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Discussion Starter #1
Any thoughts on this? I seem to notice a little more tramlining and/or sensitivity to crosswinds on the highway after a 7mm front and 15mm rear wheel spacer install.

Thanks!
 

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Discussion Starter #3
Trev,

I agree, camber will not change at the spindle as a result of installing spacers, but does the center of the weight on the tire contact patch move slightly towards the middle of the car as a result of the negative camber inherent in these cars? In other words, without significant cornering force, like travelling down a straight highway, do the spacers make more of the car's weight bear on the inside of the tire?
 

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No, if anything by widening your track you are shifting the tire/wheel weight outside. Not sure why you think its the opposite when you widen. Please explain the physics behind your thoughts.
 

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No, if anything by widening your track you are shifting the tire/wheel weight outside. Not sure why you think its the opposite when you widen. Please explain the physics behind your thoughts.
More leverage on the suspension. Move the tire out is like getting a larger breaker bar. One typically doesn't get a smaller ratchet when a 3/8ths isn't enough to break a bolt loose.

I too have seen more than one person say to get an alignment after adding anything bigger than 5mm spacers. I questioned why but at 20mm a side, the geometry is slightly more askew than from the factory. Not so much that you'd see horrible wear after 100 miles but it might wear the tires just a tad faster. It might also make the suspension just a tab softer. I doubt it has any real effect at less than 10/10.
 

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More leverage on the suspension. Move the tire out is like getting a larger breaker bar. One typically doesn't get a smaller ratchet when a 3/8ths isn't enough to break a bolt loose.

I too have seen more than one person say to get an alignment after adding anything bigger than 5mm spacers. I questioned why but at 20mm a side, the geometry is slightly more askew than from the factory. Not so much that you'd see horrible wear after 100 miles but it might wear the tires just a tad faster. It might also make the suspension just a tab softer. I doubt it has any real effect at less than 10/10.
Look at your basic geometry; shifting it out in a straight line (180 degrees) will not change the angle. The angle can change via force based on weight - loading. But that isn't a factor here unless you consider fractions of an ounce as being pertinent which can be affected by an additional passenger, luggage, gas in the tank, alignment without you in the car, etc, etc. If you do that, and believe all those comments from unnamed others you read, than I will back out.
 

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Discussion Starter #7
Amdeutsch,

I agree, shifting the wheels out with a spacer in a straight line (180 degrees), will not change the angle, but these cars have a negative camber, particularly in the rear. The increased leverage on the suspension may cause even more of the car's weight to bear on the inside of the tires, and result in increased sensitivity to tram-lining and darting when crossing road crests.
 

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Amdeutsch,

I agree, shifting the wheels out with a spacer in a straight line (180 degrees), will not change the angle, but these cars have a negative camber, particularly in the rear. The increased leverage on the suspension may cause even more of the car's weight to bear on the inside of the tires, and result in increased sensitivity to tram-lining and darting when crossing road crests.
Please read my post to az erik about weight. You seem to be focusing on one thing and are ignoring all else - some which will have more of an effect than spacers.
 

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I think it might be a decrease in effective castor due to the longer arm that the wheel is pulling.
 

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Adding spacer doesn't change your camber or toe. It will marginally improve the handling due to increase in width. It may wearout the bearling a little faster but I doubt if it really measurable.

If you experience vibration or strange handling then I'd say you have a defective or poorly made spacer.
 

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Does anyone know why Porsche only offers 5mm OEM spacers for the 981? Everyone on the forums wants 7mm and/or 15mm.
 

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I'm running 10/15mm F/R - but I think I will reduce fronts to 7s or 5s. Also feel the "trammeling" effect (for lack of a better word), but only apparent when making slow very tight turns at close to lock.

It has nothing to do with how the spacer is made - just the increase track width on the suspension geometry. Zero vibrations or any ill handing effects.
 
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