Bump steer spacers for lowered cars?

Gransin

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Hi guys,

I've been searching for a pair of bump steer spacers, but I haven't been able to find any. In my opinion this would improve handling after lowering the car as the wishbone and tie rod would get back closer to the intended (original) position/angle.
My questions are, does anybody know where to get a pair? Anybody here using these, or have been using them in the past? Worth it?

Spacers.jpg


Spacers1.jpg
 
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HB Chris

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I would think the tension strut to control arm angle change is negligible. I have seen these used as a camber adjustment, BluMax had them, but these aren’t those.
 

'69 2800cs

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I have a pair from AKG Motorsport waiting to go in. BTS12 is the part number, which the website indicates is for E12 and early E24, but I must have done my homework when I bought them to make sure they fit.

Eventually, I will cut my struts and use shorter inserts combined with these. And agreed, if you lower the car it makes sense to get the A arm and steering geometry back close to where it is at stock ride height.
 

stphers

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Interesting but how do they change the position of where the tie rod end attaches to the steering arm? It looks like it goes between the strut and the steering arm. Doesn't adding the spacer there just negate the lowering of the car. You are just moving the strut up higher from the steering arm . Don't you want the tierods to be level when the car is sitting there. I don't see how this will change that. I could see using a special bolt set up that raises the connection at where the tierod bolts to the steering arm to make it level to try to reduce the bump steer. Porsche has these special bolts for just that. A lot of Porsche guys cut the strut and raise the steering arm but they are different than BMW, their steering arm is part of the strut.

If this does work to reduce bump steer, please enlighten me. Cant get my head wrapped around these reducing bump steer.
 

Markos

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It looks like it goes between the strut and the steering arm. Doesn't adding the spacer there just negate the lowering of the car. You are just moving the strut up higher from the steering arm.

No look again closely. The spacer doesn’t affect ride height. Ride height is set between the front axle and the fender top. The spacer and steering linkages are below that. When you lower the car the control arm angles up more. The spacer gets it back closer to horizontal. You are correct that you want it to be level and the spacer does just that.

You see the same setup but the opposite direction on lifted trucks with IFS. Spacers to correct the LCA angles. Here is a terrible extreme example for mall crawlers that want the look of a lifted rig without buying a real front suspension. Imagine the angle of the LCA’s if that big diamond patterned spacer wasn’t there.

76A09D7F-C03C-4B05-9F04-91F02B54A826.jpeg
 

Gransin

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I have a pair from AKG Motorsport waiting to go in. BTS12 is the part number, which the website indicates is for E12 and early E24, but I must have done my homework when I bought them to make sure they fit.

Eventually, I will cut my struts and use shorter inserts combined with these. And agreed, if you lower the car it makes sense to get the A arm and steering geometry back close to where it is at stock ride height.

Thanks, I'll check up AKG Motorsports as soon as I'm back home!

Interesting but how do they change the position of where the tie rod end attaches to the steering arm? It looks like it goes between the strut and the steering arm. Doesn't adding the spacer there just negate the lowering of the car. You are just moving the strut up higher from the steering arm . Don't you want the tierods to be level when the car is sitting there. I don't see how this will change that. I could see using a special bolt set up that raises the connection at where the tierod bolts to the steering arm to make it level to try to reduce the bump steer. Porsche has these special bolts for just that. A lot of Porsche guys cut the strut and raise the steering arm but they are different than BMW, their steering arm is part of the strut.


If this does work to reduce bump steer, please enlighten me. Cant get my head wrapped around these reducing bump steer.

Check this picture:
2013-08-21-23-08-52_cimg2100.jpg

With the spacers in place, between the steering arm and the strut, you'll move both wishbone and steering arm back down, closer to the original angle.
 
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Gransin

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I would think the tension strut to control arm angle change is negligible. I have seen these used as a camber adjustment, BluMax had them, but these aren’t those.

