10J x 18 ET58 - someone with experience please

[Gary H]

Hi all

After spending hours with various offset calculators I'm almost there, but would really like someone's advice, who's done it:

I've just bought a set of Carrera III alloys:
Fronts: 8J x 18 ET 57
Rears: 10J x18 ET58

My current Turbo twists are:

Fronts: 7.5J x 18 ET50
Rears: 9J x 18 ET52

The car is a 2001 Boxster 986 3.2S

What I'm trying to work out is the size of Spacer required at the back - I currently have a 22mm and whilst it easily clears the strut, the tyre does stick out of the arch slightly.

The research I've done suggests a 15mm or an 18 mm spacer will be perfect, but not having the luxury to try before I buy I don't want to make a mistake and I'm finding mixed results re. rubbing - whilst the 18 will definitely work, will the 15 tuck in slightly without rubbing on the strut? I'm getting confused!

Cheers

[TriGem2k]

Gary,

You need 25mm spacers to fit the rears comfortably. You can get away with 20mm but it will be tight. I run 18x10 et 48mm with 5mm spacers for comfortable fit.

The front will fit but for cosmetics sake I would put 5-10mm spacers on. I run 18x8.5 et55 and have no spacers with no issues.

James D

[Johnny Danger]

Originally Posted by Gary H

Hi all

After spending hours with various offset calculators I'm almost there, but would really like someone's advice, who's done it:

I've just bought a set of Carrera III alloys:
Fronts: 8J x 18 ET 57
Rears: 10J x18 ET58

My current Turbo twists are:

Fronts: 7.5J x 18 ET50
Rears: 9J x 18 ET52

The car is a 2001 Boxster 986 3.2S

What I'm trying to work out is the size of Spacer required at the back - I currently have a 22mm and whilst it easily clears the strut, the tyre does stick out of the arch slightly.

The research I've done suggests a 15mm or an 18 mm spacer will be perfect, but not having the luxury to try before I buy I don't want to make a mistake and I'm finding mixed results re. rubbing - whilst the 18 will definitely work, will the 15 tuck in slightly without rubbing on the strut? I'm getting confused!

Cheers

According to my rough calculations, the change in fitment on the rear wheels will decrease inner clearance by approximately 19 mm and will cause the wheel to extend outward an additional 7 mm. The problem with this wheel set is not so much the size (i.e. width), but rather the very high offset. To give you an example, depending upon one's suspension set-up, most of 986 boxster wheel applications that I have been involved with, have utilized the following fitment: fronts: widths of 8 to 8.5 inches with offsets ranging from +47 and lower Rears: 9.5 to 10 inches with offsets ranging from +45 and lower. Try using a 20 mm spacer on the rears, that should give you adequate inner clearance, without extending too far outward. I would also recommend using spacers up front to lower the effective offset as well. You will especially need to do this if you ever decide to install adjustable coilovers.

[ChrisZang]

you will also need to get the e-brake cables out of the way by zip-tying them to the lower control arms. Otherwise they'll be touching the inside of the tires.
After you've done that you'll need to re-adjust the e-brake

[Gary H]

Excellent - thank you all.
I'm now beginning to think that I should just sell them and search for a closer offset

[Gary H]

Just an update - After some trial and error, I'm now running a 15mm at the rear and a 21mm at the front with these wheels. Fills the arches perfectly, nothing sticking out and no fouling or rubbing.

[Johnny Danger]

Originally Posted by Gary H

Just an update - After some trial and error, I'm now running a 15mm at the rear and a 21mm at the front with these wheels. Fills the arches perfectly, nothing sticking out and no fouling or rubbing.

Let's see some photos .

[Gary H]

These are my Track wheels - a set of 987 17's, running 225's up front and 245's at the back.



So that's with a 15mm spacer at the back and a 21 up front

Will get a picture of the Carrera III's soon with the new spacers soon. However, with a 21mm on the back and 25 up front: