I think your the only person to have this problem bro. with the stock brace there should be no reason that they are shearing off besides installer error.

I did run the car with these studs and no brace so the damage might have already been done. But I'm leaning on blaming the 8500 rpms.

Im using a 94-97 manifold. heavily modified and made to fit a 99 head its a few pounds lighter than stock and might be 8 or 9 pounds lighter than a Vics. No EGR features no bracing no casting flash and with extra cast material and webs etc ground out removed and smoothed over. And no intake manifold issues with 8600 rpm rev limit.

Is there enough clearance to drill/tap larger and use exhaust manifold studs on the intake side?

--Ian

We had this issue on Laz, only when I used my shitty torque wrench and over torqued all of them to probably 30ft/lbs instead of 14-19.

We replaced all of them with new OEM studs, and used locktite on both sides. We'll try to report back at the end of the season with results.

Something no one's discussed, but the stock brace is molded to give easier access to the oil filter. Add in a oil/water cooler, oil cooler sandwich plate, and/or sensor plate, and/or an oversized filter, and there's no way it'll clear.

I've snapped a couple here or there, but it never seemed to be a chronic problem. 30lb of supercharger would probably change that. Eric, I'm surprised you haven't considered a brace - trying to keep the weight off?

I made a brace for the manifold. I think my issues went as follows. Blower manifold flange was too think to use stock length studs. I (like an idiot) went to the local hardware store and found the proper length "automotive studs" which I later found out to be class 5 hardware. So this off season rather than only half fixing the problem, I did what I do and went overboard with the ARP hardware. Like all ARP stuff I was impressed with the quality and would recommend those studs to anyone. (but they are a bit spendy)

Running factory studs in mine with the same charger hanging off the side that TNTUBA has. Zero issues.

Drive harder. :giggle:

Your setup isn't exactly like mine. :/ The catalyst for my issues was the thickness of the manifold flange requiring longer studs.

I know. That wasn't a poke at you. We fabbed our own intake with a flange thickness to utilize the factory studs. The point was to everyone else that I have substantially more weight than a factory intake hanging off the side of the engine on the factory studs.

I just found the 3 studs surrounding the #1 cylinder broken. They all broke within the nut. two of them still had the nut on by a thread, but the end of the stud was gone.

I was not running a brace. I did have a fabricated brace on it, but the lower attachment point had failed, so I just took it off. looks like I need to improve the lower mount.

Those of you breaking intake manifold studs, is 8000+rpm the common denominator? If so, are you running an aftermarket balancer? How about fully balanced rotating assembly? (Wondering if the SuperMiata balancer and the like would reduce high rpm vibration enough to combat vibration related failures?)

Mine was balanced by trackspeed when they built it and has a 949 damper on it.

Rotating assembly was static and spin balanced and runs a ATI damper. Still broke several.

Jury is still out on the ARPs....but so far so good.

Stock, stock, stock

Never seen a stud break like this, doesn't make sense. It's like the threads within the nuts crumbled and failed.

Yup, thats how all mine have done it. Between old OEM, new OEM, and Doorman grade 8.

I used a grade 10.9 stud (Rockford) and used Locktite blue on the nuts. Maybe the thread locker can support the threads better?

One track day!
 

https://www.miataturbo.net/attachmen...ine=1434225019


One failed stud, (I removed the other one in the photo)
Never saw above 7400, brace was installed and did not fail this time.
Looks like I will drop some coin on the ARP studs, since the heads coming off for valve seals.

Was your crank knife edged, or any weight taken off for the purposes of "lightweighting"?