About to buy wheels, need offset advice?

[FlatSix]

Hey all, So I have finally decided on wheels for the 964, Work Wheels Brombacher's!

 

 

My only issue is offsets! It's doing my head in! My current wheels are 18" Speedlines 8" 52ET front and 9.5" 47ET rear (well thats the numbers on the wheel lip) I was going to go with 8.5" fronts and 10" rears for the new wheels but have no idea what the offset should be. 

 

Can anyone shine some light on this for me? Thanks PFA'ers!

[OZ930]

Don't know if this will help or confuse

 

http://www.willtheyfit.com

[mph911]

Here is basically the same thing.. just type in the old and new..

1010TIRES.COM - Wheel Offset Calculator

[FlatSix]

Thanks for the links guys. I have just figured out what was causing my confusion. The Speedlines on my car are the correct offset for a NB 964, not a Turbo. NB wheels are 18x9.5 ET47 (What is on my car) and correct Turbo fitment should be 18x10 ET54. Seems like one of the PO bought the wrong wheels.

[FlatSix]

aarrrrhhh this is frustrating, now I have found a few posts saying the original speedlines are 18x10 ET61 !! My brain hurts!

[FlatSix]

Ok I think my brain was having a mid week holiday yesterday. I also found Works fitment guide. So its going to be 18x8.5 ET54 on the front and 18x10 ET60 rears. According to willtheyfit that should give me a front inner rim which is 8.3mm closer to the suspension strut. The outer rim will poke out 4.3mm more than before. The rears will be inner rim which is 19.4mm closer to the suspension strut. The outer rim will poke out 6.6mm less than before. 

[CarreraG50]

From a previous post I made, hope it helps

Wheel Fittment Chart

Front Fittments: Wheel Offsets Max Tire Notes:

911 Narrow 70-89 7x15 10.8, 12.5, 23 225/50/15 Easy

7x16 10.8 225/50/16 Tight 911 Offset

7x16 23 225/50/16 Medium 951 Offset

6x16 12.8 205/50/16 Tight 930 hubs on narrow body or 19mm spacer

8x16 53 225/50/16 Easy 930 hubs on narrow body or 19mm spacer

7.5x17 23 205/50/17 Easy

7.5x17 23 225/50/17 Tight

7.5x17 53 235/45/17 Easy 930 hubs on narrow body or 19mm spacer

8.5x17 53 235/45/17 Easy 930 hubs on narrow body or 19mm spacer

9x17 53 245/40/17 Medium 12.5-19mmmm spacer

7.5x18 53 225/40/18 Tight 12.5-19mmmm spacer

8x18 53 235/40/18 Tight 12.5-19mmmm spacer

911 Wide 70-89 8x15 10.8, 12.5 225/50/15 Easy 930 hub or 911 hub -w- 19mm spacer.

7x16 12.5 225/50/16 Easy 930 hub or 911 hub -w- 19mm spacer.

8x16 12.8, 23 245/45/16 Easy 930 hub or 911 hub -w- 19mm spacer.

9x17 23 255/40/17 Easy 930 hub or 911 hub -w- 19mm spacer. 930 Rear

10x17 23 275/40/17 Tight 930 hub or 911 hub -w- 19mm spacer.

10x18 40 285/30/18 Tight 931 hub or 911 hub -w- 19mm spacer. 993TT Rear

964 Narrow 89-94 8x16 53 225/50/16 Easy

9x16 53 245/45/16 Very Tight

7.5x17 53 225/45/17 Easy

8.5x17 53 235/45/17 Tight

9x17 60 235/45/17 Tight 1/4" Spacer

7.5x18 53 225/40/18 Tight

8x18 53 235/40/18 Tight

993 All 95-98 7x16 53 225/50/16 Easy 951F

8x16 53 225/50/16 Easy C2/951 Rear

9x16 70 245/45/16 TIght 993-16" rear

7x17 53 225/45/17 Easy 993/C2 Cup

8x17 53 235/45/17 Easy RSA Rear

9x17 53 245/45/17 TIGHT 993/C2Cup Rear

Rear Fittments: Wheel Offsets Max Tire Notes:

911 RS, S, Carrera 7x15 12.5, 23 225/50/15 Tight Fuchs

8x15 23 245/50/15 Tight 911/944 rear

7x16 10.8/23 225/50/16 Easy Fuchs

8x16 23 245/45/16 Easy Fuchs or 951 Rear Phone

9x16 23 245/45/16 Easy Fuchs

8x16 53 245/45/16 Easy Use 30mm 1"-1.25" Spacer 951 Late or C2

9x16 70 245/45/16 Easy Use 50mm-2" Spacer 993 Rear

9x17 23 275/40/17 TIGHT May use 255/40/17, depends on car Aftermarket C2/993 Knockoff

9x17 53 275/40/17 Med Use 23mm Spacer Watch inner fender/Oil Lines

10x17 23 275/40/17 Very Tight Aftermarket, Borbet/HRE etc.

