Increasing Track

[Russman]

Hi all.

I have 2 cars. R32 gtst that I use mostly for track and an FG XR6 Turbo ute.

The reason I'm asking about increasing track is for 2 different reasons. Increasing front camber on the 32 and trying to get the wheels to fill the rear guards in the ute.

I'm planning on installing R33 lower control arms (longer by 15mm I believe) for my 32 and it will increase the front track. What I want to know is how much it will increase by and how much will it effect my handling? and in what way? more oversteer???

For my ute I want to use 30mm spacers for the rear to try and push the wheels out into the guards to make it look better (30mm each side). What will this do to the car? Will it be more prone to understeer???

So yeah. Comments and feedback on what experiences you guys have had with playing around with increasing track.

[Roy]

You are better off going for wider rims to increase the track and throw in some upper adjustment to get the camber you need.

Changing the lower control arm length means you may end up with bump steer issues and need to change the tie rod length and location etc. I dont know to be honest, but suspect that unless you are in for the whole hog with testing, then with suspesion less is often more.

I want to mod lots of my suspension and have a few plams, to that i can drop the ride height whilst still having neat std geometry...lol but i reckon it will be a disaster and my car is destined to look like a pansy with its std ride height

[Russman]

You are better off going for wider rims to increase the track and throw in some upper adjustment to get the camber you need.

Changing the lower control arm length means you may end up with bump steer issues and need to change the tie rod length and location etc. I dont know to be honest, but suspect that unless you are in for the whole hog with testing, then with suspesion less is often more.

I want to mod lots of my suspension and have a few plams, to that i can drop the ride height whilst still having neat std geometry...lol but i reckon it will be a disaster and my car is destined to look like a pansy with its std ride height

Yeah.

I really wanna stick with 33 GTR rims (I have lots of them) and not sure if adjustable upper arms will give that much camber? I really don't want to widen track at all. Just at $50, 33 lca's seem like a cheap way of getting camber.

Have you considered roll centre adjusters? The longer ball joint things? From what I understand they allow a lowered car to maintain std geometry.

[R32Abuser]

Have not played around with this on road cars, however the same principles apply to the Formula SAE vehicles I have worked on.

Essentially, the goal to maximizing the potential of the tyres to generate grip is to equally load (vertically) each tyre. In racing, the aim is to run as wider track as practically possible (or as the rules allow) in order to minimise weight transfer during cornering (known as lateral load transfer). This ensures that each tyre is evenly laden. In essence, what you are changing will generate more grip on that SPECIFIC axle, and hence will cause oversteer (if anything). Since it is the front, the tendency will be for the front to generate more grip. However, the change you are talking about (less than 30mm overall due to the inclination of the lower control arm) is small (30/1460 = 2.1% change in track) and I doubt a hugely noticeable effect will be felt. You could also achieve the same track change from running more negative offset in your rims (-15 less than what your current setup is).

The more noticeable effect will be the additional camber which is achievable which will help to generate heat in the tyre faster, whilst also providing more lateral force due to camber thrust. Alternatively, this will obviously wear tyres quicker aswell as well as potentially overheating the tyres (depending on how much negative camber you run).

You will also increase your King Pin Inclination (KPI), which will increase the amount of positive camber that will occur during any steering/cornering manoeuver. This is good for generating grip on the inside tyre, but detrimental for the outside tyre. Another problem is that KPI increases the 'jacking' forces seen during cornering, which generally cause the inside rear (and even front in some racing vehicles) to unload and in some cases lift of the ground. This is bad for utilising your tyres evenly.

As Roy stated, you may also end up with bump steer, although Im not entirely sure this would occur as you are simply increasing the length of the bottom pivot, rather than changing the angle it generates with the ground.

Take all this with a grain of salt so to speak...

If I were you, and your simply after camber, just get a good set of adjustable upper arms and be done with it.

Cheers,

David

Edited March 29, 2010 by R32Abuser

[Russman]

Thanks. that's good info. The increased grip on the specific axle is what I needed to know most.

Happy with the camber that should be achieved. About 3deg which should be fine. I still have whiteline adjustable bushes for a bit of adjustment.

You lost me with the KPI stuff though haha.

2.1% doesnt seem that much. If the oversteer is increased hopefully I can dial that out with swaybar adjustments.

I'm starting to think that I should wait for the next track day and pyro the tyres to see how much camber I really need.

