Wheel Studs & Lug Nuts

[Sleeper_08]

So far I have been stock wheel studs and lug nuts on my car and after 16 or so track days over two seasons the only problem I had was one on the left front was hard to get off when they put the snows on last October.

Up to now I been running KDW2s for both street and track. The wheels are Steeda Ulta Lites 18 x 9.5 x 45 mm offset.

For next season I'm probably going to a dedicated set of track tires and rims, 275/40/18 Nitto NT01s on the same Steeda rims.

My question is whether or not, as the studs and lug nuts will be more highly stressed with the NT01s and removed more frequently to swap the track only tires on and off whether the stock ones should be changed and if so to what?

All other related comments and suggestions will be appreciated.

 

[SoundGuyDave]

On one hand: I've got a PISSPOT full of track days on the stock studs, and aftermarket Gorilla splined lugs. No issues at all, knock wood. That said, see below...

On the other hand: Given the kinds of stresses that the car sees on track days, if you DO decide to replace the studs, the best "deal" out there is FRPP part number M-1104-A, which is a complete replacement assembly for the entire hub, and includes the extended length racing studs. It's just a touch over twice the price of a set of studs, but the bearings in the hub are a known failure (wear=slop) point, so if you're going to do the studs, I would swap the whole assembly out and just start fresh from there. I'm planning on ordering in a set in early June as a PM point. That, a set of M-1107-B rear wheel studs, and four sets of M-1012-G open-end steel lugnuts, and I'll be off to the races, pardon the pun.

 

[DusterRT]

and four sets of M-1012-G open-end steel lugnuts, and I'll be off to the races, pardon the pun.

I'm thinking those lug nuts aren't going to have the proper taper for your aftermarket wheels since the FR500S uses the OE GT500 wheels..I believe OEM wheels use a 45 degree taper, and aftermarket wheels use 60 degree. Of course, correct me if I'm wrong!!

 

[SoundGuyDave]

Good point! I'll have to double-check that... Worst case, I take a cutoff wheel to the Gorilla lugs, or source others that have the correct taper. I have a while before I have to worry about that, though.

 

[marksti]

The studs should be fine as far a wear and tear go

Most racers only upgarde when they swap to custom wheels that require longer studs

 

[Philostang]

Hmmm, well I like Dave's line of reasoning on the route to go if you're going to replace the studs...so how about if you happened to recently order (and had shipped out to you) a set of front ARP studs anyway...

...and if you found that the hubs gave up the ghost in the middle or at the end of this year, would you be able to reuse the studs on new hubs? I guess I'm wondering if it makes sense to use the new studs for one season on these hubs, or should I just wait until I'm doing standard maintenance? Any thoughts?

Best,
-j

 

[Kobie]

It's just a touch over twice the price of a set of studs, but the bearings in the hub are a known failure (wear=slop) point, so if you're going to do the studs, I would swap the whole assembly out and just start fresh from there.

Is this common knowledge that the wheel bearings are a known failure point on these cars? If so, what might the service intervals be on them for street and for track? How would you diagnose this problem?

 

[Kaldar142]

Kind of off topic, but what is the maximum safest spacer to run on stock studs? 3mm? 5mm?

 

[SoundGuyDave]

Yeah, it certainly seems to be trending it that way. All the racers that I know that are running S197's seem to keep a spare set of hub assemblies on their trailers. The list of known failure points is actually pretty small... trans synchros, differentials, ball joints, and front wheel bearings, which are unititzed, so you swap the hub out. I have "hard data" on none of this, it's all observational and anecdotal, but it all seems to make sense, given either heavy DOT-R or racing slick usage, and the side-loads those impose.

Symptomatically, this is what I can offer:
Synchros: Trans becomes progressively more difficult to get into gear on a shift, probably related to the frequency of higher RPM shifts compared to a street car.
Diff: One-tire-fire on the inside rear under corner exit. Usually clutch wear, and progressive.
Ball Joints: Two modes: mechanical (curb hopping, cornering loads?), and boot failure from brake heat. I can't find the part number offhand, but FRPP sells a high-temp boot replacement... Nuff said. boot failure is obvious, and mechanical imparts a "loose" feel to things, as the ball joint gets sloppy, allowing small camber, caster and toe changes dynamically.
Wheel bearings: increased play (progressive) from cornering loads, brake heat (breaks down the lube). Evidenced as slop, like the ball joints, but most noticeable with the Brembo (or other fixed-caliper BBK) as pad knock-back. When the bearing wears, the rotor is no longer held rigidly in place, and can wobble on the spindle. With fixed calipers, this wobble will push alternately against the pads, and can actually wind up compressing the pistons slightly, so that when you go to hit the pedal entering the braking zone, you're halfway to the floor before you know it, just re-positioning the pads. If you've ever seen footwell video of a racer left-foot stabbing the brake on the straight before the braking zone, this is the issue he's (hopefully) preventing. The "brake check" will let him know that yes, the pedal is still high and tight, OR that he needs to pump them, and gives him time to do just that before he really needs the brakes.

For all of these, it's not necessarily service-interval based, so much as "fix it when it breaks" or when you just can't deal with the effects any more. With the hubs, my thought is that if you're going to be tearing down to do the studs, you might as well just do the whole assembly, particularly if you've seen fairly heavy track time on the original. My personal spares kit is just brake parts and assorted fluids, but I'm also not trailering the car either. Guys with trailers (not just S197s, either) tend to haul LOTS of spares around, like transmissions, engines, steering racks, dampers, etc. This is why you see 28' trailers for 17' long cars...

Hope that helps!

 

[SoundGuyDave]

Kind of off topic, but what is the maximum safest spacer to run on stock studs? 3mm? 5mm?

