Outer Limits 4x4 Board

Grrrrr. Have done about 4 hours research on here, had 8 relevent thread tabs open for reference ... and IE crashed

Planning out suspension mods for early next year ... trying to keep it simple and relatively tame visually, but get a decent amount of flex.

- Simex Centipede ET 31x10.5-15" (nom. diameter 32.2")
- Speedy 15x7" -15 (unless there's a particular reason for going 8" -28?)
- Redrill fixed spring mounts 30mm towards centre of car front and rear; 3mm fish plates each side
- 30mm extended shackles using 50x25x3 C-channel, no brace
- Fit existing stock (almost flat) rear springs up front with load leaf removed - gives 3 leaf pack that should keep near standard ride height (maybe a small amount of lift) with good shackle angle (?)
- Fit 2" OME rears (part no GAD07 - not sure if they're HD/LD) with the larger overload leaf removed, leaving a three leaf + single overload pack at the rear
- Redrill front spring pads 25mm, moving the diff 1" forward away from the firewall
- TrailGear 6.5's (speedo will be slightly out still, but should give reasonable highway revs)
- 2" body lift + beaten up seams, but no cutting
- Remove spring retainers all round
- Relocate bump stops to chassis and extend as required to prevent scrubbing / shocks bottoming on compression
- Measure up for shocks when done - custom front mounts to allow full compression

Is this going to work, or am I barking up the wrong tree?

I have 2" OME fronts here too (part no 9P07) that I can pinch leaves from too if required to give a bit more lift to the front.

Moph wrote: - Speedy 15x7" -15 (unless there's a particular reason for going 8" -28?)

- Measure up for shocks when done - custom front mounts to allow full compression

Sounds like you’ve got it all covered.

2 things..
my mates car is running 31” mtz’s on 15x8 -28s, tyres only protrude 3/4” to 1” from the flares, and don’t seem to rub much when flexing steering.
My other mates car was running 15x7’s, with 31x10.5s, & he ended up flipping his rims.

If you can get around the scrub radius thing (which you seem to have covered, moving diff, bashing seams etc) then I’d opt for the bigger offset. I prefer the fitment of a 10.5 tyre on a 7” rim to an 8” rim though. (dunno if flipped rims is an option for you though)

Also don’t really think you’d need custom shock mounts, once you’ve set your bumpstops to prevent tyre rubbing (lots of flex with rears up front) you should have no problem finding shocks that wont top/bottom out.

Dee wrote: my mates car is running 31” mtz’s on 15x8 -28s, tyres only protrude 3/4” to 1” from the flares, and don’t seem to rub much when flexing steering.
My other mates car was running 15x7’s, with 31x10.5s, & he ended up flipping his rims.

Hmmmm this has always confused me about rims. For a 1" wider rim (8" vs 7") with 13mm more offset (-28 vs -15), the inside edge of the rim is basically at the same position as extra rim width balances out extra offset. So I take it the only 'benefit' running the 8" vs 7" with the same tyre gives is that the tyre will not be quite as tall on the 8" as the 7", and hence less likely to scrub under compression / turning?

The tyre doesn't protrude past the rim so much. Rim width aside the tyre is still 10.5 wide thus 5.25 either side of centre, therefore any rim with -28 compared to -15 is going to help.

The transfer gears don't effect the speedo as the drive for the speedo is at the back of the transfer, it's the diff gearing and tyre size that matter.

Ah right - thanks. Speedo doesn't worry me anyway as I have a GPS.

you can have the speedo professionally calibrated for about $100 anyways dude - well worth it to know its accurate.

just cruizin' wrote: The transfer gears don't effect the speedo as the drive for the speedo is at the back of the transfer, it's the diff gearing and tyre size that matter.

This is correct as I geared mine on the weekend. Speedo on 31" tyres is out by about 15km/h at 100km/h.

2" body lift + beaten up seams, but no cutting.

I found with 15x8 wheels after moving my diff forward by 22mm, no gaurd massaging was required.

Cool - my guards have already had a soothing massage as my 235/75R15 MTR's were scrubbing on compression before I fitted the body lift.

Will definately look at speedo calibration alien, but need to work out first whether I'll run the 'Pedes full time, or swap them off for some AT's around town. I'd probably run a true 31" AT so would get the speedo calibrated to that.

Just to let you know I went the 8" speedy's for the extra width (they stick out and extra inch) and I find them great. The bump stear/wobble is noticably worse but livable and I also have the same tyres you are getting. I air the 31X10.5 pedes down to about 8psi offroad and I'm yet to roll a rim off the bead and I do some pretty hardcore wheeling.