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      01-26-2016, 10:05 PM   #1
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Offset required for square setup?

Maybe a bit premature since my car hasn't even started production but I'm already thinking about a way to dial out some understeer in the likely event that it will have more than desired when unmodified. So I'm looking at a square wheel setup with either square tires or stagger of only 10 mm instead of 20. My guess is that a 9.5 width with et35 will be my best bet if I want to have a choice of wheels to choose from. This would leave the wheel gap to fender at about the same as stock both front and rear. .5 wider in front means 6mm wider on each side of the wheel. Then tuck the wheel in from 29 to 35 offset and I'm back where I started on the fender side. Unfortunately though that means the side of the wheel closest to the strut is reduced by 12mm. I'm inclined to crawl under the car at the upcoming Chicago show to see if this will fly. I looked at the Brussels pics and you can't really tell if there is enough space. Anyone with some pics?
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      01-27-2016, 08:17 AM   #2
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You're going to be limited in what wheel offsets are available to you. Your best bet is probably doing to be going with something like a 35, and dialing it in (out) with spacers.
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      02-05-2016, 01:14 PM   #3
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Quote:
Originally Posted by HeelToe View Post
Maybe a bit premature since my car hasn't even started production but I'm already thinking about a way to dial out some understeer in the likely event that it will have more than desired when unmodified. So I'm looking at a square wheel setup with either square tires or stagger of only 10 mm instead of 20. My guess is that a 9.5 width with et35 will be my best bet if I want to have a choice of wheels to choose from. This would leave the wheel gap to fender at about the same as stock both front and rear. .5 wider in front means 6mm wider on each side of the wheel. Then tuck the wheel in from 29 to 35 offset and I'm back where I started on the fender side. Unfortunately though that means the side of the wheel closest to the strut is reduced by 12mm. I'm inclined to crawl under the car at the upcoming Chicago show to see if this will fly. I looked at the Brussels pics and you can't really tell if there is enough space. Anyone with some pics?
u will probably be able to run 9.5" wheels ET 22 (265 tires) and have no rubbing issues.
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      02-06-2016, 09:00 AM   #4
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Quote:
Originally Posted by PrematureApex View Post
You're going to be limited in what wheel offsets are available to you. Your best bet is probably doing to be going with something like a 35, and dialing it in (out) with spacers.
Agree. I have a host of wheels on my cars or in the garage to experiment with. ET 30, 32, 34, 35, 37, 45, 49, and 52 with 3 and 5mm spacers available. That should pretty much allow me to fine tune front and rear down to the mm.
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      02-06-2016, 09:03 AM   #5
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Quote:
Originally Posted by -JLT- View Post
u will probably be able to run 9.5" wheels ET 22 (265 tires) and have no rubbing issues.
Might be tight in both front and rear depending on how much fender space is there when stock.

Front would push by roughly 7mm + 20/2 = 17mm
Rear would push by 18 mm.
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      02-06-2016, 09:48 AM   #6
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I'm interested in fender clearance and not necessarily how much the wheel pushed although that is the primary contributor for sure.

Stock front is 29 offset and tire width is 245.
If you went with 22 offset with a 265 then you would push out by 7 mm plus approximately an additional 10 mm of tire width on both sides of the wheel since you are going from 245 to 265. Tire Rack Shows the section width on a 245 RE11 is 9.8 inches and a 265 is 10.7 inches. Therefore its wider by 22.86 mm or about 10 or 11 mm on each side. 7 mm + 10 mm = 17mm

Stock rear is 40 offset and tire size is 265.
If you went with a 22 offset you would push by 18mm. There would be no additional clearance issues from the tire since the size is the same.

Where did I go wrong in my calculation?

Last edited by Pyrat 2; 02-06-2016 at 10:02 AM..
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      02-06-2016, 10:13 AM   #7
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Quote:
Originally Posted by metrickid View Post
I don't know if your are drunk or if I'm not getting what you are after.

Stock is 9" ET29 and the optional fitment here is 9.5" ET22. That pushes the outer edge of the wheel out 13 mm more, not 7 mm.
The rear is a 10" ET40 and the optional fitment here is a 9.5" ET22. That pushes the outer edge of the wheel out 12 mm, not 18.

And just because you put on a wider tire it doesn't automatically mean it sticks out 10mm on each side. In the first instance the wheel itself is also 12.7 wider to start with...
Not sure I follow.
40 - 22 = 18 mm not 12mm. I have ignored the wheel width since the maximum width is dictated by the tire in this case since its section width is wider than the wheel itself. So the fact that the wheel is 0.5 inches narrower doesn't make the tire narrower. In this scenario the fender clearance will be dictated by the tire width. If the tire section width was narrower than the wheel width then the situation would be different That why I ignored the wheel width.

Anyhow not worth the debate.
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      02-06-2016, 01:45 PM   #8
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Quote:
Originally Posted by HeelToe
Quote:
Originally Posted by -JLT- View Post
u will probably be able to run 9.5" wheels ET 22 (265 tires) and have no rubbing issues.
Might be tight in both front and rear depending on how much fender space is there when stock.

