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Author Topic: Longer Rear Wheel Studs
LS2 V8 Miata
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Could anybody please direct me to a company or individual's contact info. where I can get longer (hopefully stronger too) wheel studs for the rear hubs on my 1994 Miata?

Deeply appreciate it!

Jeff Mosing Verified Driver Made Donation to Website
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Check with Karl Zimmerman with http://www.appliedracingtechnology.com/

He should have what you are needing. BTW, I'm still considering building a V8 track Miata one day with my old(?)LS-6 outa my Caddy! 400hp in a 2300lb car has to =fun!! [Smile]

Jeff

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Jeff Mosing
2006 Playboy MX-5 CUP #31
1992 SM #16
1999 SM #17

Kim Ouye Verified Driver Made Donation to Website
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Karl's a good source for these, he uses ARP studs.

BTW - You can replace the studs on the rear hubs w/o removing the hub if you grind down a tiny bit of the carrier to allow the studs to clear. At least this works on a '91 Miata.

--------------------
Kim

91 BRG SMT RIP
06 MX-5 Cup

"Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting 'Holy sh*t...what a ride!'" - Unknown

Derek Luney Verified Driver
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Unless I got a bad batch Karl's stuff is ARP for the front of the 1.8 but it looks like specialty made stuff for the rears. Not as good quality as the front. They will install without pulling the hub. The threads are not great and ideally need to be chased with a die before install.

Kim Ouye Verified Driver Made Donation to Website
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Interesting...what is different about the 1.8L rears? On the 1.6L both front and rear are ARP.

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Kim

91 BRG SMT RIP
06 MX-5 Cup

"Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting 'Holy sh*t...what a ride!'" - Unknown

Derek Luney Verified Driver
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I don't know why they are different but if you look up the specs for the front and rear 1.8 studs an appropriate ARP part can be found for the front which is a Camaro part I believe. I couldn't find the rear so I suspect (I don't know) the part had to be made.

Don't get me wrong the parts work fine once on the car I just found the threads were not as clean as the fronts.

The rears are also of a different alloy than the front. Silver r/t bronze color as the ARP ones.

Derek

Jim Boemler Verified Driver
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That bronze color is just cadmium plating, for corrosion resistance. Good to have, but not particularly an indicator of strength.

BTW, the studs on the Miata are the same thread as those on the Z06 (although there's one less of them), so I doubt you'll have troubles with strength.

jim

--------------------
Just a clown

Derek Luney Verified Driver
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Thanks for that info Jim.

The threads for the studs may be the same as a Camaro (or Z06) but the other dimensions are not necessarily correct. The ones I got had a little too long of a shoulder which meant the rear disc would not sit flat against the hub without me adding some clearance. Not a big deal but a bother.

Jim Boemler Verified Driver
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Very true, the rest isn't necessarily the same. I was just pretty blown away when when the lug nuts from my cute little girly Miata fit my he-man Corvette. [Wink]

jim

--------------------
Just a clown

LS2 V8 Miata
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The fronts are easy, I found you can use the Mazda MPV (Mini-Van) studs with no modifications, they are longer and for a much heavier weight range vehicle. From what you guys are saying the the 1.6 guys could probably use the MPV ones for both front & back. They work perfect and are cheap dealer item.

The 1.8 rear hub however has a larger diameter "knurl" and holes. The stud is a little different to accomodate and position the disc rotor also. None of the Mazda,Ford or any normal racing replacement studs I found available would fit properly. I really spent alot of time on something so basic. Our Miatas use a M-12 nut so that must mean the newer Corvettes metric too eh? Cool!

EBudman Verified Driver
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GM hasn't used SAE lug nuts since the '80s. My car is using the same M12x1.5 lug nuts that I had on my '84-86 Fieros.(And every other GM car within the last 20 years) The size & strength of the lugs is irrelevent when using the current drivetrain & proper wheels. Using wheels with an incorrect hub center diameter or thickness may stress the stock lugs, as well as a V8 conversion. But that discussion is a whole different website.

davew Verified Driver Made Donation to Website
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I have sold about a thousand of these studs.

Mazda redesigned the rear stud during the 1992 model year. Prior to the redeign the knurl size was the same front and rear. The newer design has a larger knurl on the rear only. The older design rear hub is no longer available. If you can find an older rear hub it is identical to the new ones except the hole size. The other option is to have 4 new holes of the proper size drilled in the new style hub. Picture a dual pattern wheel with 8 holes. I have done this and found it to work fine.

I am currently taking with a manufacturer about making the proper rear studs. When I know anything I will post it.

Dave

Bernard Verified Driver
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quote:
Originally posted by davew:
Picture a dual pattern wheel with 8 holes. I have done this and found it to work fine.

Dave

Being the satisfied owner of your longer studs (still patiently waiting for the aluminum lug nuts though), I like to go a step further: I picture a hub with countless holes drilled into it. While I like the idea of such modification, I'm not sure competitors at the Runoffs or even tech see this the same way . . . .