It's just that, with my H&R -40mm front springs I can feel a little bit of bump steer, not a crazy amount but still enough to irritate me.
My problem is that I haven't driven a coupe with a stock suspension, so I don't know how they are supposed to handle, but I suspect there isn't any noticeable bump steer in stock form.

EDIT:
Here are the AKG Motorsport spacers, unfortunately they are listed as both NLA and out of stock, will send them a mail and ask if they will produce more of them at some point.
https://www.akgmotorsport.com/product/bump-steer-correction-spacers-bmw-e12-pre-1983-e24/
 
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Wladek

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Thanks Robert for starting the thread;)
Also want to use -40mm H&R's on fronts, so now started to think of this spacers (didn't thought of them before):confused:
The only thing i'm not sure about AKG is aluminium material. And was thinking that SS probably will be more durable material in that type of sandwich.
Part itself, technically is not much complicated:)
 

Gransin

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Thanks Robert for starting the thread;)
Also want to use -40mm H&R's on fronts, so now started to think of this spacers (didn't thought of them before):confused:
The only thing i'm not sure about AKG is aluminium material. And was thinking that SS probably will be more durable material in that type of sandwich.
Part itself, technically is not much complicated:)

Happy to put ideas in peoples heads, Wladek;)
I'm quite confident the aluminium would last a lifetime on our street coupes, but making them in SS wouldn't hurt except for the added unsprung weight, which after all isn't a real factor for us.
My biggest problem with the AKG spacers is that they are only 13mm, IMO they could be thicker to compensate more.
Someone with better machinery than me could easily make some spacers, it's just that I currently don't have any good connections like that.
 

Gransin

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You can stack them.
I hesitated to buy a 3rd set, but in the end I thought 26mm would be enough.

Yes of course, but at $110/set + shipping and tax it gets expensive real fast, and one solid spacer just feels better even if there necessarily isn't any problems with stacking.
And they aren't available right now, but let's see what they answer.
Please tell us more about your suspension setup, and if the 26mm did help to get rid of any bumpsteer?
 

Bert Poliakoff

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As said, they are still available. I have the ability to make them in various thicknesses. It will take about a month to set up an do them and we wouldn't do it without at least 6 people stepping up .
I can provide the required bolts by figuring the length of the stock ones plus the thickness of the spacer. I would get them in grade 8 Allen bolts or just plain hex heads . If enough interest I will come up with a price but I am leaning towards $125 shipped and if thicker than 1/2" $150. It will take me several weeks to put a firm price together if the interest is there.
 
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Markos

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As said, they are still available. I have the ability to make them in various thicknesses. It will take about a month to set up an do them and we wouldn't do it without at least 6 people stepping up .
I can provide the required bolts by figuring the length of the stock ones plus the thickness of the spacer. I would get them in grade 8 Allen bolts or just plain hex heads . If enough interest I will come up with a price but I am leaning towards $125 shipped and if thicker than 1/2" $150. It will take me several weeks to put a firm price together if the interest is there.

One thing that I have learned over the past couple of years is how expensive it is fabricate parts from scratch. Kudos to folks like @Stan / @Bert Poliakoff / @Wladek / @Keshav etc. for making it happen. Bert - That price is very fair for custom fabrication and I hope there is some room in there to justify your intervention. I would buy a set to keep the ball rolling.
 

Gransin

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As said, they are still available. I have the ability to make them in various thicknesses. It will take about a month to set up an do them and we wouldn't do it without at least 6 people stepping up .
I can provide the required bolts by figuring the length of the stock ones plus the thickness of the spacer. I would get them in grade 8 Allen bolts or just plain hex heads . If enough interest I will come up with a price but I am leaning towards $125 shipped and if thicker than 1/2" $150. It will take me several weeks to put a firm price together if the interest is there.

I'm in for one set aswell!
 

Bert Poliakoff

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I will start figuring this out in the next several weeks and post what I come up with then. Things will be a bit scattered over the holiday .
 
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