New to P Cars...and doing custom wheels in general...I just bought Zulu's/John's '01 996 Turbo.

I am going to a set of 18" wheels - 18x8.5 front and 18x11 rear - and need help with recommended offsets please!

The car is currently slammed on coil overs and is currently running some 19" BBS F1 wheels, that came off a 997. They have 245/35/19 fronts and 315/25/19 rear tires and are both pushed out with what look to be 1/2" spacers and longer lug bolts. No rubbing what-so-ever.

My wheel/tire considerations are:

• 18 x 8.5 w/ 225 or 235-245/40/18
• 18 x 11 w/ 295 or 315/30/18

(I'd prefer to run the wider tire configuration if possible but am concerned about clearance/rubbing)

As I understand, stock rim sizes and offsets are:

• 18 x 8 50mm
• 18 x 11 45mm

I have a 996TT buddy with factory suspension that suggested I go to the same offsets he is running (to push them out a bit):

• 18 x 8.5 et45
• 18 x 11 et38

My wheel mfg however just came back today with these recommendations:

• 18 x 8.5 et47
• 18 x 11 et42

"This will be 3mm more aggressive than the oem fitment based on the information we have. Now keep in mind that's on OEM ride height. You're lowered on coil overs and we can't estimate the amount of camber you may have. If you want we can make them right in the middle of the offsets your friend is running and with what we know, should work without any issues."

I would prefer to run:

• 18 x 8.5 w/235 or 245/40/18
• 18 x 11 w/315/30/18

Can anyone please help a newbie understand what rim offsets and tire sizes I should consider going with?

Other questions please:
I'll be changing my lug bolts - OEM lugs are ball seat but the rim maker normally makes the wheels conical seat. They can make ball seat if I want. What do you suggest I go with?

Thank you for any help you can provide. Much appreciated.

 

I'm in a similar debate.

I'm looking at a set of wheels that state they were built for a GT2, but i'm not sure the offset will be pushed out enough for me.

18x8.5 - 44mm
18x12 - 44 mm




btw, what suspension are you running?

 

You have a lot of numbers there but its pretty simple, do you like the way the wheels are currently or do you want them pushed out more?

 

FWIW, stock GT2 wheel specs are 18x8.5" et40, 18x12" et45
If you want to run a 11" rear, et32 gives you the same outer fitment as GT2
Go ball seat for sure...parts availability/simplicity

 

Your listed choices are too conservative if you want the wide look with a low car.

Offsets are easy to calculate, just compare to your current setup:
12" rim goes ½ inch outward than 11" rim. So you can deduct 25.4mm/2 = 12.7mm of the offset when comparing to 11" rim.
Your BBS FI are 12x19" ET50. That means it sits the same as 11" ET37.

With the spacers, probably have around 15mm spacers so you have 12" ET35 there currently. So, that's like 11" ET22....(I drive with this setup with my BBS FI...it's very wide, but doable with negative camber and rolled fenders).

In front, you have now 8.75x19" ET50 with spacers.

I would opt for approx 8.5" ET40 for the front.
For the rear, approx. 11" ET25.

That's a setup I've used previously with 18" rims.

Btw. Do 12" rear instead of 11" rear if you plan to use 315/30/18 tires. I don't know current range of 315 18" tires, if they are lacking, then 11" could be a safer bet (you can use both 295 and 315 with 11")..

 

I found almost any 18" wheels needed spacers to fill the wheel wells. When I was running stock 18" Turbo hollows, I used 7mm front and 15mm rear spacers.

Wheel Enhancement had all sizes of spacers and longer lug bolts on hand so I was able to get the exact fit I wanted. A good wheel shop is going to make it easy for you.

 

I recommended Josh go with an 11" rear wheel just like I did. Mainly for the ability to run either 295 or 315s (based on tire availability).

 

That is the key right there, "Tire Availability". Not many options out there now for 315/30 on 18s. I have the R888, but they are way noisy. They do grip like hell though.

 

Rivals!

 

lots of 315's available...Rival's, Rosso's, PS2's, RT615K's, NT01's, R888, various Hoosier's, BFG R1's
Only negative of 315 over 295 is some extra tire cost

 

You just named most of the R compounds which is not what most owners are looking for. I would go for the PS2s, though I thought those were no longer available in 315/30/18? I couldn't find any when I was looking, hence going with the R888s. If you have a good source for the PS2s on 315/30/18, def pass it along.

 

RT615K is a completely happy street tire as well, a bit more NVH but otherwise 'normal', likewise the PZero Rosso is the OE tire.
PS2's were on a long back order recently but have been available lately, I know Tirerack has them on and off now, think supply chain is catching up

 

Just checked Tirerack, but it says not available till 3/31. I'll keep on checking and maybe I get lucky.

 

might be worth sending an email/call to double check stock and/or see if you can get your name on a set

 

Thank you for all of the help and input Gents.