Will 18in rims on STI affect alignment

hilfiger4you · 08-10-2005, 03:34 AM

Hey guys, just got a 05 sti. I am thinking about getting some 18inch rims. Just wondering if thats a bad idea in terms of affecting the alignment, I am not looking to mod the car, and the rims are for show. The car handles great so I would;nt do anything if it compromises the proformance.
thanks

* Registered users of the site do not see these ads.

ripvw · 08-10-2005, 04:29 AM

Your STI comes with some very strong, very light 17x8 BBS rims and 225/45x17 Bridgestone RE070 tires. There are not very many tires that will perform as well as the RE070's in the dry, so you would need to be careful which 18" tires you choose to maintain performance. The Falken ST615, Yokohama Neova AD07 and the Hankook Ventus RS2 Z212 tires are all equal to or better than the RE070's in the dry and would offer a performance alternative in the 225/40x18 size. They are all at least a pound or two lighter than the 27lb RE070's so that won't hurt performance either.

The BBS wheels are great - but expensive to replace. An 18x8.5 alternative that I would recommend is the SSR GT2. At 17lbs they are almost as light as the BBS wheels and are a 1/2" wider to help increase the width of the contact patch and improve dry cornering. Of course, you may already have some other wheels in mind, but from a performance perspective the 18x8.5 size is a good option to consider to allow you to maintain performance when going with 18" wheels.

a real performance enhancement could come from rolling the fenders and going with 18x9" wheels and 265/35x18 tires. it would look way cool too...

changing wheels and tires does not usually affect alignment, but it does give you an opportunity to improve upon the factory alignment settings and get even better handling. The strut suspensions on the Imprezas tend to gain camber when cornering, causing the tires to roll inwards exactly when you don't want them to. To compensate, we add more static negative camber both front and rear - making the tires look like this: / \. Adding some front and rear camber bolts for $20 to $30 per pair will allow you to adjust the front camber to about -2 degress and the rear to -1.5. This will give you more front grip - reducing the built-in factory understeer - and allow the car to handle better when cornering. To prevent the extra camber from eating up your tires, make sure the alignment tech sets the toe to 0 degrees front and rear.

If you really want to improve the STI's handling, add larger front and rear swaybars - 22/22 minimium, 24/24 even better. This will help to control body roll and even more importantly help to maintain camber when cornering. I know that you don't want to mod the car, but tests have shown that the STI really benefits from the larger bars. compared to most other suspension mods they offer a real bang for the buck improvement in performance.

having said all this, if it was my STI I would go with 17x8.5 wheels and 255/40x17 tires - best performance combination for the STI in my mind. But for running on the street it really won't make that much difference, so get the 18's if you want them - just get good wheels and tires since you already have one helluva car

STiyiyi · 08-10-2005, 08:35 AM

Nice post. I have a question regarding the proposal of going the 18X9" route. If I did do that and roll the fenders, would there still be any projection of the wheel/tire beyond the fenderwells? If not, all I need to do is find a competent person to do the rolling. Are there many manufacturers that make a 18X9" wheel for the '05 STi?

hilfiger4you · 08-10-2005, 02:45 PM

Wow thank you RIP. that was great info. I was thinking 18x8 wheels. So if I get 18x8 wheels and 225 tires. would the alignment be off some what to wear the tires ? I mean do I have to get at least alignment check?
thanks

bsbg · 08-10-2005, 05:55 PM

Quote:

Originally Posted by hilfiger4you

Wow thank you RIP. that was great info. I was thinking 18x8 wheels. So if I get 18x8 wheels and 225 tires. would the alignment be off some what to wear the tires ? I mean do I have to get at least alignment check?
thanks

Changing tires will not affect your alignment.

That said, you should have it checked and set because most factory set ups are not perfect.

eqlized_aero · 08-10-2005, 06:51 PM

why not DIY - www.rollyourfender.com

dchou · 08-10-2005, 08:33 PM

On the 05 STi you cannot roll the rear fender, there is nothing to roll. Unlike the 04's. The 05 STi has more room in back stock. You should search to see if anyone has put a 18x9 wheel successfully.

kcook · 08-10-2005, 09:11 PM

dude.. u have 17x8... thats plenty dude... it sux enough the 05 wrx's come with 16x6.5.. and 04 sti with 17x7.5... , but hey

ripvw · 08-11-2005, 01:33 AM

Quote:

Originally Posted by dchou

On the 05 STi you cannot roll the rear fender, there is nothing to roll.

umm - never heard that before...

Quote:

Originally Posted by dchou

The 05 STi has more room in back stock.

now that I've heard - but I still think that any 9" wheel will be tight

Quote:

Originally Posted by dchou

You should search to see if anyone has put a 18x9 wheel successfully.

ok:

http://forums.nasioc.com/forums/show...highlight=18x9

http://forums.nasioc.com/forums/show...highlight=18x9

http://forums.nasioc.com/forums/show...highlight=18x9

looks like at least 1 running 18x9, a couple of others who are thinking about it and someone else running 19x9!!!

