[bjf66]

I was strongly advised by the people at two different tire shops to not run spacers or studs at the track.

I want to say that I did my homework and have plenty of anecdotal evidence from other members; however, the tire shop people were very passionate in their explaining how that studs (more specifically: stud conversion kits) are a lot less sturdy than bolts, and spacers will ruin my handling. If they are so dangerous, why do so many reputable vendors like Turner and APEX sell them?

Part of me feels that they've seen one too many incorrectly installed stud kits (like the RX-7 video on YouTube).

If studs and spacers are installed properly according to factory instructions, with red loctite, torqued to the right settings and all, what are the chances of something going wrong?

Has there been incidents of correctly installed studs, from a good manufacturer, in good condition failing?

What's the verdict?

[3002 tii]

Originally Posted by Karura

I was strongly advised by the people at two different tire shops to not run spacers or studs at the track.

I want to say that I did my homework and have plenty of anecdotal evidence from other members; however, the tire shop people were very passionate in their explaining how that studs (more specifically: stud conversion kits) are a lot less sturdy than bolts, and spacers will ruin my handling. If they are so dangerous, why do so many reputable vendors like Turner and APEX sell them?

Part of me feels that they've seen one too many incorrectly installed stud kits (like the RX-7 video on YouTube).

If studs and spacers are installed properly according to factory instructions, with red loctite, torqued to the right settings and all, what are the chances of something going wrong?

Has there been incidents of correctly installed studs, from a good manufacturer, in good condition failing?

What's the verdict?

Plenty of race cars use studs and spacers. As long as studs are properly installed and replaced ever so often, you'll be fine. In fact, even lug nuts should be replaced if you find yourself removing the wheels frequent. Studs also make swapping wheels much easier... Just pick a quality kit (that means no eBay!) and remember Loctite is your friend.

I can see why some folks don't like spacers; it's "one extra" thing that could go wrong. I also agree spacers should be avoided IF possible (ie get the right wheel width and offset to begin with) but sometimes they are unavoidable especially once you start lowering the car. I would use spacers as a way to "fine tune" the track and not for stupid visual stanceworks cr@p. And by fine tune, the spacer should be quite small (5mm or less) or if you must go bigger stick with 12's (10's can be problematic and anything bigger tells me you have the wrong wheel). As long as the spacer has enough lip and is hubcentric, you will be fine.

[DallasBoosted]

Originally Posted by DSC_OFF

Plenty of race cars use studs and spacers. As long as studs are properly installed and replaced ever so often, you'll be fine. In fact, even lugnuts should be replaced if you find yourself removing the wheels frequent. Studs also make swapping wheels much easier... Just pick a quality kit (that means no eBay!) and remember Loctite is your friend.

I can see why some folks don't like spacers; it's "one extra" thing that could go wrong. I also agree spacers should be avoided IF possible (ie get the right wheel width and offset to begin with) but sometimes they are unavoidable especially once you start lowering the car. I would use spacers as a way to "fine tune" the track and not for stupid visual stanceworks cr@p. And by fine tune, the spacer should be quite small (5mm or less) or if you must go bigger stick with 12's (10's can be problematic and anythign bigger tells me you have the wrong wheel). As long as the spacer has enough lip and is hubcentric, you will be fine.

This is correct. Nothing wrong with using studs, and small spacers should be fine. This advice is spot on.

[CJ421]

Agreed in full with DSC_OFF.

I run a 10mm front spacer to clear the front struts since getting my new suspension installed.
Most of the modifications to my car including the spacers and studs have been done by a BMW race shop, VAC Motorsports. They know I track the car frequently, and would have told me if the parts had negative effects.

I'll vouch for the quality of VAC's stud kits, spacers, and pretty much all the parts they fabricate/machine or recommend.

[The HACK]

I'll bring a SLIGHTLY different perspective to this discussion.

Generic stud conversions are not as strong as pressed in studs in the hub. But seeing how we don't have pressed in studs as an option, stud conversions are a good compromise/alternative to lug nuts.

