OZDAT
http://www.ozdat.com.au/forum/

Tricks to re-installing rear a-arms to crossmember!!
http://www.ozdat.com.au/forum/viewtopic.php?t=19253		 Page 2 of 2
Author:  Baz [ Mon Sep 21, 2009 12:18 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
chris1818 wrote:
Baz, I know that reduced camber is great for drag racing as more tyre on the road etc etc,

but what are the consequences of having excessive rear camber on a lowered, low powered Lseries car being driven on the street through the hills and occasional fang?

Basically what are the handling problems with a seriously lowered car without your kit. (not for drag racing).

Cheers, chris
As you lower a 1600/180B the camber increases which reduces tyre contact.
The rear wheels toe out excessively.
the toe out leads to initial understeer followed by final oversteer.

the alignment off the rear end is just as critical as the front end.
A low powered car will benefit just as much as a high powered car.
Drag of the toed out rear is removed. Thus allowing more speed or better economy.
The handling will be greatly improved & drag reduced allowing the car to maintain momentum through the corners.
this is apart from the tyre wear. $$$

Note that drag racing is not the main purpose of an ARC. Its for street & race useage.
tho it does help a lot with straight line traction.
Author:  datdrift [ Mon Sep 21, 2009 1:35 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
1onenil0 wrote:
The other thing from my limited knowledge of car handling and suspension talk, is major oversteer, you will turn into a corner and you can feel the back of the car trying to turn aswell, like its being steered from the back. Have you ever riden a bike backwards, its kinda like that in a way.... It feels crap :)
1600 sought of do 4 wheel steer,the rears turn a little what ever way the frontend is pointing.
when they body roll, more weight goes on the outside wheel and it turns inwards,while theres less weight on the inner wheel and it turns outwards.I find this may help the rear of the car to keep more grip through cornering
Author:  Baz [ Mon Sep 21, 2009 2:22 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
datdrift wrote:
1onenil0 wrote:
The other thing from my limited knowledge of car handling and suspension talk, is major oversteer, you will turn into a corner and you can feel the back of the car trying to turn aswell, like its being steered from the back. Have you ever riden a bike backwards, its kinda like that in a way.... It feels crap :)
1600 sought of do 4 wheel steer,the rears turn a little what ever way the frontend is pointing.
when they body roll, more weight goes on the outside wheel and it turns inwards,while theres less weight on the inner wheel and it turns outwards.I find this may help the rear of the car to keep more grip through cornering
opposite way around, nissans passive rear steer.
replacing rear xmember bushes helps as well.
Assume you are turning left, the weight shifts to the RH side, camber increases RH and toes out.
LH side camber decreases & toes in, thus steering the rear around the corner.
This is why the alignment needs to be toe in static, to reduce the rear steer and tyre scrub.
Author:  chris1818 [ Mon Sep 21, 2009 5:47 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
Thanks Baz i didnt realise they toed out aswel... thats another thing to add to the wish list then :lol:
Author:  datdrift [ Thu Sep 24, 2009 11:39 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
I did write that backwards when i now think about it :oops:
Author:  socrates [ Wed Mar 03, 2010 7:11 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
thought id just clear something up..

the rear end gains toe-in as it moves away from horizontal...

good link, its for a bmw but the system is the same as the datsun one..
http://www.e30m3project.com/e30m3perfor ... page-2.htm
Author:  Baz [ Wed Mar 03, 2010 8:48 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
socrates wrote:
thought id just clear something up..

the rear end gains toe-in as it moves away from horizontal...

good link, its for a bmw but the system is the same as the datsun one..
http://www.e30m3project.com/e30m3perfor ... page-2.htm
depends on how they reference the readings.
Its not rocket science.
jack up the rear of a 1600/180B etc centre of xmember.
note the wheels toe in referenced from the front.
put it down & fill up the boot, push the car forwards 500mm
and it now toes out.
Author:  24TKman [ Sun Feb 06, 2011 9:56 am ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
sorry to bring up an old thread, does anyone have any picks of the Datsport ARC installed, looking at getting one but want to see what work is really involved.

thanks
Author:  DAZDA [ Wed Feb 09, 2011 11:56 am ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
socrates wrote:
thought id just clear something up..

the rear end gains toe-in as it moves away from horizontal...
Almost but not quite.

Baz is on the money (as usual). The Datsun 1600 IRS gains toe OUT during bump (or being lowered) and gains toe IN during droop (or being raised). NOTE: It depends on the initial static toe as to whether or not you end up with actual toe in or out once you lower the car.

In other words, if at standard ride height the rear wheels have ZERO TOE, once you lower it, it will have TOE OUT. If it has lots of TOE IN at standard ride height, it will have LESS TOE IN once the car has been lowered. If the car has lots of TOE OUT at standard ride height it will have even more TOE OUT once the car has been lowered...


Sorry 24TKman, I can't help you with any photos.
Author:  SR20Datsun [ Wed Feb 09, 2011 12:24 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
DAZDA wrote:
socrates wrote:
....static toe.....
Camel toe?

I can also vouch for toe out when the suspension is undergoing bump. By physically raising the pick up points on the cross member (so cutting and re-welding) and then when you lower the car, you bring the static toe point back similar to factory. This allows kind of less of the transfer from small amounts of static toe out to larger amount of toe out, to more of neutral to toe out when body roll or bump occurs. It also provide a small amount of semi trailing arm 'anti squat' (if that is possible - technically it should be called 'less squat' :D ).

By replacing the X-member bushes in the semi-trailing arms from rubber to urethane, you change how the cars rear end toes out/in under braking and acceleration (respectively). This changes the way the car behaves under power or under brakes during cornering. For example: Cornering around LH corner. RH wheel would be toeing out, but with power would pull the wheel in slightly to compress the rubber. It might still be toe out, but less. Braking through a corner only makes the toe out worse.
Author:  SR20Datsun [ Wed Feb 09, 2011 12:34 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
Note to those DIY'ers:

When welding the DIY brackets in (I can only speak from experience of welding my custom designed versions in), make sure you weld a small amount on one side which will pull in the direction of where you welded (as the Heat Affected Zone contracts). You then have to weld on the opposite side of equal length to 'pull' the bracket back into position.
Swearing helps
Hitting with a bloody great big hammer helps too.
Use a stitch timer on your MIG welder (or do it manually), which will put less heat into the area, in turn making the bracket pull less.
Author:  DAZDA [ Thu Feb 10, 2011 1:06 pm ]
Post subject:  Re: Tricks to re-installing rear a-arms to crossmember!!
SR20Datsun wrote:
DAZDA wrote:
socrates wrote:
....static toe.....
Camel toe?
:rofl:
Page 2 of 2 All times are UTC+11:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/