what offset?

[Guest traub83]

for a 9" wide wheel for my Z what offset would i need to buy for a stock suspension setup?? Im lookin at buyin some 18x9 for the rear and some 18x8's up front just i donno what offset id need? and my car is at the paint shop for the next 2 weeks so i cant really go measure anyone help me out with this?? and is a 9" wide in the back the most I can go or can i go even wider??

[Guest JAMIE T]

FWIW, have 18 x 9.5's on all four corners. Granted, I have ZG flares. My wheels have a 5.5" back-space. I don't know how many mm's offset that is. I've never taken the time to figure it out. They DO NOT fit under the stock fenders. The ZG's are a modest flare. I do have a pair of 18 x 8's w/ 5" backspace. I was going to try them on the front to see how they looked. I would have to use a wheel spacer put them out to edge of my flare like I want. They should fit nicely under a stock fender. I bought them becuase at some point I want to put Brembo calipers on my car, and needed a few more mm's to clear them(hence, the wheel spacer).

[Drftn280zxt]

you would want 0 offset. Because a 9inch rim is really 10" wide. thus with 5inches of backspace, correct me If I'm wrong Jamie, which is required at minimum on a 240Z that would would put the offset at Zero since the centerline is at 5". Hope that helps.

[tonycharger72]

Hi mate,

 

I thought this might help,

 

http://album.hybridz.org/showphoto.php?photo=4611&cat=500&page=1

 

Its a pretty dodgy drawing and its not to scale, but it shows what i have found through lots of measuring and personal experience about how much room you will find under the guards of a stock bodied stock suspensioned zed,

 

I figure there to be at most 230mm worth of space at the front, i am using different hubs which increase offset 8mm, and using 17 x 8" rims with a 6+ offset and 235/45-17 tyres, this equates to effectively a -2 offset and an 8" rim,

Below are pics of the result,

Lots of clearance between the springs and the wheels/tyres - 15mm approx, should try and not have less than 10mm,

And on the outside the wheels poke past the guards by around 20-25mm,

 

http://album.hybridz.org/showphoto.php?photo=4381&cat=500&page=1

 

http://album.hybridz.org/showphoto.php?photo=4380&cat=500&page=1

 

In answer to your questions,

 

"for a 9" wide wheel for my Z what offset would i need to buy for a stock suspension setup??"

 

Max space i would say you have is 115mm for backspacing, this is 4.5" approx worth of backspacing available, so for an 9" rim (actaully 10" wide approx), this would mean,

10" x 25.4 = 254mm

Divide this number by 2 = 254/2 = 127mm (this is so we get to a zero offset),

Now we know that we have 115mm worth of backspacing before we hit the springs, therefore,

115-127 = -12,

 

So, to run 9" rims on the front of your stock suspensioned zed you would need a -12 offset,

 

But we know that we have 105mm worth of clearance for forward-spacing, now lets get back to the zero offset figure, 127mm, and add 12mm to this figure (because this is how much we have decreased backspacing by, so it has the opposite effect on the forward spacing), 127+12 = 139mm, which is 5.47" approx of forward spacing,

Depending on tyre choice, i'd say your wheels/tyres are going to be poking past the guards by around 30-40mm, so you are going to need some flares if you want to put 9" rims on the front of your zed,

 

To be honest i think the biggest rim you can stick on the front of a stock bodied, stock suspension zed is 7.5 and you would have to get the right offset, 0 would be about right, anything bigger and you will either need to modify the guards (like i have to) or use smaller OD coilovers,

 

 

As for the rears,

 

I have the same 17 x 8" rims with 235/45-17 tyres, but no increase in offset, there is miles of space between the spring perch/strut and the wheels/tyres, sorry i dont have an exact measurement for you,

But the wheels/tyres sit in a straight plain down underneath the guard, they are perfectly in line,

So you could probably go to an 8.5", maybe 9" rim and probably a 255 tyre, but i think that wide would be seriously pushing your luck,

[Guest traub83]

well darnit!!

 

I wish I would have gotten this about 10 hours ago but ohh well ill make them work. But I just bought a set of wheels no tires tho as im unsure on which to get.. But I bought a set of 18x7.5" with a 48mm offset, and a set of 18x9.5" with 35mm offset, now I will be needing to get the wheel adaptors to the honda bolt pattern so my front wheels should be ok, however my backs will be off so I will then order the subtle Z fenders which will give me another 1.5" to mess with and I decided to just do it and get coilovers so that should help out also.. SO with getting coilovers, and the fenders I should be able to fit these wheels in the back depending on the tire size I choose correct?? Im thinking on running Nittos all round prob the 555 extremes up front and the drag radials in back just what size's I am not positive yet...

[tonycharger72]

Ummmmmm, probably not mate,

 

You will approx 168mm worth of BS with those rims on the rear, even if you did get coilovers you will probably still run out of space, i think you are going to need adapters on the rears aswell mate,

 

I'd just f#ck off the coilovers and get adapters for the fronts and the rears, save yourself alot of coin,

[NZeder]

Here is pic of my wheels on a Zed (dads) with stock suspension. These rims have 4.5" backspace are 16x8.5 -6 (so from rim to rim 9.5" = BS 4.5")

 

Hope this helps with what will work with stock setup.

 

[Drftn280zxt]

okay now I'm confused. Does backspacing take into account the outer flange? I thought it did. Okay so refresh, 240Z's need at least 4.5" bs w/o coilovers and at least 5" bs with coilovers. So what about S130's, same thing or different?

[Zhadman]

Here guys:

 

http://www.rsracing.com/tech-wheel.html

 

Very informative.

