Daddylonglegs
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| posted on 3/6/09 at 04:24 PM |
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HELP!
I am getting really frustrated with my steering issue 
I have a +442 chassis and as such made the wishbones longer to cater for the rear end being wider.
My problem is, I have tried several times to get the steering rack in the best position to reduce bumpsteer to a minimum, but I cannot seem to sort
the issue I have where the offside trackrod has an extension on but is as far on the arm as poss, and the nearside won't take an extension
without giving a serious amount of toe-out. Without the extension on that side, the trackrod end is only on by around 4 threads.
I assumed the rack must not be central, but if I move it any more to the offside, I will have issues on that side too!
Any help much appreciated.
JB
It looks like the Midget is winning at the moment......
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adithorp
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| posted on 3/6/09 at 04:32 PM |
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I may be missing someting here, but isn't it a case of your extentions are too long? Can't you just use shorter extentions?
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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mad4x4
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| posted on 3/6/09 at 04:37 PM |
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quote:
Originally posted by adithorp
I may be missing someting here, but isn't it a case of your extentions are too long? Can't you just use shorter extentions?
adrian
Or extensions to Short - then make Extensions Longer
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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Ivan
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| posted on 3/6/09 at 04:49 PM |
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I don't understand your situation - if your rack is off centre then one side will have bump sterr and the other not
The first thing to do is to check that your front suspension is an equal distance from the centre line of the car on both sides, if it's not and
the suspension arms are the same length then set your rack so that the rack ends are the same distance from the steering arms on each side and with
the wheels parallel with the cl of the car make sure the steering arms and extensions are the same length and then sort out the bump steer - you will
never get it right if the tie rods are unequal lengths.
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oldtimer
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| posted on 3/6/09 at 05:01 PM |
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Hi, first make sure your rack is central. If you need more thread to screw onto then just cut some more with a die. Sorry if this is too simple an
answer. Are you maybe right up inside the female threaded section and need to cut a few threads off the male end? - I had to both cut more thread on
the rack arms and chop a few threads off the ends to give me adjustment room. Like the blue - how are my old seats??
Cheers
Martin
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Steve G
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| posted on 3/6/09 at 05:18 PM |
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The rack has got to be central in the chassis in order to allow you to position the rack to eliminate or minimise bump steer. Its the relationship
between the suspension mounting points and the steering rack inner ball joints that is critical (ie they all need to be in a straight line at the
straight ahead position and the rack properly centred). The length of the wishbones doesnt really come into the rack position at all - the steering
arm extensions are simply made longer or shorter as required by the length of the wishbones.
Have you centred the rack at all before trying to fit the extensions??
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Dangle_kt
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| posted on 3/6/09 at 05:43 PM |
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if that is your car in the avatar then you have a WIDE car mate.
I agree whith what has been said about reducing extensions to match rack. If you have significantly increased the wishbones then have you had a model
in solidworks (or someone clever) look over them to check they will be strong enough?
You might have done it yourself, and be an engineering lecuturer for all I know, but that is a VERY wide track on the front of the car.
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hellbent345
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| posted on 3/6/09 at 07:11 PM |
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is it that the extension on the offside is screwed on as far as possible, so it cant be retracted in any more, and the steering rack arm on the
nearside is then so close the extension cant even fit in?
if this is the case then you should centralise the steering rack so that the ends of the arms with no extensions on are equal from your wheels on both
sides, wheels should be in straight ahead position on both sides. Then you will need to make up another set of adapters, which are smaller, and will
allow you to thread the same amount onto both sides to reach the uprights themselves.
It does sound to me like your adapters are too big (somehow!) and you need to have make some smaller ones.
[Edited on 3/6/09 by hellbent345]
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Daddylonglegs
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| posted on 3/6/09 at 07:47 PM |
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Thanks for all the input guys 
Right, here goes....
I know the rack needs to be dead-ahead and central between the wheels, and I have tried to do it several times, my main issue being how to hold the
damn thing in place whilst I check the bumpsteer.
Yes, the offside is screwed right home and the nearside won't fit! I thought about trying to shorten the rods, and cut some more thread down
them, but apparently, they are rolled threads, so the arm is actually thinner than the threaded portion? I can't say one way or the other.
I think I must be having a senior moment or two 
Regards the wishbones, I used 25mm x 2.3mm seamless for the lowers and I also made them longer whilst still retaining the ratio of width to length
(this meant the pivot points were further apart so I modded the chassis to suit. I have been informed that this should be more than strong enough?
The track looks really wide because the +442 has a standard 'book' nose width which makes it more exaggerated. The front is actually
around 2" narrower than the rear.
Hope this puts it more into perspective chaps?
JB
P.S. Martin, the seats are just as comfy as they were and the blue is our 4th colour change 
It looks like the Midget is winning at the moment......
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maartenromijn
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| posted on 3/6/09 at 09:13 PM |
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Fitting the rack 2
quote:
I know the rack needs to be dead-ahead and central between the wheels, and I have tried to do it several times, my main issue being how to hold the
damn thing in place whilst I check the bumpsteer.
The pic shows how to fix the rack whilst checking for bumpsteer. Screw a couple of boards together, fit the rack in between, screw a board on top of
it to fixate the rack. Then use clamps / calipers (don't know correct word in English) to fixate the boards with rack onto your chassis. Now you
can start moving the rack a bit each time, and check bump steer in every posistion using the laser method.
good luck.
Edited the picture
[Edited on 3/6/09 by maartenromijn]
[Edited on 3/6/09 by maartenromijn]
BLOG: http://thunderroad-super7.blogspot.com/
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Daddylonglegs
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| posted on 4/6/09 at 08:10 AM |
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quote:
Originally posted by maartenromijn
Screw a couple of boards together, fit the rack in between, screw a board on top of it to fixate the rack. Then use clamps / calipers (don't
know correct word in English) to fixate the boards with rack onto your chassis. Now you can start moving the rack a bit each time, and check bump
steer in every posistion using the laser method.
good luck.
Thanks for that, absolutely perfect! Why didn't I think of that? Told you I was having a senior moment
I think the main problem I have is that I've read too much on the subject and am almost paranoid about the whole thing 
I think I need to take a step back and start with a fresh mind. I'm just putting pressure on myself now as I want to finish by my deadline and I
think it's actually counter-productive!.
Cheers.
JB 
[Edited on 4/6/09 by Daddylonglegs]
It looks like the Midget is winning at the moment......
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