RichPugh

I've been digging around the forums on wide wheel specs and width/offset/tiresizes for NB 993's. I am buying/building a custom set of wheels from Fifteen52. My buddy Ed and I are going with a set each of their new 2pc forged wheels. Formula's for Ed and Tarmac's for me

2pc Forged Tarmacs - http://images-cdn.ecwid.com/images/185392/133491030.jpg

2pc Forged Formulas - http://images-cdn.ecwid.com/images/185392/133491199.jpg

Here's the dilemma... The only barrel widths avail are 8", 9.5" and 11". Ed's got a NB 964 so he's gonna do 8"F and 9.5"R with maybe 10-15mm more aggressive offset to push his out to the edge of the fender lip (the centers are CNC'd and the welding dictates the final offset). No biggie for him...

I, on the other hand, want wider wheels mostly for aesthetic purposes with a deeper lip. I was going to try to run 9.5"F and 11"R on my NB 993 C4... and thats why I'm polling the gallery here.

After reading tons and tons of forum threads, I found a few ppl talking about running 18x9 ET57 up front (one with w/ 7mm spacers to push them out further for aesthetics w/ 225/40's without problems), it looks like an 18x9.5 ET52-56 range up front with 235/40 could work ok... Correct me if I'm off. I will be running KW coilovers and going pretty low. Maybe a bit under RS spec... I'm just not too sure on inner/clearance of suspension.

The rears at 18x11 is where I'm concerned... offset specifically. If I can fit the 18x11, I had planned on running a 265/35 tire. I KNOW the 265 is narrow for the 11 but, 11's are the only wider option they have and I would need them to fit so, I dont think I'm gonna be able to run a wider tire on an 11" NB 993 and go very low... I dont mind a bit of a stretch. Will 2-2.5 degree neg camber assist it? Does the wheel hit inboard? I dont have a problem with rolling the rear fenders either if there is some scrubbing (I'm a long time VW/Audi guy... thats just what we do LOL). The 19x11 "Lobster Claw" and RUF replica wheels that ppl run on 993's are 67et and I assume theyre running 275/35's?

Whats your take? I really dont wanna run 8F/9.5R or 8F/11R... 9.5F/11R seems doable. Who's got some solid fitment info?

I've already asked Bill Verbug. His experience with running 18x9 up front was very tight so he doesnt think there's a way for it to fit. Then 18x10 65ET with a 285/30 was as wide as he could go in rear... saying lower height would restrict it more. Figured I'd ask a few more ppl...

Anyone else have experience trying to fit 18x9.5/11 on NB 993?

jim dorociak

Well when I build Speedline Daytona wheels for narrow body 993 cars I usually build 8.5 Et 53 and in the rears I usually build 10.5 or 10.75" rear wheels that fit. Again these are 3 piece wheels so minor adjustments can be made. Most guys have moved to 235 front wheels and 285 rears on stock size wheels (8" & 10") and I would never run a 225 on a 9 or 9.5 front wheel nor would I run a 265 with a wheel larger than 10". jdorociak@gmail.com jim

RichPugh

Thanks Jim. Yea, I plan on 235's up front. 275's might be the choice in rear depending on clearance. They do have Pilot Super Sports in 235/40 and 275/35 or 285/35

JPS

Hard to get better info than Bill's...

996

I've put 11" ET60 wheels with 275-30-19 on NB 993 and they fit. 11" ET63 is the minimum offset to clear inside shock. Front, I've try 9" ET46, you need 225 tires to clear fenders if you car is lower than RS spec. So 18x9.5 ET54, 18x11 ET61 should works. Pick some tires with more angle side wall which will give you more clearance. Conti, Toyo, Hankook are good, Michelin and Pirelli give you less clarance in same size of tires

bigrig

i have 18x9 front and 18x11 rear on my car with rolled fenders and spacers.
i have posted offsets with and without spacers-i think it should answer alot of your questions.
tire sizes and fitment pictures are included in my original post.
i am sending my wheels back to Rotiform to have them widened, 18x9.5 front and 18x11.5 rear (putting my rear lips on the front and having new lips made for the rear)
here is the link to my original post, hope it helps.

https://rennlist.com/forums/993-foru...iform-bbs.html

Bill Verburg

-front, 18x9 et48 + 7mm spacer=final et 41
225/40/18
-rear, 18x11 et60 + 7mm spacer=final et 53
275/35/18
I'm having a very tough time wrapping my head around these #s for a n/b 993

The front certainly has room for a 9" wheel w/ 225/40 x18 tire, I used that setup myself but w/ 9ET50, which leaves no additional room at the lip. a 9" ET41 wheel has it's outer edge 9mm further outboard.

