[MidLifeZ]

Am considering the Beyern wheels listed here
Wheel Search by Style - Discount Tire

Wheel Details - Discount Tire

Looking at doing fronts in 18 x 8.5 and rears in 18 x 9.5 (yes, I know my Saturns are 10" wide in the rear but 1/2" is not really that much wider and I have not found any wheels I like which are reasonably priced in 10")

They list the following offsets with the 5 x 108 bolt pattern:

FRONT
15
30
40

REAR
15
25
30
45

Goal for years would be to have pushed out to fill wheel well of course.

I know I will have to get an adapter due so the bolt patters will work though no idea on what thickness or what offset for the wheels themselves.

Tried the offset tools but it is something my brain just doesnt compute..

The wheels are these, which look VERY close to the Nova

So.. what offset should I get for front and rear and what MM adapter thickness

Yes, I know adapters should not be used for track use which is ok since I dont track the car...



THANKS!

Then all I gotta do is choose tires..

 

[sleekgt]

When I go to their website, there are no 5x108 bolt patterns- only 5x120 (G car, not S car)

 

[MidLifeZ]

When I go to their website, there are no 5x108 bolt patterns- only 5x120 (G car, not S car)

Correct, my plan is to get 5x108 to 5x120 spacer/adapter

Checking the 1010TIRES.COM - Wheel Offset Calculator

and inputting the current widths of

FRONT
8.5" +19mm

and

REAR
10" +17MM

it looks like if I am reading the 1010tires site correctly the closest fits would be:

FRONTS
8.5" 40MM

and

REAR
9.5" 30

then get these which are 20mm adapters
5x108 to 5x120 Skinny Wheel Adapter | eBay

This would make the front wheels move in toward the body by only 1 MM and the rears move out by 1 MM

Doubting 1 MM would be noticeable..

Correct on all the above?

 

[sleekgt]

30-20 = 10 mm vs 17mm - 7 mm INWARD. Not 1 mm OUTWARD?

 

[MidLifeZ]

30-20 = 10 mm vs 17mm - 7 mm INWARD. Not 1 mm OUTWARD?

Using the 1010tire calculator and inputting

CURRENT (Saturn) REAR at 10" wide and 17mm offset and then the wheels I am looking at are 9.5" and 30mm offset it says

Inner Clearance: is 7mm LESS
Outer Position: RETRACT by 19mm
then inserting the 5x108 to 5x120 adapter which is 20mm means Inner clearance would be: 13mm MORE and outer would EXTEND an extra 1mm.

Correct?

Only other item to decide would be tire size for the rear.. Am thinking either

265-35-18
or
275-35-18

 

[ageshelin]

re: Offset

The beauty of using offset for wheel fitment is that whatever you do to change the wheel size, if you want it to remain where it was the offset should be the same!

The 20mm wheel adapter acts as a spacer and decreases offset by 20mm.

Hence, front wheel is 40 - 20 for spacer = +20mm offset. It is 1mm different from stock. you are right, nobody will notice.

The rear wheel is 30 - 20 spacer = +10mm of offset. This is 7mm inward from the stock. This is not really good, since most fo the interference is from the inboard components.... You can get a 5mm or 8mm or 10mm or 3/8" spacer to
get you within a few mm of stock (or a custom made 7mm spacer but 5mm and 8mm is common and gets you close).

You are right, since the wheel will be 1/2" narrow, you will get 1/2"= 12mm divide by 2 = 6mm of clearance from the wheel itself. os at least for the wheel, you are OK. If the wheel has larger or smaller diameter, then the edge will show up higher or lower and may hit some suspension parts. Again, a good idea to keep offsets close to stock..

However, the wheel is not the only concern what about the tire that is on that wheel. The tire is much wider then the wheel. So with 7mm less offset you will need to run 7mm * 2 = 14mm narrow tire, to be within the same dimensions as before...

It would be better to buy 45mm offset wheel and end up with 25mm offset that would push the wheel and tire 8mm out. Is the clerance with the fender?

It is safer to buy the 30mm wheel and then have anb extra spacer or a wider adapter. The downside of extra spacers and adapters is that they weaken the wheel to hub assembly, put extra stress on wheel bearings, make it harder to torque the wheel down and add unsprung weight....

Anton

Using the 1010tire calculator and inputting

CURRENT (Saturn) REAR at 10" wide and 17mm offset and then the wheels I am looking at are 9.5" and 30mm offset it says

Inner Clearance: is 7mm LESS
Outer Position: RETRACT by 19mm
then inserting the 5x108 to 5x120 adapter which is 20mm means Inner clearance would be: 13mm MORE and outer would EXTEND an extra 1mm.

Correct?

Only other item to decide would be tire size for the rear.. Am thinking either

265-35-18
or
275-35-18

 

[sleekgt]

[snip]
Inner Clearance: is 7mm LESS
Outer Position: RETRACT by 19mm
then inserting the 5x108 to 5x120 adapter which is 20mm means Inner clearance would be: 13mm MORE and outer would EXTEND an extra 1mm.