10x17 53 275/40/17 Depends on car Use 23mm-1" Spacer

10x18 40 285/30/18 Very Tight No spacer to 1/4" 993TT wheel

10x18 65 285/30/18 Very Tight 1.5-1.75" spacer

911 Wide All up to 11 wide

23mm or add spacers

12x17 Easy 315/35/17

12.5x17 Carefully! 335/35/17

12x18 Carefully! 335/30/18

964 Narrow 89-94 8x16 53 245/45/16 Easy Stock wheel with upside tire

9x16 70 245/45/16 Med 993 16" wheel

9x17 53 255/50/17 Easy 965 / 993 Cup wheel

9x17 53 275/40/17 Tight 965 / 993 Cup wheel

10x17 53 275/40/17 TIGHT

9x18 65 265/35/18 TIGHT 1/2" spacer needed to clear trailing arm Boxster wheel

10x18 65 285/30/18 Good Luck 1/2" spacer needed to clear trailing arm 993 twist or sportclassic II

993 All 95-98 9x17 53 275/49 17 Note lots of space to the inside. 993 cup

10x17 53 275/40/17

9x18 50 265/35/18 Med Boxster SCII

9x18 70 265/35/18 Easy Optional

9x18 65 265/35/18 Easy

10x18 65 285/30/18 Very Tight 285 is tight on 993, trick is to inset wheel. 993/996 fittment twist or SportClassic II

[Russ]

your ET should be cast into your current wheels shouldn't it? get something that matches?

[clutch-monkey]

if you still get stuck, PM or email jim dorociak:
http://forums.pelicanparts.com/porsche-964-993-technical-forum/780540-widebody-964-18-wheel-fitment-help.html

he rebuilds speedlines etc for 911's and knows the offsets off by heart

[Russ]

I still think you should roll your guards some more and get those gemballa's too lol

[J.J.]

a higher offset will mean less dish, if i were you i'd run a 10" wheel and the lowest offest possible to get the maximum dish.

use the offset calculator and measure the difference with the new wheels, lower offset will mean the wheels stick out further

[clutch-monkey]

a higher offset will mean less dish, if i were you i'd run a 10" wheel and the lowest offest possible to get the maximum dish.

use the offset calculator and measure the difference with the new wheels, lower offset will mean the wheels stick out further

have 10"s on the 964 turbo here- it really needs 11"s

[FlatSix]

if you still get stuck, PM or email jim dorociak:

http://forums.pelicanparts.com/porsche-964-993-technical-forum/780540-widebody-964-18-wheel-fitment-help.html

he rebuilds speedlines etc for 911's and knows the offsets off by heart

 

Just had a chat with Jim on Rennlist, He suggested that 18x10 ET60 was a good choice.

 

your ET should be cast into your current wheels shouldn't it? get something that matches?

 

It is Russ but the Speedlines on my car have the correct offset and width for a NB 964 (so maybe they are not genuine speedlines?) Genuine 964 Turbo Speedlines are 18x10 ET61 rears. Mine are 18x9.5 ET47. I am not going to get another set of 9.5's so the ET changes.

 

a higher offset will mean less dish, if i were you i'd run a 10" wheel and the lowest offest possible to get the maximum dish.

use the offset calculator and measure the difference with the new wheels, lower offset will mean the wheels stick out further

 

My current rears are just under 5mm from the top edge of the fender, my choices for rear ET are 47 or 60. ET47 puts the wheels 6.4mm further out. ET60 brings them in 6.6mm away from the edge. The more dish the better but I dont want anything to foul, especially if my car gets any lower     

 

have 10"s on the 964 turbo here- it really needs 11"s

 

It looks like there is plenty of room behind my wheels but the offset for these in 11" are the same, 47 or 60. I just dont want the wheel sitting any further outboard than it already is. The Gemallas I found were 11" rears but they stuck out of the fenders about an inch without tyres, not sure of the offset. I am happy with 10''.

[Tit]

The BBS thread on the rennlist 964 forum has swayed into this topic too (list three pages):

http://m.rennlist.com/rennforums/showthread.php?t=727369&page=12

[clutch-monkey]

Just had a chat with Jim on Rennlist, He suggested that 18x10 ET60 was a good choice.

 

 

It is Russ but the Speedlines on my car have the correct offset and width for a NB 964 (so maybe they are not genuine speedlines?) Genuine 964 Turbo Speedlines are 18x10 ET61 rears. Mine are 18x9.5 ET47. I am not going to get another set of 9.5's so the ET changes.

