Bilstein B8 with Stock Springs

[ZDan]

Originally Posted by knapper

Question regarding the MCA mod after looking at it. One of the questions that we are asking when classing our cars for MCO (Ottawa Club) is whether we have changed the suspension geometry at all. If we do, I get dinged a few points, and then into next class. Do you think this would qualify as changing the suspension geometry. As far as I can tell, you can run standard alignment etc. so I am thinking I should be OK with it.

If it didn't change suspension geometry, it wouldn't have much if any effect. My understanding is it reduces anti-squat.

[strat61caster]

Originally Posted by knapper

Question regarding the MCA mod after looking at it. One of the questions that we are asking when classing our cars for MCO (Ottawa Club) is whether we have changed the suspension geometry at all. If we do, I get dinged a few points, and then into next class. Do you think this would qualify as changing the suspension geometry. As far as I can tell, you can run standard alignment etc. so I am thinking I should be OK with it.

MCA traction mod absolutely changes suspension geometry.

suspension geometry =/= alignment

Think of something like the whiteline roll center/bumpsteer kit. While it's just a longer ball joint it changes how the different lever arms of the suspension are located/move through their range of motion. That is a cost that is generally kept out of lower classes on purpose, even though some chassis have inexpensive parts with good results, not all chassis have that opportunity and would have to spend $$$ on custom fabricated parts to keep up.

Some changes are usually accounted for, like adjustable lower control arms for the rear also change the suspension geometry moving the chassis/damper/swaybar/wheel points relative to each other (depending on the mechanism), but it's usually a small amount (unless a control arm has different mount points on purpose) that is accounted for in the allowance.

i.e. in the SCCA rulebook for street touring:
"Changes in suspension geometry are not allowed except as incidental
to the effective arm length change."

[knapper]

Originally Posted by strat61caster

MCA traction mod absolutely changes suspension geometry.

suspension geometry =/= alignment

Think of something like the whiteline roll center/bumpsteer kit. While it's just a longer ball joint it changes how the different lever arms of the suspension are located/move through their range of motion. That is a cost that is generally kept out of lower classes on purpose, even though some chassis have inexpensive parts with good results, not all chassis have that opportunity and would have to spend $$$ on custom fabricated parts to keep up.

Some changes are usually accounted for, like adjustable lower control arms for the rear also change the suspension geometry moving the chassis/damper/swaybar/wheel points relative to each other (depending on the mechanism), but it's usually a small amount (unless a control arm has different mount points on purpose) that is accounted for in the allowance.

i.e. in the SCCA rulebook for street touring:
"Changes in suspension geometry are not allowed except as incidental
to the effective arm length change."

Appreciate the info. Now that I watched an install video, its very clear what is happening here. Looks like this will have to be a next season mod when I do sways and bushings throughout.