:squint:

These aren't LCA bushings. They're metal offset bushings that replace the lower metal OE NC upright insert bushing where the LCA ball joint attaches to it. I'm not at the shop and can't recall if the RX8 front upright has the same ball joint attachment bushing or not. I know the rear uprights have bushings. Remains to be seen if they can be used or not.


https://cimg8.ibsrv.net/gimg/www.rx8...4c6aa60e25.jpg

https://cimg9.ibsrv.net/gimg/www.rx8...37d6075b40.jpg



.

Ok, well the RX8 upright does have a metal bushing insert for the LCA ball joint connection. Without actually pressing the bushing out of the upright I can't be 100% sure, but it appears to be the same size. However, there is one difference/hang up. It turns out the offset hole in the bushing is tapered to match the tapered LCA ball joint stud. I just couldn't tell the difference without a caliper to measure them.

When I pushed the MX5 offset bushing up on the RX8 ball joint stud it had the proper taper, but stopped short of fulling seating by 3/16" - 1/4 " of the stud length. The only reason I can see this ocurring is if the RX8 LCA ball joint stud is a larger diameter overall than the MX5 ball joint stud.

So my initial assessment is that these won't work on an RX8 without modification. They also might not be an allowable modification for some racing classes. Great idea conceptually though.

So my latest settings are based on consideration of lots of feedback from the folks here on the forums and other folks at the track.


FRONT
13.5" ride height
-2.7 camber
Maximum caster
Zero toe


REAR
13.5" ride height
-2.3 camber
+1/16" total toe (1/32" per side)


Pyronometer indicates these are good settings for street tires and 100TW R-comps, but Hoosiers may need a smidge more camber (-3.0 / -2.5 ?). I like the balance of the car with that camber stagger and stock sways and 10k/7k springs. Very neutral.

and just FYI that Mazdatrix still has some of the Drop Engineering delrin front UCA bushing kits in stock

Cart Price Check Part:B-RX8-03UCA

Looks really good. I wonder if you mean minimum caster?
I've actually recently increased caster as I prefer it that way, at a similar ride height and toe, but not able to get that amount of camber in both front wheels (even if I went with minimum caster).

FRONT
13.5" ride height
-2.1L/-2.5R camber
-7.5 caster
Zero toe

REAR
13.5" ride height
-2.0L/2.1R camber
0.11 degrees total toe in (~0.06 degrees per side)

Thanks... I assume these are straight, so no change to camber right?

I'm running the maximum possible caster that allowed an even value side to side. I like the steering feel.

That's correct, I have a shop that will modify them to camber offset, but it costs as much as the bushing set. The design is superior to polyurethane though, very low stiction and no fore/aft or flexure movement at all.

I'm not sold on high camber settings. What feels good and what goes faster are not always mutual.


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I followed up with MER on this, and Ryan told me they turn the bushing to be the right size to fit RX-8s. So, I took my car in to have a set installed. To his surprise, they are a direct fit in the 2011 model year. He said he knows they do not fit 2004 through 2009 models without modification. Apparently, Mazda made a change either in 2010 or 2011. That saved me 1.5 hours of labor, and the total cost for installation, alignment, and time on the scales was $400. I really hate letting other people wrench on my cars, but I don't have the tools for this job, so I was happy to pay MER to fix me up.

My settings are now:

Front
Camber: -3.5
Caster: Max
Toe: 0.0

Rear
Camber -3.0
Toe: 1/32

Woot!

.

Apparently there was a running change on the uprights because both the F151 and F189 parts numbers are listed for 2009, but only F189 after that. The LCA must be different too then (didn't think to look) because the ball joint taper either isn't correct or wasn't reamed enough in the bushing set that I have. Thought I had changed to the S2 LCA though. Will have to go back and check, maybe not. I certainly wouldn't have expected those details to have changed.

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Ryan was sure about having to machine them to fit 2009 cars, as his personal car is a 2009. He said they noticed the different diameter, when they removed my spindle, then measured it, and realized it would press right in, without modification. He said mine is the first car they have done without modification of the part, but he has never had a 2010 or 2011 in his shop before.