Typically, most club racers will replace their studs every 2 seasons at the minimum. I've heard recommendations for lug nut replacement interval in the 5 year range, but few club racers use lug nuts so it's hard for me to imagine that the recommendation is for track use. As far as stud conversions vs. lug nuts, stud's benefits far out weight what little inconvenience in initial installation and removal. There's a good reason why most club racers use them. It makes changing wheels that much easier and allow them the flexibility to run various size spacers if necessary.

The ONLY caveat, is that the studs absolutely MUST be installed properly. Follow manufacturer installation instructions to the tee. If it calls for 20 ft-lbs with loctite 272, don't skimp out and order blue loctite and try to install it at 60 ft-lbs. Some studs come with allen key holes on the tip or hex shaped ends for easy installation, most don't, thus it is required to double-nut the studs to install. While the process itself isn't complicated, it does govern a critical part of the vehicle operation, namely securing the 4 contact patches to the chassis so screw up here will be catastrophic. And there are plenty of stud kits out there that do not adhere to basic engineering principal and use a lower grade material to save money. Make sure the studs you get are using grade 10.9 fasteners (read: not better than 10.9, specifically and exactly 10.9 rated fasteners!).

Spacers, on the other hand...I've always felt that the only reason to get spacers is if you can't find wheels in the right offset. Given the choice, I'd rather run a wheel with ET38 offset rather than a 10mm spacer and a ET48 offset. It's not an elegant solution. Actually, given the choice I'd rather run the right offset that produces the correct scrub radius as designed by the engineers, that accommodates the right size tires without rubbing any components.

But that isn't always possible. As others have pointed out, you may need to run spacers to clear aftermarket strut or spring perches. You may need to run spacers to fit over your massive, 380mm 8 piston Brembos. You may need to run spacers to fit 275mm tires up front without rubbing the strut. There are multiple reasons why you need to run spacers, to me, it's all about compromises. The inherent addition of a shearing surface and the risk is low enough that it does not offset the benefit of being able to run larger brakes, or lower the center of gravity to decrease the distance between roll center and CoG, or add more width in tire up front because 265mm tires are being overheated due to the style and speed at which you drive (or not enough cooling to the tires are provided). And quite often, it's far easier to find the right size spacers than it is to find a ET35 wheel in a style you like with the proper width and size.

While I don't run Apex wheels, this is where I really like what they do. They have wheels in nearly every width from 8" to 10.5" (or maybe more?) in various offset combinations to fit just about any given BMW. Scott Cary who runs SCTS racing with a 135i and E92 M3 do not use spacers, but rather get Apex wheels in the right size to fit MASSIVE 275mm slicks up front. That, IMO, is the right way to do it.

If I were to do it, and do it right, I wouldn't hesitate to put stud conversions on a BMW that sees significant track time, especially if it's studs from a reputable company with the right feature set and material. I would only put on spacers if the choices I've made in increasing grip leaves little to no choice in the wheels that I use that necessitates the use of spacers. And especially with the front wheels, I'd pick up spacers with either the proper hub lips, or get a set of hub extenders. And for ANY spacers larger than 15mm, I'd get ones that bolts to the hub rather than pass through.

But to answer the OP's question. I know why the shop refuses to install studs and spacers. Both are components that are directly tied to one of the most critical aspect of operating your vehicle. The control surface that fastens the 4 contact patches. Again, if ANYTHING were to fail, they will fail in a catastrophic manner. Their liability increases dramatically compared to say, working on the engine. When a stud or spacer fails at speed, you lose all control of the vehicle and the resulting crash will be far more harsh than say, if an exhaust were to fail or an engine blows up. From a liability's stand point, any shop that does not normally work with the race or HPDE community will likely turn down these type of request. Even if they do work with said community regularly, they may want to make sure you are aware of the liabilities before any work is performed.

It's the same reason why my favorite mechanic refuses to patch my run-flats.

[bjf66]

Thanks for all the replies; it echoes what I've been thinking.

I will probably be buying a torque wrench soon and properly install the stud kit myself; any recommendation for a good wrench? (1/2"?) I don't mind investing money into good tools.

About the double lugnut method to torque the studs, how far in should the lugnuts be? I'm guessing the closer to the hub the better.

