Originally Posted by Tatsu333 (Post 3617340)

https://www.justengineering.ca/shop/subaru/frs-brz-gt86-gr86-adjustable-traction-arms/

With it using a similar configuration to the MCA's but with what looks to be MUCH more robust materials and finish

Originally Posted by Ohio Enthusiast (Post 3617342)

This looks like a combination of the MCA mod (attaching to the original mounting point on the subframe) and the GP Sport mod (attaching to the frame). I wonder what side-effects this will have - it seems to be tying the subframe very rigidly to the frame.

Originally Posted by Tatsu333 (Post 3617352)

I've never quite understood the argument against / around the GP Sports ones (and now these) in that regard, because there already is a stamped metal bracket / brace tying in that subframe mounting bolt to the same point that these traction mod variants do.

Originally Posted by Tatsu333 (Post 3617352)

I've never quite understood the argument against / around the GP Sports ones (and now these) in that regard, because there already is a stamped metal bracket / brace tying in that subframe mounting bolt to the same point that these traction mod variants do. They both just replace that piece, where it's left in place with the MCA Traction Mod. :iono:

I do like that with these vs. the GP Sports ones, there is the extra structure tying to the original trailing link mounting bolt. My worry with the GP Sports design when I was comparing them back in the day was that the relocated mounting point was just kind of floating off the end of the flat bracket, and this addresses that. Not that there is a ton of load going through that pivot, but it just made me a little nervous...

Anyway - we'll see how it goes once I receive the new setup!

Originally Posted by norcalpb (Post 3617388)

The V1 MCA traction mods were poorly designed IMO. The V2 fixed this from happening though.

Originally Posted by norcalpb (Post 3617388)

The V1 MCA traction mods were poorly designed IMO. The V2 fixed this from happening though.

Originally Posted by Tatsu333 (Post 3617389)

From what MCA told me when I inquired about upgrading when V2 came out, and from what is clearly visible, the difference between V1 and V2 was the addition of the polyurethane inserts where it bolts through to the subframe, and according to MCA that change was made primarily for user complaints of noise (which I never experienced). The overall construction and design are otherwise unchanged.

Originally Posted by Racecomp Engineering (Post 3617393)

My V1 look fine after inspection. I may get a set of either the V2 or the GP Sports over the winter...I'll have to look into it a bit more.

- Andrew

Originally Posted by Tatsu333 (Post 3617389)

From what MCA told me when I inquired about upgrading when V2 came out, and from what is clearly visible, the difference between V1 and V2 was the addition of the polyurethane inserts where it bolts through to the subframe, and according to MCA that change was made primarily for user complaints of noise (which I never experienced). The overall construction and design are otherwise unchanged.

Originally Posted by norcalpb (Post 3617407)

The blue circled bolt is connected to the subframe and the orange circled bolt is connected to the frame of the vehicle. ..

...The traction mod snapped in two right next to where the chassis mounted bolt goes, which is where the mod is most securely connected.

...The chassis mounted bolt, not the subframe bolt goes through a poly bushing, which seems to prevent shock from subframe movement being transferred directly to the frame of the mod. But even with added flexibility, if the durometer of the poly bushings is higher than stock subframe bushings there will still be tension, but a failure becomes less likely.

Originally Posted by norcalpb (Post 3617407)

I personally run GP Sports because with their design the new trailing arm mounting point becomes completely independent of the subframe.

Originally Posted by Tatsu333 (Post 3617419)

Yeah, what I meant by "subframe bolt" is the bolt that attaches the subframe to the body, not the Traction Mod bracket to the subframe. We're talking about the same bolt location.

I agree that the V2 would allow for more movement around that bolt, and that MCA's communication to me could very well have been a CYA way of explaining a fix for a different issue. If anything, though, I would see that introducing a possible second point / mode of failure with the head of the bolt being somewhat less supported than the original design / more leverage being put on the shaft of the bolt as it passes through the OEM reinforcement bracket that ties that bolt location to the chassis if there is any horizontal or twisting force being applied. It essentially puts the head of the bolt kind of "free floating" (albeit with tension applied through the bushing). That said, given the orientation of the bolt and the subframe bushing, you'd expect that virtually all movement there is vertical, so that might be a non-issue.



From what I understand, that has been the argument against this design from those that don't like it because they feel that mounting point *should* move with the subframe in concert with others in the rear suspension, as it does with the OEM design.

Then there's the GK Tech design that's different again, and the Just Engineering one that I've ordered that's also different...

So which is better? :iono:

They're all different approaches to the same idea of relocating that mounting / pivot point to reduce anti-squat, and each has their own compromises. What seems to be universal is that the idea of reducing anti-squat is worthwhile on this chassis, and having experienced the effect, I definitely agree with that!

For me, I have always been a little worried about the material thickness used in the MCA bracket, and with the corrosion seen on mine with so little mileage, I have been a little *more* worried than before. That combined with this reported failure is why I'm now exploring alternatives.