 

 

My current rears are just under 5mm from the top edge of the fender, my choices for rear ET are 47 or 60. ET47 puts the wheels 6.4mm further out. ET60 brings them in 6.6mm away from the edge. The more dish the better but I dont want anything to foul, especially if my car gets any lower     

 

 

It looks like there is plenty of room behind my wheels but the offset for these in 11" are the same, 47 or 60. I just dont want the wheel sitting any further outboard than it already is. The Gemallas I found were 11" rears but they stuck out of the fenders about an inch without tyres, not sure of the offset. I am happy with 10''.

11" ET60 will protrude 6mm outwards compared to your current wheel, and 32mm inwards. if you are going lower, the negative camber will bring that top lip back in line more with your current wheels. it's the inner clearance i'd double check, if you have 32mm space there between wheel and strut. 

the 10"s do have more margin for error there.

i spent time with a ruler under my car before ordering wheels haha, ended up with custom offset 9.5"s under the narrowbody

[FlatSix]

Thanks for that link Tit. I keep seeing pics of 964 widebody's with a big dish but I'm pretty sure they are RS and NB's with changed fenders. They have smaller suspension arms and the hubs are more in board than turbo hubs.

Sam what wheels do you have on the purple beast? Are they the speedline 18x10 ET61?

I could go to a 10.5 with a ET54 and it should fit. Gives me a slightly bigger dish.

[Tit]

Most of the guys on that RL thread are NB cars.

Yes, I've read its common to put NB control arms on turbo cars for more dish...

I've said it before, but have you looked at CCW? They do three piece wheel sets down to mm spec...

[FlatSix]

I have sent CCW an email about pricing shipped here but have yet to hear back. I think I have decided on a 10'' rear with ET47. That will add an extra 5mm on the inner and outer edges. So I will have the same dish as the current wheels. The more I research different offset options the more confused its making me. If I dont hear from CCW by today I am going to bite the bullet and order the Works ones.

[clutch-monkey]

Sam what wheels do you have on the purple beast? Are they the speedline 18x10 ET61?

 

 

some knock off speedlines made in japan- no brand on them. can't remember offset- haven't looked at them, but i'll be doing the same as you later in the year.

the speedline knock off's that came with it

 

now i did put on the cup wheels for laughs, 9" ET23. they protrude 19mm more than your current wheels would, which ends up being this much past the guard. this is the exact same as you would see in 11" ET47 as you can see might work once lowered with some camber, but yeah.. rules it out i'd say

assuming no spacers, 18x10 ET60 does NOT sound right - that would be sunken in over the current wheels by 7mm. 18x10 ET54 will be spot on IF you do not want the wheel lip protruding out any further- will be the same as current spec wheels. this is your safest bet!

10.5" ET54 extends 6mm and will sit more flush, especially if you are lowering it

i triple checked everything before ordering these from fikse haha. glad i got it right though.

[FlatSix]

Thanks Sam, yes the ET60 would be further in. I have been over thinking it a bit, 10'' ET47 should keep me sane. Now I just need to sneak over to your place and pinch that wing What car are the Fikse's on? They look awesome.

[FlatSix]

Got a response from CCW, they cant do the wheels I want with the correct bolt pattern.

''will have to be lm5 or classics as the lm20 isnt designed to do a 130mm bolt circle.keep in mind you can go a bit wider on the rear

cost for classics or lm5's with the gold centers will be 2980 for the set. shipping to the east side of austraila will run 480''

Price works out about the same.

[Quozl]

Try ship2anywhere.com.au might get it cheaper.

[clutch-monkey]

Thanks Sam, yes the ET60 would be further in. I have been over thinking it a bit, 10'' ET47 should keep me sane. Now I just need to sneak over to your place and pinch that wing What car are the Fikse's on? They look awesome.

yep that ought to do it. definitely a safe option. if the clearance on the inside is enough i'd go 10.5 ET54 (this is what i am aiming for i think, will see, it's not my car haha).

the fiske's are on my white SC- they are spot on, just need to lower the front 5-10mm..

[Tit]

I knew this about the LM20. I like them so much I have considered changing my hubs!

Got a response from CCW, they cant do the wheels I want with the correct bolt pattern.

''will have to be lm5 or classics as the lm20 isnt designed to do a 130mm bolt circle.keep in mind you can go a bit wider on the rear

cost for classics or lm5's with the gold centers will be 2980 for the set. shipping to the east side of austraila will run 480''

Price works out about the same.

[FlatSix]

I knew this about the LM20. I like them so much I have considered changing my hubs!

No need! Work brombachers are almost identical and have the correct bolt pattern.

Fiske's look awesome on your SC Sam. You didn't have them on at the first skidpan did you?