[bcozican]

i think i have gone just about as wide as you can go without using spacers on the front of my r32 gtst got r33 LCA's (10mm longer and give -2.5 deg camber at my ride hieght) , Kazama extra length tie rod ends with extra lock with bump steer adjusters on each end, s14 steering rack (bout 5mm longer each end) and run 17 x 9 +17 p1's with 235's on the front. I also have camber adj up top run total of -3.25 deg and castior running 7 deg. Running 27mm whiteline adj swaybars front n rear too front on medium

People told me everything from rims wouldnt fit in gaurds to that much increase in front track will tram line you... i use mainly for drift but do sprint series as well and can say that personally i think the handling for both is awesome can dial out most oversteer with sway bar adj and coiler damper adj

go wide ... go big

[Harry-Hotpants]

i will say it again and again, u have too much dosh lol, ur car is far superior to mine

[bcozican]

i will say it again and again, u have too much dosh lol, ur car is far superior to mine

haha you nob... dont spend money on painting like you do lol spend the coin on parts

superior car maybe but driver has to be able to too... still working on that bit

[NZM.031]

im still in the build stage, but ive been playing so far with s14 rack and r33 lca's, i really dont have anything to report though so consider this post useless but im going to keep one side competly stock, wheels and play around with the angles of the other side to get it to be all sweet.

no in all seriousness...

the boys at ns.com are chopping and rewelding extensions and strengthening their lca's.. i think one guy even has extended 30mm.. they are also drilling new holes in the crossmember and mounting the lcas higher..

could you possibly reinforce the end of the crossmember by boxing it in at the bottom, and drill a closer to the end and higher up than before??

now i know that sydney kid warns against r33 lca's, due to bump steer... but im wondering..

what if you extend everything out by... lets say 30mm... so you add 30mm to your top arm or fabricate a new top mount... or add a 30mm plate behind the original mount, 30mm to your lower arm and 30mm to your tie rod..

keep all the same alignment, but everything extended out 30mm.. then play from there... would that work?? you would have to mount the castor rod at its original angle by drilling new holes in the control arm.. but thats easy.

because everything is the same.. would you need rca's?? the longer arms at the same spring height will make the car higher, so youll need to lower it more, but it would be then no different to how it was before...

if you get rca's do you need to then do something with the top arm??

having said all that...

on one side i have a 17x9 +25 and on the other side i have a 17x8.5 +not sure but less than 20 and the 8.5 sits way more out than the 9 does.. and the 9 has an r33 lca and the 8.5 side has the original r32 lca.

[R32Abuser]

hahah notice a mistake with the KPI...KPI affects the steer-camber characteristics of the car. That is, how turning the steering wheel causes the wheel to gain or lose camber. Its reasonably in depth, but overall the thing to keep in mind is that increasing KPI (more positive KPI) will cause both the wheels to gain greater amount of positive camber. Positive camber will help the inside tyre generate grip, whilst decreasing the grip generated by the outside.

In terms of bump steer, although I said that I couldnt see how it would cause greater amounts, I would only really know the answer when I would install the LCA. If Sydneykid has said it will cause bumpsteer...BELIEVE IT. He is a wealth of knowledge with more experience than 99.99% of members on this forum. If he has warned against them, dont use them if I were you.

[Duncan]

just be careful with the ns parallels, they run strut fronts which are totally different to double wishbones.

i have a modified subframe with LCA about 2cm further out for about 2o more camber, and also 2cm more track. feels much better up front with reduced understeer

[NZM.031]

is that with r33 lcas or r32 lcas duncan??

yeh the ns.com boys have mac sturts... so it s a bit differnt, but still, it can be done..

how do bump steer adhjusators work>??

p.s. if im talking like fatz is because imj in a fatz like state.. my apologies.

[TurboDoseBro]

It's all about the tyres bro!

[Duncan]

32 LCAs.

bump steer adjusters - depends which ones and where. To me it's about protecting the carefully researched/developed factory geometery with a little more of what I want like lower and more camber. Thats why I run the wider LCA point instead of shorter upper arms, to keep it more like factory setup.

longer lower ball joints help give lower ride height but it is very difficult to do the same with the UCAs.

spacing the tie rod end down is probably more important in most cases but you would need to measure the bump steer fully to be sure you are in the right place for a given setup.