pbura
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| posted on 24/4/04 at 08:28 PM |
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The de Dion's awfully nice, and frankly that's how I'd go if I weren't doing inboard shocks. IRS is good, too, especially if
you've got your chassis built already and all you need is to sort the wishbones.
How far along are you?
Pete
Pete
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Digger Barnes
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| posted on 24/4/04 at 11:04 PM |
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quote:
Originally posted by dblissett
i have to hold my hands up and say most of what is being said is way above my knowledge of suspension
with that in mind i think it might be better to admit my limitations and buy a dedion tube from gts
the last thing i want is to spend two years building a car that wont drive properly and i wont be happy with
it seemed like a good idea at the time
thanks every body dave
[Edited on 24/4/04 by dblissett]
Dave it was way over my head about one month ago, but with a bit of reading you will start to understand how it all works well enough to use one of
the tools available to play with loads of different designs and by trial and error you get to a good design in a day or two.
Well thats what I am hoping once I know a bit more about what I want the camber to do in bump and roll in a track situation.
Good luck with what ever route you decide on
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WIMMERA
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| posted on 25/4/04 at 05:54 AM |
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The late Arthur Mallocks comment on roll centre movement in relation to chassis movement allways brings a smile to my face, he said, when describing
the nine different systems they had used up to that point, " if you use a chassis mounted Watts linkage it can't move because it's
got a bolt through it"
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Bob C
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| posted on 25/4/04 at 01:01 PM |
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Love the quote from Mallock!
The problem with IRS isn't the suspension geometry - the fact is all the wheel loads feed to places that just aren't there on the tried
& tested book design. A problem neatly side-stepped by the dedion solution!
Cheers
Bob C
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WIMMERA
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| posted on 26/4/04 at 01:25 PM |
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It's going to be interesting to experience the difference, I have a book version finished which is a great drive and a new car under way which
has inboard front suspension and IRS rear, the front also features zero scrub radius I'm treating it as an R&D exercise, I enjoy the build
as much as the driving, the new car is very adjustable, front and rear
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dblissett
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| posted on 26/4/04 at 07:39 PM |
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thanks
with the kind help from pbura i am going to try and sort my irs out
i will keep you all posted as to if i win or loose
only rons book said it was easy
cheers dave
[Edited on 26/4/04 by dblissett]
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Northy
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| posted on 26/4/04 at 08:24 PM |
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Dave,
Is your IRS an exact copy of the Avon? Does this mean the Avon is shite aswell?
I'd be very interested to hear how you solve it. Guess thats another Winter upgrade to add to the list 
Cheers
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing! 
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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dblissett
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| posted on 26/4/04 at 08:39 PM |
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avon irs
hello northy
no its not all the same the bottom wishbones dimentions are the same
the supports for top and bottom wishbones are in the same place but my top wishbones are shorter than the avon ones they conect in almost the same
place as the shocks there was a thread on the standard avon irs that thought the camber went posative as the suspension rose
search for a guy from portugal i think his name is juao or jcdoc he posted the comments on it but i have come to the conclusion that it must be a lot
better than any standard production box that we all drive day to day.
cheers dave
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Northy
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| posted on 26/4/04 at 08:49 PM |
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Cheers Dave,
I'll have a look, seem to remember seeing it now.
Has anyone modeled the std Avon rear suspension in one of these packages? Don't think I'll be able to manage it
Cheers
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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dblissett
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| posted on 26/4/04 at 08:52 PM |
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irs
when i have learnt how to put mine through i will put the standard avon through
this might take me a couple of months to learn though
cheers dave
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Northy
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| posted on 26/4/04 at 08:55 PM |
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Cheers Dave,
I'm not changing it now, perhaps next winter........
Cheers
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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pbura
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| posted on 26/4/04 at 09:17 PM |
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It's really not hard to do; I'll post the results for everybody to see, so you can try it on your own. Probably won't be until
Wednesday morning, though, because I have some rush work to do.
I'd be glad to play around with the Tiger setup, too, front and rear. The dimensions needed are the locations of ball joints and chassis
pivots, plus tire diameter (rolling) and track. Steering data is optional. You can see the data screen on page 3 of this thread.
Pete
Pete
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Northy
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| posted on 26/4/04 at 09:19 PM |
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Cheers,
Wonder if my book will fall on the scanner tommorrow........
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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jcduroc
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| posted on 26/4/04 at 09:55 PM |
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quote:
Originally posted by dblissett
there was a thread on the standard avon irs that thought the camber went positive as the suspension rose
search for a guy from portugal i think his name is juao or jcdoc he posted the comments on it but i have come to the conclusion that it must be a lot
better than any standard production box that we all drive day to day.
cheers dave
Hi Dave
My forenames are "Joćo Carlos" and my ID is "jcduroc" and yes, I'm from Portugal.
quote:
Originally posted by dblissett
hello northy
no its not all the same the bottom wishbones dimentions are the same
the supports for top and bottom wishbones are in the same place but my top wishbones are shorter than the avon ones they conect in almost the same
place as the shocks ...
Doing that the only thing you'll achieve is to get static negative camber but in bump you'll gain positive camber all the same.
quote:
Originally posted by dblissett
... but i have come to the conclusion that it must be a lot better than any standard production box that we all drive day to day.
cheers dave
May be so ... may be not.
I cannot state positively on the Avon as I've never seen and/or driven one but conceptually (if it is built with Dudley's book dimensions)
it's a big "merde".