Correct?
[snip]

No - you're mixing together the EXISTING WHEEL OFFSET (17mm) with the 20mm wheel adapter, without taking into account the 30mm NEW WHEEL OFFSET.

Simplify this way - KEEP YOUR OFFSET THE SAME REGARDLESS of WHEEL WIDTH.

a 9.5" 30mm WHEEL offset will need a 13mm adapter to remain at 17mm HUB offset (13+17) = 30mm. In this scenario, your new 9.5" wheel is exactly 1/4" narrower on BOTH SIDES (2 * 1/4" = 0.5" wheel width) compared to 10" wheel.

You can do the match seeing how far OUT it can go using the above - narrower tire/rim and adjusting offset to suit.

Note that every 1mm you add to the offset, your wheel bearings will experience higher loading that the factory spec at 17mm, especially when cornering. That may reduce bearing life - how much is any guess.

And any change in wheel offset may impact the careful tuning done by the factory that ASSUMED a factory wheel offset.

A full topic unto itself anic:

 

[MidLifeZ]

Eddie, I may have confused it a bit. What I meant specific to post you replied to is that the existing Saturn wheel at 18 x 10 with 17 mm offset as compared to (according to 1010tires.com

In other words,

When I input shows the below image with 10" width and 17 MM offset in top and 9.5" and 30 MM offset at bottom

Then if I change the 30 MM to 10 MM to take into account the 20 MM spacer it shows the next calculation results of 13 MM more space inside and 1 MM less to fender. Correct?

I think though I understand what you are saying in mixing the two (offset and use of a spacer)...

Key is finding which combinaton of offset and spacer/adapter (since an adapter is required to match to the 108 bolt pattern and the thinnest I have found is 20 MM). The available offsets for the 18" x 10" are:
15, 25, 30 and 45 MM. Would it be correct then that using the 30 MM wheel offset and then using the 20 MM adapter would push out the wheel and thus my calculations above are correct since the net result is the same. TO clarify;

with just the wheel and 30 mm offset, the outside edge is moved in toward the body by 19mm and thus adding a 20 mm spacer would mean it would be 1 MM to the outside by 1 MM and the inside would have 13 MM more distance since it would also move out from the hub.

 

[ageshelin]

re: Offset and clearance

Your reasoning is NOT correct.

Yes, if you look at the wheel, alone. The lip of the wheel will give you clearance as per the calculator. You will move the wheel 7mm more (10mm vs. 17mm effective offset), but the lip is 1/4"=6mm less, so you will have similar wheel lip to inside clearacne.

The key question is: Are You going to put a TIRE on that wheel?

I think You need tires.

Are you going to put a smaller tire on as well? 6mm per side smaller?

If the tire is the same size as before, you would have moved the tire in by 7mm. It will not fill-out the fender as good as it used to and it may touch some components on the inside.

The reqason why people use offset instead of backspacing is because, you can change the size of the wheel and backspacing all you like, but to make it fit, as before, the rule is OFFSET has to stay the SAME. If it does not, you have to start measuring how much clearance you will have.

(To a lesser degree, if you change the diameter of wheel and tire you should start measuring also, as the wide bits do no end-up in the same spots as they used to be. Remember the widest parts on the inside are the rim lip and tire cross-section i.e. about the middle of the sidewall where it bulges out).

The bottom line is that offset calculator is mis-leading. What about the tire size? i.e. the whole wheel/tire package. To be safe keep same offset.

Anton

Eddie, I may have confused it a bit. What I meant specific to post you replied to is that the existing Saturn wheel at 18 x 10 with 17 mm offset as compared to (according to 1010tires.com

In other words,

When I input shows the below image with 10" width and 17 MM offset in top and 9.5" and 30 MM offset at bottom

Then if I change the 30 MM to 10 MM to take into account the 20 MM spacer it shows the next calculation results of 13 MM more space inside and 1 MM less to fender. Correct?

I think though I understand what you are saying in mixing the two (offset and use of a spacer)...

Key is finding which combinaton of offset and spacer/adapter (since an adapter is required to match to the 108 bolt pattern and the thinnest I have found is 20 MM). The available offsets for the 18" x 10" are:
15, 25, 30 and 45 MM. Would it be correct then that using the 30 MM wheel offset and then using the 20 MM adapter would push out the wheel and thus my calculations above are correct since the net result is the same. TO clarify;

with just the wheel and 30 mm offset, the outside edge is moved in toward the body by 19mm and thus adding a 20 mm spacer would mean it would be 1 MM to the outside by 1 MM and the inside would have 13 MM more distance since it would also move out from the hub.

 

[MidLifeZ]

Tires looking at would be either

275/35/18
or
267/35/18

Right now the tires are 295/35/18

The 275 would be 0.4" narrower

I also used this calculator as it includes tires

http://www.rimsntires.com/specs.jsp

Am not changing the diameters of front or rears BTW

 

[sleekgt]

Ignore the tire calculator for a second - It is correct, but it's only displaying the NEW wheel final position (not relating it to EXISTING WHEEL position).

