Increasing track/offset

[CrUZida]

Any help on this one is appreciated - i'd also like to get the car engineered in WA - so I'd like to make it all legal

Never ever ever going to happen.
25mm increase in track total is all that is allowed.

[oldcorollas]

unless you are say.. swapping cross-member, lower arms, and struts from a wider track car....

for diff it onyl relates to the original width of the diff (as a bearing issue), but for fronts, i reckon it can be interpreted to be the track of the components, whichever ones are used...
so.. 12.5mm more track from each rim, and then 50mm or so from using different components?

[merc-blue]

ok well..........
don do it unless your prepared to build it as a track only car.
the bloke who recommended S13 coilovers is a idiot... anyone who puts a S13 front in anything but a S13 is a idiot...
could be nicer about it but to lazy.

Increasing the track width of the car through offset will put more load on your wheel bearings and studs.

It can be done but you would really want to fabricate axel stiffners.
But you will lose alot of the front end geometry, would be fine for a show car but not for track.

I haven't been under many coronas but I'm pretty sure it wouldn't be that hard to legitimately widen the front but there is no way in hell you will drive anywhere without getting alot of attention from police.

The rear will be harder but can be done.
find yourself a legitimate engineer who understands the dynamics and requirements of a track car (which is pretty hard to do in WA).

If your going to do it, do it properly.
I would estimate your looking at a 5grand or more spend to do it properly and that without worrying about some of the more "minor" geometry changes you will encounter

[WDE_BDY]

I've put a TA63/TT142 under my KP60 Starlet which stretched the wheelbase 4 inches and put the wheels out 4 inches each side. There are not many donor options to do the same to the TT142 though unless you want to get into really serious fabrication work which would probably never be road legal in Oz anyway.

Callum

[CrUZida]

unless you are say.. swapping cross-member, lower arms, and struts from a wider track car....

for diff it onyl relates to the original width of the diff (as a bearing issue), but for fronts, i reckon it can be interpreted to be the track of the components, whichever ones are used...
so.. 12.5mm more track from each rim, and then 50mm or so from using different components?

Even then it still needs to remain within 0 - +25mm of factory track.

[oldcorollas]

but which cars factory track?
for diff, it is the track of the diff (if it is a replacement diff from another vehicle), as long as wheels are within bodywork (or so i was recently told). for front, it is a little more hazy.. but still should maintain track in relation to the donor stub axles, to keep scrub radius and bearing load the same, btu the relative position of them on the car allows a vehicles track to be wider?
is there anything that specifically prohibits it?

[CrUZida]

The car you are engineering's original track.

Regardless of what suspension/diff/axles/rims/struts you put in a car, the track must be no more than 25mm wider than the widest track that car came with.

Now, whether they will phyiscally check it is a different matter. Thats only something you worry about when you've just killed someone. But you have to state original and modified track on your mod request forms. So if you want to lie there, its up to you.

[oldcorollas]

for WA or NCOP?
for front susp, NCOP says (P38 LS-LS3/4?)

"where non-original axle or suspension cross-member components are fitted, the offset of the wheel in relation to the axle or hub assembly used must not be increased by more than 12.5mm each side of the vehicle based on the specifications of the axle components used
if an axle assembly is shortened, then the track width limit is taken as the manufacturers original track dimension, less the amount the assembly has been narrowed, plus 25mm"

i read that as, if you swap in cross-member, LCA's, struts and steering from another car, it is then based on the donor parts?
but whatever components are used, you have to keep within 12.5mm each side to protect bearings and scrub radius?

[CrUZida]

WA's transport departments interpretation of the NCOP.

[JustCallMeOrlando]

Could be registered as an ICV? Lots of dicking around though...

[camshere]

OK - Starting to look like a LOT of work here, perhaps its just better to run one set of rims normally, then another set for taking it over the pits if that ever happens - bit of a PIA - i'm sure there are structurally sound methods to widen the track of a car, shame it always comes down to the interpretation of a set of rules that everyone is supposed to fit into.

So if i go for a Zero offset rim, wider than the stock rims also, could i manage 75mm of extra track either side? Or would this just be stupidly unsafe? I really want the look of the widebody kit on this car, but i'm not going to throw 5K plus rims down the toilet when i'm only going to have a car thats not road legal anyway.

NCOP cracks me up. Sure, i can throw a 600hp 1JZ into my 1000kg car, but adding any more than 12.5mm on either side of it and it becomes a death trap

[JustCallMeOrlando]

There is perhaps an alternative. Ring the guys at the technical section in Welshpool, explain everything, and find out what your options are. Alternatively, you can ring an engineer and ask them what they can get away with, it *may* be slightly different from the "rules".

[CrUZida]

Last time I rang them up around increasing track by 38mm I got the 'well maybe if it was a special circumstance, such as building a car for the Police' or something along those lines.

Basically it was a 'no chance in hell' response from him.

[oldcorollas]

was that changing suspension components as well? or just changing rims?

[CrUZida]

That was just the rims.

A friend rang up regarding putting a diff from another car into his, and asked them which car the track/offset needs to suit, and they said you need to get the diff shortened to be the same size at the factory one.
From what you've posted they may be misinterpreting the NCOP, or vice-versa.