Running spacers dangerous??
 

Hello-

So just curious, running a thick spacer(s), am I running a risk of it breaking on me :confused: The last thing I want is to take a chance with this. The long and short of the story is I bought new rims, are different offset and now looking into spacers...in addition to my spacer?! my fear is this might put too much stress on the spacer(s) and they might send my wheel in the wrong direction :eek: anyone have experience with running a thick spacer(s) with or without problems? I have a 77 911 widebody....Thanks.

Baker.

Are you saying you already have spacers, and you want to add more spacers? I'm a little confused.

If you're just talking about one set of spacers, I've got an 88 coupe, with 29mm (about 1") spacers on my rear wheels. I am about as far from knowledgable as a person can be about tech stuff, but I am told that as long as you have the proper length studs (solid piece, no "extensions" or anything like that) they are perfectly safe. The spacers on my car have been there since 1989 and I'm not aware of any issues with them. I've only had the car since July, but no problems from the spacers for me, either.

You have to be sure they'll fit into your wheel wells & not scrub when you turn. You may need to roll your fender lips or go to flares back there to accommodate the extra width.

The factory ran spacers on both production and race cars, so they are a safe practice within reason. You need the proper studs / lug bolts, and you also need good quality spacers that mate well with the hub. As with anything moderation is the key. If you can imagine for a minute spacers that are one foot long - those would probably not be safe, as the loads would change significantly on the wheel bearings. That said, increasing the width of the wheel track does indeed put more / different loads on the wheel bearings. But, within reason, the spacers should be fine...

-Wayne

There are spacers you can buy that are TUV approved.

If you can find the thickness you want this would be the way to go for safety...
Try: http://www.hrsprings.com/products/trak/

BTW" RUF have been using their own designed spacers on their cars for decades. Porsche used spacers on some model Turbos from the factory.

So spacers in themselves are not dangerous as long as they are properly designed and fitted. I'm sure someone will chime in about excessive wheel bearing wear...

Having said that all spacers / adapters are illegal in Australia. They are only legal if the car had them fitted by the manufacturer of the car, like a Porsche turbo.

This has probably happened because at some point a "yobbo" built his own adapters out of "pot belly stove lids" to fit Mercedes wheels to his "ute"... And as luck would have it, he drove past Parliament house and a wheel came off and ended up in the Prime Ministers office :rolleyes:

Is your car a M491 turbo look or is it a Carrera/SC with an aftermarket widebody kit? If it is an aftermarket kit, I have seen C2 wheels fitted on them and it was not pretty. The spacers needed to push the wheels out were HUGE, something like 3"+. I really would not suggest this approach as it puts a lot of stress on the wheel bearings. If it was a factory turbo look with the turbo suspension, your spacers will be a little smaller, but still not something I would like to run on my car.

I would say to sell the Keskins and get wheels with the proper offset. Another option would be to run those Cup wheels and perhaps paint the lip silver to give it a 2 tone look and they look great!

A small spacer probably isn't a big deal, the bigger the spacer the bigger the problem. For one thing it weakens or at least increases the flex at the wheel/chassis interface.

TUV the German version of US DoT limits the width of spacers on street cars. Porsche had to get special dispensation to use the relatively large spacers on 930s. Part of the spec for the bigger spacers is bigger bearings.

The other part of spacers is the large change they can impose on suspension geometry. This is of particular concern in the front where the steering scrub radius is very sensitive to changes in where the wheel sits relative to the rest of the chassis.

Now spacers don't always cause problems other than weakening the connection to the chassis. For instance suppose a stock 9" ET 15 wheel is replaced by a 9" ET55 wheel. In this case using a 40mm spacer on the new wheel results in exactly the same bearing load and suspension geometry as the original wheel. The only down side is the additional weight of the longer(or extra) studs and reduced rigidity of the connection.

On the other hand, using a 50mm spacer cause the wheel to move an additional 10mm outboard, this increase wheel bearing loads and alters geometry.

I know it doesn't seem inuititve but once the wheel is bolted to the spacer, as far as the bearings are concerned, the spacer is part of the wheel. If you had a 50MM ET wheel and used a 50MM Spacer, you effectively now have a wheel with Zero offset and, no, the bearings can't tell the difference.

edit* oh, bill covered this. Out of curiosity what size spacers have been used on factory porsches, anyone have any pictures?

Spacers use long studs that are in the brake assembly and pass thru the spacer. There are some spacers, more truthfully called adapters that have studs in the spacers. They can mimic the bolt pattern or change the pattern to use other manufacturers wheel. They bolt onto the face of the hub and then have a surface for the wheel to bolt onto.

The most spacing I would even consider would be 2-2.5 inches. After that I would just buy the right wheels. Adpaters get the the bad rap as they are typically banned by most race, DE and AX rules. You go from 5 lugnuts to 10 on each wheel. The internal nuts can't be seen or checked easily for tightness/torque.

Not the safest....

Having way different backsets is not a good idea, but if the tire tread is in the same position as the original, it does not necessarily change the load on the wheel bearings. If the track is wider, the load shifts as noted above. There is also a spring rate change if the track is wider. The car gets softer.

The second part is not true.

If you would normally use an ET50 wheel, then use a 50mm spacer on it, yes, it behaves as a unit, but a unit w/ an ET0. This unit now sticks outboard 50mm more than previously and applies a much leveraged increase in bearing load. It also dramatically changes the suspension scrub radius greatly changing the handling characteristics.

The only time a spacer doesn't change bearing load is when the net ET w/ spacer for the same width wheels is the same as what you started w/ w/o a spacer. As inthe example I posted above.

Yeah, I was trying to be concise but yes I suppose what I meant to say is that bearing load is unchanged between a ET0 Wheel and an ET50 wheel with a 50MM spacer. Moment imposed by the wheel is determined by the distance (And vector... well getting off topic) of the load from hub.

Here is my problem!? my car came with a spacer and it is not enough to fill the wheel well. I am told that I need to add another 40mm spacer... feedback??


http://forums.pelicanparts.com/uploa...1234752248.jpg

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http://forums.pelicanparts.com/uploa...1234752317.jpg

You really don't want to stack spacers. As I've said before, get wheels with the proper offset. It'll be safer for you and will eliminate lots of headaches.

While we talk about spacers, let's also remember to discuss only using spacers that are hub-centric. The good ones- H&R as an example- are hub-centric. You never want to use a spacer that isn't. If you run a big flat spacer without a precisely machined lip for the inner bore of your wheel to align with, then you are now using your bolt and studs to properly align the wheel and they were never designed for that. You WILL get vibration, or worse.

The one exception is the very thin spacers (typically 5mm or less) that still leave a sufficient amount of the hub's bore protruding to properly center the wheel.

baq911
you have the same problem i have. i can add another inch or inch and a half to what i already have. my concern has been to use a 2.5 inch spacer or adapter. i dont want to have to deal with changing the studs, but i want to be able to autoX or DE the car.

If that was my car, I would find wheels with a more appropriate offset before I started thinking about spacers.

+1 to get the right off-set wheels.

baq911: What size wheels front & rear are on there now?

If those are true 3-piece wheels, why not just install a wider outer section?

i would much prefer wider with proper offset and no spacers, but the price, wow.

So am I at risk running one inch spacer with extension lugs???