[Guest traub83]

Ummmmmm' date=' probably not mate,

 

You will approx 168mm worth of BS with those rims on the rear, even if you did get coilovers you will probably still run out of space, i think you are going to need adapters on the rears aswell mate,

 

I'd just f#ck off the coilovers and get adapters for the fronts and the rears, save yourself alot of coin,[/quote']

 

So pretty much with the subtle z rear fenders and the honda wheel adaptors from modern motorsports, the 9.5" wheels should then fit without the coilovers? or would i then need coilovers for those to fit and what is the max size of a tire id be able to sqeeze on those wheels and under the car with the subtle z fenders?? If it will help i can switch the rear wheel size to 18x8.5" with the same 42 offset, as my 18x9.5's are on back order.. if I go with the 8.5" wide wheels then what would be my max size on tire then?? I want the most meat I can fit under this car with what I have...

[Guest traub83]

Here is pic of my wheels on a Zed (dads) with stock suspension. These rims have 4.5" backspace are 16x8.5 -6 (so from rim to rim 9.5" = BS 4.5")

 

Hope this helps with what will work with stock setup.

 

 

Was this setup on stock fenders as well?? and what tire size was this??

[Clifton]

For a 17x9" or larger to fit in the rear without flares on with the stock thickness drum it would need to have a 24mm offset and you'd also need an 8" coil over. The less offset the furhter out it'll move it. An 18x9.5 would fit too, you would have more room on the strut to move it in but you would need to massage the inner body some as moving the offset out 12mm would cause quite a bit of rubbing with a 275. 0 offset on the front.

[Guest traub83]

so how much of an offset do those modern motorsport wheel adaptors add to the car? does it push it out another 20mm so then the 25mm whell I would need before would then need to be a 5mm? I hope I said that right but basically how much of an offset do those adaptors add?

[Clifton]

Are you going to be able to find 4 lug wheels in the offset and width you want? You might want to look at your wheel options first. They will be VERY limited in the width you are talking about without going to 5 lug , 3 peice, or Volk.

[tonycharger72]

Traub83,

 

http://www.modern-motorsports.com/catalog/product_info.php?cPath=24_44&products_id=6

 

These adapters seem like they are 36-40mm offset wheel adapters, so with the fronts you bought "18x7.5" with a 48mm offset", lets assume you get the biggest adapters Ross has got, the 40mm,

This increase in positive offset effectley means you will end up with a 8mm offset on the fronts (this is what the adapters do, effectively decrease the wheel's positive offset - ie........push the wheel out),

So on the fronts you now have a 8+ offset and 7.5" rims,

So 8.5" x 25.4 = 215.9mm/2 = 108mm approx,

Now add 8mm to find you Back-Spacing = 116mm

Fordward-Spacing = 100mm,

Therefore if you use these wheel adapters on the front with you new wheels and tyres they should fit and you should not have to roll your fenders or change to smaller OD coilovers,

 

As for the rears, i cant give you an exact figure at the moment, but i will do some measuring for you tonight and get back to you,

[Guest traub83]

cool thanx tony, please let me know on the rears with the 8.5" wheels. Also what would be the max tire size ya think I would be able to squeeze under there? 245/40zr18's? maybe?? or for drag radials think i could squeeze those nitto 555 drag radials that are 305/35r18?? I knw those ones are wide but hey never hurts to ask i guess.. remember Im askin based on stock fender's. and if those 305's wont fit how much would they stick out from my fender?, enough to be covered by the subtle z fenders or still too wide?

[NZeder]

 

Was this setup on stock fenders as well?? and what tire size was this??

 

if you visit my site your questions will be answered with pics but tire = 225/50/16 on 16x8.5-6 on the fronts. Yes this was installed on dads car with stock fenders but there will be clearance issues (see pics on my site). These wheels are for my car which is flared - I need to check the BS to make sure I did not need coilovers (suspension still out of my car).

[Guest traub83]

nice pcs of the cars, there really nice!! those pics i see of you fittin your wheels on your dads Z, the last picture has me confised a lil tho, did you test fit 16x8.5" wheels up front and 16x9.5" in back or just the 16x8.5" in back. Im just tryin to figure out what size is in that #9 photo as the wordin has me confised some... Cause it says front 16x8.5" with 225/50r16 and rears with 245/45/r16 tires on 16x9.5" wheels is this correct and what the pics show?? if so I really like it and would look really good with my rear fender flares...!! Thanks for the info man!!

[NZeder]

nice pcs of the cars, there really nice!! those pics i see of you fittin your wheels on your dads Z, the last picture has me confised a lil tho, did you test fit 16x8.5" wheels up front and 16x9.5" in back or just the 16x8.5" in back. Im just tryin to figure out what size is in that #9 photo as the wordin has me confised some... Cause it says front 16x8.5" with 225/50r16 and rears with 245/45/r16 tires on 16x9.5" wheels is this correct and what the pics show?? if so I really like it and would look really good with my rear fender flares...!! Thanks for the info man!!

 

Thanks for the comments - when test fitting my wheels on Dad's car I installed the 8.5" on the front and the 9.5" on the rear. The fronts tires are 225/50/16 and the rear tires are 245/45/16. Hope that clears things up a little.

[Guest traub83]

yes it does and it looks really good, a small fender flare would cover up the rear tire very easy it looks and ya will have plenty of traction out of them.. I think I will go the same size tires just in my wheel size and change my rear wheels to a 4.5" backspacing then I got my wheels and tires!!! Thanks a good amount bro... also what wheels did you get there for your car anyways there pretty sharp lookin on the Z..??