This is strictly my opinion, but I wouldn't go more than 5mm. I also wouldn't EVER use a bolt-on spacer for tracking the car. We all check lugnut torque right before every session (or at least we should), but with bolt-on spacers, you'd have to pull the wheel to check the torque on the spacers, then replace the wheel, and check the torque on that... every session. Also, unless you have fitment issues, I would doubt that you'll gain anything by using spacers just to increase track width on the car. Much easier to get track wheels with the correct offset to begin with. +35, +36, +41, +45 are all common offsets for wheels, so it stands to reason that you can find SOMETHING that will work, and without a spacer. If you're having brake fitment issues, and you're not missing by much, you can always take a die grinder to the caliper, or swap calipers out.

ANECDOTAL: I don't remember who it was, but I did see an S197 with 14" brakes and 17" wheels (Cobra R's). IIRC, he swapped the Brembo F40 calipers for F50's, which are essentially the same, but with a lower-profile housing. It may have been the other way around, but it was something like that.

 

[Kaldar142]

Dave is a walking encyclopedia, LOL

I have a custom set of DPEs getting ready to be made, the reason I ask about the spacer is that my current wheels are really close to the strut housing, so close that if I went to a 295 I would rub. (currently run 285). Plus I was never sure how wide of a spacer I could use on stock studs.

I think I'm going to get a set of 18x10 +38 RPF1s for track use, 19x10.5 DPE S20 for street.

 

[DusterRT]

ANECDOTAL: I don't remember who it was, but I did see an S197 with 14" brakes and 17" wheels (Cobra R's). IIRC, he swapped the Brembo F40 calipers for F50's, which are essentially the same, but with a lower-profile housing. It may have been the other way around, but it was something like that.

That was Steve Poe..and it's the other way around, the F40's are the slightly smaller caliper, the F50 is what the GT500 caliper is based on. I think the F40 is also the same caliper used on the FR500C, while the FR500S uses the GT500 based brake package. I don't have any information as far as if the piston diameters are the same or not..

As far as the hubs, the FR500S parts are the way to go. You can get them for $200ish, and you'll drop at least $140 on regular hubs anyway. If I'm not mistaken, the ARP studs specifically made for our cars run about $100 alone.

 

[SoundGuyDave]

That was Steve Poe..and it's the other way around, the F40's are the slightly smaller caliper, the F50 is what the GT500 caliper is based on. I think the F40 is also the same caliper used on the FR500C, while the FR500S uses the GT500 based brake package. I don't have any information as far as if the piston diameters are the same or not..

Yup, that was it! I do TRY to differentiate between what I KNOW, and what I seem to remember, which are two different things! Thanks for bringing the hard tech.

As far as the hubs, the FR500S parts are the way to go. You can get them for $200ish, and you'll drop at least $140 on regular hubs anyway. If I'm not mistaken, the ARP studs specifically made for our cars run about $100 alone.[/QUOTE] If you know where to shop, you can get the for quite a bit less than $200... I won't post names, since they're not vendors here.

 

[Sam Strano]

Um, ARP studs are $69/wheel alone, not $100 fwiw. Not cheap, but not $100, and a hub is only about $100. So you could get new hubs and ARP's for $169-ish vs. $200-ish for the FR500S stuff (which I believe are just stock bearings/hub anyway).

Doesn't seem to make much sense to me mathematically.

 

[Philostang]

Um, ... a hub is only about $100. So you could get new hubs and ARP's for $169-ish vs. $200-ish for the FR500S stuff (which I believe are just stock bearings/hub anyway).

Doesn't seem to make much sense to me mathematically.

Hell I feel better already! Does anyone have a confirmation on FR500S bearing/hub being the same as a stock GT?

 

[DusterRT]

Sure about that Sam? Hubs are $70 each on Rock Auto, and studs are $69 per set of 5 at Summit..that adds up to $278 before shipping.

 

[Sam Strano]

I guess we need to be more clear about the quantities here. I assumed we were talking about a hub unit, not a pair.

I sell the ARP studs too, for $.95 less than Summit. I don't sell hubs. So $140 for a hub and ARP's x 2 = $280. Ok, more than the FR500S stuff if it's $200/pair but not exactly double or even close and you get studs we can trust for sure. I have no idea what Ford is using on FR500S's... I mean they are also using hugely heavy stock GT500 wheels (presumably because they have them and are cheap).

 

[DusterRT]

I guess we need to be more clear about the quantities here. I assumed we were talking about a hub unit, not a pair.

Yeah they're sold in pairs..surprisingly. I figured at that price it would be per hub with an FRPP tax (such as their "Ford Racing" $50-a-pop center caps..), but they can indeed be had for under $200/pr.

 

[Philostang]

Ok, so just for clarification, I found this as the description for the FR500S hub:

Fits 2005-2010 Mustang V6 GT, SVT
Standard equipment on the Ford Racing FR500S Mustang Challenge Race Car M-FR500-S
Equipped with ARP Front Wheel Studs M-1107-A
Kit Includes:
One Pair of Upgrade Hubs with 3" ARP studs
New hub nuts
NOTE: Replacement open end wheel lug nuts M-1012-G


The listing I saw was for $220, part #M-1104-A. Nice deal if you consider the ARP studs alone for both sides will run you $100 - $140 depending on where you get them. That puts the pair of hubs at $40 - $60 ea. if you cobbled the same set up yourself (not incl. the hub nuts).

 

[pieperz06]

i didint read this whole thread but as far as studs i have sheered 2 off at autocross but they had been over tightened at discount tire to the point i was almost not able to get them off so that im sure played a factor