry I'd love to hear some ideas.

[KipVR 1]

I'm not quite sure what you are explaining Jon, but what is to stop you moving the lbj mounting position on the upright/hub carrier down to meet the lbj? (other than it may hit the splash guard)