Welcome to the North American Subaru Impreza Owners Club Thursday July 24, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Click here to visit TireRack
Tire & Wheel Forum sponsored by The Tire Rack

Losing traction? Need new tires?
Click here to visit the NASIOC Upgrade Garage...
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Tire & Wheel

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 12-30-2010, 02:02 PM   #1
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Have a Nice Day? 18x8 Front 18x9 Rear - BBS Wheels

Hey guys,

I have a friend who has an 05 STI and he bought some BBS wheels, somehow he didn't quite understand the fact that on a AWD vehicule you CANT have wheels with different width. (18x8 Front 18x9 Rear)

Anyhow, I'm sure I have herd it somewhere, but I would like to confirm this...

Do they really mess up the differentials?

I mean, its kinda logical that if the car is AWD and you put this wheel on it, something might not work right... but exactly what would that be?

Is there something he could do, other than not using them?

I am sorry if there is a thread about this but I couldn't find it.

Thx,

Dan
* Registered users of the site do not see these ads.
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 02:47 PM   #2
.clipse
Scooby Specialist
 
Member#: 212265
Join Date: May 2009
Chapter/Region: SCIC
Location: SoCal
Vehicle:
2013 Legacy
SWP

Default

well iirc, as long as the rolling diameter is the same, then it wouldn't strain the diff. all too much. that goes to all AWD diffs.

but my knowledge is coming from my old haldex diff on my audi TT. not sure if it's all too different with the diffs in the subie.

but general rule of thumb, just make sure all four wheels are of equal rolling diameter.
.clipse is offline   Reply With Quote
Old 12-30-2010, 02:54 PM   #3
sc00by4life
Scooby Guru
 
Member#: 97135
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Bothell
Default

Quote:
Originally Posted by .clipse View Post
well iirc, as long as the rolling diameter is the same, then it wouldn't strain the diff. all too much. that goes to all AWD diffs.
The problem is that the rolling diameter WONT be the same.
sc00by4life is offline   Reply With Quote
Old 12-30-2010, 02:55 PM   #4
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by sc00by4life View Post
The problem is that the rolling diameter WONT be the same.

What exactly is the rolling diameter, and sorry for my stupidity.
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 02:58 PM   #5
sc00by4life
Scooby Guru
 
Member#: 97135
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Bothell
Default

the circumference of the wheel.
sc00by4life is offline   Reply With Quote
Old 12-30-2010, 03:01 PM   #6
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by sc00by4life View Post
the circumference of the wheel.

Wouldn't it be the same, I mean the wheels do have diffenrent width but the size and the tires they have on are exactly the same.

18" with 235/40/18 tires.
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 03:03 PM   #7
.clipse
Scooby Specialist
 
Member#: 212265
Join Date: May 2009
Chapter/Region: SCIC
Location: SoCal
Vehicle:
2013 Legacy
SWP

Default

Quote:
Originally Posted by sc00by4life View Post
The problem is that the rolling diameter WONT be the same.
well not sure if there's a % marginal buffer/correction on subie diffs, again im going off the haldex diff and thought i'd provide my insight.

for example going staggered and going 245/35 on 9" rears and 225/40 8" fronts would be fairly close to the same rolling diameter front and rear given maybe a small % marginal correction. thought it would apply similarly.

but this is all haldex knowledge, so dont mind me
.clipse is offline   Reply With Quote
Old 12-30-2010, 03:07 PM   #8
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by .clipse View Post
well not sure if there's a % marginal buffer/correction on subie diffs, again im going off the haldex diff and thought i'd provide my insight.

for example going staggered and going 245/35 on 9" rears and 225/40 8" fronts would be fairly close to the same rolling diameter front and rear given maybe a small % marginal correction. thought it would apply similarly.

but this is all haldex knowledge, so dont mind me

But how about if you use the same tire dimensions on all wheels, 235 / 40 / 18 for example.
?
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 04:28 PM   #9
.clipse
Scooby Specialist
 
Member#: 212265
Join Date: May 2009
Chapter/Region: SCIC
Location: SoCal
Vehicle:
2013 Legacy
SWP

Default

^ then yes, rolling diameter will be off bc of the stretch of the tires on the wider rear wheels

edit: hopefully these little diagrams help. the rim size isnt increasing but it's kind of the same concept.





on staggered setups you're going to need to use bigger tires/smaller sidewall on the wider wheels to compensate for the extra width to keep the rolling diam. similar from the fronts to the rears.

Last edited by .clipse; 12-30-2010 at 04:36 PM.
.clipse is offline   Reply With Quote
Old 12-30-2010, 07:02 PM   #10
sc00by4life
Scooby Guru
 
Member#: 97135
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Bothell
Default

You also need to keep in mind the variances in contact patch between the front and rear causing the same slip-grip-slip of the center diff. Many people ignore this fact when trying to justify a staggered setup.

