This topic contains 1,535 replies, has 19 voices, and was last updated by Micks 4 weeks ago.
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July 13, 2019 at 10:00 pm #29099
Bugger… This whole getting old thing both sucks and blows…
The thumb went Ebola washing the dishes then again in the shower, it’s actually looking a bit better now some of the manky old blood is out of it..
July 14, 2019 at 11:28 am #29101Goldilocks Pan installed! Slight change in plan with the steering, off to Bendigo for a change…
July 14, 2019 at 3:49 pm #29103
RichardParticipant- Macquarie Fields
- VT Commodore
View build HERE
Posts: 91Love love this build, so much enginuity & ‘can do’ involved…
Also, how did you nail not fall off? 😩
July 14, 2019 at 4:31 pm #29104Thanks Richard, it’s a fun hobby, on the nail it’s just a matter of time now, it’ll fall off soon, I’ve lost that one 4 times now, the nurse remarked it looks like a toe compared to the one on my left hand.. Harsh Wench..
July 15, 2019 at 7:00 am #29107
ImmortalityParticipant- 97 HSV Senator 185i 02 VX L67 Calais
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Posts: 535Having a nail fall off is much better than seeing a doctor rip it off even though you can’t fully feel it.
July 15, 2019 at 11:52 am #29111Half of mine is still well attached, I’m thinking it’s gonna be a doctor job once the new nail starts growing in…
July 15, 2019 at 2:11 pm #29118Spent the morning pondering the front end geometry, it’s further complicated by the fact it needs to do double duty so this means the second set of Coilovers are 100mm longer totally screwing with the Rack position.
I could optimise it for Tarmac and then just live with the compromise when on dirt but that doesn’t appeal as 80% of my events are on dirt, can’t go the other way as it’d be diabolical on Tarmac..
Had a chat with Craig and bounced a bunch of ideas around till we came up with something workable, it means fabricating a new crossmember and using a rear mounted rack as the Holden uprights can’t be swapped side for side to work with a front mount rack..
It got me thinking about some of the Lexcens handling woes so I mocked up the old front end to check, sure enough as back then I was limited by the engine location I had moved the rack backwards to miss the starter motor… DOH.
This in turn caused the overcentre condition that required the steering stops in turn giving the turning circle of the Titanic.. live and learn.
July 15, 2019 at 10:12 pm #29121
Chris (agentcrm)Participant- SC, CT
- VR Statesman 1968 Skoda 1202
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Posts: 82Can you set up dual mounts?
If you’re 80% on dirt then I’d optimise for that at the moment and figure out a second sub frame for tarmac.
Since it’s only the suspension attached to it this time it should be easier and quicker to swap over.July 16, 2019 at 6:19 am #29122Had already worked out a set of male/female extension mounts to cover the control arms Chris, problem was if you move the control arm position you then have to move the rack height to suit or you get bump steer, I had planned to just use a 100mm spacer on the Tie Rod end when using the longer shocks..
This is problematic in that the rack stays in the same position but the Tie Rod end needs to be on an imaginary line that Intersects the top shock mount, solution we came up with is to twist the steering arm and use a 16mm bolt and spacer, this allows Roll centre changes without screwing the rest of the geometry.
July 16, 2019 at 8:40 am #29123Thanks for your input Chris, it has me thinking in a whole different direction now… luckily nothing is set in Steel yet
July 16, 2019 at 4:34 pm #29125
VRSenator065Participant- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777Thanks for your input Chris, it has me thinking in a whole different direction now… luckily nothing is set in Steel yet
And once again, thats why forums rock.
July 16, 2019 at 5:22 pm #29126Yep always handy having a different PoV on a build like this, I know where I want the car to be but there’s quite a few ways of getting it there that I may not have thought of… any and all input is always welcome, I may not follow it to the letter but often it gives me a fresh perspective that leads me in a direction I hadn’t considered and means a much better result..
I’m pretty much making this up as I go…
July 17, 2019 at 1:23 pm #29129This is what was hurting my brain the other day… I don’t have the Math needed to work it out on paper (being expelled in year 9 wasn’t such a good idea after all)
The software to plot it all is $400 USD, bit much for something I’ll use once, I figured back to basics and employed the CAD suite (concrete aided design) quick run into town for some tape, a LOT of measurements and I have a plan.
Glad I took the time to do this as it’s NOT a linear progression, I plotted it in 50mm increments and got roll centres of 40mm 110mm and 140mm.. will think some more on this as the Lexcen didn’t have the ultra low roll centres I thought but the opposite..
July 17, 2019 at 2:57 pm #29130Ok Thinking led to Wondering, Wondering led to Doing, Doing led to I went back down and fiddled, turns out I didn’t allow for the 50mm kickup in the crossmember where the stock balljoint bolts up.. It’s all perfectly doable now as I have enough room to move the rack up into it’s correct posi!
July 17, 2019 at 4:21 pm #29132
VRSenator065Participant- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777Just remember IJ, (actually all C+ members) I am a 3D CAD modeler, if I am able, happy to help out with 3D modeling, including ranges of motion, etc. But there is always a place for Cardboard (or Concrete) aided design
July 17, 2019 at 5:12 pm #29134Thanks Gary, it was an interesting exercise, I had made a few fundamental errors with the Lexcen that I now understand much better.
Turns out it’s problem was too high a roll centre causing the lack of mid corner grip under power, you get a jacking effect which in this case was just about locking out the suspension, couple that with the camber reduction as the suspension compressed and the rack location screwing with the Ackerman effect I’m amazed it was as fast as it was…
Living and Learning..
July 18, 2019 at 11:37 am #29138
VRSenator065Participant- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777Living and Learning..
Always…
July 18, 2019 at 6:25 pm #29142
ImmortalityParticipant- 97 HSV Senator 185i 02 VX L67 Calais
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Posts: 535If I remember correctly the boys spent a fair bit of time playing with the steering angles on Binky to fix the bump steer problem. Had to re-manufacture a fair bit of the structure in the end. I believe they had similar CAD drawing on the ground that you ended up with too.
- This reply was modified 5 years, 4 months ago by Immortality.
July 19, 2019 at 9:53 am #29145
VRSenator065Participant- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777If I remember correctly the boys spent a fair bit of time playing with the steering angles on Binky to fix the bump steer problem. Had to re-manufacture a fair bit of the structure in the end. I believe they had similar CAD drawing on the ground that you ended up with too.
I bet it also involved designing and making a very intricate bracket (or three) ha ha
July 19, 2019 at 3:18 pm #29147LOL that they did, there were many brackets built..
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Back into it today, had to do a material/supplies run again yesterday, made a start on the new Crossmember mounts, also built a jig to relocate the front Diff mounts onto the new Crossmember.
As with everything I do there’s more than meets the eye with this phase, The BMW being a production car needs things to fit + or -, in this case it’s 2mm, the vertical holes for the crossmember are 14mm and the bolts are 12mm, I want my diff back in the exact same spot so I had to make some 1mm wall sleeves for the holes.. my tolerance is + or – .5mm on the crossmember, on the Jig it’s on size.
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