In any case, the information is out there now. Those bushings can and have been made to work in all model year RX-8s.

Yes, aside for some mid-year 2009 models which as you explained even MER was not aware of, I did my best to present it that way too. Sorry if I wasn't clear enough:


Thank you for sharing this with us.


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so guys a little update on my maximum caster project. Due to a slight crahs i had i cant get mere caster than 6,5 degress with my current right height. Where do you guys measure that by the way?.
wo my first attempt was

camber 1,2
caster 6,5
to +0,5 and the car felt great.

however i was experiencing understeer i then decided to try 2,2 camber han the car i s now awesom. i have to fix my suspension problem this witnher but with racing every weekend i dont have the time to pull down the front subframe.

Do any of you guys wanna share your spring rates?
I really need a harder setup for next year and some kind of steering quickener with power steering

Oh. Crap. Not sure how I missed that. Allow me to facepalm myself. :uh:

Well after some careful measuring my assessment of the ball joint taper was incorrect. The reason this NC camber bushing won't seat fully on the S1 RX8 LCA ball joint stud is because it has a 7.15 deg taper (1.5" per foot) and my S1 ball joint stud had a 10 deg taper (2" per foot). So at a minimum the bushing ball joint stud seat needs to be reamed out with a commonly available 2"/10 deg ball joint ream tool

0.780" major diameter
0.665" minor diameter
O.750" length between major-minor diameter

The only way to compare the actual bushing dimensions is to press one out of the upright and measure it, stay tuned ....

edit: I did verify that these are the S1/early S2 front LCA with the F151- part code



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Great info on the offset bushings. Thank you Steve and TeamRX8. I can see myself trying these in the future. I have a 2004 so looks like I will need to get the spindle machined, or find some of the later ones to swap in...

That is an awesome amount of front camber. I wonder if you might even have too much now, if that is possible :-). Definitely interested to hear how it works on track.

Well if what was reported is the whole story then it'd require new spindles with at least new matching LCAs and possibly new UCAs too from a 2010+ RX8

It would make a lot more sense to machine the NC bushings to fit what you already have

We shall see. Those are basically the same alignment settings I run on my Miata, where they yield excellent grip and even tire wear. They may or may not be appropriate, since it is a different chassis with a different wheelbase, but it seems like a good place to start.

Might depend a lot on your tire choice. I can't recall what you're running on at the track?

some pics from last weekend at the summit point main. best I can get on the car (stock suspension) is -1.1 of front camber (drives side limited ~something bent from accident as this was salvage car I fixed - passenger side can go to -1.6).

I wonder if I should do the LCA camber insert only on driver side to equalize, then some aftermarket suspension for more camber?


https://cimg7.ibsrv.net/gimg/www.rx8...ce111ffe0a.png

https://cimg1.ibsrv.net/gimg/www.rx8...ca270e402d.png

https://cimg4.ibsrv.net/gimg/www.rx8...0fce5c896b.png

https://cimg3.ibsrv.net/gimg/www.rx8...4e2fb0c9ac.png

https://cimg8.ibsrv.net/gimg/www.rx8...d5d1d7632c.png

You could try to figure out of whatever is bent is a replaceable component, and get another 0.5 degree that way?

Not everyone likes them but I'm running the whiteline eccentric upper control arm bushings and that helps me gain camber.

You need to figure out what the actual problem is. While my direct experience is with S1 rather than S2, something is either bent/out of spec or the suspension has not been adjusted properly to achieve max camber. “Adjusted properly” is more than just turning the alignment bolts. Preloading the arm bushings in the proper position, a 4 ft crowbar to leverage out tolerance slack, etc. make a difference.

nothing looks out of order visually, I guess I could measure and see if driver side LCA is in any way different than passenger side or perhaps sub-frame mounting points shifted?

Find the crash repair guide and start taking measurements. Likely the whole front end is tweaked. It doesn't take much, don't ask me how I know. In the case it is tweaked, the only way to fix it is put it on a frame machine and pull it straight.

Great photos, btw. The one in my sig is from etech photos too. Fun running with you, I'm going to try and get video up this weekend I took while following you. Don't ask about the Dominion video... ;)