Northy
|
| posted on 1/7/09 at 07:04 PM |
|
|
DIY wheel alignment
Hi all,
After a 3 year lay up of my car I think I'm now not as brave as I used to be and have realised that the suspension is basically all set up to
shit! 
Any pointers on what I need to do? I know the principals, just not sure the best way to do it on the Avon.
I've read some threads on here, that suggest centring the rack first, but I'm not sure what that means 
What sort of figures should I be aiming at to set everything to?
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
|
|
|
|
|
andyd
|
| posted on 1/7/09 at 07:18 PM |
|
|
quote:
Originally posted by Northy
I've read some threads on here, that suggest centring the rack first, but I'm not sure what that means
You should check that the steering rack is truly centred in terms of its mount across the car. Put the steering on full lock one way, measure how far
the steering arms extend past a known chassis point then do the opposite lock and compare the measurements. They should be the same assuming the
chassis is straight.
Andy
|
|
|
nick205
|
| posted on 1/7/09 at 08:46 PM |
|
|
I would recomend you buy/borrow a copy of this book by Des Hammill on setting up kit cars. Very easy to read an understand and gives real world
advice - i.e. man in the garage with basic tools - on how to check, measure and adjust to get the best out of your car.
http://www.veloce.co.uk/shop/products/productDetail.php?prod_id=V4207&prod_group=Performance Tuning &
Modification&
|
|
|
Northy
|
| posted on 1/7/09 at 09:16 PM |
|
|
Where is the 'blush' smilie? I've just gone and got my copy of that from upstairs to have a read
Thanks,
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
|
|
|
Ben_Copeland
|
| posted on 2/7/09 at 07:19 AM |
|
|
That book must be gold plated... 2 sellers on amazon for new books, one price at £68.03 plus postage and the other at £104.96 plus
postage,............ Are they MAD ????
Ben
Locost Map on Google Maps
Z20LET Astra Turbo, into a Haynes
Roadster
Enter Your Details Here
http://www.facebook.com/EquinoxProducts for all your bodywork needs!
|
|
|
Northy
|
| posted on 2/7/09 at 08:11 AM |
|
|
Thanks for the heads up about the book lol, but it I read in another thread on here somewhere about centring the INTERNAL part of the rack in the
chassis, not the rack case.
Can anyone tell me how this is done?
G
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
|
|
|
andyd
|
| posted on 2/7/09 at 08:33 AM |
|
|
Was my first reply not good enough?
By using the lock to lock method it shouldn't matter if the outside casing is "off" compared to the internals... or am I making it
up? I've not tried it myself but it makes sense to me.
Andy
|
|
|
Northy
|
| posted on 2/7/09 at 09:06 AM |
|
|
Ah, ok, I think I understand.
So lock to lock the distance say from the centre of the chassis to where the threads start on the rack tie rods should be the same? If they are not
adjust the rack 'accross' the car (alter both tie rods) until it is?
Is that correct? 
G
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
|
|
|
nick205
|
| posted on 2/7/09 at 04:02 PM |
|
|
The rack needs to be central in the car, it also needs to be parallel horizontaly and vertically to the lower wishbone inner pivot points. The track
rod inner ball joints should also be in line with the upper and lower wishbone inner pivot points - all this will help to eliminate (or minimise) bump
steer.
First up disconnect the TREs from the uprights and wind the steering lock to lock and check that the steering wheel is correctly centred within the
travel of the rack. Then adjust your track rods to be exactly the same length and reconnect the TREs to the uprights - now check and adjust the toe
of the front wheels to the desired setting by adjusting BOTH track rods by EQUAL amounts so they're still exactly the same length.
If when you drive the car in a straight line the steering wheel is not in the correct dead ahead position then you know your rack is not centred in
the chassis and which way to start moving it.
ETA...
...this assumes of course that your front lower wishbones are exactly the same length (worth checking) and that your ride height is level across the
front of the car - i.e. front lower wishbone inner pivot points are parallel to the (flat/level) floor (again needs to be checked). You'll also
need to check that camber is equal left and right too and then re-check after making rack/toe adjustments.
At the rear of the car, check that the wheels have between 2-3mm total toe in across the car - IIRC the Avon has rosejointed wishbones at the rear so
this should be easy to adjust. Getting this right makes big difference to the way the car rides over uneven roads and passes round bends.
On top of this you'll need to consider corner weighting the car - search for posts on here for details of bathroom scale methods.
Lots to consider, check and adjust - it's quite time consuming, but very rewarding when you can feel improvements in the cars handling.
[Edited on 3/7/09 by nick205]
|
|
|
andyd
|
| posted on 2/7/09 at 04:03 PM |
|
|
Sounds logical to me.
I'd first ignore the tie rods and just make sure the measurement from the known chassis point (and centre of one of the front rails sounds like
a good bet) to the start of the threads is equal.
After that the amount the tie rod ends screw on should in theory be the same for both sides but will no doubt be slightly different to compensate for
whatever toe-in/out you want to run. But you'll know that the rack is moving an equal distance from straight ahead to full left lock and from
straight ahead to full right lock.
Edit to say: Yeah... what Nick said ^^^^
[Edited on 2/7/2009 by andyd]
Andy
|
|
|