Try this:

A 9.5" wheel is 6mm narrower on each side than a 10" wheel.
If you keep identical offset, your outer wheel edge moves 6mm INSIDE the wheel well.
(this assumes a proportional tire - the 9.5" wheel using a 1/2" smaller tire than 10")

A 30mm wheel with 13mm adapter maintains 17mm offset. Your wheel bearings will be happy, but now your tire-to-fender edge is 6mm narrower.

But WAIT = the smallest adapter for 5x108 to 5x120 is 20mm - you CAN'T have a 13mm adapter because it won't fit. So your wheel offset has to accomodate 20mm+ adapter

Going with 40mm offset wheel with a 23mm adapter would have a 17mm offset - back to normal but still 6mm narrower on the outside wheel edge.

If you insist on moving the 9.5" wheel edge to the SAME position as the original 10" wheel, you need to add 6mm to the adapter to push it out - 23mm+6 = 29mm. That assumes a 40mm wheel offset.

Your new effective wheel offset-to-hub is 17mm+6mm - same fender edge as before, but your wheel bearings now have more stress.

So forget about the 30mm offset wheel with 20mm adapter - that likely will interfere with the suspension/brake caliper.

 

[bharper]

If you really want to make your head hurt, maybe consider calculating from the original set of wheels and tires, instead of the v8 wheels.

Brian

 

[MidLifeZ]

Eddie (and others).. where I was looking for comparison info was from the 1010tire site.

Where it displays the comparison:

Results
Inner Clearance: 7mm LESS (the inside of the wheel to the strut housing)

Outer Position: RETRACT by 19mm (position of the outside edge of the wheel)

Thus what I was doing (incorrectly from you say?) was taking the 7mm and then by pushing wheel out by 20 mm (the spacer/adapter) would mean the wheel has 13mm MORE clearance on the inside and doing the same for the outside edge it would have 1mm LESS clearance.

Is this thinking flawed?

 

[MidLifeZ]

If you really want to make your head hurt, maybe consider calculating from the original set of wheels and tires, instead of the v8 wheels.

Brian

Made me think.. so I input the OEM wheels which came on the car (18x8.5 and 30mm offset), and compared to the Saturns which are 18 x 10 and 17mm offset and the Saturns fit perfectly fine.

The calculator for OEM to Saturns says:

Inner Clearance: 6MM less (the inside of the wheel to the strut housing)
Outer Position: EXTEND an extra 32mm (position of the outside edge of the wheel)

Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

 

[sleekgt]

Made me think.. so I input the OEM wheels which came on the car (18x8.5 and 30mm offset), and compared to the Saturns which are 18 x 10 and 17mm offset and the Saturns fit perfectly fine.

The calculator for OEM to Saturns says:

Inner Clearance: 6MM less (the inside of the wheel to the strut housing)
Outer Position: EXTEND an extra 32mm (position of the outside edge of the wheel)

Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

Remember - that calculator is given delta values from the 8.5" wheel to 10" wheel AND mixing in the offsets. This run appears weird - not sure it's correct.

Try drawing on graph paper - I believe my last post is correct, but try keeping the offset at 17mm - it makes it easier to understand where the 1.5" wheel difference goes (or 0.5" if you do 9.5").

And keep in mind the smallest adapter 5x108 to 5x120 is 20mm - for the rear you have flexibility, but the front may be a problem with rubbing if you change the overall offset.

 

[carbuff]

My buddy's S4s has wheels with a different offset than his OE items. (Perhaps some of you saw the fly-yellow car at LOG)

They must be a different offset as the Brembo calipers just BARELY clear the wheels. But he has never had any interference, even on the track.

Did European cars have different-offset wheels than North American?

 

[ArtB]

Be sure you get the spacers with hub centric center bores! I didn't see any hub centric centering components on the spacers you linked. Also, consider that you will need a set of bolts in the stock size to attach the spacer to the hub, the stock lug bolts most likely will interfere with the back side of the new wheel. I had to find specialty bolts to attach my 25mm spacers to my hubs when I had them made. Without these components attached correctly, it will be like driving a car with egg shaped wheels!
Artie

 

[MidLifeZ]

About to give up.. found wheels yesterday which look VERY much like Nova's and they will even custom drill the bolt holes! Only problem is the narrowest wheel for the front is 9" which I doubt very much would work.. ARRRGGGHHH!

Varrstoen | Custom Performance Wheels and Accessories ES 1

 

[MidLifeZ]

About to give up.. found wheels yesterday which look VERY much like Nova's and they will even custom drill the bolt holes! Only problem is the narrowest wheel for the front is 9" which I doubt very much would work.. ARRRGGGHHH!

http://varrstoen.com/products/es-1/

 

[bharper]

Just have your saturn's refinished in gold for a change up, and be happy!

The nova look is nice, but not the end all in wheels.... I have seen many v8 guys that had nova's change to something else. I just do not buy all the hype regarding nova's, other than they are selling for four times or more than they are worth. So to me, it seems more like a money and snob statement than styling.

If you got to have nova's, and got to have round rear lights, and a v8 wing, just buy a damn late model v8 where they belong.

I am quite happy to have the saturn's to play with, and have better things to waste money on than nova's, or nova clones.

Brian