The ST185 wheel size thread (offsets, widths, etc)

furpo

New member
SuperWhite92":acw7lqa4 said:
okay, how about massive spacers to both clear the strut and get the good flush look? does that sound good to you.


Actually, I found that stock 2.5RS wheels and wrx don't fit at all on the rears. They're both somewhere around a 50 offset. They hit the strut .


My vote goes to buying Celica/Toyota offset rims rather than Subaru

lets go through this in detail then, hang on i will just go get the measurements that i took off my car ........................... are yes here we are, keep in mind this is for a narrow body car however, the distance from the hub to the strut should be the same unless toyota has got their wires crossed somewhere.

on the front the distance from the hub to the strut is 180mm - the distance from the hub to the guard is 80mm. so in total 260mm or 10 inchs, so a 9 inch wheel will fit just.

a 225 mm tyre on a 8 inch rim measures about 9 inches accross. so the max offset that can be used is 60mm. this makes sence as my 17 x 8's with a 35mm offset have about 25mm gap to the strut. so bring on the subaru wheels, most aftermarket subaru wheels have a 45mm offset.

on the rear the distance to the strut from the hub is less. i measure it to be 160mm and then 90mm to the guard. with the same wheel as pointed out above the minimum offset is 40mm. again this makes sence as i have a gap of about 5mm to the strut with my wheels. so a subaru wheel will not fit on the back however, if you run a 10mm spacer it will.

so AWDios's 9inch wide wheel probably measures 10 inches with the tyre on it. with a 30mm offset this would mean the back spacing is 155mm on the outside they would be 95mm. this would mean the hub to guard measurement on the wide body car is about 110mm.

the distance for a 17 x 8 inch wheel measuring 9 inches and a 45mm offset but having a 10mm spacer will sit 30mm from being flush with the guard. with a more typical 25mm wheel spacer this will be 15mm from the guard.

ruffneck, personally i would look around for a wider wheel and go for the larger offset. your car will drive a lot better when you get rid of the large scrub raduis on the front. i brought my wheels from the states and there is a large number of possibilities particuarly when you go for a subaru wheel.

run
 

CMS-GT4

Active member
It depends on how flush you want it. There is no real magic number, since people want a different flush and setup. Width also affects how flush the wheel is vs offset. THat is why people need to learn how to use the offset calcualtors to figure out what they want.

The magic number with no spacers would seem to be 17x9 30 et and 5 et in the rear. Not everyone wants 17x9 wheels. Some people want 8.5, or 8 or what ever looks good.

A decent option is 17x8 w/30 et as well. W/ 25 mm spacer on the rear.

What it comes down to is taking some measurements of you car as is, then deciding on what offset/width you want then finding a wheel to match.
 

db

Active member
My question. Can those 9 inch rims still do a full lock turn without having the tires rub? I see everyone doing math and whatnot, but not a mention of rubbing during sharp turns. The front wheels do turn.
 

CMS-GT4

Active member
For those wanting a magic number I say 17x8 w/ 30-35 et and 225-235 tires 40 profile.

I still think people should measure and figure out what they need but from the pics posted on the forum 17x8 30et fit nice on a gtfour.

Now a new topic.

We have seen 2 race gtfours with different front and rear tire profile sizes.

Bob that autox'es his alltrac, and the garage cruise celica.

I posted a thread on the scca forum, but have little feedback as of yet.
My hypothosis is that a taller rear tire will rotate slower than the front tire.
For example
F: 245/40/17
R: 255/45/17
The rear will be ~5% slower than the front.
I am not sure how this tranlates to power split, but the idea is that the vc diff senses that the front wheels moving faster is "slip" therefore sending more power to the rear constsantly.

This could only be used for racing and autox cause it will edventually wear out the center diff.

The question now is, do we make the rear tires wider, more narrow, or the same size?

Garage cruise had wider front tires, bob had wider rear tires.
I think the narrow tire would act more like a stiff rear sway bar and cause the rear tires to slide out, and the wider tires would just rotate out.
Its really hard to say.


Now a new topic.

I think I am going to gather some data and get some alltrac people to help redo this thread so it isn't so garbaged up.

Maybe a pic of how the tire/wheel relates to the fender and making a visual guide of where the wheels will sit when the width and offset is changed.

Anyone interested in helping?
We need someone with stock wheels, then maybe some other wheel options, 6.5-9" widths.
Anyone game?
 

CMS-GT4

Active member
I need pics from this angle, font and back. No need to lean a tire against the car. ;)
http://pg.photos.yahoo.com/ph/gtfour77/ ... pg&.src=ph

Then I need tire width, offset, amount lowered and tire size.

Try and get them as dead on as you can.

This may be best for someone who has muitiple sets of wheels around.

Perhaps a angle shot simular to the one in your sig will help too.

If I get time later this week, I will do something simular excewpt maybe use my 1" spacer in addtion to the wheel in the front to show an example of where the wheel will go with a certain offset.

It would be nice if someone with 18"s can help too. We can do a style version and a performance version.
 

abraxxa

Member
I can only supply pictures of my suspension-stock ST205.
I'm looking for 18" Gram Lights 57F-Pro but I can't find a dealer in Austria who is able to deliver them :x
 

furpo

New member
it may help to measure the wheels as different companies size them differently.

here are links to my narrow body gt4 with 16 x 7 advanti mags. they measure 7 inches wide (inside to inside) or 7 1/2 inches (outside to outside). the offset is 40mm.

http://www.alltrac.net/phpBB2/viewtopic ... hlight=gt4
http://www.alltrac.net/phpBB2/viewtopic ... c&start=15

here is a link to the same car with 17 x 8 oz superleggra's. they measure 17 x 8 1/2 (inside to inside) and 17 x 9 (outside to outside). the offset is 35mm.

http://www.alltrac.net/phpBB2/viewtopic ... highlight=

another interesting thing to note is that on the front one wheel sits in a different position to the other. i found out when doing a wheel allignment this is due to the huge factory tolarance in allignment settings.

roger
 

BlackGT4

New member
I am looking at ordering a set of Simmons 3 piece wheels.
I spoke with the guys at the shop, and was told that I can order them in any offset, etc..
as i am after dished wheels, he mentioned that coz of the brake setup i dont have much options. so i am pretty much confused how that red car has massive dish on the first page of this thread.
i then asked about the possibility of using spacers so the brake wouldnt intefere with the rim.. he then realised how desperate i was for dish and booked me in for next week to try out some different sizes and stuff.
hopefully this goes good.
at the moment i'm thinking 16x8s with spacers will work..
but we will be trying it all out next tuesday i will let you all know how things pan out.
 

SuperWhite92

New member
Keep in mind that the 17x9's want a 10-15mm spacer in front, and a 25mm in back. This makes the effective specs on those wheels like this:

Front: 17x9, +25ET

Rear: 17x9, +13ET

You can use those specs to match other wheels of other widths and offsets to the fender. This setup allows vitually no room to go out or in with it, so make sure your new wheel doesn't extend much, if at all, further in either direction.
 

Akira-R

New member
Found this site with some wheels 17x8 +35 that should fit, and they are only 18 lbs and on sale for under $100 a rim
 
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