Visually, an 8 and 9 won't look that different. Might as well get matching sizes and stagger the offsets.
sc00by4life is offline   Reply With Quote
Old 12-30-2010, 07:15 PM   #11
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by .clipse View Post
^ then yes, rolling diameter will be off bc of the stretch of the tires on the wider rear wheels

edit: hopefully these little diagrams help. the rim size isnt increasing but it's kind of the same concept.





on staggered setups you're going to need to use bigger tires/smaller sidewall on the wider wheels to compensate for the extra width to keep the rolling diam. similar from the fronts to the rears.

Thankd alot for all the info.

By going with bigger tires on the wider wheels you meand that i could use for example

235/40/18 on the 18x8
265/35/18 on the 18x9

Would this be a correct and safe set up?

I mean, cause I though that the correct way to go was putting smaller tires on the bigger wheels, hence the difference is compesated.

But I know much about tire/wheel set up as a monkey know how to cook a nice lobster. hehe

Last edited by Daniel_WRX; 12-30-2010 at 07:20 PM.
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 07:16 PM   #12
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by sc00by4life View Post
You also need to keep in mind the variances in contact patch between the front and rear causing the same slip-grip-slip of the center diff. Many people ignore this fact when trying to justify a staggered setup.

Visually, an 8 and 9 won't look that different. Might as well get matching sizes and stagger the offsets.

I see.

I did told him, that he should consider selling them.

But if case he keeps them you think that slip-grip-slip situation will damage the center diff?
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 07:17 PM   #13
MrSlowbaru
Scooby Specialist
 
Member#: 129231
Join Date: Oct 2006
Chapter/Region: Tri-State
Location: Long Island NY
Vehicle:
2005 wrx
cgm

Default

what offsets did he get, if he wants to sell i might scoop them up for my s2000
MrSlowbaru is offline   Reply With Quote
Old 12-30-2010, 07:22 PM   #14
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by MrSlowbaru View Post
what offsets did he get, if he wants to sell i might scoop them up for my s2000

Let me ask him and get back to you.
Daniel_WRX is offline   Reply With Quote
Old 12-30-2010, 07:27 PM   #15
nhat
Scooby Guru
 
Member#: 140163
Join Date: Feb 2007
Chapter/Region: MAIC
Location: 3MI Racing
Vehicle:
03 STi
hellaflunctional

Default

Quote:
Originally Posted by Daniel_WRX View Post
I did told him, that he should consider selling them.

But if case he keeps them you think that slip-grip-slip situation will damage the center diff?
tell him to sell the wheels and shop for something new. and like sc00by said, stagger offsets not width.

if he decides to keep them, i guess he'll find out what happens.
nhat is offline   Reply With Quote
Old 12-30-2010, 07:36 PM   #16
Daniel_WRX
Scooby Newbie
 
Member#: 259126
Join Date: Sep 2010
Chapter/Region: International
Location: Dominican Republic
Vehicle:
2004 WRX
San Remo Red

Default

Quote:
Originally Posted by Daniel_WRX View Post
Let me ask him and get back to you.
my dear friend doesn't have the offset. (I really wanna punch him right now)

This is all the info I got:

BBS ML-R 18" wheels

18x8 front 235/ 40 / 18 corsa 2233 tires
18x9 rear 265 / 35 / 18 corsa 2233 tires

I can get you a pic as well. just let me get it from him.
Daniel_WRX is offline   Reply With Quote
Old 12-31-2010, 12:05 AM   #17
secondhandloser
Scooby Newbie
 
Member#: 250925
Join Date: Jul 2010
Location: NOVA/AL
Vehicle:
'12 Mustang, '11WRX
Black/Spark Silver

Default

Quote:
Originally Posted by MrSlowbaru View Post
what offsets did he get, if he wants to sell i might scoop them up for my s2000

Also depending on offset, I may be interested for the Z
secondhandloser is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Clicking noise in front and rear suspension/wheel area trhoppe Brakes, Steering & Suspension 2 01-11-2012 09:16 AM
BBS LM Custom GFM faces 18x8+35 18x9 +35 5x114.3 SO-CAL xagenesis Wheels/Tires 3 04-29-2010 02:53 PM
STi Brembo brake kit, front and rear, BBS rims RicanLynk Private 'For Sale' Classifieds 51 08-01-2006 08:27 PM
Norcal: 2005 STI front seats, stock BBS wheels 05soobieSTi Private 'For Sale' Classifieds 23 07-18-2006 12:33 AM
Clicking noise in front and rear suspension/wheel area trhoppe South East Region Forum 9 06-26-2003 08:54 AM


All times are GMT -4. The time now is 12:46 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.