Would you be concerned using 3mm wheel spacers on track?

I'm looking to change up the wheel/tire setup on my Integra. Some of the wheels I'm looking at might be close to the knuckles up front and close to the trailing arms in the rear. We're talking 1-2mm, if that. 

I'm still on stock-ish wheel studs (I replaced the fronts a year ago with whatever was on Rock Auto when I was putting in fresh new Timken bearings- unfortunately, I threw my old stock ones away-doh!) and am considering picking up a set of 3mm wheel spacers in order to avoid any potential issues. I would rather not have to pick up extended wheel studs if I don't have to, as it would require me to buy new wheel bearings and new front hubs... unfortunately, the front wheel hubs I put in aren't OEM and won't fit with ARP extended studs. I would have to buy OEM hubs which are $200+ a piece, plus the cost of new bearings (they are seemingly always destroyed when I remove Honda front hubs). It becomes a more expensive proposition and a good bit more of a headache. Hence me considering to skip it if possible. 

Would you be concerned with running a 3mm spacer on track, if needed? 

No concern if I had enough thread engagement. Go with the rule of thumb of 1.5x the diameter, so a 12mm stud needs 18mm of engagement. Do you have that with your spacers?

Some good talk from James at BimmerWorld on spacers.

Keith Tanner said:

No concern if I had enough thread engagement. Go with the rule of thumb of 1.5x the diameter, so a 12mm stud needs 18mm of engagement. Do you have that with your spacers?

Good question, I'll get some measurements when I get home! Thanks Keith! 

In reply to David S. Wallens :

I'll be sure to give that a watch! 

In reply to roninsoldier83 :

I've had 5mm spacers on my race car for 25 years......no issues.

As Keith mentioned just make sure you have the right length stud.

Keith Tanner said:

No concern if I had enough thread engagement. Go with the rule of thumb of 1.5x the diameter, so a 12mm stud needs 18mm of engagement. Do you have that with your spacers?

Can someone please provide a visual of this? My feable mind is finding it difficult to understand this... 

If your studs are 12mm in diameter (pretty common for smaller street cars), then you need a minimum of 1.5x12=18 mm of exposed threads for the lug nuts to be fully engaged. If you have 14mm studs, then you need 21mm.

Best way to figure this is to take off one lug nut and measure how much stud is sticking out past the seat. If you've got 21mm or more on a 12mm stud, then you can use a 3mm spacer. For a 14mm stud, you'll need at least 24mm. The reason you ideally want to measure it with the wheel in question is because steel and alloy wheels can be quite different in thickness. I don't know if there's a standard for alloys, but they do seem to be pretty consistent.

If you don't like the metrics and you run 9/16" studs instead of 14mm, then you need...uhh...27/32"+1/8"= 31/32" or more of exposed thread to run a 1/8" spacer. Let's call that an inch :)

FYI, we have found that Miatas can run a 3mm spacer on stock studs. 5mm...you might get away with it if you're a frame scraping stancebro but I would recommend studs because I don't like it when wheels come off after I've given someone advice.

I run about 10mm on the front of my champcar.  Have for about 11 years now.

Zero issues.

However, I also make sure that my studs are in good shape.

roninsoldier83 said:

In reply to David S. Wallens :

I'll be sure to give that a watch! 

I once had a setup not pass muster. 

David S. Wallens said:

roninsoldier83 said:

In reply to David S. Wallens :

I'll be sure to give that a watch! 

I once had a setup not pass muster. 

I had a few minutes to watch that video... I guess me concern would be that the spacers I'm looking to pick up are only 3mm and don't have that chamfered lip on them: 

https://www.titanwheelaccessories.com/products/3mm-titan-wheel-spacers-for-honda-ef-eg-ek-ep-civic-4x100-56-1-hubcentric-set-of-4?_pos=2&_fid=42944ccec&_ss=c

My guess is that as long as there's still some portion of the hub snout sticking out, that it shouldn't be an issue? 

