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I have an Aussie r31 and purchased some cheap rims, ideally they would have been the right offset, but they were cheap.

I need to buy spacers.... so how do I increase my track evenly?

Was guessing 25mm for the front and 20mm for the rear. Hopefully, putting the wheels closer to the guards, increase track and let me use my wheels :)

The new wheels specs are:

16x7(?) wearing 205/55/16's

16x8 wearing 225/50/16's

Offset for the rear is +34, not sure of the front as the stickers are worn. Technically speaking the rear "fit" with no spacers. The fronts won't fit to my liking, a bit too close to hitting the strut.

The stock wheel specs are:

tyres.jpg

^^ linked to r31skylineclub.com ! (will change link if asked)

Will I need to try to find out the front offset before this question can be answered? If so how do I measure it?

Thank you :)

+34 offset for an 8" rim is perfect fit for r32/r33. But keep in mind, it's not goign to look fat on an r32/r33 guard. It isn't 'out enough'

However, it really depends on the particular car. I'm not sure of the stock offset of the r31 wheels. You really need to find this out first.

Hopefully the offset of the front wheels you've got will be matched to the rear ones in typical jap mismatched width style. Hopefully the offset of the fronts will be about + 30 or +28

I would not run spacers on your car especially if drifting. If the reason for the spacers is performance, it won't be noticeable. If it is for looks, sorry, but you're not trying to build a show car are you?

PS: offsets should normally be stamped ontot he back of the wheel. you'll ahve to look carefully because it mgiht be on a sticker or stamped, but it's probably covered in brake dust.

Can't you try the wheels on? or are they 5 stud and you havent' done the conversion yet?

There is also some geometry aspect to messing with the track width and all, there is some tech term that describes the projected line from the suspension pivot points(i think) that put an imaginary point on the ground where the centre of your wheel should be sitting, when you widen the track with spacers you throw this out. Cant remember what its called nor how bad or relevant it is to motorsport but it stuck in the back of my mind.

Hopefully SK or someother suspension guru can explain this point better or if it even exists...maybe im talking shit and getting confused with something else.

Edited by r33_racer
There is also some geometry aspect to messing with the track width and all, there is some tech term that describes the projected line from the suspension pivot points(i think) that put an imaginary point on the ground where the centre of your wheel should be sitting, when you widen the track with spacers you throw this out. Cant remember what its called nor how bad or relevant it is to motorsport but it stuck in the back of my mind.

This is EXACTLY what I would like to know. If I was keeping the stock tyres, it would be easy, I would just put the the same sized spacers all around... But with the addition of different sized wheels, not to mention the fact they're different sized front to back makes my brain hide thinking about it :P

There is also some geometry aspect to messing with the track width and all, there is some tech term that describes the projected line from the suspension pivot points(i think) that put an imaginary point on the ground where the centre of your wheel should be sitting, when you widen the track with spacers you throw this out. Cant remember what its called nor how bad or relevant it is to motorsport but it stuck in the back of my mind.

Hopefully SK or someother suspension guru can explain this point better or if it even exists...maybe im talking shit and getting confused with something else.

how would running a 20mm spacer be any different to the following scenario:

stock wheels are 8" +30 offset. If you run an 8" wheel with a +10 offset, isn't the net effect the same?

I believe that alignment issue is to do with std setup and probably std wheels and offsets. But i would say your logic behind the 20mm different offset is right, well it makes sense.

A spacer, i guess is effectively creating an artificial offset to help make the wrong rim fit right.

There is also some geometry aspect to messing with the track width and all, there is some tech term that describes the projected line from the suspension pivot points(i think) that put an imaginary point on the ground where the centre of your wheel should be sitting, when you widen the track with spacers you throw this out. Cant remember what its called nor how bad or relevant it is to motorsport but it stuck in the back of my mind.

Hopefully SK or someother suspension guru can explain this point better or if it even exists...maybe im talking shit and getting confused with something else.

You talking "scrub radius"?

Frankly, wheels that aren't designed to fit your application are bloody expensive, regardless of how much you didn't pay for them. Buy wheels designed for the purpose and you can't go wrong.

