BUILD THREAD 86 GP 2+2~Blown 6.0
- Thread starter 81cutlass
- Start date
I'll need to check. It's borderline.
I can get to 120 safe on 1/2-20 and they are cheaper than anther set of 12mm oddly enough
I'm curious where you get your torque specs? I know you're an engineer but trade, so smarter than me. Thing is though 1/2" is 12.7mm, so not exactly a quantum leap.
Conical is a big reason they bent for sure. 1/2 might hold up, especially because they will likely be made from better material, but eventually they will bend too.
I'm not an expert by any means. But 12mm is what's used on many stock oem's. 1/2" isn't much better as stated. I'd be looking at 5/8" with your power level.
My torque specs come from the internet. Hardly a reliable place lol. I need to dig through my clamp load calculator and see. I've seen 80-90 for M12 and 110-120 for 1/2-20.
The big leap in capacity is minor diameter.
An M12x1.5 is a relatively coarse fastener, the minor diameter (thread root) is 9.93mm, .390"
A 1/2-20 minor is .4374.
An M14x1.5 minor is .469
A 5/8 minor is .565
The cross sectional area of the 1/2-20 is .150 square inch where the m12 is .119 square inch so the 1/2-20 is ~25% larger. M14 is .172 (45% better than M12), 5/8-18 is .250, (66% better than M12).
Big issue with 5/8 for me is then I get stuck into shank lug nuts and my wheels need to be custom machined to accept the larger hardware. I am in this weird spot where I'm really at a power level that's beyond where (historically) street wheel stuff lives.
The joys of street/strip cars!
That makes perfect sense, and I've never thought about the difference between lug nut type. Is that the reason for the flat spacers that go under the lug nut and no conical lug nuts?
I'm running Weld Drag Lites that take a straight shank lug nut with a 'thinnish' washer that are a Weld part number (1/2" 20) and I keep eating up the washers and lug nuts where the lug engages the washer. Torquing to 95ft/lbs per Weld. FWIW, I had a wheel off last night and I was looking hard at my studs to make sure they didn't look like Jake's, and they don't.
I could run a thicker washer if I could find them as I still have about an 1/8" or so of wheel stud thread sticking out of the lug nut? I have 3" wheel studs.
Jake - I'm stealing your thread haha. But it sounds like you might need a wheel upgrade and I might need a both a wheel stud and wheel upgrade (which sucks because I like the Drag Lites and have 3 sets of them.)
Ooof. Drag wheels, at least the ones I want, are expensive....
My local Pontiac guy Randy has a 70 GP with pontiac steelies that runs in the 9's. I should bug him and see what he has done to make 5/8 studs work on his steel wheels.
My local Pontiac guy Randy has a 70 GP with pontiac steelies that runs in the 9's. I should bug him and see what he has done to make 5/8 studs work on his steel wheels.
Yeah, and then there's the price lol. I mentioned I have 3 sets. Ummm.....3 used sets as Drag Lites are becoming less popular so they are easy to find at a budget (used) price haha. I priced some new wheels this spring. That process ended quickly at over $1k for two wheels. I probably should be looking for some hand me downs on marketplace.
I'm interested to hear what your friend is doing.
I'm interested to hear what your friend is doing.
