Hello all, I have two sets of wheels/tires. OEM 18x8 +30mm offset and a set of Konig Dekagrams 18x9.5 +35mm offset. Due to the +35 on my Dekagrams spacers are required, and that brings me here for clarification as I've never used spacers before. As I've read on this forum I believe either a 15 or 20 mm spacer will work well.

The Dekagrams will be for track use (HPDE), I haven't purchased tires yet but am looking at something like a 265/40 or 275/35 all around (square). Would it be best to go with the 20mm or the 15mm spacers? Additionally will there be any concerns using the spacer with the OEM 18x8 wheel and will the OEM wheel with spacer clear the OEM Brembo brakes.

Thanks,
RIch

 

I'm not a fan of spacers, especially for track, but you want to make sure the spacers are hub-centric. And for those size spacers, you will need the bolt on style, that have wheel studs.

Depending on the length of the studs on the spacers, you may need open-end lug nuts, or just cut them so your current lugs seat. You may also need hub-centric rings that fill the bore difference of your aftermarket wheels, compared to the hub of the spacer.

If your wheels are +35, a 20mm spacer will bring the offset to +15, which is pretty flush with the stock fenders. As such, a 265/40 tire, may rub up front depending on suspension height/ stiffness. If you want to fit more tire, and try to avoid rubbing, it may be better to go with a smaller spacer.

You shouldn't have any problems clearing the brembo brakes with stock wheels.

 

@ Chihuahuamaster, thanks for taking time to help. The hub spacers I've looked at so far claim to be hub centric and forged. I do have hub centric spacer that came with the Dekagrams.
Should I change out the OEM wheel studs as well as the spacer studs to something stronger like an ARP stud?
I test fit just one Dekagram wheel on the front to check clearance and the inner edge is very close to the strut, perhaps about 2mm space. Would the 15mm spacer allow for 265/40 or 275/35 tire up front without fender lip issues, while also having enough room to clear the strut? I don't; mind rolling the fender lip and quarter panel lip if that is required.... this car is in nice shape for its age, but she ain't no classic show car.
My previous HPDE track car was a fully gutted fully caged race car that needed to be trailered. No idea where the Z will progress to, my goal is 1:35 laps at Mid-Ohio
One more clarification, the OEM 18x8 +30mm wheels clear the Brembo brakes without spacers or only with spacers?

 

Are you running camber arms, a 20mm spacer will require added camber up front with a 275/35-18. If you plan on camber arms of 20mm, if not play it safe with 10mm

whatever direction, use ARP studs and slip on spacers. Been tracking that combo on my car without issues, it's the industry standard for tracked cars

 

@Terrasmak thanks for replying. Currently my Z is totally stock, only had it about 3 months and just getting started on the journey. So no adjustable control arms yet, those components are on the list but I won't have them before my first track event. You think (know) a 10mm spacer with a +35 9.5 wide wheel and 275/35 tire will provide enough inner clearance? I appreciate getting your input being that you have track usage experience.

 

9.5 +35 has cleared without a spacer and 275/35-18 . It was close, but fit.

 

I'm surprised you were able to get 275/35 tire clear without rubbing the strut... was that with your 10mm spacer? had to have been? I like the idea of smallest spacer needed and then swapping in longer ARP wheel studs and open ended lug nuts.

 

without a spacer it will fit, there is tons of room on the inside up front. You will never hit the strut, it's the spindle that will rub.

Even more room on the inside on the rear.

 

Terrasmak thanks, you saved me a few bucks. And yes I miss spoke about hitting the strut and you're right about how much room in the rear, I think I could fit a 55 gallon out back without issue.

Will the factory lug studs accommodate a 10mm slip on style spacer? Ideally using longer ARP studs.

 

nope ,they need to be replaced. Even a 5mm spacers needs longer studs.

I swapped to ARP long ago, have never destroyed one and can run any spacer up to 20mm

 

Much appreciated ,thanks for clearing this up for me.

 

^^^ This!

FWIW, I mounted one of my LMZ5 (Z34 S-Tune) wheels up front without a spacer just to see how much space there was (or wasn't). (Here.) Plenty, that's a +47 offset wheel and fitted with a 255/35 and they weren't even close to the strut nor spindle. It killed steering response but it fit and rolled.

And yes, if you HAVE to run spacers, go the extended stud route (or bolt ons, which isn't optimal but functional - but I don't recommend for serious track use). I ran a 10mm slip-on spacer (on stock lugs) and hooboy..... lost torque on both front wheels after a short run in the hills; even though it felt like I had enough stud for the stock lugs to grip.

 

Micvelo, thanks for replying, I recall reading the thread you linked prior to me making my post... I'll need to re-install my Dekagram and take a better look at clearance.

Will the base model 03' 18x8 +30mm wheel clear the factory Brembo brake package without spacers? If so, I may return my 18x9.5 +35mm Dekagrams for a wheel with an offset closer to +25 and avoid the wheel spacer issue all together. I'll still install longer ARP wheel studs, used them on my previous track car for 4 seasons no problems at all.

 

all OEM Z33 wheels clear OEM brembo brakes

 

Gntlemen thanks again for helping me out. I'm sure you've answered the questions I asked a hundred times on here over the years; I really have been searching and reading to find out on my own. Now to Solve this Drivability issue I'm having.