So I need to run a 5mm spacer on my front wheels. After this size spacer is installed and the wheels are on, I’ll have 12mm of stud left for my lugs to grip. Is 12mm enough? 5x114 bolt pattern.
I want to be safe, and I don’t care if I have to spend the money on longer studs - I just can’t find an answer to this question.
When I was searching wheel sizes and offsets for my car…I kept coming across an answer of 4-5 full turns on the lug nut itself. Granted, these were from nation-wide DSM boards…so I cannot garuntee the accuracy. That may be a good guideline, but I am sure there is a written rule/law that has to be dug up somwhere since you want to be 100% sure.
your fine josh…15mm or bigger u should run longer studs…i havw been threw this i had to get spacers too…i have to run 20mm spacers :gay:…so i had to get teh spacers with new studs pressed into them
Hum… I’m going to email my man at Tirerack since their site says thread engagement should never be less than stock…
Thats TireRack for ya…they always do that just to cover their ass…when in reality the few good companies that make good spacers liek Eibach and H&R usually dont make 5mm spacers with new studs…even Baer doesnt…ps if u really do need studs…courtesyparts.com has Nismo studs for like 65 for 10
http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=40222-PK105
http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=40222-PK106
I think it depends on the shape of the nut.
If it is a cone shape, 5 turns is probably ok.
If it is the flange type like an Evolution you need more turns.
his are cone i am sure
Yup me = cone.
Long studs are soooooo nice. And I think they look pimp too. I actually picked up ARPs and it cost about $70 for 20 of them. Those Nismo ones seem kinda overpriced IMO. If you can find your knurl and thread numbers, which I’m sure you can, I’d try to cross em with other companies who sell em cheaper. And also, I know a few of our locals rep ARP, so they’ll get em quick for ya.
he also has to watch cause if he needs “tuner lugs” or is using the nissan OEM shallow lugs he cant go to big…many places only carry 12x1.5 when he needs 12x1.25…i am sure u can get them though
I’m going to stick with stock Z lugs. They’re free, they’re not shallow and they look good with new wheels 
Speaking as a mechanical engineer, the general rule of thumb is you always want 1-1/2" the diameter of the stud’s threaded engagement for maximum holding, er clamp load. Basically, if you have a 12mm stud, 1-1/2 of that is 18mm.
Your lug stud is a Dorman P/N 610-378 Which is an M12-1.25 thread Knurl Dia 14.35mm OAL 42mm with a shoulder of 13.5mm (Coincidentally the same as a 95-98 240SX), and those are your front studs. Your rear studs are Dorman P/N 610-320 With M12-1.25 threads Knurl Dia. 12.83mm OAL 41.5mm and shoulder of 14mm, FYI
Basically, here it is:
12mm of threads you said you have leaves you with:
12mm x 1.25threads/mm = 15 threads of engagement
Ideal situation:
12mm x 1.5 dia stud = 18mm x 1.25threads/mm = 22.5 threads engaged.
You have decreased the thread engagement of the ideal situation by 33.33%
Is it safe? Probably. Engineers always design with a safety factor in mind. At American Axle, our safety margin was 1.333. Coincidentally, your safety factor is at 1 now. (Minusing out the 33%, or 0.33) You will probably be OK, if it was my car, I would get new lug studs because I like to error on the side of safety.
I believe I might be able to do just that.
no u like spending money…i just know i was contemplating longer studs instead of spacers with studs pressed in and everywhere i looked didnt carry 12x1.25 they were all special order so me i would havw gotten the Nismo ones cause i am NISMO gay…but it eneded up i needed larger spacers than anticipated so i just went with H&R 20mm with studs pressed in still maintaining the Nissan gayness of 12x1.25 ness