Increasing track width.

[NeoNasty]

I understand that if you increase the width of the rear wheels it can have a negative effect on your handeling. What about if you increase them both.

Ie. Spacers and some fat ass bolt on guards? I presume you can still set it up OK as you see it so often.

What about increasing the front track width? Ie. FWD celica, with bigger wheels on the front. Any problems?

[Lambolica]

It would be Illegal on a road car unless engineered for starters....

increaseing the rear would have a negative effect.

Increasting the front would be positive effect.

Both would be a positive.

However before doing this on a road car look at the springs, sway bars etc and improve these first.

[wiso]

What about increasing the front track width? Ie. FWD celica, with bigger wheels on the front. Any problems?

thats also impossible to get engineered, you can never have wider wheels at the front of a car, the widest wheels always have to be at the back unless they are the same all round. I asked an engineer about that when i did my celica

and make sure if you do choose to go with spacers do it properly and get longer wheel studs, more safe that way

[ra23celica]

Increasing track greater than 25mm is illegal generally in all states of Australia. You can get right up to this limit with bigger/wider rims and the right offset, but I would caution you in doing this to both ends of the car at the same time, just the front only will make it handle worse. If its an ST162 I would not touch it as they are a great handling car in standard spec.
If you are chasing better handling you should be looking at bigger/better sway bars, springs and struts.

[oldcorollas]

increasing track "for a given suspension/axle unit" by more than 25mm is not legal (due to extra bearing loads etc...

however... there is nothing specific to prevent you from transplanting in an axle or front suspension setup with wider track to begin with, as long as it is done well.... and then the track measurement is based on the bew bits, not the original body.

perhaps not so feasible for a FWD tho...

[Cool1]

increasing track "for a given suspension/axle unit" by more than 25mm is not legal (due to extra bearing loads etc...

however... there is nothing specific to prevent you from transplanting in an axle or front suspension setup with wider track to begin with, as long as it is done well.... and then the track measurement is based on the bew bits, not the original body.

This doesn't work in Queensland and i'm not sure about anywhere else.

[WDE_BDY]

I've done the "transplant from another car" thing with my Starlet, but had cost reasons rather than just to widen the track. For details and pics see my members rides thread http://www.toymods.net/forums/showthread.php?t=711
The big thing is though this car is in NZ, where pretty much anything goes as long as you do it properly. The important question is what do you hope to achieve and are there easier/cheaper/more legal ways to do it? For a road car I would say don't bother, a wider set of wheels with factory offset and GOOD tyres will be a lot more effective.

Callum

[Norbie]

This doesn't work in Queensland and i'm not sure about anywhere else.

According to John Kean (who engineered my car), that's exactly how it works in Qld.

[Cool1]

Nope. Cause I have RA40 struts with the MS65 hubs which increases the width more than 25mm. This is causing some serious engineering troubles

[NeoNasty]

Kick ass, thanks guys. Yeah I would do all the usual up grades first anyway. Just seeing what avenues I had.

[oldcorollas]

Nope. Cause I have RA40 struts with the MS65 hubs which increases the width more than 25mm. This is causing some serious engineering troubles

are the hubs increasing the (effective) track of the RA40 struts? ie spacing the wheel mounting point further out?
if all you have changed is the struts and hubs, then the track change is in relation to your original cross-member, lower arms and (more specifically) steering... the idea is to inimise the changes in bump steer and gemoetry changes..
perhaps you could swap in cross-member of different car and get around it

code LS3, point 4. re: complete steering and suspension conversion

for modified suspension systems, it states camber change should be minimised. but if you transplant a stock system from a slightly wider car, then the actual suspension design is unmodified.. ie you are not changing steering and suspension gemoetry from original design.

the a little further down it says specifically:

TRACK. where non-original axle or suspension cross-member components are fitted, the offset 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 being used. if an axle asembly is shortened then the track width limit is taken as the manufacturers original track dimension, less the amont the assembly has been narowed, plus 25mm.

they are pretty specific that the track change is based on the components. so if you swap in sayy.. celica front and rear suspension systes into a corolla (or whatever) then the track is based on the suspension components, no the car itself..

this is from the new national draft of mods, but is the same wording to what NSW had before.
i would think based on the wording above, that, within reason, you cold argue that it is fine to increase track by whatever as long as the whels are covered by guards.

how do you read the above extract?

[Cool1]

I dont have the blue book in front of me, but I would say there is more specification to what you have posted.
When I fitted the hilux diff to the Celica, the blue book stated silmilar information about axle upgrades saying that the upgraded axle had to be within 25mm of the receiving cars original specification.

[Cool1]

In saying that, most engineers I doubt would even bother looking up such a thing let alone measure it.

[oldcorollas]

true...

perhaps QLD had more strict wording compared to the current NSW and these new national draft regs
http://www.dotars.gov.au/transreg/vs...19sept2005.pdf

my reading of the previous NSW rules (virtually identical to these) and initial consultation with conservative engineer seemed to indicate no issues, as locg as track change of donor to recieveing car was not too substantial (100mm total was thought to be ok as long as it didn't affect ackermann angles greatly)

[Youngy]

What old Corollas has stated is true in far as my experience within NSW. Even so if you have used the front end components of a slightly wider car etc as your donor most engineers I have dealt with (outside Sydney) will be more concerned with bump steer and adverse steering/suspension affects than they are over track.

Which is sensible.

[magicmitch]

i have reason to believe that my ra28 has modified track width in the front...as u can see in the pic it looks wider than normal..from wat i can see i dont see any spacers or anything..wat could i look for so i know for sure wat mods were done?

[Billzilla]

I widened the front track of my Sprinter about 50mm, by making the lower control arms longer and using the camber adjusters on the tops of the struts to keep the camber how I wanted it.
The extra width was well worth it, the car handles much better.

[45aken]

the wider your wheels are apart, the lower your centre of gravity. it is effectively the same thing as lowering your car. if you increase front track, you will have better turn in, better response and the car will want to oversteer more. increasing the rear track will make the car harder to turn, and more likely to understeer.
increasing the front track is worth it, as long as it is done properly, if you are modifying the track fron tand rear, i would suggest a little more on the front. you'll be amazed in how it changes the feeling of your car.

[RobertoX]

^^ huh? you could have a higher centre of gravity and a larger track width...

the track width and CoG height determine the weight transfer for a given lateral load, wider track gives less transfer as does lower centre of gravity. Less weight transfer between sides is generally a good thing as it increases the overall cornering potential of the car.
I think having a wider front will induce some forward weight transfer also, in a FWD car this might be beneficial particularly (similar to adding a stiffer rear sway bar)


I did the sigma control arm thing with camber adjusters on my sprinter, something like 20mm each side I think and the effect was much better than I expected,
Less body roll and turn in seems to be a lot better now. I was worried that the reduction in ackerman might have an effect but it hasn't done anything noticible.


magicmitch I believe that this can also be done on an ra28, if you really want to know check the length of the front lower control arms on your car and compare them with standard. There are plenty of different length toyota ones that could have been put in also. Another thing to check is whether your struts/hubs are the standard ones, I know that when I changed to ra40/ma61 gear on the front of my last car it pushed the wheels out marginally. (nice celica btw )

[Billzilla]

the wider your wheels are apart, the lower your centre of gravity.

How do you work that one out?
You can have the track as wide as you like, but it'll make no difference to the height of the centre of gravity.
It does, however, increase roll stiffness.