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Discussion Starter #1
Most BMWs use 12 x 1.5 moderate length wheels bolts with a 17 mm hex head. They have some nice black one for roughly 4 bucks apiece at full tilt retail. They are much less via mail order.

I don't think the Elise wheels are much of a theft target and don't like the spline and wheel lock set up. For staying stock, maybe an all-spline approach would work well. Some of the spline bolts have a crummy fit with the supplied tool. The tool can be tough to remove.

It turns out that E30/E36 and other BMW wheel bolts are a perfect match. Same underhead shape and angle, same thread, same grade of metal, same length, better finish.

Here is a black one compared to a stock spline drive bolt.





They fit fine and a standard 17 mm socket clears everything no problem.
 

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Just curious, how do you know they're the same grade of metal?

Bolts that may look identical may vary a lot in their strength (there is a grading system specifically for this). One could assume that Lotus and BMW would both use high grade bolts for a critical application like this, but remember, it'd be an assumption.

While I think the risk of any failure is low, it's important that people recognize that the risk exists.


EDIT - maybe I see how you recognized the bolt grades. The Lotus one clearly states it's a grade 10.9 bolt; I assume the BMW one has a similar marking?
 

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I'm pretty sure the BMW bolts that are designed for a
4 to 5 thousand pound car are going to be plenty strong
for a 1,900lb car...
Can you weigh each lug bolt and give us figures?
 

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Discussion Starter #10
The BMW and Lotus wheel bolts are of the same grade, 10.9. The BMW bolts are not marked as they are not a generic, they were made for their particular application. Properly torqued, either is fine on their own cars. If you track your car a lot you can replace your bolts yearly for some peace of mind. Or convert to studs, even better.

The BMW bolts appears to be a hair lighter, using my calibrated fingers....but a scale would be a better source!
 

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Discussion Starter #11
Oh BTW, if you want to keep the black finish perfect, you need to use lined sockets. They have a thin nylon inner surface so that metal to metal contact is prevented.
 

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Oh, THAT kind of splined lugnuts...

In another thread I mentioned splined lugnuts as an alternative to the stock Elise lugnuts. The type I was talking about had splines on the outside that you fit a special tool over to remove. The nice thing is that the tool is about 6" long and so you just use it instead of an adapter on the breaker bar. You get a really nice positive bite on the lugnut to torque them too. Now I see that the Elise uses lug bolts, so none of that ends up mattering...
 

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Discussion Starter #14 (Edited)
Okay, using a postal scale that only goes down to 0.1 ounces:

BMW: 2.2 ounces per bolt

Lotus: 2.6 ounces per bolt

I think that the large spline head adds some extra mass. Also, the finish and certain characteristics of the threads appears to be a bit better on the BMW items to this set of eyes. You can see some of what I mean in the posted pics...look at the finish of the head ODs, and look into the threads themselves.
 

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Bavarian Autosport has the lug bolts in both silver and black for $2.95 each, part numbers 36 13 1 126 191 for silver and 36 13 1 126 014 for black. www.bavauto.com
Also locking bolts are availabe from BMW that use a small key and are around $45 for four, also Bavarian Auto haas some other locking ones shown that look much better than the stock Elise, they are $45 for the set of four.
 

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So I'm assuming that my wheel pins from my M Roadster would work. Awesome, those things are nice for putting on the wheels. Guess I won't be selling those.

I have a co-worker that makes wheel pins. Not sure of the price but if you guys want them I'll ask him.
 

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Discussion Starter #19
>>>So I'm assuming that my wheel pins from my M Roadster would work. Awesome, those things are nice for putting on the wheels. Guess I won't be selling those. <<<

Sure, they will fit just fine. Along with aftermarket wheel stud kits. BBS makes nice ones in various lengths. TC Kline has a nice set with a bullet tip that is useful besides looking nice. There is ample room on our wheels for 17 mm socket clearance.

Alloy studs:



Bullet / Rounded tip steel:



Alloy nuts for studs, black anodized too. For those items noted here see: http://tcklineracing.com/wheelstud.htm
 

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Discussion Starter #20 (Edited)
>>>Bavarian Autosport has the lug bolts in both silver and black for $2.95 each, part numbers 36 13 1 126 191 for silver and 36 13 1 126 014 for black. www.bavauto.com Also locking bolts are availabe from BMW that use a small key and are around $45 for four, also Bavarian Auto haas some other locking ones shown that look much better than the stock Elise, they are $45 for the set of four.<<<

Chrome and bronze are also available for fashion conscious types... As are natural and black anodized aluminum nuts for stud conversions.

Some BMW folks like these particular wheel locks because when you screw on the protective cap, they look stock. The caps come in silver or black. Good ole McGard is available anywhere for BMW and is endorsed by Tire Rack.

 
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