Front would push by roughly 7mm + 20/2 = 17mm
Rear would push by 18 mm.
if M2 is similar to M3 than it should be ok. on stock wheels (same as M2) and stock tires (larger than M2) I ran 20f/18r spacers, lowered, with no rubbing.

that's why i think it should be ok
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      02-06-2016, 03:33 PM   #9
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References on wheel offset:

http://www.discounttire.com/dtcs/infoWheelOffsets.do

http://www.tirerack.com/wheels/tech/...jsp?techid=101

http://www.tsw.com/explore/what-is-wheel-offset.php

http://cocomponents.com/dealer/blog/...set-explained/

Definition is the same everywhere. Distance from hub to centerline of the wheel. Has nothing to do with the width of the wheel.

I do stand corrected though in that there is in reality some variance in the section width of a tire depending on the width of the wheel that it is mounted on. For example, the section width of a tire may be slightly narrower on a 9.5 inch wheel than on a 10 inch wheel. This of course assumes that the nominal section width is greater than the wheel width.

For example, an 11" section width tire when mounted on a 10" wheel will likely be <11" when mounted on a 9.5 inch wheel. Unlikely to be 0.5 inches narrower though. On the other hand a 9.5" section width tire when mounted on a 10" wheel (stretch application) will likely still be approximately the same width if mounted on a 9.5" wheel.
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      02-06-2016, 03:35 PM   #10
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Quote:
Originally Posted by -JLT- View Post
if M2 is similar to M3 than it should be ok. on stock wheels (same as M2) and stock tires (larger than M2) I ran 20f/18r spacers, lowered, with no rubbing.

that's why i think it should be ok
Hope your right as I like a more concave look. Anecdotally people had said it looks like there is less space than an M3. Will see. Auto show is in town starting next week and I'll get to gauge for myself.
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      02-06-2016, 04:35 PM   #11
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Agree to disagree. 11" section width tire will still be roughly 11 inches on a 10 inch wheel or a 9.5 inch wheel and so will stick out about the same 5.5" inches from wheel center in each direction. Thanks for the debate.
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      02-07-2016, 11:18 AM   #12
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Quote:
Originally Posted by metrickid View Post
It has EVERYTHING to do with wheel width as the offset is the distance from the wheel center line to the mounting hub surface.
Hey guys, take it easy.

Check this out:
http://www.rimsntires.com/specspro.jsp

Put the numbers and you will find how much it sticks out to the fender or closer to the suspension.

Lets say you have a 265 tire and you change from a 10" wheel ET40 to 9" wheel ET40, it will be exactly the same. Why? Even though the wheel will be IN 0,5" on each side of the centerline, the centerline of both wheels will be in the same position as they both have ET40. As you know this means that the distance between the centerline of the wheel and the plane of the hub-mounting surface is 40mm. So if the wheels centerlines are displaced 40mm from the hub-mounting surface and you do not change the tire width which is wider than the wheel there is no IN or OUT. Use this example in the above mentioned link and see the charts, it is cristal clear.
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      02-08-2016, 05:53 AM   #13
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Nice calculator. First one I've seen that properly accounts for the tire section width in addition to the wheel width. Thanks for posting.
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      05-10-2018, 06:59 PM   #14
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Reviving a super old thread... first one I found on google

I'm thinking of doing square for mostly street + some light HDPE duty, does anyone know whether or not I can directly translate my spacer fitment to the fender clearance shown in the calculator?

http://www.rimsntires.com/specspro.j...0Civic%20wheel

I am currently running 12mm spacers front on stock rims/tires lowered on MPS /w no camber plates. With the calculator showing 7mm pushed out, I should have 5mm clearance still? Does this mean I could run a 3-5mm spacer?

Rims: 19x10 ET 32 (http://vorsteinerwheels.com/wheels/v-ff-103/#1)
Tires: 265/35/19 PS4S
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      05-11-2018, 05:56 PM   #15
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Some good info in here, figured I'd chime in with some known-good square fitments:

Direct fit:
Front & Rear: 18x9" ET30 or ET31 with 245/40-18 tires

Front negative camber required:
Front & Rear: 18x9.5" ET28 with 265/35-18
- 275/35-18 tires can also be used.

5mm front spacers + negative camber required:
Front & Rear: 18x9.5" ET35 with 265/35-18 tires

10-12mm front spacers + negative camber required
Front & Rear: 18x10" ET33 with 265/35-18 tires
- 275/35-18 tires may also be used with additional

We've put together an M2 fitment guide with a ton of great info, which can be found here: https://support.apexraceparts.com/hc...-Fitment-Guide

Feel free to reach out or post with any questions!

--Dylan
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      05-11-2018, 11:12 PM   #16
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I'm just gonna throw this out there, this car is very over steer happy. I bet putting a bit more camber up front would help solve any and all understeer.
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