Nissan 370Z Forum - View Single Post

semtex · 04-23-2009, 01:22 PM

Imagine looking at a wheel from the top down. So the wheel is standing upright (not laying flat), and you're looking down at it. Now in the middle of the wheel is the hub where you actually mount it up to the lugs on the car. If that hub is dead center, then the offset is 0. If the hub is moved outwards towards the outside of the wheel, then it has positive offset. For example, +22 means that it is 22mm to the outside of dead center. If you move it inwards, it has negative offset. -22 would be 22mm inside of dead center.

Now here's where it gets a little tricky to visualize. The smaller the offset, the more the wheel pushes out away from the car. Most people think the higher the offset, the more the wheels push out, but it's actually the opposite. Because think about it. The higher the offset, the more the center is pushed outwards, right? Well, the more the center is pushed outwards, the deeper in the wheel must go before it contacts the lugs. So if you want to push the wheels outwards (for a wider stance), you actually want to decrease the offset, not increase it.

Our stock rear wheels have an offset of +30. So if you wanted them to be pushed out by 10mm, you'd want an offset of +20. You can accomplish this by getting new wheels, or with spacers. For example, Minicobra put 15mm spacers on his rears. So his rear wheels effectively now sit where they would if they had an offset of +15 (30-15=15).

The Rays G2 fitment chart says for rears, we should get an offset of 22. So they are pushing out by 8mm relative to the stock offset.

Make sense?

04-23-2009, 01:22 PM	#5 (permalink)
semtex A True Z Fanatic Join Date: Jan 2009 Location: Behind enemy lines Age: 53 Posts: 5,995 Drives: People to drink Rep Power: 32	Imagine looking at a wheel from the top down. So the wheel is standing upright (not laying flat), and you're looking down at it. Now in the middle of the wheel is the hub where you actually mount it up to the lugs on the car. If that hub is dead center, then the offset is 0. If the hub is moved outwards towards the outside of the wheel, then it has positive offset. For example, +22 means that it is 22mm to the outside of dead center. If you move it inwards, it has negative offset. -22 would be 22mm inside of dead center. Now here's where it gets a little tricky to visualize. The smaller the offset, the more the wheel pushes out away from the car. Most people think the higher the offset, the more the wheels push out, but it's actually the opposite. Because think about it. The higher the offset, the more the center is pushed outwards, right? Well, the more the center is pushed outwards, the deeper in the wheel must go before it contacts the lugs. So if you want to push the wheels outwards (for a wider stance), you actually want to decrease the offset, not increase it. Our stock rear wheels have an offset of +30. So if you wanted them to be pushed out by 10mm, you'd want an offset of +20. You can accomplish this by getting new wheels, or with spacers. For example, Minicobra put 15mm spacers on his rears. So his rear wheels effectively now sit where they would if they had an offset of +15 (30-15=15). The Rays G2 fitment chart says for rears, we should get an offset of 22. So they are pushing out by 8mm relative to the stock offset. Make sense? __________________ "There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) \| 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf.