What is the safe amount of wheelspacing I can do with the factory studs? ie wheels spacers of 1/8"? 1/4"? Also, this modification increases wheel base, therefore increasing handling. Is this correct?

I dont know about the largest amount but handling wise an inch more in width really isn't going to do anything for your handling... nothing noticable anyways...

as long as your lug nuts tighten down all the way you should be fine.... so long as they don't hang off the end...[ and yes i've seen a honda like that]

I don't think this will help performance enough to 'off-set' (pun intended) the negative aspects of wheel spacers. They put off-camber stress on the lug bolts, and can create some undesirable results. Just a thought... I don't think they are a good idea, and often look silly as well. IMHO

well he prolly got some 17x7 wheels and they look silly if you don't push them out a lil, 17x8 look good

I know that the 25mm spacers requires longer bolts...if i had to guess, i'd say that you could get away with 15mm spacers with the current bolts...don't quote me on that though.

I don't understand all this talk about negative aspects of spacers. I have 15 mm H&R spacers so I could clear my z32 brakes, which also means I will be able to clear coilovers no problem. This off camber stress on the lug bolts. What is that? I hear this every time spacers are mentioned, so does anyone have experience with lug bolts breaking or some facts that would back up that statement. Also I would think the makers of the the longer wheel studs would take into account any additional stress (ie, Nismo, and H&R) because I';m sure they have plenty of race experience with spacers and longer wheel studs. And yes a 15 mm spacer does require new wheel studs. It seems like this is all some rumor that has no factual basis, but I don't have experience with it either so I could be wrong.

clearing Z brakes does not necessarily mean clearing coilovers, and vice versa. Clearing Z brakes is a wheel design issue more than offset, generally, while clearing coilvoers is an offset issue.

I would never use a spacre, and definately never go over 10mm, anything over than, and you should have gotten the RIGHT offset wheel in the first place!

onto your situation, I would reccomend getting the NISMO longer/strengthened studs ASAP, and torquing the lugs to around...oh. 90ft/lbs(a bit tighter than stock) just to be sure you wont have problems and have full thread engagement.-chet

A good structural rule of thumb is to have as much thread as the diameter of the stud. So if the stud was 1/2" diameter, you would want 1/2" thread engagement. This is a bit conservative though. In reality the 1st 4 threads are taking almost all of tension regardless of how many are actually engaged. The studs are not at risk of failing with a little offset assuming they're in good shape and they're all torqued up right.I think "camber stress" is referring to the extra bending in the studs because the moment arm is larger with spacers. Like using a long wrench vs. a short one. However, I don't know if there is actually any bending happening...I would *think* that the conical nuts would center themselves on the studs, and that the tension force applied to the wheel against the hub would provide enough friction to ensure that the studs were in tension only. However, there is more stress on the other suspension components. What keeps the hub from turning upward? Whatever geometry and linkage is in place to keep it where it's at will feel the greater moment of the offset wheel. Reasonably, that component will need to be replaced sooner than normal. By how much, I don't know. Just my thoughts--don't quote me.

Quote »90ft/lbs(a bit tighter than stock)[/quote]I think you mean 90 ft*lbs, if you're talking about torque that is.

Quote »A good structural rule of thumb is to have as much thread as the diameter of the stud. So if the stud was 1/2" diameter, you would want 1/2" thread engagement. This is a bit conservative though. In reality the 1st 4 threads are taking almost all of tension regardless of how many are actually engaged. [/quote]yes you're right. good point. I learned it was the first 3 threads, but that's a minor discrepency.

Quote »I think "camber stress" is referring to the extra bending in the studs because the moment arm is larger with spacers. Like using a long wrench vs. a short one. However, I don't know if there is actually any bending happening...[/quote]yes....bending really can't occurr much since the studs are tightly securred around the surface of the threads, so it really can't possibly bend. but it can shear.

Quote »to ensure that the studs were in tension only.[/quote]I do believe the studs experience a shear stress as well, but considering the technique you just talked about, it is minimized through the friction in the contact area from the tension.

You also have to take into account; greater offset increases the distance between the wheel and the suspesion, thus increasing the amount of sensativity your car will have to the road. Also, in theory, you're car will be lower to the ground. I'm not sure if these results will be noticiable or not b/c i've never done this, but just so you are aware.

I learned 3 threads too BUT because of wear and thread relief (typical) I add on another thread. Figure there's probably well over 10,000 lbs of compression between the wheel and the hub. The friction coefficient between the 2 surfaces would have to be pretty low to allow any slippage to cause shear on the studs. I'll agree there might be a small component, but I think it would be negligible next to the tensile stress.

yeah, i'm mailnly talking about the rear wheels, not the front. the front wheel studs don't experience hardly any shear stresses, because they're just free-rolling...but during hard accelleration, the rear studs would have to experience a much greater amount of course, though it still will be small in comparison to the tensile stress. In any case, enough beating this to death (though technical talk is always enjoyable ), if you go with a decent set of heat treated studs (the the one Exar pointed out), you should be fine.

All four corners experience shear stress when braking. Most would-be racers brake hard on the street(for whatever reason) from time to time. Greater force is generated from braking than acceleration.

Also, different aluminum wheel manufacturers cast different thickness depths at the lug nut mounting point(thickness of the wheel in between your lug nut, when tightened, and the mounting surface of the wheel). The only way to know for sure if you have enought thread engagement with a particular is to test fit.

good point about the brakes. but don't forget smithSR, that when you brake, the load is distributed to all four wheels. when you accelerate, the load is concentrated on the rear two wheels. So although braking may cause a greater net stress (and this is debatable depending on what you have under the hood and what brake setup you have), the localized stress on the studs will still be less during maximum braking than maximum acceleration. But to give you credit for your correction, yes the front brakes would cause some shear stress on the front studs.

All this talk of stress kinda worries me, however my point before was that is it really enough to cause failure in any of the components mentioned. I have had them on there and for one they do not look silly, it actually makes it look better if you ask me. As for the CORRECT offset that I should have got according to chet, My wheels are racing hart C3's I figured they would be fine for the brakes, but due to the spoke design and the lip on the outside they didn't. Yea I probably should have done a little more homework on my selection, but until something breaks on the setup I have I'm not going to worry about it because I doubt something happen. If it does I will post again and bow down to those who hate the evil wheel spacer and chime in on criticism.

my 2 cents

1) yes you can stick the spacers on

2) but, if your gonna be racing around town, longer/stronger bolts would be a welcome addition

3) yes it looks cooler, anyone who says that a wider wheel base looks ugly can take his ECCO and sho..... :icesangel

Quote »3) yes it looks cooler, anyone who says that a wider wheel base looks ugly can take his ECCO and sho..... [/quote]there's a point too of course, beyond which it begins to look ridiculous...take those crazy mexicano rides for instance. I'm sure those cars bounce and bottom out left and right. that's an extreme though. i think in moderation, it can look pretty sharp and it won't noticibly affect the performance of your car.