adjusting koni perch height affect alignment?

GP14 · Postby **GP14** » Mon May 31, 2010 11:07 am

I replaced my springs on the wkend and set the konis to low but they are too low so I will adjust to top perch next wkend. I had an alignment this morning and asked the guy if i were to change the height of the konis on the car without removing them(ie compress the springs and adjust the perch while still attached) would this affect the alignment and he said yes it would.

If this is true how much will my alignment be out? I see people on this forum adjusting heights all the time but do you guys get an alignment after you have done this every time you adjust?!

cheers

broady · Postby **broady** » Mon May 31, 2010 11:13 am

Depends how much of course but changing ride height will affect your camber setting.

And yes, every time I've changed my ride height I have got a new alignment.

If its only 5mm or so then I wouldn't worry.

JBT · Postby **JBT** » Mon May 31, 2010 11:18 am

Yes, true. Changing the ride height geometry will change camber, caster and probably toe as well. You may not see much change in performance but, there could be significant tyre wear issues caused by the small changes.

GP14 · Postby **GP14** » Mon May 31, 2010 11:20 am

oh damn. the konis only have about 10-15mm to play with from top to bottom. Will that require realignment?

Si.G · Postby **Si.G** » Mon May 31, 2010 9:45 pm

GP14 wrote:oh damn. the konis only have about 10-15mm to play with from top to bottom. Will that require realignment?

Yes - any change in ride height will alter the alignment.

It is because of the angle of the suspension arms (including steering arms) relative to the chassis change when changing the ride height. Remember the outer suspension arm joint can only move on an arc (not a straight line) because the inner joint has fixed mounting points. It will change pretty much everything.

Here is a vid showing bump steer only, but you can see the general idea as the car's suspension is moved the geometry changes.

Si.