--------------------
Bernard
World's Tallest Ex SM Pilot

mazrcr Verified Driver
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so what is the problem ?? just ream the hole a bit for the knurl to fit properly, no need to drill more holes....

--------------------
senior miata racer

EBudman Verified Driver
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The problem is that the holes in the later hubs are too big to use common studs all the way around.(read the thread) The studs that are currently available with the later knurl do not fit the hubs, as received. Reaming the holes will send your hubs to the dumpster, but you are free to try.

Eric

RP Performance Verified Driver Made Donation to Website
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I hope to have a line on the studs for the rear that will be about 2 1/2 inches long. These will be with the size knurl for the 1.8 rear hubs. I will post when they come in.

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Bret de PedroRP PerformanceRentals,construction,track supportwww.rpperformanceracing.com2005 MARRS ITA Champion1st place Summit point 12 hour 2004,2005,20061st place SSM Summit Point 12 hour2007,20081st, 2nd place NE 2006

Karl Verified Driver Made Donation to Website
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Our larger knurl rear studs will be here this week. We designed them one inch longer than OE. They should be much higher quality than the half inch longer studs we sold until these came in.

Bernard, we've had the aluminum lug nuts for a few months now. 17 mm head, silver, red, blue or black.

This shipment also includes 17 mm head steel lug nuts.

Bernard Verified Driver
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Karl,
now that you mention it, I'm not sure if I got my studs from Dave or you (would have to look it up at home). But one of the reasons I ordered aluminum lug nuts from you is that I felt the threads of the "longer" studs are going away quickly, despite me being extremely careful and not using an impact wrench ever. I rather destroy the thread of a lug nut, instead of a wheel stud . . .

--------------------
Bernard
World's Tallest Ex SM Pilot

LS2 V8 Miata
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I initially thought I was asking a stupid question but from the responses it appears the question's a legitimate one.

Safety is number one, my Miata is more than capable of hurtin' me and I know it!

Thanks again Karl, we are eagerly anticipating your new batch.

Karl Verified Driver Made Donation to Website
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The studs are in. As far as I know we are the only ones with them. This completes our line until Mazda changes things. [Smile]

I'll put them in the classified section soon and on our site later.

Until then, we have (all 12 x 1.5 mm):
2.75" studs (front all years)
2.75" studs (rear 1800s and all updated 1600s)
17 mm head open end steel lug nuts
17 mm head open end aluminum lug nuts

Spacers are now machined to within 0.001" tolerance at roughly 9.3 mm thick.

The never ending pursuit of perfection. [Big Grin]

TillerTech
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I have a question, what is the updated 1600 rear studs? Are the studs larger?

John

--------------------
Miata Race glass and CF from Legacy Molds. 4 1/2# CF Hood
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Karl Verified Driver Made Donation to Website
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John,

The OE studs are still the same length, but the knurl is larger.

If you order a new rear hub for a '90 - '93 you will get the '94 part. Both hubs came with standard length studs (1.75"), so the average person would never know there was a difference in the knurl diameter until they replaced the studs.

CTB27 Verified Driver
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Does anyone know what the actual knurl diameter is for both of the studs? I need this info for an application that is something other than my racing Miata, but I can't find it anywhere. Thanks.

modernbeat
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Best info that I've got is:

Stock front and early rear=
42mm/1.75" long under the shoulder
13.08mm/.515" knurl
M12-1.5 thread

Late rear=
14.94mm/.588" knurl

I posted a photo I stole off a Chevy racing site on Miata Net that shows stock, ARP, and GM Racing studs with the small knurl.

http://forum.miata.net/vb/showthread.php?t=160167

CTB27 Verified Driver
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Thanks!

jigou Verified Driver
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What they said about the GM stud on the Miata forum is correct. I bought one to play with, and (assuming Toyos) the end of the stud, using my 30mm Kazeras, would be within 1/4" of the face of the wheel/tire combo.

I really wanted the unthreaded/quickstart nose, but it's just not out there for Miatas right now.

And in a class like this, I want more protection for those studs than < 1/4" would provide. [duck]

Bought a set from Karl Z - they go in this week (probably).

Jarrod

--------------------
http://www.plainoldgas.com

Dwayne Hoover Verified Driver Made Donation to Website
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FWIW, the ARPs are 12 X 1.5mm, 0.509" knurl, 2.5" underhead length (other lengths available).

--------------------
Visit the Midland City Arts Festival!

weargle
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searched ARP, wheel studs

FWIW, the ARP numbers are out for the newer Miatas.

PN 100-7719 fronts: 0.507" knurl dia., 0.335" knurl length and 2.750" underhead length

PN 100-7720 rears: 0.579"/0.300"/2.750".

Numbers from Summit Racing. At $27/corner, they're mighty proud of them.

