Outer Limits 4x4 Board

Gday, i wanna get new tyres for my f78 but i dont know how big i can gon on near stock height. back has been lifted 40mm thats it i think. what is the biggest i can go? i was thinking about 30"?? I looked at the previous threads but could only find infor on ferozas. cheers

I found even with the stock 29's (well, 235 instead of 215's) they scrub on the chassis at full lock on mine, but clear the guards by heaps, thats with 2" lift. I think you'll need wheelspacers or offset rims(cheaper and better IMO). - I THINK you'd get 31's to just clear the guards with no lift, but it'd be tight. Might need a bit of grinding, or if its IFS just wind up the front.

If you get new offset cheapo rims, should be about 55-60$, and you can get really cool retread MTRs for about $100ea (http://www.motorway-tyres.com.au/p300.htm#254) - Look down at the ground hogs or even better, the mongrels, i had ground hogs and the only fault I found with em was they wore down pretty fast (lasted about 9 months ) but thats doing about 35-40K a year on the black top.
I hope to soon get a set of 31 mongrels and rims and have them as paly tyres, so only put em on for trips.

hey mate...

Being an F78 you wont have any clearance issues on full lock up to a 10.5 or 11.5 inch wide tyre with stock rims.

I had 30x9.5 on my F78 Rocky when i bought it and have now gone up to a 31x10.5 Goodyear MTR.
You get a bit of diff clearance out of the 31", but the extra inch of width makes it look phatter and gives a bit wider footprint when offroad. There is also more options in a 31" tyre.
You can fit both sizes on the stock 15x7" rim.. backspacing is fine.. it wont need changing.
You say the rear is raised 40mm...new coils??
You can wind the front suspension up really easily and thats what I have done to mine. At stock height, the 31" rubbed slightly on the corners of the front bumper (them plastic bits) so I neatly trimmed them back a little.. wouldn't even notice. Now its higher theres no rubbing at all.

The only issue with moving to a 31" is gearing... The 31" lowers your gearing slightly so you lose some acceleration and your speedo reads slower than you're actually going.
I'd recommend if you tow a lot go with 30" but otherwise a 31" is sweet... and they look HAWT!!
I wouldn't trade my tyres at all.. best thing I have bought so far hands down... couldnt be happier

RockyF70 wrote:I found even with the stock 29's (well, 235 instead of 215's)

The F70 must have also been used as a cheese cutter skinny tyres

The F78 came stock with 255/70r15 So Phat!

yeah, well, must be the ONE advantage IFS has over solid

(yes, i will always revert to that argument )

lol

hot4ok thanks, you talk about winding up the torsion bar to get more height, is that easy to do? i havnt got my car yet its on a truck and she arrives in a week. is it something you just tighten to get more height? Is it as simple as that. cheers

Yeh it simple... theres heaps of info on here about it too for Feroza's.

Under the car about where the front doors are, there is a nut on the outside of the chassis and a nut with a long thread going through it on the other side. This one has a double nut locking it so it wont move by itself.

You undo these double nuts, then tighten the nut closest to the chassis while holding the one on the other side to prevent it from turning.
You need to do both sides and take measurements... they have to be the same height on each side.. A turn gives you a few mm each time.\

If you need more help later on give us a yell... i can take pics too if u need them mate.

thanks mate for the advise, the rocky arrives in a bout 5 days so ill give it a go. cheers

Just a tip- jack up the front end first so you take the weight off the wheels and don't break something. It will make the job so much easier.

31's can go on, but some aftermarket suspension helps.
However on really rough stuff the real tyres rub on the body and so some wheel spacers ( 12mm+ ) should stop this.

The fronts will rub on the mudflaps on lock - but the solutions obvious.

Gearing is more of an issue, with a stock motor the thing can become a real slug.

tyres rub on the body and so some wheel spacers

Mine dont rub at all with 31"s.. even at full articulation and lock

Doesn't a bigger offset makes the tyre more prone to rubbing on the guards and body (when turning) as the centre of rotation is taken out further. Thus the outer edge of the tyre will travel further than before along the circumference of the wheel travel (under steering).

P.S- I run standard rims (15x7) with 31x10.5x15 MTRs.

What can I say - mine rub at the rear under "extreme" conditions...
The front - I don't know. Perhaps different tyres have slightly different profiles especially when running at low pressures ( 15 PSI ).

Yeah all tyres bag differently and have differing overall diameter from the factory... Also, suspensions undergo different amounts of flex also...

Do you have an F78?? Or do you drive a Fez?