Thanks for your replies guys... I don't mean to sound unappreciative so I guess I'd better re-phrase my question:

What size spacers will I need to use in order to change the effective offset of the wheels while also widening my track and keeping the track alignment front to back even? :)

As it stands, because I don't know the offset of the front wheels, I am thinking of using 25mm spacers on the front and back - thereby keeping the same offset variation all around the car. The downside with this approach is assuming that the wheels I've purchased were actually correctly offset in relation to each other. I'm thinking the likelihood of this is high however if there is some advantage gained by moving the 7" (thinner) front wheels outward, increasing the front track in relation to the rear, then I would fit 30mm to the front and 25mm to the rear. Or perhaps 25mm to the front and 20mm to the rear.

That are my thoughts so far.. not sure if I'm on the right track (no pun intended) :happy:

Any on topic answers more than welcome !!

well if you want to conver a +30 to an effective +20 then you need 10mm spacer.

Hello ,

You must work out the offset of your front(new) rims you are wishing to install.

If the rears are +34mm and 8 inch. More than likely the front are +22mm at 7"(Or close too) this would have given the balance that the original suspension was set up to do.Do a quick measurement to see if this is true.

The previous owner of these rims worked it out and purchased the correct offsets.

By putting spacers as what was stated you are loading pressure on different points of the suspension

that were not designed to take.

Smaller front tyres allow you to steer better and larger back tyres allow you to put more power onto the ground, this is the logic. :ninja:

Thanks for the posts guys :laugh:

All very good points... ... none really answered what I was getting at :P anyone else see what I'm getting at?

Provided you get your offsets correct, as long as you use the same tyres on the front,and the same tyres at the back all is good. :):):):):):ninja:

DID I GET IT NOW?

your basically asking us to work out for you what sized spacers you required inorder to achieve an even offset all round so your track is not uneven from its std setting?

You have given us the rear offset, now we require the front rim offset which as stated before should be stamped on the back of the rim somewhere. Go find it out for us.

Based on what youve given us so far a 20mm spacer is required on the back, which is a common sized spacer to use.

Once you get the front then we can work out the required spacer needed to maintain the front offset so they clear and work for you.

From what you stated in the first post, thats what your asking. For a road car if the track is actually out of whack from stock its not really that big a deal, so long as its not way way out, which it wont be.

Edited by r33_racer
Provided you get your offsets correct, as long as you use the same tyres on the front,and the same tyres at the back all is good. :D:):):):):P

DID I GET IT NOW?

HEHE.. actually yes.

Except that the front and rear tyres and wheels are different :):D

I wouldn't ask if they were the same hehe I'd just whack on the spacers to maintain close to default offset.

your basically asking us to work out for you what sized spacers you required inorder to achieve an even offset all round so your track is not uneven from its std setting?

You have given us the rear offset, now we require the front rim offset which as stated before should be stamped on the back of the rim somewhere. Go find it out for us.

Based on what youve given us so far a 20mm spacer is required on the back, which is a common sized spacer to use.

Once you get the front then we can work out the required spacer needed to maintain the front offset so they clear and work for you.

From what you stated in the first post, thats what your asking. For a road car if the track is actually out of whack from stock its not really that big a deal, so long as its not way way out, which it wont be.

That's right - except I don't want to have the original offset, I'd like to increase track... evenly.

I don't actually need for you to work out the offset and spacer by adding the sum of the two in order to give me the actual offset of the wheel :) I just want to know that when I whack on a 25mm spacer on the front and 20mm on theback (for example) that the middle of the front tyre and the middle of the rear tyre are on the same vertical axis (assuming the steering wheel is straight and everything is aligned properly).

I should break out the paint diagrams hehe.. :)

  • 3 weeks later...
adding a 25mm spacer to a +34 wheel makes it effectively a +9 offset.

Thank you - I stand corrected :P

So if I have a rear 8" rim with +9 offset... what offset will I need on my 7" rim on the front so the middle of the front wheel is the same as the middle of the rear wheel?

I assume my highly technical diagram below will show what I'm getting it. This is all driven by the assumption that the picture on the left is ideal, that the middle of both wheels should be the same front to back. Maybe I could be wrong....

post-3612-1158558484.gif

When you are talking track, width is not applicable. Because offset is measured from the centre of the wheel, where track also happens to be measured from, then the offset directly relates to the track. So if you want it even with the rear wheels, then you will need a +9.

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