Dave Lewis
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Jim, hate to call you out publicly, but the color you referred to does not indicate plating type,(cad or zinc). The yelow you see is a dichromate used, I believe, to protect the plating. In the North American fastener market fasteners up to and including grade 5 are zinc with a clear dichromate showing a silver color, grade 8 are yellow. Cadmium plated fasteners are always yellow.

Stan Clayton
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quote:
Originally posted by Jeff Mosing:
I'm still considering building a V8 track Miata one day with my old(?)LS-6 outa my Caddy! 400hp in a 2300lb car has to =fun!! [Smile]

Yeah...I'd say! [Wink]

SM at 2300/130 = 17.7 lbs per hp...is well, Spec Miata fun. [censored]

Swift 014 Atlantic at 1305/250 = 5.2 lbs/hp...major fun! [yep]

Miata at 2300/400 = 5.8 lbs/hp...major fun, even if the engine is at the wrong end of the car. [thumbsup]

--------------------
Stan Clayton

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quote:
Originally posted by weargle:
searched ARP, wheel studs

FWIW, the ARP numbers are out for the newer Miatas.

PN 100-7719 fronts: 0.507" knurl dia., 0.335" knurl length and 2.750" underhead length

PN 100-7720 rears: 0.579"/0.300"/2.750".

Numbers from Summit Racing. At $27/corner, they're mighty proud of them.

For 1600s and the fronts of 1800s, use the Camaro fitment ARP-100-7708. 5 studs for $12.00 ... no different except 1/4" shorter.

--------------------
Visit the Midland City Arts Festival!

Craig Northcutt Verified Driver Made Donation to Website
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quote:
Originally posted by Karl:
John,

The OE studs are still the same length, but the knurl is larger.

If you order a new rear hub for a '90 - '93 you will get the '94 part. Both hubs came with standard length studs (1.75"), so the average person would never know there was a difference in the knurl diameter until they replaced the studs.

Thanks Karl, just the info I needed. I just placed an order for some.

Thanks,

--------------------
The best "things" in life aren't things.

Muda Verified Driver Made Donation to Website
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quote:
Originally posted by MBennett:
For 1600s and the fronts of 1800s, use the Camaro fitment ARP-100-7708. 5 studs for $12.00 ... no different except 1/4" shorter.

I would like to replace the stock studs with longer studs with the quickstart nose as I've used these on other cars and I am not getting full thread engagement with the stock setup.

Can anyone confirm that the Camaro part # above works as this would be a big savings.

--------------------
Muda Motorsports
"We're all here 'cause we're not all there."

cnj
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I suggest that you confirm the studs/rotor/hub combination you plan will work correctly and safely. I recently went through an expensive and potentially dangerous exercise where I installed long studs and rotors (rear of 99 SM) and they did not seat correctly due to a long shank on the stud, or lack of undercut on the rotor - depending on how you look at it. The rotor holes wore open under load and the lug nuts came loose. I was lucky and the wheels did not come off but it was exciting to have my wheel held on by 1 nut. The supplier subsequently figured out why this occurred and is no longer mating the long studs with those rotors (Brembo in this case).

A test is to use blue marking compound to ensure your rotors actually mate up with your hub after installation with the long studs.

Craig

Muda Verified Driver Made Donation to Website
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Thanks Craig. This is a new car for me and I don't know whether it has the original rear hubs or the revised ones. Is there an easy was to tell without having a stud to use to check it? I have also read that I must be sure that the rotors fit properly if the long shank is used. This is a bit more complicated than I am used to for this swap but if the Camaro studs fit the front and the rears end up being the newer design I won't be out $75 for buying the wrong studs for the rear.

--------------------
Muda Motorsports
"We're all here 'cause we're not all there."

Casey Z Verified Driver Made Donation to Website
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I think this thread is the issue Craig is referring to: http://forum.specmiata.com/cgi-bin/ultimatebb.cgi?/topic/1/3025.html

Give Karl a call at ART and he will be able to answer this for you. http://www.appliedracingtechnology.com/

Good luck!

--------------------
----------------
Z Brothers Racing / East Street Auto

Casey Z - 1.6 Kettle
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cnj
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Casey is right - this is exactly the issue I am referring to. I was the test case for Karl with respect to Brembo rotors and ART long studs with 99 hubs. ART (Ed) have told me that the stock Mazda rotors will work correctly with their long studs. I have not tried this yet.

As to determining which hubs you have, others will have to advise. With that said I am pretty sure you will have to update them at some point with the new versions and so consider planning the correct stud combination now. ARP also make long studs, not as elegant as the ART studs but with a very similar shank length hence a similar result.

Craig

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Did some more homework on this. It does appear that the ART studs are the elegant solution and reasonably priced. Time to figure out which hubs I have on the rear and whether the rotors are an issue.

Thanks, all!

--------------------
Muda Motorsports
"We're all here 'cause we're not all there."

   

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