87 300ZX Turbo Offset Question

[sparticus13]

I have a 1987 300ZX Turbo Auto. It has stock tires and wheels on it. I am planning on buying some new custom wheels and tires. According to

 

http://www.az-zbum.com/information.wheels.and.tires.shtml

 

My car has a stock of 16"x7" wheels with and offset of +30 on both front and rear. Has a bolt pat of 5x4(5x114.3).

 

I am looking at a few different wheels right now. All have the same specs of:

 

17"x7", 5/114.3, 40mm offset.

 

So its 10mm diff in offset. I tried looking at the guide on

 

http://www.az-zbum.com/information.wheels.and.tires.shtml

 

I think Im not reading it right. If some one could tell me if these wheels will work without a spcer or if I will need one and what size, that would be great.

 

According to the guide

 

"To figure out how much of a spacer/adapter you need, it is only simple math. For instance, you pick up a set of wheels that are 17x7 with an offset of +42 for your 86 300ZX. First, expect people (especially butter) to laugh at you. Second, get some adapters IMMEDIATELY. To determine the actual spacer width you need, look at the chart above. Find the 7.0" width row. Find the applicable year column. Look at the number where they meet. Minimum recommended offset is -16mm. To determine thickness, you subtract the recommended offset from the wheel's offset. In this case, you'd subtract -16 from 42.

42 - (-16) = 58. You'd want spacers/adapters that are 58mm thick. Or roughly 2". "

 

If that is right and if I'm reading it right (proly not). The wheel chart shows -6 for the min offsett on both front and rear on the 1987 model and a 7" tire width. So I would do.

 

40 - (-6) = 46.

 

So do I really need a 46mm spacer for a wheel that is only 10mm diff in offset?????

 

 

Any help would be great.

 

Also I will be lowering the car by exactly 1" all around.

 

Thanks

Chris

[sparticus13]

bump

[h4nsm0l3m4n]

I dont know much about the Z31s but I think youre doing the math exactly as its done in that paragraph. I could be wrong but it seems to me that 46 mm spacers seem awfully huge for a wheel that is only 10 mm different in offset. By the same logic your stock +30 offset wheels would need 26 mm spacers and you know they fit fine.. theyre stock. I think whats going on is that 46 mm spacer is what's required to get the car to the minimal recommended offset on the chart.. this does not necessarily mean that your wheels wont fit as they are now. Does that make sense? Someone let me know if I'm wrong.

 

I would try to determine how much clearance you have behind your wheels currently and use that as a judge on what will fit and what wont. If you cant stick your head back there to look you can get something to use as a feeler gauge and poke around. My guess is ~10 mm (3/8 in) spacers will be the thickest youd need, should be reasonably cheap to make too.

[itsadatsun240z]

Got a friend with similarly sized wheels?

 

Wouldn't take long to take his wheels off and mount them on your Z31 just to see if they even clear the suspension/brakes.