08-10-2005, 03:34 AM	#1
hilfiger4you Scooby Newbie Member#: 93015 Join Date: Aug 2005 Vehicle: 02 wrx black	Will 18in rims on STI affect alignment Hey guys, just got a 05 sti. I am thinking about getting some 18inch rims. Just wondering if thats a bad idea in terms of affecting the alignment, I am not looking to mod the car, and the rims are for show. The car handles great so I would;nt do anything if it compromises the proformance. thanks * Registered users of the site do not see these ads.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Any pics of 18' rims on STI???	silversubisti	Member's Car Gallery	11	11-13-2004 05:12 PM
18in rims on a 2.5RS (GC8 body style)?	Rabidbyte	Tire & Wheel	6	03-11-2004 03:00 AM
Black/gunmetal Rims On Sti	ant2004sti	Tire & Wheel	2	02-19-2004 11:23 AM
Fitment of 98/99 RS Rims on STi?	YoSmiley	Tire & Wheel	6	10-31-2003 12:22 AM
Any Subaru dealers NOT willing to gouge on STi?	98ForesterS	STi Forum Archive	2	05-05-2003 11:58 AM

08-10-2005, 04:29 AM	#2
ripvw NASIOC Supporter Member#: 27790 Join Date: Oct 2002 Chapter/Region: E. Canada	Your STI comes with some very strong, very light 17x8 BBS rims and 225/45x17 Bridgestone RE070 tires. There are not very many tires that will perform as well as the RE070's in the dry, so you would need to be careful which 18" tires you choose to maintain performance. The Falken ST615, Yokohama Neova AD07 and the Hankook Ventus RS2 Z212 tires are all equal to or better than the RE070's in the dry and would offer a performance alternative in the 225/40x18 size. They are all at least a pound or two lighter than the 27lb RE070's so that won't hurt performance either. The BBS wheels are great - but expensive to replace. An 18x8.5 alternative that I would recommend is the SSR GT2. At 17lbs they are almost as light as the BBS wheels and are a 1/2" wider to help increase the width of the contact patch and improve dry cornering. Of course, you may already have some other wheels in mind, but from a performance perspective the 18x8.5 size is a good option to consider to allow you to maintain performance when going with 18" wheels. a real performance enhancement could come from rolling the fenders and going with 18x9" wheels and 265/35x18 tires. it would look way cool too... changing wheels and tires does not usually affect alignment, but it does give you an opportunity to improve upon the factory alignment settings and get even better handling. The strut suspensions on the Imprezas tend to gain camber when cornering, causing the tires to roll inwards exactly when you don't want them to. To compensate, we add more static negative camber both front and rear - making the tires look like this: / \. Adding some front and rear camber bolts for $20 to $30 per pair will allow you to adjust the front camber to about -2 degress and the rear to -1.5. This will give you more front grip - reducing the built-in factory understeer - and allow the car to handle better when cornering. To prevent the extra camber from eating up your tires, make sure the alignment tech sets the toe to 0 degrees front and rear. If you really want to improve the STI's handling, add larger front and rear swaybars - 22/22 minimium, 24/24 even better. This will help to control body roll and even more importantly help to maintain camber when cornering. I know that you don't want to mod the car, but tests have shown that the STI really benefits from the larger bars. compared to most other suspension mods they offer a real bang for the buck improvement in performance. having said all this, if it was my STI I would go with 17x8.5 wheels and 255/40x17 tires - best performance combination for the STI in my mind. But for running on the street it really won't make that much difference, so get the 18's if you want them - just get good wheels and tires since you already have one helluva car

08-10-2005, 08:35 AM	#3
STiyiyi Scooby Specialist Member#: 88067 Join Date: May 2005 Chapter/Region: NWIC	Nice post. I have a question regarding the proposal of going the 18X9" route. If I did do that and roll the fenders, would there still be any projection of the wheel/tire beyond the fenderwells? If not, all I need to do is find a competent person to do the rolling. Are there many manufacturers that make a 18X9" wheel for the '05 STi?

08-10-2005, 02:45 PM	#4
hilfiger4you Scooby Newbie Member#: 93015 Join Date: Aug 2005 Vehicle: 02 wrx black	Wow thank you RIP. that was great info. I was thinking 18x8 wheels. So if I get 18x8 wheels and 225 tires. would the alignment be off some what to wear the tires ? I mean do I have to get at least alignment check? thanks

08-10-2005, 06:51 PM	#6
eqlized_aero Scooby Newbie Member#: 88699 Join Date: Jun 2005 Chapter/Region: MWSOC Location: West Michigan Vehicle: 2005 92x V8 92x V9 Spec C Type RA	why not DIY - www.rollyourfender.com

08-10-2005, 08:33 PM	#7
dchou Scooby Newbie Member#: 39137 Join Date: Jun 2003 Location: Dublin, CA Vehicle: 2005 PSM STi Silver	On the 05 STi you cannot roll the rear fender, there is nothing to roll. Unlike the 04's. The 05 STi has more room in back stock. You should search to see if anyone has put a 18x9 wheel successfully.

08-10-2005, 09:11 PM	#8
kcook Scooby Newbie Member#: 78074 Join Date: Dec 2004 Chapter/Region: MAIC Location: NoVA Vehicle: 2005 STi Aspen White	dude.. u have 17x8... thats plenty dude... it sux enough the 05 wrx's come with 16x6.5.. and 04 sti with 17x7.5... , but hey