Similarly in back I have 10 ET65 w/ 275/35 x18 tires, there is almost no room at the rolled lips, an 11" ET53 wheel has it's outer edge 24.7mm further outboard

The tires are similarly moved outboard.

Meaning no offense the only way I can reconcile these facts is that the wheels in question are actually 8" and 10" which would be the bead width and which is the common way to spec wheels. I've seen this mistake often.
It's common(but confusing) to have the overall width quoted rather than the bead width


Most oe late model Porsche wheels have .5" flanges, so an 8" wheel measures 9" across the flanges, a 10 will measure 11" etc.

I don't have the specs for BBS E28 but for BBS E88 the flanges are narrower, on these wheels a 10" wheel will measure 10.875" across the flanges
These are 8.5ET54 235/40 & 10ET65 275/35 x18

bigrig

wheel dimensions are correct, 18x9 and 18x11
i ordered them to be:
-front, 18x9 et48
-rear, 18x11 et60
after rolling my fenders, i saw that i had i little more room, that is when i added my 7mm spacers front and rear.

in this picture of the back wheel you can see that i am stretching my 275/35/18-this would not happen if my wheel were 10" wide.


my fenders have been rolled as quite a bit-i have no rubbing at all, and my car is pretty low.
i will take a couple of pictures in the next couple of days upwards into the wheel housing to show clearance, there is not much, but it does travel with no interference.

also i am using Bilstein PSS9's with them set at 6/7, quite stiff.
if anyone wants more info feel free-just looking to help out if i can.

last example, ADVAN TCIII
Front - 18x9 +46mm with 235/40/18
Rear - 18x11 +60mm with 285/35/18

Bill Verburg

The tire certainly is stretched and sits proud of the lip, I suppose if the ride height is limited and the suspension is stiff it's ok, not what I would want on mine though.

bigrig

i would agree with you on that point, my car is a street car, will probably never see the track versus yours that is a track car.
i would think that the forces you put on your suspension would cause deflection to the point that 10" et 65 is where you need to be.

as always Bill...thank you for your clarification and help!
Neil

RichPugh

I believe you... no harm in trying though, LOL. I'm gonna do some test fitments possibly with some different wheels and potentially even a test wheel/tire in very high offsets and then add spacers to check for actual applications. Thanks everyone!

RichPugh

(sorry for the excessive posting... I just figured I'd follow up on the original threads)

Well... I took a chance and bought some wheels/tires (used) from eBay and they fit like a charm! 18x8.5F ET41 w/ 225/40 Pzero Rosso's and 18x11R ET60 w/ 285/30 Pzero Rosso's. If I were to lower my car another 15-20mm, it would probably need the rear fenders rolled but I'm on totally stock fenders til I bother. Spirited 3 mile test drive thru sh!tty Baltimore city streets... Not a rub/scuff/mark/noise (FYI, I'm on KW V1 Coilovers and probably a bit higher than RS spec in rear, around RS height up front).

If I do go lower and eventually replace these Rosso's, I might go with a 275/35 in rear just cause I'd like Pilot Super Sports

18x11 on Narrow Body. NB guys, have at it. Just gotta do the 9.5 front now LOL...

Ignore the missing center caps LOL... I'm working on a matching set.

luckyJ

nice looking wheels there!....I have Fikse FM-10s rears 18x11 et60 with Super Sport 265/35/18s and no rubbing on my NB 993 fyi

P-daddy

Rich- When is the next C & C or gathering in the Balto area? I would love to see your set up? Gorgeous!

RichPugh

It's EVERY Saturday morning... 80-120 cars weekly... but the next BIG event is October 19th. Toys For Tots C&C. 200-300 cars easy. Come up! I'll be there by 7:45am. Usually were there around 8:30am.