Keith Tanner said:

If your studs are 12mm in diameter (pretty common for smaller street cars), then you need a minimum of 1.5x12=18 mm of exposed threads for the lug nuts to be fully engaged. If you have 14mm studs, then you need 21mm.

Best way to figure this is to take off one lug nut and measure how much stud is sticking out past the seat. If you've got 21mm or more on a 12mm stud, then you can use a 3mm spacer. For a 14mm stud, you'll need at least 24mm. The reason you ideally want to measure it with the wheel in question is because steel and alloy wheels can be quite different in thickness. I don't know if there's a standard for alloys, but they do seem to be pretty consistent.

 

If you don't like the metrics and you run 9/16" studs instead of 14mm, then you need...uhh...27/32"+1/8"= 31/32" or more of exposed thread to run a 1/8" spacer. Let's call that an inch :)

 

FYI, we have found that Miatas can run a 3mm spacer on stock studs. 5mm...you might get away with it if you're a frame scraping stancebro but I would recommend studs because I don't like it when wheels come off after I've given someone advice.

Keith, as always, thank you, sir! 

As irony would have it, the wheels I'm looking at picking up are actually Flyin Miata wheels lol... I was looking into a staggered set of Kogeki 15x8 +36 and 15x9 +36 wheels. I know for a fact that a +35 fits, but while searching some old HT forums, I found some folks that had an issue with fitting some of the older 6UL +36 wheels. The clearance is very tight to say the least. I know you're an encyclopedia of all things Miata, but do you happen to know if said wheels clear old wishbone Honda's? Namely the DC2? 

Keith has it nailed, as usual. 

In reply to roninsoldier83 :

Sorry, I haven't heard any feedback about how they fit on a wishbone Honda.

About the Bimmerworld video - the hub lip isn't "carrying the load" on a wheel, it's only there for ease of alignment. The tapered seats on the lug nuts will make sure it's perfectly centered and the lug nuts will clamp the wheel to the hub. All good. The spacer definitely needs to be a nice fit on the hub lip because it doesn't have anything else centering it.

What they're really warning about is an incompatibility between machined lips on the spacer - again, not really necessary - and the wheel itself that causes the wheel to not fully seat. This basically means some loose lug nuts and that means a stud failure. Get flat spacers, no more problem. About the only time you need those lips on the spacer is if you want to stack spacers.

In reply to Keith Tanner :

Thanks Keith! 

Well, I measured my wheel studs that are M12 studs/bolts... it looks like I'm at about 17mm worth of exposed stud with my current wheels (Konig's) and no spacers at all, so it's probably not a great idea to run a spacer on stock studs. That's unfortunate. 

Based on this online calculator, it looks like the 15x9 +36 will stick inward by an extra ~14mm... I tried measuring the gap between my current wheel and the knuckle, and the most narrow point is around, you guessed it, 14mm. Not sure if that's where it would make contact or not. Upwards, towards the tire, there should be plenty of extra clearance. 

Same thing in the rear: I'm currently running a 15x8 +35 square and while there's a few mm between the wheel/tire and the control arm (I'm not terribly concerned with it being 1mm closer), it's CLOSE to where the upper arm mounts to the RTA. Fortunately, if needed, I wouldn't be concerned with shaving that down 1mm or so. 

I suppose there's only 1 way to find out. 

Small piggy back

Any brand of spacer that is particularly recommended?

Before my new wheels. I just to run 20mm spacers on track. As long you have the right studs and the spacers are hub centric you be fine. And always used a torque wrench especially on aluminum spacers

While your non-OE hubs might not fit the ARP studs intended for your car, you can definitely press one out and measure the knurl to find something that will work.

It's pretty well known that Timken rear hubs on Miatas aren't made with the studs in the same dimensions as stock, but I think it was some Mitsubishi Evo application that was a perfect fit. I did this to an NB Miata I owned for a short time.

