my JTOP - big new tyres and raised vs low - PICTURES!

[WTF]

heyas

after an incident last night, involving some debris spiking through my front tyre sidewall, and also through my CV (which i got fixed this morning), i took a visit down to 'FOURBYS' in moorooka, and decided (as i always do) since ive busted something i wont just replace, ill upgrade.

so, i decided to see what i could get in the way of larger tyres (since i already had 265/75/16 on there, i didnt think i could go much bigger). Fourbys hooked me up three cooper discoverers - 285/75/16 with a pretty agressive pattern and lots of tread for the front (and spare), and a pair of goodyear 285/75/16 for the rear with near new tread - cost (after trading my old 3x maxxis mudder bukshots) was $300 fitted and balanced. which i was pretty damn happy with no trouble recommending them for people on here

was a little concerned about rubbing with the larger tyres, also since these ones have a bit of sidewall tread as well. But on high or low settings on the height adjustable factory suspension i found no rubbing for the drive home on full lock either way. Off road at full travel remains to be seen though... i dont have a body lift, but i have a suspension upgrade, not sure how much higher over standard, prob around 2" ... has upgraded HD springs and torsion bars.

I took a few pics of the car with the bigger tyres, but unfortunately from these you cant really tell the difference between UP/DOWN mode (i took a few pics showing the wheel arch gap which helps illustrate the different modes though).

LOW WITH 33s:


HIGH WITH 33s:



I had a bit of a play with the height adjustable suspension as well and took a look at travel left in the IFS when at full high mode.. seems its pretty much running on the (already trimmed down!) bumpstops at high!

image below shows how close the stop is on high mode:



whats the implications of running the car so close to the bump stops? i mean i know it will be not going to travel down any further once it hits, but is that really a bad thing? im guessing i cant really get any more travel out of them by the look of them hehe - maybe another couple of millimeters.

i pretty much only intend on using HIGH mode when i really need it (ie if i get bogged or the terrain calls for it), since the hydraulic system seems to leak over time, and id rather it be there when i really need it, instead of just having it high all the time.

heres a couple of pics for those interested in the amount of lift the factory hydraulic suspension gives. Since i wasnt standing exactly the same distance back between shots its hard to tell but compare the position of the chassis rails to the wheel rather than the wheel arch itself cos they dont stay a consistent size.

FRONT LOW:


FRONT HIGH:



REAR LOW:


REAR HIGH:



hope this helps some people who are curious, and if anyone has any suggestions as to whether im going to have issues rubbing on these tyres at full excursion, or about their ideas on cranking the suspension to near bump stop, let me know

thanks,

mark

[J Top]

Hi Mark
do a search on ball joint flip

[WTF]

thanks for the pointer.

spent a while reading through the ball joint flip idea.


my impression thus far pretty much is that i dont see that im going to want the car to sit any higher than it is now already (for fear of busting the cv's - ive already caned two in a fortnite heh), and secondly that, the whole idea of gaining 'droop', well how much is that really going to help? considering that droop is pretty much just going to be the weight of the wheel/tyre/unsprung mass falling into the hole or gap under the wheel itself, so the fact remains without weight pressing down on that wheel, whats the point of it touching the ground when it wont get you any traction anyway?

i just dont see much point in having a wheel sitting on the ground for the sake of it just balancing there when it wont contribute to traction anyway?

at least with the way the car is sitting now, even though its pretty much at max excursion downwards, at least at this height i know this is where some weight is being pushed down on it ?

i guess theres always going to be a 'little' weight, and every little bit counts, but i dont know if its worth doing at the expense of breaking a cv (when the joint is bent at such a harsh angle), i guess taking a better line or taking your time would be a better thing rather than just going hell bent on the line that requires the most travel.

though im not very experienced with IFS, so i might be missing something here.

i guess i come from the old Solid axle in my past cars, so it kind of sucks to realise i only have like 8inches of travel up and down hehe.

[J Top]

I dont think you did enough reading. The wheel is under tension for as far as it can travel. If you flip the ball joint the cv angles improve.

[WTF]

heya,

thanks again for the reply

im still slightly confused.. if the car sits at that height, no matter where the ball joint is, unless you make the wheel itself tilt knocked knee'd (ie positive camber - and that would only change the lower cv itself), how can the cv angles change?

i mean the transfer case stays in the same place, and the wheel itself is staying at the same place, changing the geometry of the wishbones shouldnt affect the angles the cv (as i can see anyway?).

the only way i can understand the cv angle should decrease at all, while maintaining or increasing the RIDE HEIGHT, would be to make longer drive shafts so the track was increased, reducing the cv angle.

i do see that the ball joint flip will change the position of the bump stop against the wishbone, and allow more movement in the wheel travel downwards, which will increase cv angles even further as the "droop" of the suspension comes into effect.

unless im totally missing the point, thats how i see it ?

thanks again,

mark

[Alex Kogan]

I dont think you did enough reading. The wheel is under tension for as far as it can travel. If you flip the ball joint the cv angles improve.

Don't. Aside of safety another bad thing about flip with adj hight susp would be incorrect castor. On normal suspension once you flipp since one's car rides at particular hight castor can be adjusted to correct value. On adjustable susp setting castor at one ride height will mess it up riding at another. Flipping bjoint will give you even opportunity to mess it up even more. Eat you tires in no time.

[Alex Kogan]

If you flip the ball joint the cv angles improve.

How is that possible?

[-Scott-]

If you flip the ball joint the cv angles improve.

How is that possible?

Good question!

[WTF]

If you flip the ball joint the cv angles improve.

How is that possible?

Good question!

thats what i was saying in my rather long message

[NJV6]

Because it is only the top arm that is being changed, as far as I can see, it is only the fact that you can get your camber/castor better with a BJ flip on a lifted vehicle that would have any effect on the cv's.

It is a good mod, ride quality improves (less hitting of bump stops) and regain down travel.

NJ

[J Top]

To quote the most famous teacher of all time,"oh ye of little faith"
Raising the suspenion effectively shortens the top A arm, tilting the top of the wheel in and increasing cv angles. There are generally not enough shims to remove to adjust this. Placing the A arm above the joint effectively lengthens the arm, pushing the top of the wheel out, which by the way is camber not castor, improving cv angles. You are creating possible engineering and insurance issues. You are also altering your Toe Out on Turns and your Bump Steer but neither has seemed significant on the maybe 10 vehicles I have changed.
J Top

[WTF]

hehe, yeah im following u now

i havent noticed my camber overly changes between the upper and lower settings, but it makes sense.

as it is my tyres sit kind of outside of my guards, so i wouldnt want the camber adjusted i dont think..

thankyou kindly for the explanation, i just didnt realise the camber changed so much between the suspension being higher and lower.

mark

[NJV6]

To quote the most famous teacher of all time,"oh ye of little faith"
Raising the suspenion effectively shortens the top A arm, tilting the top of the wheel in and increasing cv angles. There are generally not enough shims to remove to adjust this. Placing the A arm above the joint effectively lengthens the arm, pushing the top of the wheel out, which by the way is camber not castor, improving cv angles. J Top

Oh ye of little faith - thats a good description above and it basically what I was trying to say but in a round about manner. And yes of course it is the camber I just didn't remember which one it was. Mine still steers nicely as well and after the flip, the cv's just look better too.
NJ