A curious thought, why specifically 10.9 steel? I got the stud kit from APEX, which are manufactured in Europe and TUV approved. The Turner ones are manufactured in the US, chromolly steel, and seem to be very good too. Let's be technical, what are the differences between the two?

About APEX wheels and spacers; I've been thinking the same about getting the correct offset from them in 17x9.5 square (or 17x9 front 17x9.5 rear, so there is no need for a spacer up front). In this instance, would the benefits of a square setup outweigh having to put a 5mm spacer up front? To rephrase, do staggered setups have quantitative benefits over square?

Sorry for slightly derailing the thread; everyone here seems knowledgable so I thought I'd ask.

[mkPOTO]

I run stud kit and spacers and do about 5-6 track events a year with no issue

[bjf66]

Originally Posted by mkPOTO

I run stud kit and spacers and do about 5-6 track events a year with no issue

How long have you been running them, and how often do you change the studs out for new ones, if ever?

[raceyBMW]

A good resource regarding spacers is at Turner Motorsports...they have some good comments regarding the various thicknesses and their implications of using them

http://www.turnermotorsport.com/BMW-...otorsport.aspx

[bjf66]

Originally Posted by raceyBMW

A good resource regarding spacers is at Turner Motorsports...they have some good comments regarding the various thicknesses and their implications of using them

http://www.turnermotorsport.com/BMW-...otorsport.aspx

Thanks

[HP Autosport]

Great stuff Dan. I happen to replace them every year just to be on the safe side and because I stress my wheels a lot on the track. However, for a person who partakes in a couple track days a year, I would say replace every 2-3 years just to be on the safe side.

-Mike

[VMRWheels]

Originally Posted by DSC_OFF

Plenty of race cars use studs and spacers. As long as studs are properly installed and replaced ever so often, you'll be fine. In fact, even lug nuts should be replaced if you find yourself removing the wheels frequent. Studs also make swapping wheels much easier... Just pick a quality kit (that means no eBay!) and remember Loctite is your friend.

I can see why some folks don't like spacers; it's "one extra" thing that could go wrong. I also agree spacers should be avoided IF possible (ie get the right wheel width and offset to begin with) but sometimes they are unavoidable especially once you start lowering the car. I would use spacers as a way to "fine tune" the track and not for stupid visual stanceworks cr@p. And by fine tune, the spacer should be quite small (5mm or less) or if you must go bigger stick with 12's (10's can be problematic and anything bigger tells me you have the wrong wheel). As long as the spacer has enough lip and is hubcentric, you will be fine.

Well said.

[3002 tii]

Originally Posted by HP Autowerks

Great stuff Dan. I happen to replace them every year just to be on the safe side and because I stress my wheels a lot on the track. However, for a person who partakes in a couple track days a year, I would say replace every 2-3 years just to be on the safe side.

-Mike

Ditto, every 2 years for me. Despite doing 10-15 days per year I've gotten lazy and don't bother swapping to my street set during the season. I only remove now to rotate the wheels and/or whenever I need to work on the brakes.

[TSM330i]

We run studs and spacers on our 335 race car and replace them every season. No issues at all and changing wheels at the track is MUCH easier with the stud kit.

[bjf66]

Thanks for all the replies, I will be getting a jack and installing the studs myself, torqued to ~30lbft and red loctite.

Is there any other thing I should do, and anything to watch out for when inspecting them? I'm guessing since loctite is used, I should never try to re-tighten then.

Thanks again for all the replies, it really helps out weekend mechanics like myself that have no experience at all.

[TSM330i]

Originally Posted by Karura

Thanks for all the replies, I will be getting a jack and installing the studs myself, torqued to ~30lbft and red loctite.

Is there any other thing I should do, and anything to watch out for when inspecting them? I'm guessing since loctite is used, I should never try to re-tighten then.

Thanks again for all the replies, it really helps out weekend mechanics like myself that have no experience at all.

Make sure to keep an eye on the torque of your wheel bolts as they may loosen in the first couple weeks. Once everything is seated properly, they will be fine.