Whatever stud is in your hubs came from SOME other application, that ARP probably could match to.

In reply to flatlander937 :

I think I saw a post on HT mentioning these hubs potentially fitting studs from a Subaru or Evo (both?). It would mean changing the thread pitch and lugs nuts, and only for the fronts (the rears are still OEM sized). I might look into it if needed. 

We just ran our Champ Car Elantra at the 24 hour race with 5mm spacers all around without any issues. It does have ARP studs though so we had plenty of thread engagement.

roninsoldier83 said:

In reply to flatlander937 :

I think I saw a post on HT mentioning these hubs potentially fitting studs from a Subaru or Evo (both?). It would mean changing the thread pitch and lugs nuts, and only for the fronts (the rears are still OEM sized). I might look into it if needed. 

There's also always the option of drilling the hubs out a tiny bit larger, and using some other application that uses M12 x 1.5 threads.

ARP's website makes it relatively easy to cross reference:

https://arp-bolts.com/kits/product-list.php?PL=55&Set1_page=1

There are 4 pages to go through, but open everything that has M12 x 1.5 threads in new tabs, and start taking some notes. If you can find out exactly WHICH Subaru/etc application it is, look that up as well and find the knurl diameter, and make sure the knurl length won't cause any issues (poking out beyond the hub surface and contacting the brake rotor, etc).

edit: It looks like all the Subaru studs are 0.565 knurl dia... As well as the EVO VIII. Which is M12 x 1.5 like you need. Coincidentally that's the exact stud I used on my aftermarket Miata hubs. 

flatlander937 said:

roninsoldier83 said:

In reply to flatlander937 :

I think I saw a post on HT mentioning these hubs potentially fitting studs from a Subaru or Evo (both?). It would mean changing the thread pitch and lugs nuts, and only for the fronts (the rears are still OEM sized). I might look into it if needed. 

There's also always the option of drilling the hubs out a tiny bit larger, and using some other application that uses M12 x 1.5 threads.

ARP's website makes it relatively easy to cross reference:

https://arp-bolts.com/kits/product-list.php?PL=55&Set1_page=1

There are 4 pages to go through, but open everything that has M12 x 1.5 threads in new tabs, and start taking some notes. If you can find out exactly WHICH Subaru/etc application it is, look that up as well and find the knurl diameter, and make sure the knurl length won't cause any issues (poking out beyond the hub surface and contacting the brake rotor, etc).

 

edit: It looks like all the Subaru studs are 0.565 knurl dia... As well as the EVO VIII. Which is M12 x 1.5 like you need. Coincidentally that's the exact stud I used on my aftermarket Miata hubs. 

Thank you for the information! 

I actually ordered the FM wheels last night. I'll see if they happen to bolt up without contacting the front knuckle. If they don't, I'll do some digging. 

The reference I found on HT was fairly vague, but seemed to point towards either Subaru or EVO knurl diameters, which after looking at the chart, would lead me to agree that it's likely a 0.565 knurl diameter. I'm skeptical of info I find on the cesspool of misinformation that is HT. So, I sent a message to the non-OEM hub company (DuraGo- they are the only hubs available on Rock Auto), asking if they'll share the knurl diameter with me. Worst case scenario, the hubs are only $17.63 on Rock Auto- I can just buy them, punch them out, measure them for myself and use the ARP link you sent to find what I'm looking for. 

I think you're right, I think the EVO VIII studs (APR part number 100-7717) are likely the droid I'm looking for as they have a 0.565" knurl diameter and an M12 x 1.5 thread pitch. 

Thank you again, brother! You might have just saved me quite a bit of money. 

The biggest issue with spacers is ensuring that they are larger in diameter than the wheel's mounting face. On a steel wheel, an undersize spacer can cut the center of the wheel out.  Nothing good has been written about losing a wheel from a car in motion.

On an aluminum wheel you'll maybe be okay, but also maybe not...