THSCC Forums

OK, bringing this thread back out of the depths of the past. I got a great deal on set of brembo 4pot brakes from a local guy. Only issue I have is my track wheels won't fit. Here's my situation, so I need input from you engineering types out there....

Scenario 1: Using my standard 3mm spacers, I have ~1.4mm of free space in between the edge of the caliper and the inside of the wheel. It's fairly close to the hub, but I'm worried about possible deflection under high cornering. See pic below. I'd prefer to run this setup, but I don't want to ruin the caliper and wheel w/ deflection rub.



Scenario 2: I've purchased at set of 5mm spacers, but I'm concerned about thread engagement. W/ the spacers in place, I've done several test turns and I consistently get 9.5 turns of the wheel nut.

Like I said, I'd prefer to run scenario 1, but possible deflection concerns me. Is 9 complete turns of the wheel nut enough? I could have the spacers turned down a mm and gain a mm in space over the 3mm and also gain maybe a full turn or so of the wheel nut.

Inquiring minds want to know. If I have to, I'll replace the front studs. There's a 1/4" boss on the end of the stock studs. Buying a standard length stud that's fully threaded would solve my concerns, but I've blown enough money on this setup so far.

I can use some THSCC brain power here please.

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Rodney

'08 Bullitt mustang, CAM 7
Autox VP '09-'10, President '11-'12, interim President 2nd half of ‘14
proud recipient of the Bowie Grey service award '12
Now just a guy driving a mustang....

Rodney - I checked a standard open end lug nut (oem steel/or hub cap covered aluminum wheel) and the thread count was between 9 and 10 depending on how you count the threads. Ditto for an 1/2 AN nut but AN may be high strength. Basically these seem to follow the "engagement equals bolt diameter" rule of thumb since they are 1/2x20 thread.

You might experiment using a standard open lug nut and see if "all" the threads are engaged.

That said, considering the loads you have subjected and will be subjecting the car to new high quality studs with high quality nuts might be a good idea in any case.

Biggest issue with longer studs if you go longer than oem and/or the taper of oem provides more inside the nut clearance is making sure that all likely wheel/spacer/lug nut configurations will allow the nuts to torque properly before the stud bottoms in the "top" of a nut that isn't open.

Dick

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Dick Rasmussen

FS 50 2018 Mustang GT

with basically any mod allowed in your class other than money spent I am not sure why you are against running longer studs?

I'm running the capped acron style lug nuts. Don't really want to run an open style lug, goofs w/ the look of the car since this is both a DD and autox car.

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Rodney

'08 Bullitt mustang, CAM 7
Autox VP '09-'10, President '11-'12, interim President 2nd half of ‘14
proud recipient of the Bowie Grey service award '12
Now just a guy driving a mustang....

Understood . . . even though a wheel falling off also tends to goof with the look of the car too:

If you go to longer studs there are acorn style with lots of stud length capability.

I measured two of my closed "acorn" lugnuts. A "long hex" (1" long hex area) and a "less long hex" (1/2 inch long hex area) both will allow 1 1/4" of threaded bolt to screw into them.

Examples here.

http://shop.mcgard.com/products/automot ... d_size=293

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Dick Rasmussen

FS 50 2018 Mustang GT