MCA Suspension "Traction Mod"

[strat61caster]

Originally Posted by norcalpb

Dang it, this was my largest fear with this kind of mod as I just got a relatively expensive alignment done.

Dropping the rear a quarter inch or whatever won’t ruin your alignment, raise the rear up to match what it was before and you’ll be bang on.

[norcalpb]

Originally Posted by NoHaveMSG

Shouldn’t effect ride height. You are just changing the pickup point for the trailing arm. It may require slightly stiffer spring rate. MCA even states there's doesn't effect alignment.

I’m not sure who makes the bracket in @makinen ‘s 2nd link, but the author mentioned a 5mm drop. I think a stiffer spring is recommended in the first link because the subject car is on stock suspension, and lowering the rear 5mm on stock spring rates may cause one to excessively ride the bump stops.

“ The bracket is about 22mm before installation.
17mm after installation
I think it's because the angle of the rod has changed and the load on the suspension has increased.
Of course, I adjusted the car height to restore it.

After this, adjust the alignment again and it's done.”

[norcalpb]

Originally Posted by strat61caster

Dropping the rear a quarter inch or whatever won’t ruin your alignment, raise the rear up to match what it was before and you’ll be bang on.

Unfortunately I am on springs/shocks so no ride height adjustability…but the drop is report-ably only 5mm so that’s not even noticeable to most.

[NoHaveMSG]

Originally Posted by norcalpb

I’m not sure who makes the bracket in @makinen ‘s 2nd link, but the author mentioned a 5mm drop. I think a stiffer spring is recommended in the first link because the subject car is on stock suspension, and lowering the rear 5mm on stock spring rates may cause one to excessively ride the bump stops.

“ The bracket is about 22mm before installation.
17mm after installation
I think it's because the angle of the rod has changed and the load on the suspension has increased.
Of course, I adjusted the car height to restore it.

After this, adjust the alignment again and it's done.”

Interesting. I wonder if it is changing the anti squat so much at that position in the travel that it is causing a bit more sag.

[makinen]

Originally Posted by norcalpb

Unfortunately I am on springs/shocks so no ride height adjustability…but the drop is report-ably only 5mm so that’s not even noticeable to most.

I've ordered GP Sports one a month ago and am waiting for its production. After collecting information from the reviews, I've prepared two things.
Slightly stiffer rear springs of GT86(FRS) as BRZ rear springs used currently, and the Subtle solutions 1/4" spacers. GR86 rear springs could be better but GT86's were free for me.

FYI the spring rates
https://www.ft86club.com/forums/show...3&postcount=11

[whataboutbob]

RLCA with different coilover mounting points allows you to change the motion ratio which can be used to mimic stiffer springs fyi. I have my coilovers on the outermost mount on the SPL RLCAs and did not have to adjust the ride height/spring rate after installing the MCA traction mods.

[Compelica]

Am in the process as well of swapping my rear 4K springs to 6K after installing the MCA traction mod, I was bottoming out too easily even on daily driving.

[norcalpb]

Originally Posted by Compelica

Am in the process as well of swapping my rear 4K springs to 6K after installing the MCA traction mod, I was bottoming out too easily even on daily driving.

Did you notice a change in the static ride height when parked? Or just changes in the travel?

[Compelica]

Originally Posted by norcalpb

Did you notice a change in the static ride height when parked? Or just changes in the travel?

Did not notice that it changed, although I had my ride height re-adjusted during the installation.

[yberther]

Thanks for all the comments and recommendations in this thread!


I ordered and also found out the MCA is redesigning these, so they are currently discontinued. I was told a couple months before the new design will be available.


Hope to try them out once I get them in.

[Compelica]

Originally Posted by yberther

Thanks for all the comments and recommendations in this thread!


I ordered and also found out the MCA is redesigning these, so they are currently discontinued. I was told a couple months before the new design will be available.


Hope to try them out once I get them in.

Will it be a redesign with the same relocation point, or otherwise?

[yberther]

Originally Posted by Compelica

Will it be a redesign with the same relocation point, or otherwise?

I asked but no response yet, I can't imagine so though? I wonder if it has to do with the international patent application as a couple other companies have come out with something similar.

[lutfy]

Originally Posted by whataboutbob

RLCA with different coilover mounting points allows you to change the motion ratio which can be used to mimic stiffer springs fyi. I have my coilovers on the outermost mount on the SPL RLCAs and did not have to adjust the ride height/spring rate after installing the MCA traction mods.

Hi Bob, does the outer mounting on the arm equates to 'softening'? Thank you in advance.

Lutfy

[whataboutbob]

Originally Posted by lutfy

Hi Bob, does the outer mounting on the arm equates to 'softening'? Thank you in advance.

Lutfy

Hey,

BLUF: The outer position equates to creating less leverage on the coilover, which in effect makes the spring seem stiffer.

There's probably a math equation that can be applied, but here's what I think is an accurate analogy.

Consider the point at the end of the RLCA to be the end of a cheater bar. Consider the point at which the coilover is mounted to the RLCA to be where the force of the cheater bar (i.e. your tire moving up in travel) is attempting to compress the coilover spring. If you decrease the distance between these 2 points by moving the coilover mounting point toward the end of the RLCA, you are effectively shortening the length of your cheater bar (i.e. you have LESS leverage). This reduced leverage is why I *think* that in this configuration your suspension will feel/act like you have stiffer springs.

I *might* be wrong, but this is how I understand motion ratio to work.