You should seriously consider (at least) lowering your rear upper wishbones' attachement points; wait for someone else's solution
(IMHO).
HTH
Joćo
[Edited on 26/4/04 by jcduroc]
JCM
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britishtrident
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| posted on 27/4/04 at 07:19 AM |
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From study of photos in mags of the Avon front end I doubts about the position of the steering rack also --- it seems quite a a lot a head of the
trackrod ends and so must give a lot of toe-in in corners.
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dblissett
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| posted on 27/4/04 at 12:59 PM |
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joao
hello joao
i was trying not to slag off the avon as some people have bought one as a built chassis and i dont want to make them unhappy with there choice
hello pete
i will email you the tiger dimensions
i have started to play with the program should all the dimentions be imperial
and i now have even less time due to the birth of my second daughter last night.
eve weighing in at 9lb 12 oz ouch
thanks dave
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jcduroc
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| posted on 27/4/04 at 01:35 PM |
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quote:
Originally posted by dblissett
hello joao
i was trying not to slag off the avon as some people have bought one as a built chassis and i dont want to make them unhappy with there choice
Dave
Better tell the truth beforehand than seeing our mates unhappy afterwards (I guess).
quote:
Originally posted by dblissett
... now have even less time due to the birth of my second daughter last night.
eve weighing in at 9lb 12 oz ouch
thanks dave
Don't know wahat that weight is but if Eve is crying full-lungs and sucking her mother's milk it is wonderful. Long life and happiness to
Eve and her parents.
Cheers
Joćo
P.S.: Father of two girls, grand-father of three girls and recently widow.
JCM
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pbura
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| posted on 27/4/04 at 03:56 PM |
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Dave,
Sent you an e-mail to confirm some measurements. When I hear back from you, then I'll post the originals and a suggested alternative, and
everybody can take some potshots
It would also help to know what your front end looks like. I know you have a +442, but would like to know also if you have book wishbones in book
locations, and what your front ride height will be. The reason I ask is that it's best to have your rear RC somewhat higher than the front, for
better turn-in. Also, I'd like to try matching the front and rear camber curves as best I can.
If the other thread about the Tiger wishbones pointing up toward the chassis is correct, probably the reason Tiger did it is to raise the RC so they
wouldn't have to have an anti-roll bar in back, IMO.
Congratulations on Eve's safe arrival, and may all of you have a happy life together
Pete
P.S. to Joćo: I'm a widower, too, and raised four children on my own for 7 years until remarrying almost two years ago now. I'm very
sorry for your loss.
Pete
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jcduroc
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| posted on 27/4/04 at 04:19 PM |
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quote:
Originally posted by pbura
P.S. to Joćo: I'm a widower, too, and raised four children on my own for 7 years until remarrying almost two years ago now. I'm very
sorry for your loss.
Thank you for your sympathy, Pete.
So you know how hard it is!...
Cheers
Joćo
JCM
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Northy
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| posted on 27/4/04 at 05:26 PM |
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Pete,
Have you got the dimensions for the std Avon rear suspension?
Would you be willing to do the front also at some point? No rush though
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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pbura
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| posted on 27/4/04 at 08:17 PM |
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Some Results for Dave
Well, I took a shot at Dave's suspension geometry, had a lot of fun, and got more behind with earning my daily bread
Here's the old data in Suspen:
 
Rescued attachment DLBIRS.jpg
Pete
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pbura
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| posted on 27/4/04 at 08:21 PM |
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Some Results for Dave (continued)
And the proposal, which was formulated to minimize extra work for him. Bottom wishbones are the same with a higher mounting, and the upper are longer
and mount further inboard, but at the same chassis tube height:
 
Rescued attachment DLBIRSREV.jpg
Pete
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pbura
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| posted on 27/4/04 at 08:42 PM |
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Some Results for Dave (continued)
The change in the ride height from 4.75" to 5.5" helped raise the RC and to put the upper wishbone in a better position for bump and roll.
For a lower ride height, I'd go with a shorter tire/wheel combination (this one is 185/65-14).
The most serious change was raising the lower chassis pivot 1.5" in the same lateral location, and I hope this is possible just by making a
Big-Ass Bracket without any other modifications. Comments are welcome on this, and on anything else.
Pete
Pete
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pbura
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| posted on 27/4/04 at 09:07 PM |
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quote:
Originally posted by Northy
Pete,
Have you got the dimensions for the std Avon rear suspension?
Would you be willing to do the front also at some point? No rush though
No, I don't have them, but I'd be glad to help anyone that wants to analyze them.
By the way, I'm not representing myself as any kind of expert in these matters. One reason I've posted the screens from these programs is
to show people how they work, and to encourage them to do the same themselves.
Generally speaking, The R/C car guys have got us Locosters buried with regard to vehicle dynamics
Pete
Pete
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Northy
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| posted on 27/4/04 at 09:18 PM |
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quote:
Originally posted by pbura
No, I don't have them, but I'd be glad to help anyone that wants to analyze them.
By the way, I'm not representing myself as any kind of expert in these matters. One reason I've posted the screens from these programs is
to show people how they work, and to encourage them to do the same themselves.
Generally speaking, The R/C car guys have got us Locosters buried with regard to vehicle dynamics
Pete
Cheers Pete,
Which program should I start off with as a beginner? Do you just plug numbers in?
I'm an RC guy
Cheers
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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